Snapped Piston on Car just out of warranty
Discussion
Hi all,
My car is just literally 6 months out of warranty and done 20k miles on the clock.
The other day I got a Drivetrain error and called the dealer I bought the car from and they advised me to take it in. They have had my car for a week struggling to find the issue and it's cost me thousands for them to strip down the engine bit by bit to find the fault. They have finally found the fault and have informed me that it is a snapped piston as a result of a remap.
What I'm struggling to understand is that how a car of this age and mileage can have such a serious engine issue after a short space of time (even if it was remapped). The dealership are telling me that the car manufacturer will not take any responsibility due to the remap and I just wanted to get some more experienced peoples thoughts.
Does a snapped piston in a period of 2 years that I've had the car sound like it a likely cause as a result of a remap? Do I have grounds to push back more with the manufacturer holding some liability for a poor car build?
Interested to hear peoples thoughts and yes, I knew the risk I was taking when I got the car remapped and it's turning out to be an very expensive lesson!
EDIT1: A lot of people asking what my car is. BMW 420i
EDIT2: For clarification, I bought the car when it was around 12-18 months old. I have had it two years meaning the car is 3.5 years old and was registered in 2018.
EDIT3: Costs to date:
£2700 for
EDIT4: Pictures page 11
My car is just literally 6 months out of warranty and done 20k miles on the clock.
The other day I got a Drivetrain error and called the dealer I bought the car from and they advised me to take it in. They have had my car for a week struggling to find the issue and it's cost me thousands for them to strip down the engine bit by bit to find the fault. They have finally found the fault and have informed me that it is a snapped piston as a result of a remap.
What I'm struggling to understand is that how a car of this age and mileage can have such a serious engine issue after a short space of time (even if it was remapped). The dealership are telling me that the car manufacturer will not take any responsibility due to the remap and I just wanted to get some more experienced peoples thoughts.
Does a snapped piston in a period of 2 years that I've had the car sound like it a likely cause as a result of a remap? Do I have grounds to push back more with the manufacturer holding some liability for a poor car build?
Interested to hear peoples thoughts and yes, I knew the risk I was taking when I got the car remapped and it's turning out to be an very expensive lesson!
EDIT1: A lot of people asking what my car is. BMW 420i
EDIT2: For clarification, I bought the car when it was around 12-18 months old. I have had it two years meaning the car is 3.5 years old and was registered in 2018.
EDIT3: Costs to date:
£2700 for
- Diagnostics
- Removal of existing remap and reset back to factory
- * Removal and investigation of cam cover (to check valves)
- Removal and investigation of cylinder head
- Removal and investigation of engine
- Refit price to put the car back together
- New tyre
- Piston kit (on back order)
- 4 days labour
EDIT4: Pictures page 11
Edited by SnappedPiston on Monday 27th September 14:59
Whether or not it’s the remap that caused the failure is going to be pretty hard to prove - but either way, it’s going to be a pretty easy get out clause for the manufacturer.
I think the best you can hope for here is to pursue some sort of goodwill gesture from them towards the cost of repair.
Or…. Potentially a cheaper option, find a replacement engine second hand and get it changed at another garage.
Either way, not going to be a cheap bill I fear.
I think the best you can hope for here is to pursue some sort of goodwill gesture from them towards the cost of repair.
Or…. Potentially a cheaper option, find a replacement engine second hand and get it changed at another garage.
Either way, not going to be a cheap bill I fear.
0ddball said:
Well looking at it from the other angle, a snapped piston on a modern 20k engine with no modifications would be extremely unlikely.
So it is very likely that the map contributed.
Absolutely this...So it is very likely that the map contributed.
OP, what car is it? What power is it running with the map, and who mapped it?
SnappedPiston said:
Hi all,
My car is just literally 6 months out of warranty and done 20k miles on the clock.
The other day I got a Drivetrain error and called the dealer I bought the car from and they advised me to take it in. They have had my car for a week struggling to find the issue and it's cost me thousands for them to strip down the engine bit by bit to find the fault. They have finally found the fault and have informed me that it is a snapped piston as a result of a remap.
What I'm struggling to understand is that how a car of this age and mileage can have such a serious engine issue after a short space of time (even if it was remapped). The dealership are telling me that the car manufacturer will not take any responsibility due to the remap and I just wanted to get some more experienced peoples thoughts.
Does a snapped piston in a period of 2 years that I've had the car sound like it a likely cause as a result of a remap? Do I have grounds to push back more with the manufacturer holding some liability for a poor car build?
Interested to hear peoples thoughts and yes, I knew the risk I was taking when I got the car remapped and it's turning out to be an very expensive lesson!
What car is it? My car is just literally 6 months out of warranty and done 20k miles on the clock.
The other day I got a Drivetrain error and called the dealer I bought the car from and they advised me to take it in. They have had my car for a week struggling to find the issue and it's cost me thousands for them to strip down the engine bit by bit to find the fault. They have finally found the fault and have informed me that it is a snapped piston as a result of a remap.
What I'm struggling to understand is that how a car of this age and mileage can have such a serious engine issue after a short space of time (even if it was remapped). The dealership are telling me that the car manufacturer will not take any responsibility due to the remap and I just wanted to get some more experienced peoples thoughts.
Does a snapped piston in a period of 2 years that I've had the car sound like it a likely cause as a result of a remap? Do I have grounds to push back more with the manufacturer holding some liability for a poor car build?
Interested to hear peoples thoughts and yes, I knew the risk I was taking when I got the car remapped and it's turning out to be an very expensive lesson!
And what remap were you running?
The joy of tuning... You pays your money you takes your choice, but the fact is if manufacturers could simply add 25% output to their entire range with a software change and see no other problems or costs, they would.
As time goes on, tolerances in manufacturing get ever tighter. Manufacturing *anything* to operate at +25% spec is wasteful and costly.
As time goes on, tolerances in manufacturing get ever tighter. Manufacturing *anything* to operate at +25% spec is wasteful and costly.
I don't think you have any chance at all. Were you also gunning it when the drivetrain error came up?
Look at it from a manufacturer's viewpoint. People who remap generally do so to go faster and we see daily instances of cars being driven badly and stupidly so it's not hard to put two and two together and conclude the remap contributed, especially if that engine is not known for such failures.
Look at it from a manufacturer's viewpoint. People who remap generally do so to go faster and we see daily instances of cars being driven badly and stupidly so it's not hard to put two and two together and conclude the remap contributed, especially if that engine is not known for such failures.
Sway said:
Krikkit said:
What does a "snapped" piston look like?
Either way mapped car with engine damage = bad map.
I've seen knock cause a piston to crack in half...Either way mapped car with engine damage = bad map.
Agreed on your point. Likely run too lean at some point, and boom...
Was it a new car warranty? Full dealer SH?
What do they mean by a snapped piston? Piston ring? Whatever it is, unless it's a manufacturer-approved remap you're probably on a hiding to nothing; you're only chance is if you can prove that the remap wasn't the cause and even if that's accepted, you're then reliant on goodwill.
There are numerous reasons why a piston could have problems and altering the fueling parameters could be one of them; I'm not saying it is, just that it's one possibility.
Did you buy new, or was it supplied by the dealer already having been remapped?
What do they mean by a snapped piston? Piston ring? Whatever it is, unless it's a manufacturer-approved remap you're probably on a hiding to nothing; you're only chance is if you can prove that the remap wasn't the cause and even if that's accepted, you're then reliant on goodwill.
There are numerous reasons why a piston could have problems and altering the fueling parameters could be one of them; I'm not saying it is, just that it's one possibility.
Did you buy new, or was it supplied by the dealer already having been remapped?
Assuming snapped piston = hole in the top or fracture around where rings sit, that usually points to extreme detonation / pre-ignition which is attributable to timing being too advanced, lean fuelling, and/or knock sensor not winding back timing or potentially major carbon deposits which can be from overfuelling or poor condition ignition components. Have seen once a throttle butterfly screw came undone and put a very neat hole in the piston.
On a remapped engine I'd say unless you can prove a pre-existing fault with the piston or failure of other engine component and can prove that was a pre-existing fault, it would reasonably be attributable to the remap.
On a remapped engine I'd say unless you can prove a pre-existing fault with the piston or failure of other engine component and can prove that was a pre-existing fault, it would reasonably be attributable to the remap.
SnappedPiston said:
Hi all,
My car is just literally 6 months out of warranty and done 20k miles on the clock.
The other day I got a Drivetrain error and called the dealer I bought the car from and they advised me to take it in. They have had my car for a week struggling to find the issue and it's cost me thousands for them to strip down the engine bit by bit to find the fault. They have finally found the fault and have informed me that it is a snapped piston as a result of a remap.
What I'm struggling to understand is that how a car of this age and mileage can have such a serious engine issue after a short space of time (even if it was remapped). The dealership are telling me that the car manufacturer will not take any responsibility due to the remap and I just wanted to get some more experienced peoples thoughts.
Does a snapped piston in a period of 2 years that I've had the car sound like it a likely cause as a result of a remap? Do I have grounds to push back more with the manufacturer holding some liability for a poor car build?
Interested to hear peoples thoughts and yes, I knew the risk I was taking when I got the car remapped and it's turning out to be an very expensive lesson!
The manufacturer will spend literally thousands of man hours fine tuning the "map" so that it performs acceptably under all conditions and will (assuming no manufacturing defects) survive the not only the warranty period but the expected life of the car while also complying with the various emissions standards, possible fuel it may run etc etc. My car is just literally 6 months out of warranty and done 20k miles on the clock.
The other day I got a Drivetrain error and called the dealer I bought the car from and they advised me to take it in. They have had my car for a week struggling to find the issue and it's cost me thousands for them to strip down the engine bit by bit to find the fault. They have finally found the fault and have informed me that it is a snapped piston as a result of a remap.
What I'm struggling to understand is that how a car of this age and mileage can have such a serious engine issue after a short space of time (even if it was remapped). The dealership are telling me that the car manufacturer will not take any responsibility due to the remap and I just wanted to get some more experienced peoples thoughts.
Does a snapped piston in a period of 2 years that I've had the car sound like it a likely cause as a result of a remap? Do I have grounds to push back more with the manufacturer holding some liability for a poor car build?
Interested to hear peoples thoughts and yes, I knew the risk I was taking when I got the car remapped and it's turning out to be an very expensive lesson!
Along comes a man in a shed who knows better and doesn't care about reliability, emissions etc and just turns things up.
Inevitably when you increase the power things *will* break sooner. Sometimes it'll reduce the life of a car from maybe 250k down to 150k. Now not many people would notice that. Sometimes it'll be other things that will break, like gearboxes etc. Of course other times it may even generally increase reliability by removing emissions related equipment (while also making the car illegal to drive on the road).
Sometimes it's bad luck, maybe there was a manufacturing defect or a failed sensor and it wasn't anything to do with the map.
The trouble is that once you've put on that map you're in the hands of the gods when it comes to warranty. You have broken their explicit terms and unfortunately that means even if the map wasn't at fault it's on you if it fails *even* if it was due to a manufacturing fault. If it's an unrelated item then maybe they may cover you but still you have broken the terms so maybe not.
To bring it back to your specific case. Not knowing what kind of car it is doesn't help but *yes*, a remap certainly could cause that issue. You *may* have a case if it's a known issue with that engine (even for non-remapped cars) but even then, because it *could* be caused by the remap it would be hard to prove (without expensive experts) that it wasn't.
At best I'd say even if it was a known fault you're probably going to have to go legal and I'd expect it to take >1year to sort.
'snapped piston' is an odd description and hard to work out whats actually happened.
It could be anything from a big end bearing cap snapping, to a cracked or melted pistion.
However, I bet its failed piston ring land failure and its very likely a poor remap has caused the piston crown to overheat and crack.
If it was a big end failure or other mech failure, then it 'might' be a manufacturer issue but it would be very difficult to prove that the increased torque or the ability to rev higher hasn't overstressed the failed part.
It could be anything from a big end bearing cap snapping, to a cracked or melted pistion.
However, I bet its failed piston ring land failure and its very likely a poor remap has caused the piston crown to overheat and crack.
If it was a big end failure or other mech failure, then it 'might' be a manufacturer issue but it would be very difficult to prove that the increased torque or the ability to rev higher hasn't overstressed the failed part.
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