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New Thermostat Blew Twice! Who is responsible?

6 months ago - Power steering broken and replaced. Dealer found leaky thermo in the process. Replaced.

3 months ago - Overheated. No coolant. I probably drove 10 miles on it while it was overheating having not noticed. Midas filled coolant. Saw coolant bubbling up and it looked oily. They predicted blown gasket. Brought to dealer. Broken thermo. Dealer apologized for faulty part, paid for tow, paid for new thermo, paid to fix a leak in the coolant tank. Saw some coolant and oil mixing but claimed that was “normal”

Yesterday - Overheated. No coolant. Noticed right away. Broken thermo again and, surprise, gasket! 2k to fix.

Is the dealer responsible for the blown gasket or am I? Did the car overheat and blow the gasket after the first thermo problem? Or did the original thermo start leaking because of the gasket issue? Chicken or the egg?

Either I’ll sell the car or convince the dealer to pay for the issue. Please help!

Year, make, model, mileage…?

Typically all dealers carry 1yr/12,000 mile warranties with their repairs that works with all same brand dealers. No idea what started what.

Best of luck with it all.

I think that you have a much bigger issue than a thermostat problem. Are you talking about the head gasket?

Caddyman - Sorry, let me clarify! Mini cooper 2003 91000 miles.

Andrew_J- The car is out of warranty with 91000 miles. The part is under a two year warranty. If the thermostat broke and that messed up the gasket, it seems reasonable for the dealer to pay for resulting repairs. It it is not faulty and just keeps breaking because of the gasket issue, then it seems reasonable for me to be responsible.

Maybe I should bring it to another shop and have them check for damage that shows overheating as the cause?

Cigroller - Agreed. But do you think the dealer’s service shop may be responsible? If as they originally thought, they placed a faulty thermostat into the car and then the car overheated, the gasket might have blown. Therefore, faulty thermostat -> overheating -> blown gasket -> dealer pays… right? At least, is there a case to be made?

" I probably drove 10 miles on it while it was overheating having not noticed."

Question: Having not noticied, how do you figure that you drove 10 miles ?

Usually when a ten dollar part fails and causes hundreds of dollars in damage, the ten dollar part is covered by a limited warranty, but not the hundreds of dollars in colatteral damage that it caused.

Cars have gauges/lights for things like oil pressure and coolant temperature that are to be monitored by the driver. The car’s owner’s manual tells what to do if something goes haywire. Driving is not it.

"Dealer found leaky thermo in the process."
Huh ?

"Chicken or the egg?"
Absolutely !


The ten miles is a guess. I drive five miles each way to work. It probably occurred on my way to work and I was still too sleepy to notice. When I parked at work, the fan was cranking loudly. On my way home, I noticed. That’s why I guess 10 miles. As soon as I noticed, I stopped and had it towed to the dealer.

The dealer’s service department found a sticky (did I say leaky? sorry…) thermostat when I brought it in for power steering repairs.

So, CSA, your opinion is that I am responsible for the repairs even if there is a possibility that their error caused the damage?

Unless you’re an experienced mechanic who has actually been there through the entire sequence of events it is normally impossible to figure out the chicken/egg issue. Even then its not always possible.

Your initial post is so staccato and sketchy that its not necessarily easy to even discern the string of events. But here’s what I’ve got: your dealer replaced your thermostat and three months later the car overheated and showed signs of a bad head gasket.

That just sounds to me like you blew a head gasket. This could have just been bad luck. It could also have been that something completely unrelated to the thermostat caused a loss of coolant -> overheating -> blown head gasket. It already seems that you don’t necessarily notice your car overheating. The first time you actually noticed might not have been the first time. So its probable that the biggest reason you have a bad head gasket (if that’s actually what it is) is that you were driving it in an overheated condition.

After your first noticed overheat, why the dealer did something with the thermostat and told you that oil in the coolant is “normal” I couldn’t say. Its possible that this is somehow their fault. But I doubt it. And even if it was there’s likely no way to show it. What you do at that point is throw yourself on their mercy and look for some “goodwill” assistance.

Something doesn’t make sense here. You brought it in for a power steering problem and they “noticed” a “sticky” thermostat? You first said “leaky” which does make sense but sticking doesn’t.

They could see a leak, but the thermostat is in a housing. They would have to remove the thermostat and test it using a pan of hot water, unless someone there has x-ray vision.

Now if you complained about overheating or lack of heat, then they would remove and maybe test (or just replace) the thermostat.

The normal failure mode for a stuck thermostat is to stick open, not closed. What would make sense here is that you did have a leak at the thermostat housing, the thermostat itself does not leak, and they attempted to fix it, but did not. It continued to leak, very slowly and the coolant went down to the point that you overheated and blew the head gasket.

The head gasket wasn’t badly damaged the first time, but they didn’t fix the leak the second time and when the coolant got low, it overheated and further damaged teh head gasket.

It is also possible that there was never anything wrong with any of the thermostats or the thermostat housing and you had a head gasket that was beginning to fail and was simply misdiagnosed all along. In that case, the dealer would not be at fault, except for faulty troubleshooting, this failure was destined to happen.

I think that you will have a tough row to hoe getting someone else to cover a head gasket repair.
The serious stuff started 3 months ago and at that point there was a serious issue developing. The latest incident just finished it off.

Oil and coolant mixing is not normal as claimed and the point could be made that if a factory part failed (thermostat) then corporate Mini may give you some consideration on the repair by covering all or part of it.
If an aftermarket thermostat failed then corporate Mini is off the hook and the point could be made that the dealer should offer some consideration or possibly even be legally on the hook if the failure is within any warranty period.

The flip side is that you drove an overheating vehicle instead of stopping then and there.
Another angle here is that the dealer said the oil/coolant mix was normal. Not. This can also easily damage the entire engine by washing down cylinder walls. washing out crankshaft bearings and cam lobes, etc. In other words, an entire new engine may be needed.

A lot will depend on what was written down on your copies of the repair orders. If what you say is in black and white then a call to corporate Mini may, or may not, get you some help. It’s worth a shot anyway.

I agree with those who said you blew a head gasket. Where I have a problem is when the dealer said “Saw some coolant and oil mixing but claimed that was “normal”.” Bull. Oil and coolant mixing is never normal, and is always indicative of something having gone wrong. On rare occasions that something might be benign - some moron at Jiffy Lube might have poured oil in the coolant reservoir by mistake - but usually it indicates that the 2 fluids are mixing within the engine, which often means a bad head gasket.

It’s entirely possible that the head gasket blew after you allowed it to overheat and then kept driving, and that it overheated in the first place because the thermostat wasn’t working properly or sprung a leak. However, had you taken the proper steps once the problem presented itself, the damage to the head gasket would not have occurred, and so I don’t think anyone but you is responsible for getting it fixed. I understand that you didn’t notice, but it’s not the dealership’s fault that you failed to notice a gauge that was indicating trouble.

The other possibility is that you have a car that’s nearly a decade old, and it just blew a head gasket, having had nothing whatsoever to do with the thermostat. In that case, it’s still not the dealer’s fault.

That said, any dealer who tells me that oil and coolant mixing is normal has lost my business permanently. I compare it to a doctor who tries to tell you that heart attacks are normal and you shouldn’t bother going to the hospital for them. So while they’re not responsible for fixing your head gasket, they also should not be the ones to do the work.

Hey, great comments! I really appreciate them, even if I’m not the best at explaining car issues. Sorry for my “staccato” first post. I actually tend to ramble, so I thought I’d just put in the basic facts. Anyway, you are all very helpful. What I am hearing is it may be worth a try to argue politely and then throw myself at their mercy. It may be their fault, it may not (more likely), but it is impossible to know. I’ll bring up the oil/coolant mixing issue and ask why they didn’t fix that issue last time when they saw the problem. I’ll bring up the fact that I never, ever had overheating problems until they replaced the thermostat. Maybe we can agree that it is impossible to know who is at fault, so I will just pay cost for the parts and that’s it. I’d be happy for that compromise.

However, I’m worried about doing the repair because it seems like throwing good money after bad. First off, there’s this problem, there’s a tie rod issue, a leak in the oil pan, there’s the 90 thousand miles/8 years old thing, and it just seems like everything about this car is falling apart lately … Once I do this repair, it seems likely there’ll be a million more down the way! Perhaps I should just trade it in and get a new one.

I don’t think I’d ever get a mini cooper again. Repairs are so expensive!

PS As to sticking or leaking thermo, they’ve described it both ways! At first, they said it was sticking open and that’s why they replaced it. Then, today, he referred to it as a leaky thermostat. So, I’m sorry; I just don’t know! :frowning: The reason why they knew to look for it when I brought my car in for the power steering is because I had a check engine light on. Perhaps that light went on because of the sticking thermostat or perhaps it was the gasket problem way back then.

I see no way a thermostat could be described as leaky. It is quite possible and common for an aged thermostat to:
A. Stick open. This can set a CEL but will not cause overheating.
B. Stick closed. This can cause overheating and possibly a CEL.
Maybe the CEL was on because of the T-stat and that’s why they suggested the repair.

It could be that you’re being fed a line of BS. At the dealer you will converse with a service writer or service manager. Very very few of these people have any mechanical aptitude to speak of.
That bogus line about oil/coolant mix being normal could be based on:
A. Trying to cover their hineys because of the prior T-stat change.
B. Pure mechanical ignorance.

It also could be that after the T-stat change the cooling system had a little air in it that was not burped out. With the onset of warmer weather maybe any abnormally low coolant level caused the engine to overheat.

Based on what you were told by the dealer there are a few red flags on this.
(I would add that if the T-stat was a genuine Mini part and most factory parts are covered under a parts warranty period. It might be a good idea to bring corporate Mini into this although getting clear-cut answers can sometimes be very difficult.)

A thought here since this has been referred to as a sticking and a leaky T-stat.
Maybe the original CEL illumination was a stuck open T-stat which they changed.
The second time around could be a LEAKING thermostat housing cover due to improper installation. Eventually the leak caused the coolant level to drop low enough to cause overheating.
(The T-stat won’t leak but the T-stat housing certainly can if care is not used when installing it.)

I don’t think I’d ever get a mini cooper again. Repairs are so expensive!

I think that’s wise, and you’re far from the first Mini owner whom I’ve heard that from. Best I can tell, Minis were build to be cute and fun, but not reliable.

If this engine problem happened to be related to an improper thermostat installation that would not be due to a Mini being an unreliable car though.
That would be a careless mechanic issue based on a leaky T-stat housing and also the possibility that this same mechanic could have been the one to refer to oil/coolant mixing as being a normal thing.

The latter would be dependent upon the communication, or lack of, between the mechanic and service writer/manager, assuming one of the latter is the person telling the OP this.