Low Compression in one cylinder
#1
Low Compression in one cylinder
I picked up my 2007 MCS in January. I tried some seafoam because it was running rough. It helped a little, but still ran rough. I was hearing the clanking of other people's cars in cold starts and thought maybe the timing chain is the culprit. Other than the rough idle though it seemed to drive really well and have good power.
I have my car up at the dealer and they are telling me I have low compression on one cylinder. They found this after replacing the timing chain tensioner, chain and so on. They say the rings are good and it is the valves.
The bad news is they found it was in some accident and the cooling fan connector was disconnected due to being damaged. So they connected the computer to BMW and are waiting to hear back if warranty will cover it. It is driving me nuts waiting, I had to wait over the weekend and still no news.
A few questions I was hoping people could help me out with. Can over heating only affect one cylinder? Note I have never seen the warning light and the previous owner claims to have never seen it. On the plus side it is winter and hasn't been above 30F. Is it possible the timing chain slipped and a valve was bent? Could the carbon build up cause cylinder leakage? What is a reasonable cost for the repair at a normal shop (ie not the dealer)? I am sure the dealer will charge me some rediculous price.
Thanks.
I have my car up at the dealer and they are telling me I have low compression on one cylinder. They found this after replacing the timing chain tensioner, chain and so on. They say the rings are good and it is the valves.
The bad news is they found it was in some accident and the cooling fan connector was disconnected due to being damaged. So they connected the computer to BMW and are waiting to hear back if warranty will cover it. It is driving me nuts waiting, I had to wait over the weekend and still no news.
A few questions I was hoping people could help me out with. Can over heating only affect one cylinder? Note I have never seen the warning light and the previous owner claims to have never seen it. On the plus side it is winter and hasn't been above 30F. Is it possible the timing chain slipped and a valve was bent? Could the carbon build up cause cylinder leakage? What is a reasonable cost for the repair at a normal shop (ie not the dealer)? I am sure the dealer will charge me some rediculous price.
Thanks.
#2
Question,
Did you buy this as a private sale or from a dealer/used car place?
If it was a private sale (i.e. off craigs list, auto trader and not a dealer) then you will probably not be covered by warranty but your state may have some way of recooping from the original owner if they did not disclose that the car was in an accident.
If it was from a used car dealer/MINI dealer then one of them should cover it and they should also have notified you that the car was in an accident.
Either way you should have some way to pay for it with out most of it coming out of your pocket.
As for real cost not at a dealer also not cheep if they have to take the engine apart. Not really sure what the cost would be though.
Did you buy this as a private sale or from a dealer/used car place?
If it was a private sale (i.e. off craigs list, auto trader and not a dealer) then you will probably not be covered by warranty but your state may have some way of recooping from the original owner if they did not disclose that the car was in an accident.
If it was from a used car dealer/MINI dealer then one of them should cover it and they should also have notified you that the car was in an accident.
Either way you should have some way to pay for it with out most of it coming out of your pocket.
As for real cost not at a dealer also not cheep if they have to take the engine apart. Not really sure what the cost would be though.
#4
Schatzy, not all accidents are created the same, it could have been a pretty minor fender bender, or something that just knocked it loose.....
My question to the OP is "Did you have a pre-purchase inspection done? Why not?
Next, why would you buy a car that's running rough when you get it, and then not have it checked out first?
How does MINI know you aren't the cause of the problem?
Is the car out of warranty on miles or time? If it's not, and there's no proof that the car overheated, seems they should cover it - I'd be curious to know what's actually causing the problem, but if it's a leaking headgasket due to overheating, there's no way it should be on MINI, should it?
My question to the OP is "Did you have a pre-purchase inspection done? Why not?
Next, why would you buy a car that's running rough when you get it, and then not have it checked out first?
How does MINI know you aren't the cause of the problem?
Is the car out of warranty on miles or time? If it's not, and there's no proof that the car overheated, seems they should cover it - I'd be curious to know what's actually causing the problem, but if it's a leaking headgasket due to overheating, there's no way it should be on MINI, should it?
#5
You are right, I should have had it inspected. I have bought a lot of cars and I always do really well though. This is my first BMW, but I have bought a few turbo cars. I did get a heck of a deal though, so I did plan for some issues. Granted not potentially a $4k issue.
The idle wasn't so bad as to think something was wrong, just a vibration and it drove great, rev'd right up, boosted good. I thought it might just be crappy gas. There were no check engine lights, and I had it scanned for codes and found nothing. Shouldn't it throw a code if there is a cylinder that bad?
If my beating is complete about getting cars inspected, can anyone answer my original questions?
The idle wasn't so bad as to think something was wrong, just a vibration and it drove great, rev'd right up, boosted good. I thought it might just be crappy gas. There were no check engine lights, and I had it scanned for codes and found nothing. Shouldn't it throw a code if there is a cylinder that bad?
If my beating is complete about getting cars inspected, can anyone answer my original questions?
#6
NAM has become such a friendly place to visit these days.
You should have thrown a code if you have a dead cylinder. Let's just hope the news from the dealer is good. I can say that during the colder months my cooling fan almost never comes on so hopefully no serious damage was done from your plug being disconnected. BTW if the dealer comes back and tells you cylinder #4 has low compression than it's more than likely carbon deposits in the valve train and piston.
You should have thrown a code if you have a dead cylinder. Let's just hope the news from the dealer is good. I can say that during the colder months my cooling fan almost never comes on so hopefully no serious damage was done from your plug being disconnected. BTW if the dealer comes back and tells you cylinder #4 has low compression than it's more than likely carbon deposits in the valve train and piston.
Last edited by Oxybluecoop; 03-08-2010 at 04:58 PM.
#7
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they should be keeping you posted on the outcome. When you bought it from the private seller, did they have a warranty w/it as well. Some warranty companies will let the old owner transfer it to the new owner. Typically this can only happen once. It really depends on the warranty company. I work for a dealer and both warranties we sell are transferable to the second owner if bought by a private seller.
I know this thread is old but any answer yet?
I know this thread is old but any answer yet?
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