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What just happened?? Over heat!

358 Views 18 Replies 5 Participants Last post by  Andrew Caple
Well I just got home from getting my mum from work.

I go to park my car in the space and I start to feel something wrong with the car!
It starts to have a slight groaning noise that I can feel on the clutch peddle, and then all of a sudden one of the water pips started to leak water all over the place!!!

I note that the rad fan is not working at all when this happened, I look at the temp and she is in the red!!

The car still runs fine but I’m letting her cool before I look at anything, and it being night here doesn’t help things.

Ok guys where to look for the problem?
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My guess is your thermostat is broken. Replace it and you should be fixed.
would that stop the rad fan from working, as the rad was red hot?
thermostat, the same thing happened to me. Has it ever been replaced before? How many miles are on the car? And yes, that does stop your fans from turning on, that is what controls your fans to go on in the first place.
What the hell is a "water pip"? Speak English, man.

Thermostat is a mechanical device that sits in the housing where your lower rad hose joins the engine. If it fails, it will prevent cool rad fluid from getting sucked out of the rad and back into the engine, so theoretically your engine would get hot as hell, while the radiator would remain at ambient temperature.

As far as I know, the rad fan is electric, driven by sensors, unrelated to the thermostat directly.

Check your two rad hoses - the upper one should be slightly warmer than the lower one, and they should both be close to the normal operating temperature of 170 (i.e. bloody hot, so be careful). If they're cold, then your thermostat probably failed.
Okay, so it sounds like I was wrong. How does the thermostat control the rad fan?
What I meant to say was it would be the reason why your fan is not turning on, it does not exactly control the fans. Sorry about that ;)
I thought that the thermostat only opens when the water in the engine gets hot and then lets the cool water in the rad come in the engine.

But my rad was red hot! so the thermostat must be opening?

This is the pipe where the water was leaking from

See less See more

need a fix for tomorrow

Are you guys sure its going to be the thermostat?as its going to be a pain to get one in the UK :/
if your fan didnt' turn on, it could be a bad fan or even a bad coolant temp sensor.

do our cars use the same thermostat as any other cars?
A failed thermostat can prevent the fans from coming on because of the location of the temp sensor. If the water isn't circulating, it can still be on the "cold" side of the radiator (still hot to the touch but not up to the trigger point).

This has happened on my DSMs before.

I would assume the Diamante engine uses the same thermostat because it's the same 3.0 NA, and I'm not sure if the NA and TT cars use the same thermostat anyway.
Since you're going to be buggering about in that area anyway, and since your car is now ten years old, and since you have a leak there, you may as well replace the upper radiator hose with a new one. And, what the hell, do the lower one too, before it blows.

Radiator hoses age, usually on the inside, where you can't see it happening.

A cheap way to see if it's your thermostat that's not opening is to just remove it and see what happens. Your engine will take longer to warm up, but at least coolant will then be going through the radiator.
Well I just ordered a thermostat for…………. 30 pounds!!! :eek:

It better be gold instead of copper! ;)

I’ll try and remove the thermostat tonight when I get home and see if it runs ok.
How hard is it to do?

Thanks for all your help guys :)
It's easy to do - it's just messy.

See my FAQ below, the part about replacing the engine coolant, and you can extract the relevant parts for removing the thermostat housing. It's just held on by three bolts, but you'll be spilling rad fluid everywhere.

Thirty pounds is outrageous - a new NAPA one was $US 12. And you'll be really pissed off if you find out that it wasn't the thermostat after all :).
Andrew Caple said:

Thirty pounds is outrageous - a new NAPA one was $US 12. And you'll be really pissed off if you find out that it wasn't the thermostat after all :).

You’re telling me! I tell ya if it is working it won’t be for long ;)

Thanks for all your help guys….. now I just have to wait for it to stop raining
Well i just took the thermostat out and the cars not Over heating anymore.

it should be ok till tomorrow with out the thermostat right?
Running with a stuck-closed thermostat does sudden immediate expensive vast damage, whereas running without one does teeny tiny imperceptible long-term damage.

The former case results in overheating the engine block and eventual welding of the pistons to the cylinders - the latter just means that your engine will take longer to warm up in the morning but, unless you live at the north pole, it *will* eventually hit normal operating temperature, at which point lack of a thermostat is irrelevant, since it would be open anyway.

(When are you gonna catch on that I'm just making all this shit up?);)
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