Temp question?

[RCP Phx]

Nope,V8! The passenger side exhaust went forward and under the harmonic balancer to meet up with the drivers side! It was a torque motor!

Edit: it was the 327 motor!

 

[voudoux]

I think it was a Rambler motor,they made or bought a 327 ci in the 60s a much better motor than the OHC 6, Jeep also used Buick 350s and their v6s along about that time ,that is a long time ago hard to remember all the details,but can not forget the ohc6. Thanks

 

[RCP Phx]

I tried to Google some good pics (but didn't find a lot), it was a version of the "Vigilante" motor!

 

[voudoux]

I was wrong on the ohc6 displacement it was a 230, sorry. Try wikipedia look up rambler AMC engines, it came in the ambassadors. Thanks

 

[Jeep Driver]

Agreed

Take some time to read about Smokey Yunick's hot vapor engines and his thoughts on engine temperature. The short answer to your question is the higher temps are a trade off by engineers for: emissions, fuel economy, engine packaging, assembly process, longevity and finally cost. We as the end consumers can determine which of those often competing issues are most important to us. I prefer a cooler running engine in normal operation so that I have a larger safety margin in severe duty situations.

Government demands the lowest emissions possible; higher engine temperature helps achieve this. Sheep go along with this nonsense.

I run a 180-degree thermostat and a 3-row, all-copper radiator in my 2001 XJ. Everything else is stock. Coolant entering the engine is 153 degrees, and coolant exiting the engine is exactly 181 degrees, measured with an IR gun, a/c on or off.

I get 25 mpg hwy, 19 city, day in, day out. It runs like new, even with 185k on the clock. Closed loop operation happens at 140 degrees. No emissions-related CEL's have ever happened. The hood is merely warm to the touch, even on a 115-degree day. It has always passed the most probative smog check imaginable, even in CA.

I see no reason to BBQ my XJ to make government smog fanatics happy. Molon labe.

 

[Jeep Driver]

Sorry to take so long to reply,I agree, l am working on my 2.5 4cyl xj now it would be a good time to try a different thermostat (160/180).But I have not ffound out at what temp the 4cyl goes to normal ( I think the term is closed loop) running. I am in the process of installing a instrument cluster with actual gauges,not just lights,what genus engineer came up with a dash for a Jeep with no heat,oil ,or battery gauges? I could go on for quite awhile on this topic, but Not now. Thanks

Go with the 180, my 4cyl does well with it.

 

[voudoux]

Thanks for the info from experience.

 

[alexgalexg]

I see lots of replies here but here is my opinion. The engines on both my 98 and 99 have run at 210 and long term idled (highway rush) at 213). these are not temps to worry about. My 99 has done 300k and had no problems at all. I live in the NE region of the US though... Pick a lower temp speced thermostat if you live in a hotter climate such as TX or southern CA

 

[old_man]

The thermostat sets the minimum temp the engine will run at. It forces the fluid to stay in the block until it hits that temp. Ideally you want the engine to run hot enough to cook out any condensation in the block. Condensation mixes with the Sulphur in the oil and forms H2SO4 Sulfuric acid, which breaks down the oil and erodes the metals in the engine.

There is a temperature at which an engine without a thermostat will reach equilibrium. Ideally, this temp will be less than the thermostat temp, and the thermostat will regulate the flow to keep the coolant temp at the thermostat temp. If the equilibrium temp is above the thermostat temp, the thermostat will have no impact on the temp. That is why putting a 160 degree thermostat in will not keep the cooling system from boiling over.

The only way a thermostat will cause a boil over is if it fails in the closed position. Ideally you should always run a "fail safe" thermostat. A fail safe thermostat normally fails by sticking open, not closed.

Over heating is normally caused by something causing the engine to generate too much heat, or the radiator isn't getting rid of the heat.

Common causes of over heating are
(1) plugged CAT
(2) running too lean (low fuel pressure, clogged injectors, vacuum leak)
(3) timing advanced too much (normally not the case since the ECU controls the timing
(4) Detonation/ping caused by too low octane fuel, running too lean, carbon buildup.
(5) Low coolant level (radiator leak, old worn out radiator cap (common))
(6) Clogged radiator (fluid)
(7) Clogged radiator (external)blocked air path

 

[Jeep Driver]

The thermostat sets the minimum temp the engine will run at. It forces the fluid to stay in the block until it hits that temp. Ideally you want the engine to run hot enough to cook out any condensation in the block. Condensation mixes with the Sulphur in the oil and forms H2SO4 Sulfuric acid, which breaks down the oil and erodes the metals in the engine.

There is a temperature at which an engine without a thermostat will reach equilibrium. Ideally, this temp will be less than the thermostat temp, and the thermostat will regulate the flow to keep the coolant temp at the thermostat temp. If the equilibrium temp is above the thermostat temp, the thermostat will have no impact on the temp. That is why putting a 160 degree thermostat in will not keep the cooling system from boiling over.

The only way a thermostat will cause a boil over is if it fails in the closed position. Ideally you should always run a "fail safe" thermostat. A fail safe thermostat normally fails by sticking open, not closed.

Over heating is normally caused by something causing the engine to generate too much heat, or the radiator isn't getting rid of the heat.

Common causes of over heating are
(1) plugged CAT
(2) running too lean (low fuel pressure, clogged injectors, vacuum leak)
(3) timing advanced too much (normally not the case since the ECU controls the timing
(4) Detonation/ping caused by too low octane fuel, running too lean, carbon buildup.
(5) Low coolant level (radiator leak, old worn out radiator cap (common))
(6) Clogged radiator (fluid)
(7) Clogged radiator (external)blocked air path

Fail-safes will stick open before you can burp on the first startup. I know I'm not the only one that has experienced that problem.


Common theme on ALL Jeep forums, 80% of us have experienced some sort of overheating at some point .

I will not argue with anyone here......done with that.......however, Jeep cooling system is inadequate at best.


Airflow, airflow, airflow.

 

[voudoux]

I have had good luck with fail safe thermostats,run them in all my vehicles. I would much rather have it stick open ,it can still be driven,than closed,you can't go far, my opinion from experience. They seem to have a life of about 3 or 4 years. Thanks