Over Cooling/Never Reaches Temp
Thread Starter
Joined: Dec 2006
Posts: 2,552
Likes: 14
From: Athens, Georgia
The clutch fan when cold will do a good revolution when you give it a spin. Its actually the second one I've had, as I found one with cleaner blades attached to it. The problem pre dates that, however. And the old fan seemed to be working just as well. Ill take it off and see what happens. It certainly doesnt seem like its bad.
I wish this were an obvious fix sort of situation...sad face
I wish this were an obvious fix sort of situation...sad face
Okay, just wanted to make sure the most obvious items were covered. This sounds like a seized clutch fan, in that it is always pulling air through the radiator and 'fighting' the thermostat. I can't say with absolute certainty as I've never experienced this myself (mine leans the other way thanks to a 20B-REW lol), but this Z-car article makes sense of it better than I can: Here are the instructions:
To determine if the clutch is seized, the only method I know of would be to try turning it by hand and watch if the water pump moves too. A seized one will move perfectly in sync with the water pump.
Aaron Cake, could you please weigh in on this and double-check me?
To determine if the clutch is seized, the only method I know of would be to try turning it by hand and watch if the water pump moves too. A seized one will move perfectly in sync with the water pump.
Aaron Cake, could you please weigh in on this and double-check me?
I'm guessing bad sensor, bad gauge, or poor placement of sensor. It's all that's left.
Joined: Aug 2002
Posts: 2,614
Likes: 31
From: Freeland, MI
Speaking of, are you positive your heat flapper is working?
MECP Certified Installer
Joined: Feb 2009
Posts: 3,176
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From: Mesquite, TX-DFW
Joined: Oct 2003
Posts: 1,600
Likes: 49
From: Norcal/Bay Area, CA
All your testing shows that 160 on your gauge equates to 180 at the thermostat. If you want it to read closer to 180, move the sensor to the water pump housing.
On top of the heater issues listed above, the heater core could also be clogged or the feed pipes may have been deformed when installing the hoses.
On top of the heater issues listed above, the heater core could also be clogged or the feed pipes may have been deformed when installing the hoses.
All your testing shows that 160 on your gauge equates to 180 at the thermostat. If you want it to read closer to 180, move the sensor to the water pump housing.
On top of the heater issues listed above, the heater core could also be clogged or the feed pipes may have been deformed when installing the hoses.
On top of the heater issues listed above, the heater core could also be clogged or the feed pipes may have been deformed when installing the hoses.
I doubt the heater core is suspect here, as it is plumbed parallel to the radiator.
Have you ever been through the summer as yet? It seems like its just too cold outside that it super cools the radiator. My fd has this issue in the winter as I daily it and my temps do sometimes stay below average however, calculating the temps you gave above, you are getting about 70-72 degrees Celsius which is quite low.
Perhaps its a pressure leak somewhere as I had a pinhole leak that only appeared above 5k on the thermowax which caused my thermostat to open extremely late. The funny thing is, my temps NEVER went above 90 for the entire duration of this issue and I only realized it after I was finding an IC leak on the dyno and saw coolant spray from the bottom. If all else fails, I am pretty positive that the oil cooler thermostat is indeed stuck open. My vert had this issue but I never bothered to fix it as I was still getting 80 Celsius.
Perhaps its a pressure leak somewhere as I had a pinhole leak that only appeared above 5k on the thermowax which caused my thermostat to open extremely late. The funny thing is, my temps NEVER went above 90 for the entire duration of this issue and I only realized it after I was finding an IC leak on the dyno and saw coolant spray from the bottom. If all else fails, I am pretty positive that the oil cooler thermostat is indeed stuck open. My vert had this issue but I never bothered to fix it as I was still getting 80 Celsius.
Thread Starter
Joined: Dec 2006
Posts: 2,552
Likes: 14
From: Athens, Georgia
I've had this particular FC for three years. I drive it year round. I've never been able to get it to run *quite* right, through timing, tps, idle mixture, all new hoses, new bits and bobbles, and a multimeter and the fsm handy at all times. The engine is a tad sluggish, gas mileage is seriously abysmal, and no heat. These are symptoms of and overcooled engine, after all. Things do not improve in warmer temperatured months.
The oil cooler leaks a bit, and I think there's one in a local salvage yard. Ill try and grab that this weekend.
All coolant hoses, once the engine is warmed up, are pretty much the same temperature. Including the heater hoses.. the temp slider works, the valve moves through what seems like its entire range. What little 'heat' there is does come through the defroster and floor vents.
Removing the clutch fan had no effect while driving. If after I've sat there holding three grand for five or ten minutes it did come up to a tiny bit over quarter on the stock gauge and 200ish on the aftermarket. Still no real heat, but the engine ran a tad smoother. Seemed happier. Cooled right back down to the temps I've previously stated after driving for a short distance.
The oil cooler leaks a bit, and I think there's one in a local salvage yard. Ill try and grab that this weekend.
All coolant hoses, once the engine is warmed up, are pretty much the same temperature. Including the heater hoses.. the temp slider works, the valve moves through what seems like its entire range. What little 'heat' there is does come through the defroster and floor vents.
Removing the clutch fan had no effect while driving. If after I've sat there holding three grand for five or ten minutes it did come up to a tiny bit over quarter on the stock gauge and 200ish on the aftermarket. Still no real heat, but the engine ran a tad smoother. Seemed happier. Cooled right back down to the temps I've previously stated after driving for a short distance.
Originally Posted by lduley
Electrical has nothing to do with the amount of heat coming out've the heater core.
I hope that clears it up.
Last edited by user 893453465346; Jan 27, 2015 at 06:19 PM.
Don't make me break out my "dump truck" metaphor to prove it.
Joined: Aug 2002
Posts: 2,614
Likes: 31
From: Freeland, MI
OK then, you did ask...
(This is from the olden days of watercooling PCs, where the debate over flow was hotly debated for years. If the name Cathar means anything to you, then you know...)
Assume the water molecules in your cooling loop are little dump trucks. Little cute Pixar things.
The heat generated by the combustion is their payload and the radiator is the dumping ground.
Each circuit through the engine, the trucks pick up as much heat as they can in the allotted time and dump as much as they can in the rad.
If the dumptruck speed is slow (remember, they all travel at the same speed, determined only by the rotation of the pump), fewer trucks per minute make the trip, but each one loads/offloads more heat. As the pump speeds up, more trucks make the journey but each one carries/dumps less heat per trip.
The net effect is basically a wash- go slow and fewer trucks are more effectively utilized, go fast and more trucks are carrying less.
"Faster" flow cannot overcool because the faster it goes, the less time it spends in contact with the heat source and the less heat gets carried away by the individual molecules.
Ultimately, the speed of the flow has less impact on the system performance than other factors (rad efficiency, ambient temp, fan efficiency, etc).
(This is from the olden days of watercooling PCs, where the debate over flow was hotly debated for years. If the name Cathar means anything to you, then you know...)
Assume the water molecules in your cooling loop are little dump trucks. Little cute Pixar things.
The heat generated by the combustion is their payload and the radiator is the dumping ground.
Each circuit through the engine, the trucks pick up as much heat as they can in the allotted time and dump as much as they can in the rad.
If the dumptruck speed is slow (remember, they all travel at the same speed, determined only by the rotation of the pump), fewer trucks per minute make the trip, but each one loads/offloads more heat. As the pump speeds up, more trucks make the journey but each one carries/dumps less heat per trip.
The net effect is basically a wash- go slow and fewer trucks are more effectively utilized, go fast and more trucks are carrying less.
"Faster" flow cannot overcool because the faster it goes, the less time it spends in contact with the heat source and the less heat gets carried away by the individual molecules.
Ultimately, the speed of the flow has less impact on the system performance than other factors (rad efficiency, ambient temp, fan efficiency, etc).
Thread Starter
Joined: Dec 2006
Posts: 2,552
Likes: 14
From: Athens, Georgia
I vote this gets archived on account of the cute pixar dump trucks...
Would there be anything wrong with using the factory temp sender location ? Or is it 'ideal' to take the readings at the waterpump housing?
Would there be anything wrong with using the factory temp sender location ? Or is it 'ideal' to take the readings at the waterpump housing?
OK then, you did ask...
(This is from the olden days of watercooling PCs, where the debate over flow was hotly debated for years. If the name Cathar means anything to you, then you know...)
Assume the water molecules in your cooling loop are little dump trucks. Little cute Pixar things.
The heat generated by the combustion is their payload and the radiator is the dumping ground.
Each circuit through the engine, the trucks pick up as much heat as they can in the allotted time and dump as much as they can in the rad.
If the dumptruck speed is slow (remember, they all travel at the same speed, determined only by the rotation of the pump), fewer trucks per minute make the trip, but each one loads/offloads more heat. As the pump speeds up, more trucks make the journey but each one carries/dumps less heat per trip.
The net effect is basically a wash- go slow and fewer trucks are more effectively utilized, go fast and more trucks are carrying less.
"Faster" flow cannot overcool because the faster it goes, the less time it spends in contact with the heat source and the less heat gets carried away by the individual molecules.
Ultimately, the speed of the flow has less impact on the system performance than other factors (rad efficiency, ambient temp, fan efficiency, etc).
(This is from the olden days of watercooling PCs, where the debate over flow was hotly debated for years. If the name Cathar means anything to you, then you know...)
Assume the water molecules in your cooling loop are little dump trucks. Little cute Pixar things.
The heat generated by the combustion is their payload and the radiator is the dumping ground.
Each circuit through the engine, the trucks pick up as much heat as they can in the allotted time and dump as much as they can in the rad.
If the dumptruck speed is slow (remember, they all travel at the same speed, determined only by the rotation of the pump), fewer trucks per minute make the trip, but each one loads/offloads more heat. As the pump speeds up, more trucks make the journey but each one carries/dumps less heat per trip.
The net effect is basically a wash- go slow and fewer trucks are more effectively utilized, go fast and more trucks are carrying less.
"Faster" flow cannot overcool because the faster it goes, the less time it spends in contact with the heat source and the less heat gets carried away by the individual molecules.
Ultimately, the speed of the flow has less impact on the system performance than other factors (rad efficiency, ambient temp, fan efficiency, etc).
I don't think it's linear but, the fact it is a curve still somewhat supports your analogy. Probably a parabolic curve where the ramp is only really seen at low flow rates, My statement comes from the fact it's possible to have too little flow (too big a load for the dump trucks that are coming through).
The biggest factor is most likely the surface area of the heat exchanger.
While I'm all for discussing little toy pixar dump trucks and the efficiency of their loads blowing through the system*, we should get this thread back on track to solve the issue at hand: overcooling
My bet is on a sketchy fan clutch that seizes up sporatically. But I think it would be best to run this by Aaron Cake first.
*too many innuendos here to make, let's save them for the Lounge
My bet is on a sketchy fan clutch that seizes up sporatically. But I think it would be best to run this by Aaron Cake first.
*too many innuendos here to make, let's save them for the Lounge
Full Member
Joined: Nov 2011
Posts: 105
Likes: 0
From: orange, ca
He did say he ran the motor without the fan, it did heat up until he drove it.
Is it possible that a po has blocked off the return in the front iron where the water pump bolts up? This would leave the housing looking normal, but still force water to travel through the radiator at all times.
Another possibility is silica has built up over the years and internally plugged up the "recirculation" port.
Is it possible that a po has blocked off the return in the front iron where the water pump bolts up? This would leave the housing looking normal, but still force water to travel through the radiator at all times.
Another possibility is silica has built up over the years and internally plugged up the "recirculation" port.
Joined: Oct 2003
Posts: 1,600
Likes: 49
From: Norcal/Bay Area, CA
I still don't think you have an issue, so I'm trying to poke holes in what has been presented thus far.
You've proven it runs at least 160 per your aftermarket gauge, so keep that in mind.
By 160 it has tripped the water temp switch and water thermosensor are triggered to run normally. Have you confirmed they are sending the correct signals to the ECU?
What do you mean by 'not quite right'? Have compression numbers?
The FC's heater is very powerful. If you don't notice anything when it is at normal operating temp, something is wrong with the heater system.
Is the heater core piping inside the car hot? The air mix motor needs to work too. Manually move the linkages to the correct positions to be sure.
The point of the fan is to simulate the airflow created while the car is moving. The real test is remove the fan and let it idle while stationary.
If you really want to put it to the test, clamp off a radiator hose to ensure the radiator is not contributing to cooling the car.
200 at the stock sensor location equates on about half on the gauge. It is skewed toward the low end and heavily damped.
Some other thoughts:
Did you reuse the automatic throttle body and double throttle system? It's a little different than the manual. And the turbo.
Did you change the rear differential when you did your manual swap?
I've had this particular FC for three years. I drive it year round. I've never been able to get it to run *quite* right, through timing, tps, idle mixture, all new hoses, new bits and bobbles, and a multimeter and the fsm handy at all times. The engine is a tad sluggish, gas mileage is seriously abysmal, and no heat. These are symptoms of and overcooled engine, after all. Things do not improve in warmer temperatured months.
By 160 it has tripped the water temp switch and water thermosensor are triggered to run normally. Have you confirmed they are sending the correct signals to the ECU?
What do you mean by 'not quite right'? Have compression numbers?
The FC's heater is very powerful. If you don't notice anything when it is at normal operating temp, something is wrong with the heater system.
All coolant hoses, once the engine is warmed up, are pretty much the same temperature. Including the heater hoses. the temp slider works, the valve moves through what seems like its entire range. What little 'heat' there is does come through the defroster and floor vents.
The point of the fan is to simulate the airflow created while the car is moving. The real test is remove the fan and let it idle while stationary.
If you really want to put it to the test, clamp off a radiator hose to ensure the radiator is not contributing to cooling the car.
If after I've sat there holding three grand for five or ten minutes it did come up to a tiny bit over quarter on the stock gauge and 200ish on the aftermarket. Still no real heat, but the engine ran a tad smoother. Seemed happier. Cooled right back down to the temps I've previously stated after driving for a short distance.
Some other thoughts:
Did you reuse the automatic throttle body and double throttle system? It's a little different than the manual. And the turbo.
Did you change the rear differential when you did your manual swap?
Thread Starter
Joined: Dec 2006
Posts: 2,552
Likes: 14
From: Athens, Georgia
Compression mid last year was 90psi.
The air mix and heater valve move normally.
I can't speak for the pipes inboard of the bulkhead , but the heater core inlet hose gets to be the same temp as the upper radiator hose, by feel. The outlet pipe is a bit cooler, but I imagine that's normal ? The heater box up under the dash gets fairly warm.
When im driving around, given low winter temps, the aftermarket gauge reads 145- 152 with no cardboard shields and my fan installed (so everything as it should be) idling for a long time with the 'heater' off, yeah itll hit 160 on the aftermarket gauge. Sometimes 162. Haven't seen 170 in a while but its been colder outside.
I did not do this manual swap. I have on a previous FC. Whoever did this swap clearly had a limited understanding of what really needed to happen. The wiring adaptations were crude and improper. As a result, I could not start the car while it was in gear, (and no clutch interlock) and while running, putting it in any gear would lift the idle speed by quite a lot, and it'd idle like cow **** in neutral. Fuel consumption was 10mpg. I put the wiring right to fix those issues. The rear end is an lsd 3.9 auto jobbie and I hate it. They left the throttle body, and that annoyed me.. so I swapped on a proper manual throttle body.. gave it a good cleaning and made sure things were set, moved freely, etc. I've verified my current tps with an analog multi meter and set it, along with the timing, idle mixture and throttle speed.. of course, with the initial set coupler utilized. I had also constructed a code checker right after that, and the ecu is quite content in both cold start and hot start conditions.
I do remember also taking readings at the ecu for the water 'thermoswitch' , tps, o2 sensor (current one about a year old bosch unit, connected to my air fuel gauge..narrowband, I know.. but I was verifying that I had the magic swing while cruising), both sets of injectors (when I had a bad one and was diagnosing the one at fault), and I want to say I verified the ecu ground. Speaking of injectors, they were serviced about ten thousand miles ago by witch hunter. New grommets, all that jazz.
Thank God for HAILERS helping me diagnose my last auto to manual car and it's fun starting problem.. I've referenced that information a few times over the years.
At this point, none of it makes a whole lot of sense, as I feel in my gut that everything should be kosher. Im tempted to say **** it and replace the - near as makes no difference - 30 year old heater core, and chalk the stock gauge reading low because the wiring probably isn't brilliant at this point...and the sensor itself could be iffy, or the gauge. The aftermarket gauge I expected, honestly, to be 10 or 12 degrees (due to the sensors current location) off 'reality' of readings taken from the holy grail that is the pump housing. I may go grab another pump housing to move the sensor so it can be a more convenient swap. I'm also going for another oil cooler.. any suggestions on how I could clean it out ? Its been sitting in the car unused for years.
Current fuel consumption is 12 - 15mpg. Quite a change from 19 - 22 that all of my other FCs have returned with the same driving style and conditions/mix.
The air mix and heater valve move normally.
I can't speak for the pipes inboard of the bulkhead , but the heater core inlet hose gets to be the same temp as the upper radiator hose, by feel. The outlet pipe is a bit cooler, but I imagine that's normal ? The heater box up under the dash gets fairly warm.
When im driving around, given low winter temps, the aftermarket gauge reads 145- 152 with no cardboard shields and my fan installed (so everything as it should be) idling for a long time with the 'heater' off, yeah itll hit 160 on the aftermarket gauge. Sometimes 162. Haven't seen 170 in a while but its been colder outside.
I did not do this manual swap. I have on a previous FC. Whoever did this swap clearly had a limited understanding of what really needed to happen. The wiring adaptations were crude and improper. As a result, I could not start the car while it was in gear, (and no clutch interlock) and while running, putting it in any gear would lift the idle speed by quite a lot, and it'd idle like cow **** in neutral. Fuel consumption was 10mpg. I put the wiring right to fix those issues. The rear end is an lsd 3.9 auto jobbie and I hate it. They left the throttle body, and that annoyed me.. so I swapped on a proper manual throttle body.. gave it a good cleaning and made sure things were set, moved freely, etc. I've verified my current tps with an analog multi meter and set it, along with the timing, idle mixture and throttle speed.. of course, with the initial set coupler utilized. I had also constructed a code checker right after that, and the ecu is quite content in both cold start and hot start conditions.
I do remember also taking readings at the ecu for the water 'thermoswitch' , tps, o2 sensor (current one about a year old bosch unit, connected to my air fuel gauge..narrowband, I know.. but I was verifying that I had the magic swing while cruising), both sets of injectors (when I had a bad one and was diagnosing the one at fault), and I want to say I verified the ecu ground. Speaking of injectors, they were serviced about ten thousand miles ago by witch hunter. New grommets, all that jazz.
Thank God for HAILERS helping me diagnose my last auto to manual car and it's fun starting problem.. I've referenced that information a few times over the years.
At this point, none of it makes a whole lot of sense, as I feel in my gut that everything should be kosher. Im tempted to say **** it and replace the - near as makes no difference - 30 year old heater core, and chalk the stock gauge reading low because the wiring probably isn't brilliant at this point...and the sensor itself could be iffy, or the gauge. The aftermarket gauge I expected, honestly, to be 10 or 12 degrees (due to the sensors current location) off 'reality' of readings taken from the holy grail that is the pump housing. I may go grab another pump housing to move the sensor so it can be a more convenient swap. I'm also going for another oil cooler.. any suggestions on how I could clean it out ? Its been sitting in the car unused for years.
Current fuel consumption is 12 - 15mpg. Quite a change from 19 - 22 that all of my other FCs have returned with the same driving style and conditions/mix.
Joined: Mar 2001
Posts: 31,811
Likes: 3,216
From: https://www2.mazda.com/en/100th/
in the 1st gen section, we've had a couple of cool running cars.
one turned out to be a bad temp sender, which caused the gauge to read low. if you put a 50ohm resistor between the gauge wire and ground, this will be 80c (the 60c and 110c are in the FSM).
the second turned out to be the oil cooler thermostat.
plan B i guess would be to move to florida, you are complaining that something is cold in the winter in vermont...
one turned out to be a bad temp sender, which caused the gauge to read low. if you put a 50ohm resistor between the gauge wire and ground, this will be 80c (the 60c and 110c are in the FSM).
the second turned out to be the oil cooler thermostat.
plan B i guess would be to move to florida, you are complaining that something is cold in the winter in vermont...
Thread Starter
Joined: Dec 2006
Posts: 2,552
Likes: 14
From: Athens, Georgia
in the 1st gen section, we've had a couple of cool running cars.
one turned out to be a bad temp sender, which caused the gauge to read low. if you put a 50ohm resistor between the gauge wire and ground, this will be 80c (the 60c and 110c are in the FSM).
the second turned out to be the oil cooler thermostat.
plan B i guess would be to move to florida, you are complaining that something is cold in the winter in vermont...
one turned out to be a bad temp sender, which caused the gauge to read low. if you put a 50ohm resistor between the gauge wire and ground, this will be 80c (the 60c and 110c are in the FSM).
the second turned out to be the oil cooler thermostat.
plan B i guess would be to move to florida, you are complaining that something is cold in the winter in vermont...
On a side note, I love winter. It is not 'complaining' that I am wanting to correct a problem and have something like my heat actually work. Not sure why you are throwing stones.
Joined: Mar 2001
Posts: 31,811
Likes: 3,216
From: https://www2.mazda.com/en/100th/
Just picked up a replacement oil cooler. Pump housing as well so I can move the temp sender.
On a side note, I love winter. It is not 'complaining' that I am wanting to correct a problem and have something like my heat actually work. Not sure why you are throwing stones.
On a side note, I love winter. It is not 'complaining' that I am wanting to correct a problem and have something like my heat actually work. Not sure why you are throwing stones.
Senior Member
Joined: Jun 2011
Posts: 303
Likes: 2
From: Md
Compression mid last year was 90psi.
The air mix and heater valve move normally.
I can't speak for the pipes inboard of the bulkhead , but the heater core inlet hose gets to be the same temp as the upper radiator hose, by feel. The outlet pipe is a bit cooler, but I imagine that's normal ? The heater box up under the dash gets fairly warm.
When im driving around, given low winter temps, the aftermarket gauge reads 145- 152 with no cardboard shields and my fan installed (so everything as it should be) idling for a long time with the 'heater' off, yeah itll hit 160 on the aftermarket gauge. Sometimes 162. Haven't seen 170 in a while but its been colder outside.
I did not do this manual swap. I have on a previous FC. Whoever did this swap clearly had a limited understanding of what really needed to happen. The wiring adaptations were crude and improper. As a result, I could not start the car while it was in gear, (and no clutch interlock) and while running, putting it in any gear would lift the idle speed by quite a lot, and it'd idle like cow **** in neutral. Fuel consumption was 10mpg. I put the wiring right to fix those issues. The rear end is an lsd 3.9 auto jobbie and I hate it. They left the throttle body, and that annoyed me.. so I swapped on a proper manual throttle body.. gave it a good cleaning and made sure things were set, moved freely, etc. I've verified my current tps with an analog multi meter and set it, along with the timing, idle mixture and throttle speed.. of course, with the initial set coupler utilized. I had also constructed a code checker right after that, and the ecu is quite content in both cold start and hot start conditions.
I do remember also taking readings at the ecu for the water 'thermoswitch' , tps, o2 sensor (current one about a year old bosch unit, connected to my air fuel gauge..narrowband, I know.. but I was verifying that I had the magic swing while cruising), both sets of injectors (when I had a bad one and was diagnosing the one at fault), and I want to say I verified the ecu ground. Speaking of injectors, they were serviced about ten thousand miles ago by witch hunter. New grommets, all that jazz.
Thank God for HAILERS helping me diagnose my last auto to manual car and it's fun starting problem.. I've referenced that information a few times over the years.
At this point, none of it makes a whole lot of sense, as I feel in my gut that everything should be kosher. Im tempted to say **** it and replace the - near as makes no difference - 30 year old heater core, and chalk the stock gauge reading low because the wiring probably isn't brilliant at this point...and the sensor itself could be iffy, or the gauge. The aftermarket gauge I expected, honestly, to be 10 or 12 degrees (due to the sensors current location) off 'reality' of readings taken from the holy grail that is the pump housing. I may go grab another pump housing to move the sensor so it can be a more convenient swap. I'm also going for another oil cooler.. any suggestions on how I could clean it out ? Its been sitting in the car unused for years.
Current fuel consumption is 12 - 15mpg. Quite a change from 19 - 22 that all of my other FCs have returned with the same driving style and conditions/mix.
The air mix and heater valve move normally.
I can't speak for the pipes inboard of the bulkhead , but the heater core inlet hose gets to be the same temp as the upper radiator hose, by feel. The outlet pipe is a bit cooler, but I imagine that's normal ? The heater box up under the dash gets fairly warm.
When im driving around, given low winter temps, the aftermarket gauge reads 145- 152 with no cardboard shields and my fan installed (so everything as it should be) idling for a long time with the 'heater' off, yeah itll hit 160 on the aftermarket gauge. Sometimes 162. Haven't seen 170 in a while but its been colder outside.
I did not do this manual swap. I have on a previous FC. Whoever did this swap clearly had a limited understanding of what really needed to happen. The wiring adaptations were crude and improper. As a result, I could not start the car while it was in gear, (and no clutch interlock) and while running, putting it in any gear would lift the idle speed by quite a lot, and it'd idle like cow **** in neutral. Fuel consumption was 10mpg. I put the wiring right to fix those issues. The rear end is an lsd 3.9 auto jobbie and I hate it. They left the throttle body, and that annoyed me.. so I swapped on a proper manual throttle body.. gave it a good cleaning and made sure things were set, moved freely, etc. I've verified my current tps with an analog multi meter and set it, along with the timing, idle mixture and throttle speed.. of course, with the initial set coupler utilized. I had also constructed a code checker right after that, and the ecu is quite content in both cold start and hot start conditions.
I do remember also taking readings at the ecu for the water 'thermoswitch' , tps, o2 sensor (current one about a year old bosch unit, connected to my air fuel gauge..narrowband, I know.. but I was verifying that I had the magic swing while cruising), both sets of injectors (when I had a bad one and was diagnosing the one at fault), and I want to say I verified the ecu ground. Speaking of injectors, they were serviced about ten thousand miles ago by witch hunter. New grommets, all that jazz.
Thank God for HAILERS helping me diagnose my last auto to manual car and it's fun starting problem.. I've referenced that information a few times over the years.
At this point, none of it makes a whole lot of sense, as I feel in my gut that everything should be kosher. Im tempted to say **** it and replace the - near as makes no difference - 30 year old heater core, and chalk the stock gauge reading low because the wiring probably isn't brilliant at this point...and the sensor itself could be iffy, or the gauge. The aftermarket gauge I expected, honestly, to be 10 or 12 degrees (due to the sensors current location) off 'reality' of readings taken from the holy grail that is the pump housing. I may go grab another pump housing to move the sensor so it can be a more convenient swap. I'm also going for another oil cooler.. any suggestions on how I could clean it out ? Its been sitting in the car unused for years.
Current fuel consumption is 12 - 15mpg. Quite a change from 19 - 22 that all of my other FCs have returned with the same driving style and conditions/mix.