Not fully warming up
01-21-19, 12:49 PM
#1
Not fully warming up
I just bought an FD that has the greddy v-mount kit and the sakebomb big oil coolers. Originally, it would only warm up to a max of 150F. After I replaced the non-OEM looking thermostat with an OEM one, the car started warming up to 180F iding. The fans kick on and it never goes about 180F. Yesterday, I drove it to the gas station and it stayed around 160F since I didnt let it warm up idling. Any suggestions or thoughts on running it at 180F?
01-21-19, 01:01 PM
#2
What are your fans set to come on at? The car should hit the tstat temperature eventually... it takes mine about 5-10 mins of driving (easy of course). I dont have a v mount or aftermarket oil coolers ( I do have some heavy ducting work to the smic, rad and oil coolers) but my car consistently runs at the tstat opening temp (82c or 179) while cruising and will go up during idling or in slow traffic. My upper rad hose probe usually shows about 10c less than that until idling or slow traffic. My fans come on at 90c.
I had been meaning to ask this question myself. Im not sure of any negative effects other than fuel economy and emissions?
I had been meaning to ask this question myself. Im not sure of any negative effects other than fuel economy and emissions?
Last edited by AE_Racer; 01-21-19 at 01:14 PM. Reason: Temperature conversion a bit off
01-21-19, 01:06 PM
#3
What are your fans set to come on at? The car should hit the tstat temperature eventually... it takes mine about 5-10 mins of driving (easy of course). I dont have a v mount or aftermarket oil coolers ( I do have some heavy ducting work to the smic, rad and oil coolers) but my car consistently runs at the tstat opening temp (82c or 176) while cruising and will go up during idling or in slow traffic. My upper rad hose probe usually shows about 10c less than that until idling or slow traffic. My fans come on at 90c.
I had been meaning to ask this question myself. Im not sure of any negative effects other than fuel economy and emissions?
I had been meaning to ask this question myself. Im not sure of any negative effects other than fuel economy and emissions?
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Net Seven (01-21-19)
01-23-19, 01:35 PM
#6
On a side note, I would really reconsider the way you warm up yor rotary. Not sure the reason why so many like to idle their rotaries up by idling. Based on my 28yrs years of experience with them from all generations, that's the #1 way to build carbon deposits.
You have to understand that it takes a very long time to heat up those 9lb hunks of cast iron called rotors. Idleing delays how fast the rotors come up to temp. Cold rotors that are wet of fuel during a cold start is when most of the carbon generates on the rotor faces. That carbon will eventually create hot spots making detonation more prone and can also breaking away causing scorching of the rotor housings (which prematurely wears out the housings anf lowers your engine compression) or apex seal breakage.
Ideally start the car, give it a rev above 2,500 rpms for about 20sec then go drive the car. I promise this is better for your engine in the long run because you more quickly burn off any excess fuel that COULD turn into carbon.
You have to understand that it takes a very long time to heat up those 9lb hunks of cast iron called rotors. Idleing delays how fast the rotors come up to temp. Cold rotors that are wet of fuel during a cold start is when most of the carbon generates on the rotor faces. That carbon will eventually create hot spots making detonation more prone and can also breaking away causing scorching of the rotor housings (which prematurely wears out the housings anf lowers your engine compression) or apex seal breakage.
Ideally start the car, give it a rev above 2,500 rpms for about 20sec then go drive the car. I promise this is better for your engine in the long run because you more quickly burn off any excess fuel that COULD turn into carbon.
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TomU (01-24-19)
01-23-19, 01:45 PM
#7
On a side note, I would really reconsider the way you warm up yor rotary. Not sure the reason why so many like to idle their rotaries up by idling. Based on my 28yrs years of experience with them from all generations, that's the #1 way to build carbon deposits.
You have to understand that it takes a very long time to heat up those 9lb hunks of cast iron called rotors. Idleing delays how fast the rotors come up to temp. Cold rotors that are wet of fuel during a cold start is when most of the carbon generates on the rotor faces. That carbon will eventually create hot spots making detonation more prone and can also breaking away causing scorching of the rotor housings (which prematurely wears out the housings anf lowers your engine compression) or apex seal breakage.
Ideally start the car, give it a rev above 2,500 rpms for about 20sec then go drive the car. I promise this is better for your engine in the long run because you more quickly burn off any excess fuel that COULD turn into carbon.
You have to understand that it takes a very long time to heat up those 9lb hunks of cast iron called rotors. Idleing delays how fast the rotors come up to temp. Cold rotors that are wet of fuel during a cold start is when most of the carbon generates on the rotor faces. That carbon will eventually create hot spots making detonation more prone and can also breaking away causing scorching of the rotor housings (which prematurely wears out the housings anf lowers your engine compression) or apex seal breakage.
Ideally start the car, give it a rev above 2,500 rpms for about 20sec then go drive the car. I promise this is better for your engine in the long run because you more quickly burn off any excess fuel that COULD turn into carbon.
I guess my question is, at what temp is it ok to start going WOT with boost?
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01-23-19, 02:33 PM
#8
RX-7 Bad Ass
iTrader: (55)
Yep, there is no good reason to let it idle and warm up. When it's running it's ready to drive. Start it up, put it in gear, and go.
Try and keep out of boost until you are at 80 deg. C or higher. Part throttle boost is fine, you just don't want to gun it when it's not warmed up yet. Not to mention with the cold enrichment it will be slow
.
Dale
Try and keep out of boost until you are at 80 deg. C or higher. Part throttle boost is fine, you just don't want to gun it when it's not warmed up yet. Not to mention with the cold enrichment it will be slow
.Dale
01-23-19, 02:38 PM
#9
Yep, there is no good reason to let it idle and warm up. When it's running it's ready to drive. Start it up, put it in gear, and go.
Try and keep out of boost until you are at 80 deg. C or higher. Part throttle boost is fine, you just don't want to gun it when it's not warmed up yet. Not to mention with the cold enrichment it will be slow.
Dale
Try and keep out of boost until you are at 80 deg. C or higher. Part throttle boost is fine, you just don't want to gun it when it's not warmed up yet. Not to mention with the cold enrichment it will be slow
.Dale
Not sure why you guys keep talking about idling to let it warm up. Like I said, I replaced the thermostat and let it idle that time to see if the thermostat resolved the issue. With the old thermostat, it never got above 150F, even during the 45min drive home after buying the car. That means the car was tuned, driven, etc all at a max of 150F coolant temp before. The seller confirmed this issue. That's kind of why I started the thread, to get a better idea of what issues the engine might have as a result of running 26PSI on an engine that isn't fully warmed up.
Last edited by Net Seven; 01-23-19 at 02:54 PM. Reason: Adding more details
01-23-19, 02:54 PM
#10
RX-7 Bad Ass
iTrader: (55)
Also, you really only want to use Mazda thermostats. I have (and have had friends) burned by aftermarket thermostats - either sticking open or sticking closed.
Stock thermostat is 82 deg. C if memory serves. No reason to get a thermostat with a different heat range. There are some aftermarket ones that are colder or whatever but it won't do you any favors.
Dale
Stock thermostat is 82 deg. C if memory serves. No reason to get a thermostat with a different heat range. There are some aftermarket ones that are colder or whatever but it won't do you any favors.
Dale
01-23-19, 02:58 PM
#11
Also, you really only want to use Mazda thermostats. I have (and have had friends) burned by aftermarket thermostats - either sticking open or sticking closed.
Stock thermostat is 82 deg. C if memory serves. No reason to get a thermostat with a different heat range. There are some aftermarket ones that are colder or whatever but it won't do you any favors.
Dale
Stock thermostat is 82 deg. C if memory serves. No reason to get a thermostat with a different heat range. There are some aftermarket ones that are colder or whatever but it won't do you any favors.
Dale
01-23-19, 08:05 PM
#12
RX-7 Bad Ass
iTrader: (55)
I doubt you've necessarily hurt anything running colder at full boost. It's generally a good idea to wait until the car is warmed up but I doubt anything has been harmed.
That said, I don't think anyone has ever truly caused lasting engine damage by boosting a cold engine.
Dale
That said, I don't think anyone has ever truly caused lasting engine damage by boosting a cold engine.
Dale
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Net Seven (01-23-19)
01-23-19, 08:40 PM
#13
As long as it's hot enough for the coolant to flow (thermostat open) so it doesn't develop hot spots, there really shouldn't be a difference to the longevity of the engine (assuming a good tune) whether it operates at 160 - 180 - 200 - 220 degrees. Unless there is some kind of proof I'm unaware of that shows the housings or seals will wear faster when cold. At 150 degrees F, the oil is already warm enough to do its job.
Above 220 then I'd start worrying about coolant seals.
Above 220 then I'd start worrying about coolant seals.
01-23-19, 08:52 PM
#14
As long as it's hot enough for the coolant to flow (thermostat open) so it doesn't develop hot spots, there really shouldn't be a difference to the longevity of the engine (assuming a good tune) whether it operates at 160 - 180 - 200 - 220 degrees. Unless there is some kind of proof I'm unaware of that shows the housings or seals will wear faster when cold. At 150 degrees F, the oil is already warm enough to do its job.
Above 220 then I'd start worrying about coolant seals.
Above 220 then I'd start worrying about coolant seals.
. While waiting for my wheel to get checked out, I spoke to Heath at Sakebomb. He thinks maybe the huge oil coolers might be too big for street application? They come with a 180F thermostat that always flows some but starts to open earlier. On the way back, I was in some stop and go traffic and the temps climbed towards 180F, if I'm on the freeway it drops to 145F. I'm going to get a 200F oil cooler thermostat from Heath and see if it fixes the problem. BTW, it was about 60F outside in sunny AZ today, so not very cold.
01-23-19, 11:08 PM
#17
My cars oil temps stay low when in the freeway, pick back up when Im boost and I’m traffic, but I’m planning to swap the thermostat as well. I don’t like cold oil temps. I don’t have the issue with the coolant temps however. Have you thought of just putting a cardboard shield to temporarily cover half the radiator and monitor the temps? I’ve covered one oil cooler and successfully raised my oil temps.
01-23-19, 11:28 PM
#18
The behavior your FD exhibits is normal for a street rotary with a track oriented cooling system in my experience.
The coolant thermostat has a bypass and cruising down the freeway just that much bleed through into the very well cooling radiator drops the coolant temps below the thermostat opening.
Sucks in the winter when you crank the heater and barely warm air comes out.
On my FC for 15 years I had a giant Griffin radiator and horizontal mount IC and even ran the less thermally conductive 100% PG coolant and it did this. I actually switched up from a 160deg F racing T-stat to a 180deg F T-stat and it helped a bit.
On my FD when I just switched to Koyo Z flow triple pass radiator with stock mount IC it also started exhibiting this same behavior.
That Z flow is crazy for how small it is (stock fit). It can be blazing hot on the inlet side and cold by the outlet side.
As long as your coolant temps are above ~ 120F and come up normally as you boost you are fine in my experience.
The only problem with running the rotary marginally cold is gas mileage won't be as good and it doesn't run as smooth- as long as your fuel map is properly compensated and not just tuned to run right at t-stat temps
The oiling system is a whole different ball of wax as viscosity matters and you will need an oil temp gauge/sender to know what is going on.
The coolant thermostat has a bypass and cruising down the freeway just that much bleed through into the very well cooling radiator drops the coolant temps below the thermostat opening.
Sucks in the winter when you crank the heater and barely warm air comes out.
On my FC for 15 years I had a giant Griffin radiator and horizontal mount IC and even ran the less thermally conductive 100% PG coolant and it did this. I actually switched up from a 160deg F racing T-stat to a 180deg F T-stat and it helped a bit.
On my FD when I just switched to Koyo Z flow triple pass radiator with stock mount IC it also started exhibiting this same behavior.
That Z flow is crazy for how small it is (stock fit). It can be blazing hot on the inlet side and cold by the outlet side.
As long as your coolant temps are above ~ 120F and come up normally as you boost you are fine in my experience.
The only problem with running the rotary marginally cold is gas mileage won't be as good and it doesn't run as smooth- as long as your fuel map is properly compensated and not just tuned to run right at t-stat temps
The oiling system is a whole different ball of wax as viscosity matters and you will need an oil temp gauge/sender to know what is going on.
01-24-19, 07:09 AM
#19
I have a theory that the oil squirter thermostat delete mod (delete the thermostat for the rotor cooling jets, save $70 instead of buying a new one) hurts engine warm up, including coolant warm up. Yeah I know they fail, but seriously, the original one lasted for years and years, and you can still get a new one from Mazda last I checked, so why delete it???? Audi uses an ECU controlled piston squirter thermostat. Now that's gotta be expensive.
Somebody un-delete theirs and report back. I've always had cars with the delete or without, but never did a before-after comparison.
Somebody un-delete theirs and report back. I've always had cars with the delete or without, but never did a before-after comparison.
Last edited by arghx; 01-24-19 at 07:14 AM.
01-24-19, 11:33 AM
#20
Best solution for large oil coolers is running them in parallel vs series with a T-stat for each cooler. That way you could have different rates of opening.
I'd recomend a lighter oil (10-50) if you have low oil temps
Also, never thought about carbon build up from idling. Learn something new on this site all the time
I'd recomend a lighter oil (10-50) if you have low oil temps
Also, never thought about carbon build up from idling. Learn something new on this site all the time
01-29-19, 02:18 PM
#21
Full Member
Same here - I'd assume that same fresh carbon would be coming off in short order as long as you're redlining and boosting frequently enough. Like they say, a redline a day keeps the mechanic away. That's generally been true for my rotary ownership haha.
05-14-20, 10:07 PM
#22
Not to revive this thread, but I have the engine out for rebuild and having harness redone for Haltech Elite 2500. I only have one coolant temp sensor for the ECU and one for the factory gauge. The doofus that sold me the car has the coolant temp defi gauge sensor in the oil pedestal, so that was showing oil temp not coolant temp the whole time. When he sold me the car he was also a little concerned about the coolant temp not fully warming up and suggested I replace the thermostat.. there you go.
05-15-20, 08:40 AM
#23
RX-7 Bad Ass
iTrader: (55)
Wow, there you go! It's the simple stuff sometimes...
Dale
Dale
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