adriangb

Hi,

I just got my UOA back from Blackstone. Had quite high metal levels.

Car has 115k on it but engine has unknown mileage (it was replaced by a previous owner). No track time but lots of hard driving including twisties.

Valve adjustment, new coil packs, new sparks and compression test were all done ~1 year ago. Everything sounds good, looks good, drives good. Only mod is a CAI.

Any thoughts? Should I be looking into preventative maintmaintenance?

Thanks

zeroptzero

My biggest concern would be the lead reading, it is quite high compared to a typical reading in a typical oil change interval (OCI). Their estimate is correct on the average reading for lead being 1ppm, so your car had 5 x the normal lead wear which is big (500% ?). So this engine shows some bearing wear during this OCI. I'd say some oil starvation occurred. Iron and Aluminum is higher than you want on an average run, likely a result of oil starvation as well (cams, lifters, cam bearings, pistons, rings, and cylinder wear). The OCI wasn't too long for that type of oil it could easily go 7000 miles.

The oil sheared a bit, being at the low end of the 30 weight viscosity, but not a huge issue as Mobil1 tends to run on the thinner side. No water, coolant, or fuel so that is good. The iron and aluminum wear can spike on an occasional OCI without too much worry, but you don't want lead and copper to spike as bearings are less forgiving. I'm positive this engine experienced some oil starvation.

Run a new UOA at the end of the next run, I'm willing to bet all of the numbers come down. Oil starvation is the biggest factor to causing increased bearing wear. I like oils with higher levels of moly and zinc, to give you a bit extra protection when you get metal to metal contact. . Post up the results after the next OCI.

adriangb

When I added that ~1qt (may have even been 1.5qt, I'm going off of memory) the reading was below low on the dipstick, which gave me a scare. So I may have been ~0.5qt or something below low.

I also remember an instance where I was driving a cold day on a cold engine and not a block away from my driveway I had to floor it to maneuver and avoid getting hit. Engine cut power at while I was flooring it, vague memory though it all happened fast.

So in summary, yes, oil starvation may have occurred. I'm most certainly going to be getting another UOA done.

zeroptzero

^ yup that all makes sense. Running low in oil is worse at high rpms and high g cornering, that's where the higher wear will manifest itself.