SprintStar

Hello All,

Yes, I did search the archives before asking this.

I installed a MLS headgasket with my O-ringed head before I read from Cometic's FAQ that I should. And reading that others had no problems, I thought I'd just see how it pans out.

I'm not sure if the MLS and O-ringed head combo is causing my high temp problem but I sure like to eliminate it as a possible cause.

Overnight cold, the car starts up well and it would take a long time (about 30 mins) before the temp would raise to the last white line and mostly stays there or a little under.

However, when I restart the car after my first journey, it will take all of 10 mins before it hits that line.

I have a new radiator (custom, big *** 5 pass) and a new waterpump and thermostat (I admit to not testing the thermostat before installation). I have bled the system enough so air is not the problem. Fans are working as they should. How to measure CFM? I do have high speed and low speed but worried if the fans may not have enough CFM if they are old.

My turbo thermostat seems stuck open and the right angle plastic connection didn't have a hole drilled previously. I drilled a hole in it.

I do not doubt my temp gauge as I brought my 951 to track and after 7 laps, the red light lit up and when I brought him back into the paddock, the coolant spilled over.

So I do have a high temp problem. How do I go about tracing it? I did check using a combustion gas fumes testing device to detect a headgasket leak but it did not change color, indicating no leak.

However, is it possible for a MLS to leak with a warmed up engine but not leak when cold?

Thanks and sorry for the lengthy post.

Sprint.

Airflite40

which thermostat do you have it there? stock is 80C my S2 had an 87C thermostat in it and it would run way too hot. there is also a lower temp thermostat available too

SprintStar

I believe I have a 83C one in there. But the themostat for the turbocharger is stuck open. Could this cause my problem?

Sprint.

theedge

Open turbo thermostat would cause slightly longer warmups.

I think you have two different problems. How long does it take to warm up to operating temp when its idling? 30 minutes is way to long, even driving around IMHO. Mine takes just a few minutes to go from ambient coolant temp to 85C.... 30 minutes, it sounds like you have a main thermostat thats stuck open, or one hell of a radiator. Did you bleed the cooling system with the cabin heat on full/max?

Ski

You can also let the car sit on an incline (jack stands or driveway), A$$ end down, overnight, and that will let the air bubble get to the top. If you just bled it, as Brian said without the fans and heat on full, you could have air in the core if you still have it installed

Chris White

Are you losing any coolant? If not then don't worry about the MLS gasket - the problem is somewhere else.
The combustion gas test does not work well with our cars (I know, I have tried!). The coolant in the block/head will never get to the white coolant expansion tank. If you take a sample from the bleed screw you will have a better shot at checking it with the test kit.

As far as the MLS leaking when it is hot vs cold it may be that it is leaking when the combustion pressure goes up. If the cylinder pressure leaks into the coolant jacket it will overpressureize the coolant and either cause leaks or push the coolant past the radiator cap.

SprintStar

Ahh... I gotta confess. I run without heat here in Hellish Singapore. So yes, I have bled the cooling system to death without the cabin heat.

New discovery... If I drive without AC, the temps don't climb! Or when hot if I switch off the AC (bloody hot cabin though), the temps drop slowly!


Sprint.

SprintStar

I wasn't losing coolant, then yesterday I saw some dripping and thought.. Man!

Turns out to be turbo pump leaking. I will replace and monitor coolant level.

Sprint.