Low compression?

[scottj]

A friend of mine with a Versa is getting an a persistent CEL, code is misfire. She had it serviced at 30k miles and missed a few oil changes and hit 50k miles before getting the CEL. Her BF changed the oil and didn't see any debris in the old oil, it was just dirty. The dealership said it needed a new engine w/o elaborating and they weren't going to warranty it even though she has an extended warranty becuase she did't have receipts for oil changes. She took it to an independent shop and they changed the coil and plugs and the CEL came right back on. They then did a compression test and said the #2 had low compression. I rode in the veh and it drove fine with plenty of power and no rod knock or anything.

I find it hard to believe that missing a few oil changes could cause a low compression condition. Anyone have a similar experience?

[biggie]

The oil wasn't changed for 20k? Yeah, that could be a problem.

[Promise Land]

missing a few oil changes would make the oil break down and provide less lubrication for the piston and rings. it would allow the components to wear a lot faster. worn rings = less compression. why it's only #2, that I couldn't explain.

[scottj]

I see plenty of people running 15-20k miles between oil changes, the guys who send in oil samples to Blackstone. And VW/Audi had a recomended oil change interval of 15k miles on some of their vehicles. I'm going to guess the independant mechanic didn't know what he was doing when he did the compression test. Maybe this is the excuse I need to buy a leakdown tester.

[They Call Me Whatshisname]

I havent heard of anyone doing that with no consequences and the diff between 15k and 20k and a german car and a versa is pretty big.

[Rand0m0sityxX]

I see plenty of people running 15-20k miles between oil changes, the guys who send in oil samples to Blackstone. And VW/Audi had a recomended oil change interval of 15k miles on some of their vehicles. I'm going to guess the independant mechanic didn't know what he was doing when he did the compression test. Maybe this is the excuse I need to buy a leakdown tester.

It all depends. Conventional can not go 15k-20k without being changed, no matter the car. Certain synthetics (That I believe aren't in the US becayse Royal purple nor Amsoil I think go that far) Can go that long, but its true synthetic.

Missing a few oil changes can easily ruin the motor.

This guy waited 60k to change it.

http://forums.bimmerforums.com/forum/sh ... ?t=1281659