I needed to get a wheel bearing replaced and the oil pan gasket replaced. The oil pan gasket was seeping oil enough that it bothered me. But I was only needing to fill up maybe 1 quart for every 10k miles of oil use. So during the oil pan gasket replacement, this is what they found....

A broken bolt! The good news? There is ZERO sludge anywhere. This could be advertising for Mobil 1 synthetic. I also change the oil at 10k miles and sometimes 13k miles. Blackstone oil analysis did not show any unusual wear. As luck would have it, this was the only oil change where I had forgotten to take an oil sampling.

It appears that the engine was probably running this way for a LONG time. Maybe about 30k miles ago, I noticed a very slight "rumbling" when revving the engine. It was very slight that I thought it was exhaust related. But when I had the oil change done (along with inspection that revealed the wheel bearing issue), we noticed that the very slight rumbling wasn't coming from the exhaust buy coming from the front of the car. This noise is NOT apparent in any way while idling or even driving the car. This is what made it more surprising. It was only evident when the engine is revved and you really have to listen for it.

 

Interesting. I see the chatter marks on the inside of the oil pan. I assume the bolt is long enough that the head just sort of rested against the bottom of the pan and chattered away down there.

 

The chains must be made of some hard steel. The cam chain tensioner in mine had a ceramic pad break off one end and the original owner ran it like that for quite some time. The chain wore tracks into the steel on the cam chain tensioner and the chain didn't show any signs of wear.

 

Bet it looked a lot like this:

 

293xxx Orignal miles?!?! Thats insane. What other maintenance has be done to the car? Replaced turbo? Have you checked compression? I am curious as to how healthy the car still is as almost 300xxx is quite an achievement.

 

definately do not just replace the bolt. odds are that the bearing is completely trashed. if it is the crank journal may be trashed too. it definately needs to be inspected further

 

We're still running the original turbo. This is really the most major (knock on wood) issue we've had with the engine. All other items like brakes, rotors, calipers, etc. have been replaced at least once. Still original radiator. We've done a compression test and it all came out great. We usually run a Blackstone oil analysis with the oil changes to monitor what's been going on with the engine. Interestingly, the car has been tracked and has been running APR chip+exhaust for a long while now.

 

The thing is, we're not really looking to spend a lot of money on this since it's my wife's daily commuter. Plus, the engine has not been making any obvious noises aside from what I described above. I think we're just going to bolt it up and take it to 300k miles and anything else above that is a bonus.

I think it would have been easier if the chain had broken so that it would have been a no brainer to justify getting a new commuter car!

 

I think 293xxx is a bonus in itself especially considering the stock turbo.

I am interested in the Blackstone oil analysis. I am going to google it right now.

 

I've seen results from a few people who did it on Audizine, it's really pretty cool. I'm always amazed at how much information they can extract just by seeing what's in the oil. Cheap too, I wanna say it was $40 or $50 with free shipping.