Coolant Boiling!!!!!!

[NobleChad]

Need help guys. Have smelled a coolant leak from the day I picked my car up. Noticed tonight after I shut it off.....the coolant is bubbling in the overflow tank...and I can also hear it bubbling through the turbo lines....what the hell is going on? I unscrewed the cap to the overflow and it started hissing even worse...now it's spraying coolant everwhere and won't stop. What do I do? What is going on that's making it boil/bubble?

Thanks


Chad

PS-engine temp is totally normal under operation

[Ronald Kienitz]

Need help guys. Have smelled a coolant leak from the day I picked my car up. Noticed tonight after I shut it off.....the coolant is bubbling in the overflow tank...and I can also hear it bubbling through the turbo lines....what the hell is going on? I unscrewed the cap to the overflow and it started hissing even worse...now it's spraying coolant everwhere and won't stop. What do I do? What is going on that's making it boil/bubble?

Thanks


Chad

PS-engine temp is totally normal under operation

Who did your install and how many miles have you put on it? If you're close to your install guy, have him sort it out; it's may well be his kuliana. If not, and even so, call Mike Evangelo at 1g stat. He's generally pretty helpful.
Ron

[NobleChad]

Who did your install and how many miles have you put on it? If you're close to your install guy, have him sort it out; it's may well be his kuliana. If not, and even so, call Mike Evangelo at 1g stat. He's generally pretty helpful.
Ron

Might do that in the morning...was hoping it was something simple....I'm entering it into a show tomorrow and was hoping to have this sorted out before then.

[Joel]

Sounds/smells like a leak somewhere in the cooling system. Have you noticed a coolant loss or a puddle under the car after it sits? Typically, pressure does not rise significantly in the system until after shutdown, but the combination of a completely sealed system and the proper water/antifreeze mixture should prevent boiling entirely. Other possibilities, unfortunately, include a blown head gasket or a crack in the head/block allowing combustion gases to enter the cooling system, which will cause bubbling. But that would mainly occur while the engine is running and most likely would also be associated with tell-tale white exhaust gases. The first order of business is a pressue holding test of the cooling system (i.e., apply external air air pressure using a special reservoir cap and see how long it holds after the supply valve is shut--done when the engine is cold).

[dino]

For what it is worth....even here in Texas, my water temp has never been about 90C, even after a track session.

What does your temp gauge read when this is happening?

Water pump? partially pinched hose?

Are your radiator fans coming on?

Is the air blowing the right direction?

I have heard of fans being wired backwards.

Let us know what you find.

Dean

[Paul Cundy]

Noblechad,
You may not have a problem. Boiling coolant in the header tank is normal on many a Noble. When I ran mine on track it used to do it all the time and I've seen amny a car do the same. Basicaly the car runs at normal temperature but when you stop the engine the coolant stops circulating and the heat in the engine continues to heat it until it boils. This is seen as bubbling in th header tank. Providing the coolant level is stable and does not drop with the car fully cold then this is normal. If the coolant level is falling then there's obviously something needs to be looked at.

To try to reduce this you can try just leaving the car on tickover and until the rad fans come on. Leaving it on tickover lets the turbos cool down and the engine generaly cool, letting the fans come on at tickover and then shutting down may help with a bit of convection in the coolant lines.

Do'nt ever take the coolant cap of whilst its boiling or hot. The system is pressurised when its boiling and you'll be unleashing even more trouble.

We have a phrase over here which is TADS; "They all do that sir".

Bubbling coolant in Noble header tanks after a spirirted run = TADS

Regards
PauL C

[Joel]

My experience tracks with Dean's--I have never seen the gauge go above 90-92 degrees C, even on days with 35+ degree C air temp. But I also have never seen or heard the boiling coolant Paul describes. Having owned various turbo cars for over 25 years, I follow the cool down (tickover) procedure Paul describes instinctively. Also, recall the M12s in the U.S. do not have water-cooled turbos, which may help keep their coolant temps down a bit. Since M400s do have cooled turbos, one might expect their cooling systems will be under more stress.

[dino]

I have seen the boiling coolant on the M400 but those turbos are water-cooled. The water temp ran higher on the M400 I saw also.

I am not an expert but something doesn't sound right.

How old is the car? How old is the coolant?

[NobleChad]

I have a water cooled set up...my car is chassis #12. So is this normal. Gauge never goes about 90 or so...just strange bubbling in the bottle and hoses after shut down....I tried letting the car cool off today before shut down...ran it a good 3-5 minutes and it still happened. When I turn the key off and leave it in the acc position...clicked all the way forward just before start....the fans turn off....I can't get them to stay on with the engine off.

[dino]

The radiator fans won't stay on when the ignition is off. But they should be on when the temp is about 80C and above. Are they blowing the right direction?

Your turbos are watercooled? I thought all M12s were oil cooled. I beleive that to be more the norm.

Do you live near anyone else with a car? You could have them check yours to see if it acts "normal"