Is it possible to prove the cause of head gasket failure?

[Geekman]

I'm currently involved in a dispute with a supposedly reputable garage relating to an engine repair on a 2006 Range Rover 4.2 supercharged and would appreciate some advice.

The timeline is as follows:

June 2024 - vehicle starts to present signs of head gasket failure and is taken to a reputable garage

July 2024 - head gasket failure diagnosed, after some discussion the decision is taken to completely rebuild the engine at considerable cost. Garage offers a 1 year / 10,000km guarantee.

January 2025 - after driving the car less than 2000km, the car again begins to present signs of head gasket failure. The garage asks to see the car in order to determine if they can repair it under guarantee

February 2025 - the garage determine that the head gasket is leaking into one of the cylinders. They state that they have not removed the head from the motor in order to confirm their diagnosis and will not provide me with any kind of written document in relation to their diagnosis. They say that the problem occurred because the car was overheated and was delivered to them without coolant. It was delivered to them with the coolant tank almost full and I am 100% sure that it was never overheated as I've been watching the temperature gauge like a hawk since the engine was repaired. Virtually all of the cooling system is new. According to them, a head gasket can only fail due to overheating and it is not possible that it failed due to a poor quality part or bad installation.

My question therefore is as follows. I can ask them to remove the head from the motor and take photos of the head gasket, with the head removed from the motor, is it possible to look at it and be able to tell whether the gasket was poorly installed or failed due to a manufacturing defect or if it was overheated? If there is a way of telling, I'm inclined to pressure them to remove the head, but I don't want to get to a stage where the head is removed and they use the evidence collected in that procedure to try to "prove" it was overheated.

Any advice would be appreciated.

Thanks

[Krikkit]

The only thing I can think of is that if they billed you for skimming the heads, and you can prove they're still the original sizes, you have a case to say they lied to you.

[Baldchap]

If you don't torque a head to the correct tightness in the correct pattern it can fail to seal. If a gasket is faulty it can fail to seal. If a head is not surfaced properly it can fail to seal.

A garage suggesting that only overheating can cause a HG to blow or fail to seal is ignorant at best and disingenuous at worst...

[Geekman]

Krikkit said:

The only thing I can think of is that if they billed you for skimming the heads, and you can prove they're still the original sizes, you have a case to say they lied to you.

I'm pretty sure they did actually skim them as I saw a picture of the heads in the machine shop, whether they skimmed them correctly is another matter.

Baldchap said:

If you don't torque a head to the correct tightness in the correct pattern it can fail to seal. If a gasket is faulty it can fail to seal. If a head is
not surfaced properly it can fail to seal.

A garage suggesting that only overheating can cause a HG to blow or fail to seal is ignorant at best and disingenuous at worst...

Exactly my thoughts. I asked them to put that statement in writing and they refused so they clearly know themselves that it's BS.

[swampy442]

it is possible they may have assembled it wrong i.e. put the gasket on upside down. Im not familiar with the architecture of the RR engine but Ive seen it done before. The only way you can guarantee they won't try and bend you over is to be there at the exact moment they remove the head and physically witness it, otherwise youre relying on them telling the truth.

As stated above incorrectly torqued bolts is another cause, or reused old stretch bolts, more than one cause

[Maxdecel]

Geekman said:

Krikkit said:

The only thing I can think of is that if they billed you for skimming the heads, and you can prove they're still the original sizes, you have a case to say they lied to you.

I'm pretty sure they did actually skim them as I saw a picture of the heads in the machine shop, whether they skimmed them correctly is another matter.

Baldchap said:

If you don't torque a head to the correct tightness in the correct pattern it can fail to seal. If a gasket is faulty it can fail to seal. If a head is
not surfaced properly it can fail to seal.

A garage suggesting that only overheating can cause a HG to blow or fail to seal is ignorant at best and disingenuous at worst...

Exactly my thoughts. I asked them to put that statement in writing and they refused so they clearly know themselves that it's BS.

Skimming the head/s will increase the compression ratio so I assume they'll have fitted an appropriate thicker H/gasket to return the ratio to standard ?
Don't mention this before ascertaining they did.
I reckon a designed comp.ratio on forced induction engines will be quite important.

Tightening procedure ? "We have a statement from our Tech who states he definately did" OR "He's no longer in our employment" Impossible to prove IMO.

[Time4another]

Sounds like they are closing ranks and have already made their mind up that it's not going to be their fault. I'd expect very little help from them in proving it is their fault. Tough one.

[M138]

Not sure it applies to more modernish cars but years ago you had to re torque the heads after 100 miles after head gasket replacement.

[Richard-D]

Some causes will be apparent during disassembly whereas others won't.

Even if it's the former, it would require the garage to be both very attentive during disassembly and honest. If they just rip it apart or aren't more knowledgeable mechanics than most they could easily miss the cause.

Your description suggests they have already decided they are not willing to find themselves at fault. You're not going to get anywhere working with people like this.

The best route forward is to make sure it is done correctly this time.

[samoht]

Richard-D said:

You're not going to get anywhere working with people like this.

+1

Collect the car.

Take it to another garage.

Ask them to fix it.

Optionally ask them, while re-fitting, to gather evidence on why it's failed a second time.

Optionally use this evidence to request a refund from the original garage / go to small claims about it.

[Master Of Puppets]

What's the chances the pictures were from another car and they filled yours with K seal which gave you a year, and ripped
you off for a heap of cash?

[RazerSauber]

It's a tough one. If you're prepared to take on the cost of the repair and subsequently taking the garage to court, you could have the engine dismantled and appoint an independent engineer to provide a report of the vehicle. Someone like Automotive Consulting Engineers would provide you with a document you can take to court if needs be to claim the costs back from the first garage.

[GreenV8S]

The work they did has clearly failed and this shows it was not done to an acceptable standard. They are liable for rectifying it, even without the warranty. It also clearly falls within the scope of their warranty.

If they refuse to accept that, I suggest you consult the citizens advice money claims hotline to find the best way to pursue your claim.

I'm not a lawyer, but as far as I understand it the legal options available to you will depend on the amount of the claim so CA will probably advise you to get an independent engineer to assess the state of the vehicle, and also to get a quote to fix it. I expect CA will advise you to send a formal 'letter before claim' and then take them to court. There is a standard template for this, and CA can provide a lot of help with it. The whole small claims process is designed so that a layman can complete it themselves.

I wouldn't be surprised in the garage change their tune when they receive a formal legal notice, but if not then CA will help you get justice.

[ChevronB19]

Geekman said:

According to them, a head gasket can only fail due to overheating and it is not possible that it failed due to a poor quality part or bad installation.

Thanks

They are talking utter, utter rubbish. I hope you have that statement in writing from them.

[Richard-D]

GreenV8S said:

The work they did has clearly failed and this shows it was not done to an acceptable standard. They are liable for rectifying it, even without the warranty. It also clearly falls within the scope of their warranty.

If they refuse to accept that, I suggest you consult the citizens advice money claims hotline to find the best way to pursue your claim.

I'm not a lawyer, but as far as I understand it the legal options available to you will depend on the amount of the claim so CA will probably advise you to get an independent engineer to assess the state of the vehicle, and also to get a quote to fix it. I expect CA will advise you to send a formal 'letter before claim' and then take them to court. There is a standard template for this, and CA can provide a lot of help with it. The whole small claims process is designed so that a layman can complete it themselves.

I wouldn't be surprised in the garage change their tune when they receive a formal legal notice, but if not then CA will help you get justice.

I don't think that's quite right. At this point it isn't even possible to say that the failure is related to the previous work at all. For all the OP knows there could be a cracked liner/head/etc that isn't apparent until the engine has been stripped.

I know that I wouldn't trust the garage from the responses they've given but it's far too early to say that the garage are liable here.

[GreenV8S]

Richard-D said:

At this point it isn't even possible to say that the failure is related to the previous work at all.

They've fixed a failed head gasket, and it has failed again very quickly. That suggests that either they didn't carry out sufficient checks for other problems (cracked liners, distorted castings etc) before replacing the gasket, or they replaced it in a way that left a much lower service life than normal. In either case it's clear that this is a recurrence of the problem they were paid to fix and their work hasn't fixed it.

A responsible business would take responsbility for the failure unless and until some other cause was found that was not their fault. But, for example, claiming it was delivered without coolant when OP says it was at the normal level seems like an outright lie intended to avoid their responsibilities. The ultimate resolution for that is to take them to court.

[Richard-D]

GreenV8S said:

They've fixed a failed head gasket, and it has failed again very quickly. That suggests that either they didn't carry out sufficient checks for other problems (cracked liners, distorted castings etc) before replacing the gasket, or they replaced it in a way that left a much lower service life than normal. In either case it's clear that this is a recurrence of the problem they were paid to fix and their work hasn't fixed it.

A responsible business would take responsbility for the failure unless and until some other cause was found that was not their fault. But, for example, claiming it was delivered without coolant when OP says it was at the normal level seems like an outright lie intended to avoid their responsibilities. The ultimate resolution for that is to take them to court.

The OP states that the garage hasn't removed the head to confirm the diagnosis. Maybe they've had a boroscope in there to confirm the leak of combustion gasses into the cylinder is via the gasket. If that is the case it either hasn't been mentioned or I've missed it.

If the OP paid for a full engine rebuild then you would be correct in your assertion that the engine would be expected to last a minimum amount of time before subsequent failure. If the OP paid for a failed head gasket to be replaced then the only thing warrantied is the head gasket and work to install it, not other components which may have subsequently failed.

For the garage to be at fault you will have to prove that the failure was actually the head gasket (not combustion gasses into the coolant via some other route) and that the garage's statement about the coolant was false. I believe that you are on a hiding to nothing trying to prove this if the garage is genuinely dishonest (as has been asserted).

[paul_c123]

Simple answer: no. Unless you do it yourself, you're always somewhat reliant on the garage being open and honest with you. If its a comeback, then the best route to pursue is that the work should have lasted longer from first time it was done.

[GreenV8S]

Richard-D said:

If the OP paid for a full engine rebuild then you would be correct in your assertion that the engine would be expected to last a minimum amount of time before subsequent failure. If the OP paid for a failed head gasket to be replaced then the only thing warrantied is the head gasket and work to install it, not other components which may have subsequently failed.

I agree, if the owner carried out the diagnosis then the owner is responsible for the diagnosis being correct.

OP said:

head gasket failure diagnosed, after some discussion the decision is taken to completely rebuild the engine at considerable cost

In this case the garage has diagnosed and charged to fix the problem, but not actually fixed it to a reasonable standard. If they can repair a failed head gasket without being responsible for the repair subsequently then I struggle to see what the warranty would actually cover.

[stevieturbo]

It has failed within their warranty period, so this should easily fall under that.

If the HG has blown, then it would not be unusual to lose the coolant, and hence arrive at them with no or low coolant.

As to cause, there are just so many scenarios.. But for them to say overheating could cause HG failure, yes it can. Equally HG failure, could lead to overheating. Chicken and the egg scenario. Both can happen.

Now the question is....would you trust them to start stripping the car to bits ?