Hot days hot engine

[TURBOTAXI]

Hi folks,

I gave in. I put a 71 degree thermostat in may car the other week.

Why so cold?

Because I fugured that cold engine meant less heat soak means more power.

My plans were dashed when the engine got quite warm. This was the time I blew a heater hose and did my bush mechaic repair on the side of the road.

So I took it out and went back to no stat.

Now with the hot weather my car gets warm when I accelerate too much or run boost for too long and when the A/C is on, other than that it is fine. It could idle in traffic all day with the A/C flat out.

So what next?

Anyone have any suggestions for how I can keep the car cool ? Would using the recommended stat make any difference?

I hate having to drive home at 90-100k's to keep the temp down!

[Baboon_AU]

give it a try... it should work because it is reccomended regardless if u have a turbo or not.

[XR6-VCT-2000]

did u reset the ecu when u put in the thermostat ????????? - this could be the cause of your problems - with any modification or change in engine specs / whatever .... the ecu should be reset so the rest of the system/motor can adjust itself to the new settings or parts.

[xr8ute]

Originally Posted by XR6-VCT-2000

the ecu should be reset so the rest of the system/motor can adjust itself to the new settings or parts.

I disagree. Resetting the computer after such a minor change will do nothing more than lose you a lot of power and economy for the next 500-1000km until your fuel trims update themselves again. A cam change, intake change, head change, or exhaust change for sure....but not for a thermostat.

Going too cold with the thermostat could leave the EEC in "Cold Start" mode. It runs alot richer because it thinks the engine is cold, kinda like running around with the choke on.

Are you sure your engine is running hot and it's not just a dodgy temp sensor?

At least put the stock thermostat back in until you find out what the real problem is with your cooling system. Running with no thermostat is baaaaaad...mmkay.

[boodek]

Originally Posted by xr8ute

I disagree. Resetting the computer after such a minor change will do nothing more than lose you a lot of power and economy for the next 500-1000km until your fuel trims update themselves again.

What are these fuel trims you mention?

[xr8ute]

Originally Posted by boodek

What are these fuel trims you mention?

The long and short term "Fuel Trims" are what the EEC's Adaptive Fuel Strategy is all about (what people mean when they talk about EEC's ability to "learn").

They are tables that store the learned corrections (as percentage), to be applied to the calculated injector pulsewidth, to achieve an AFR of 14.64:1 during closed loop. I think the tables are 2D load x rpm??

[TURBOTAXI]

But the stat is a heat controlled device?

[XR6-VCT-2000]

Yeah the stat is heat controlled, but alot of the other stuff on the engine that is ecu controlled runs accordinglly to the engine temperature too , im NOT saying that reseting the ecu will fix the problem , but they way everything else relies on each other in these new engines these days, it might definatelly be worth a shot an might fix the problem .... just a suggestion . ;) , good luck

[TURBOTAXI]

OK. Anything free is worth a try!

[TURBOTAXI]

Why bad Mr Mackay?

[xr8ute]

It takes much longer for your engine to reach operating temperature because the thermostat is normally shut while the engine warms up.

Your engine wears much much quicker when it is cooler than operating temp :(

[XR6-VCT-2000]

XR8UTE ....quoted "Going too cold with the thermostat could leave the EEC in "Cold Start" mode. It runs alot richer because it thinks the engine is cold, kinda like running around with the choke on." ...........

That is the exact reason why i said for maybe trying to rest the ecu , a really rich fuel mixture or something of that sort ( or other things ecu controlled effected by engine temp ) could be causing something as a mislead engine temp by the ecu - thus causing other ecu related parts on the motor to which have to do with temp to be misread.

[XR6-VCT-2000]

by the above, clearing up what i meant, is that the car/ecu could actually be thinking that now after suposablly warmed up with the new thermostat that it actually hasnt warmed up because the fuel system and other parts are relying on setting their settings to the original older hotter temperature . Yeah it reseting the ecu might make the car think it hasnt warmed up , but it may also passed it as warmed up , then allow it to set the new running condition temps for the fuel / air mix and so forth , nothing to loose in trying it , can allways just reset the ecu again if it doesnt work , and its something free to try before spending $$

[xr8ute]

Yep, I can see your point. However the adaptive fuel strategy is really just for fine tuning idle, cruise and some part throttle. Fuel enrichment strategies like cold start would be unaffected.

Certainly not going to have an impact on an engine thats overheating when driven hard.

Assuming its not just a simple issue with cooling capacity, it may be worth getting a radiator specialist or similar check over your cooling setup.

Make sure theres nothing simple like a radiator cap not holding pressure or a buggered water pump or whatever...

Have you got any heat shielding around your turbine housing/dump pipe? Maybe just heatsoak from the turbo install rather than a cooling system issue..?

[XR6-VCT-2000]

XR8 ... lol yeah thats a good point too...quoted "Make sure theres nothing simple like a radiator cap not holding pressure or a buggered water pump or whatever..." , i forgot all about the little things like that , more than likelly something like that - ....or -- i dont know if its possible on new cars cos i havent changed a thermostat on 1 yet , but in alot of older cars it was possible to put it in BACKWARDS (inwards faceing out and vise versa ) accidentlly and this would cause the above proplems !!!!!

[Stav]

Turbo taxi I know im NA in my AU six ..but I ran a cooler thermostat some time ago.I found that while the car had better power for a while but the plugs fouled up easier and chewed alot more fuel.The cars ecu thinks it is still warming up and makes it run too rich.Heatsoak really kills all 4.0 sixes but running a proper thermostat avoids other hassles

[EFFalcon]

the problem is, once the cars upto temp, the thermostats open almost all the time anyway.
running a colder thermostat will only delay the car getting to that full operating temp.
i'd be looking at things like airflow to radiator or other blockages.

[Stav]

Originally Posted by EFFalcon

the problem is, once the cars upto temp, the thermostats open almost all the time anyway.
running a colder thermostat will only delay the car getting to that full operating temp.
.

This is what I believed too!! What happened for me in reality was that the car would actually run cooler.The temp gauge would creep back to cold as I drove and the car would idle rougher.Even after driving for hours.I think the factory thermostat actually heats the engine above where it should be.Maybe I can try the edit and stick the cooler thermostat back in to maintain cool start maps at the time I want? Imagine how many less head gaskets leaks there would be if I am correct?

[TURBOTAXI]

I will fit a standard stat and perhaps flush out the radiator.
I will check every where for air/water blockages.

[xr8ute]

To get the best result you should have the thermofans set to switch on at the same time the thermostat opens so they can work together to keep the engine temp stable.

[cArSiK]

meh , i was going to do a cooler thermostat but its going to be winter in a few months...

James