new thermostat still not working?? help!
12-30-05, 07:37 AM
#26
Seduced by the DARK SIDE
Join Date: Apr 2001
Location: Orange Park FL (near Jax)
Posts: 7,323
Likes: 0
Received 2 Likes
on
2 Posts
Sureshot’s Overheating – check list
1) Replace the thermostat. Make sure it fits. The spring loaded disc under the stat valve must close the bypass port, or guess what? - You get symptoms like a blocked radiator.
2) Replace the radiator cap. Low pressure = steam bubbles = spit out coolant.
3) Look for leaks. (same symptoms as #2) Some can be very hard to find. You may have to pressure test it. A common failure spot is the 3/8” coolant line that runs from the top of the rear housing (under the intake runners) to the throttle body, to the BAC, to the water pump. Another one is the heater hose under the oil filter.
4) The fan clutch will slowly start slipping as it ages. The fan should pull really hard up to about 3k when the motor is hot. It should maintain about 3k as the motor revs higher. Sometimes you can get more life from it by bending outward the bi-metal strip on the front of the fan clutch. The cut-in for the series 4 fan clutch is gradual – it pulls some even when cold. The series 5 fan clutch is more on/off. If your fan only revs to 2K, the clutch is worn out.
5) The rotary engine gets almost half its cooling from the oil. The oil cooler is as important as the radiator.
.
Banzaitoyota’s checklist
1.Are the Oil Cooler fins clear of debris and clean?
2.Does the Oil Cooler thermostat function properly?
3.Are the Radiator Fins clean of debris?
4.Is the Stock Bottom shroud still in place?
5.Are you running a Dual Belt Pulley on the Alt?
6.Did you install a NEW Water Pump when you installed the engine?
7.Is the bottom hose collapsing under load?
8.Did you have the Radiator and Oil Cooler cleaned and Flushed when installing the rebuild ( AS required by MOST REPUTABLE REBUILDERS)?
9. Have you verified water temps with a real gauge instead of the sock POS?
10. What ratio Coolant to Water are you running?
11. Are you running a new STOCK MAZDA OEM thermostat?
12. Mazda Rad Caps?
13. Stock Fan Shroud installed ( For those of you running stock Mechanical Fan)
14. Electric Fan users: Do you have a Shroud installed at all. Most installations only draw air directly across ~60% of the available core surface area.
15. are the stock deflectors installed around the relays forward of the Radiator Core Support?
16. If 15 is a no: Do you have an plate mounted across the support to direct air-flow?
17. Install a spring in the lower rad hose to keep it from collapsing at high RPM
1) Replace the thermostat. Make sure it fits. The spring loaded disc under the stat valve must close the bypass port, or guess what? - You get symptoms like a blocked radiator.
2) Replace the radiator cap. Low pressure = steam bubbles = spit out coolant.
3) Look for leaks. (same symptoms as #2) Some can be very hard to find. You may have to pressure test it. A common failure spot is the 3/8” coolant line that runs from the top of the rear housing (under the intake runners) to the throttle body, to the BAC, to the water pump. Another one is the heater hose under the oil filter.
4) The fan clutch will slowly start slipping as it ages. The fan should pull really hard up to about 3k when the motor is hot. It should maintain about 3k as the motor revs higher. Sometimes you can get more life from it by bending outward the bi-metal strip on the front of the fan clutch. The cut-in for the series 4 fan clutch is gradual – it pulls some even when cold. The series 5 fan clutch is more on/off. If your fan only revs to 2K, the clutch is worn out.
5) The rotary engine gets almost half its cooling from the oil. The oil cooler is as important as the radiator.
.
Banzaitoyota’s checklist
1.Are the Oil Cooler fins clear of debris and clean?
2.Does the Oil Cooler thermostat function properly?
3.Are the Radiator Fins clean of debris?
4.Is the Stock Bottom shroud still in place?
5.Are you running a Dual Belt Pulley on the Alt?
6.Did you install a NEW Water Pump when you installed the engine?
7.Is the bottom hose collapsing under load?
8.Did you have the Radiator and Oil Cooler cleaned and Flushed when installing the rebuild ( AS required by MOST REPUTABLE REBUILDERS)?
9. Have you verified water temps with a real gauge instead of the sock POS?
10. What ratio Coolant to Water are you running?
11. Are you running a new STOCK MAZDA OEM thermostat?
12. Mazda Rad Caps?
13. Stock Fan Shroud installed ( For those of you running stock Mechanical Fan)
14. Electric Fan users: Do you have a Shroud installed at all. Most installations only draw air directly across ~60% of the available core surface area.
15. are the stock deflectors installed around the relays forward of the Radiator Core Support?
16. If 15 is a no: Do you have an plate mounted across the support to direct air-flow?
17. Install a spring in the lower rad hose to keep it from collapsing at high RPM
Last edited by SureShot; 12-30-05 at 07:43 AM.
12-30-05, 08:03 AM
#27
Full Member
Join Date: Aug 2005
Location: Tampa
Posts: 187
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by kompressorlogic
thats the most BS ive ever heard, lets see ive put over 30K on my car with no thermostat with out any problems!
Thats not bs. Several mechanics told me that. I doubt all of them are going to be wrong. and just because you never ran into problems doesn't mean others havent.
12-30-05, 08:53 AM
#28
Engine, Not Motor
iTrader: (1)
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,789
Likes: 0
Received 109 Likes
on
92 Posts
Originally Posted by CoRDiTe
leave the thermostat in it. Thermostat is in it for a reason. Your injectors start to work correctly at a certain temp. If you have the thermostat out of the car and run the car like that you can damage your injectors.
True, the thermostat is there for a reason. An engine is designed to work a specific temperature. Materials and tolerances in an engine have been set with this temperature in mind, not to mention choice of lubricants. But it has nothing to do with fuel injectors.
To the original poster, this may help:
http://www.aaroncake.net/rx-7/cooling.htm
12-30-05, 05:33 PM
#29
Full Member
Join Date: Aug 2005
Location: Tampa
Posts: 187
Likes: 0
Received 0 Likes
on
0 Posts
I was always told that you NEED the thermostat in the car because the car needs to warm up to normal temperature. Also with the thermostat out of the car and your running the motor cold and you rev it up or take off with the thermostat out of the car without letting it warm up to normal temperature can cause problems in the motor and could also cause problems with the injectors. If im wrong excuse me for the wrong information. I apologize for stating missinformation.. That is what I was told so sorry.
- Ivan
- Ivan
01-01-06, 03:48 PM
#30
Newbie
Join Date: Dec 2005
Location: Grapeview, Washington
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Okay here's my update....
We had a few rainouts(it's washington, it happens) we replaced the waterpump and thermostat, put in a 195 degree instead of the 192 it had in it, put it all back together, put water in, instead of coolant(cheaper for troubleshooting) and we started it up ran it a bit(ran cold)and drove it about a half a mile total and it was half up on the water temp on the dash and still rising when I got it back it was still smoking coolant vapors, popped the hood and we heard a small hissing so we found a break in the gasket on the opposite side of the waterpump, we sealed it with something(I'm no mechanic I just do what I'm told) and started it today, it ran fairly smooth and the heat gauge only got a 1/3 up and held steady for the duration of the drive(probably 4-5 miles) but coolant vapors are still rising from near the bottom hose of the radiator, I cant pinpoint it because the vapors are fairly thin and there's no hiss anymore, anysuggestions or comments?
We had a few rainouts(it's washington, it happens) we replaced the waterpump and thermostat, put in a 195 degree instead of the 192 it had in it, put it all back together, put water in, instead of coolant(cheaper for troubleshooting) and we started it up ran it a bit(ran cold)and drove it about a half a mile total and it was half up on the water temp on the dash and still rising when I got it back it was still smoking coolant vapors, popped the hood and we heard a small hissing so we found a break in the gasket on the opposite side of the waterpump, we sealed it with something(I'm no mechanic I just do what I'm told) and started it today, it ran fairly smooth and the heat gauge only got a 1/3 up and held steady for the duration of the drive(probably 4-5 miles) but coolant vapors are still rising from near the bottom hose of the radiator, I cant pinpoint it because the vapors are fairly thin and there's no hiss anymore, anysuggestions or comments?
Thread
Thread Starter
Forum
Replies
Last Post
