Rotella T6 5W-40 - 5K miles - 02 Subaru WRX

[Edison]

My first post! This is my first oil analysis for this car: 2002 Subaru WRX with 95K miles. A bit of background. I bought the car last summer with 89K miles, one owner car. 51 miles after I bought it, one of the timing belt idlers seized and the belt snapped. I had to rebuild the heads. After the head job, I ran conventional oil for 290 miles and then switched to Rotella T6 (this analysis). The oil was run for 5,260 miles (5-months) and I had to add 3 qts during the period. Factory Subaru oil filter. I was having a slight knock noise during cold start ups for a couple seconds, this happened during the last month before the oil change. Now I'm trying Mobil1 10W40 to see if the oil consumption goes down, and the knocking noise is gone. What would be your opinion of the metals in the analysis?

 

[userfriendly]

Are you using leaded fuel or an additive?

 

[Edison]

Originally Posted By: used_0il

Are you using leaded fuel or an additive?

Nope.

 

[CT8]

Scoobydoo !!!

 

[Bigdaddyeasy]

Maybe do a couple shorter ocis to get the metals from failure and rebuild under control

 

[Garak]

Yep, it's still early, and we don't have any trending, either. There's not much to recommend since there's really not much to assess.

 

[chrisri]

When your tensioner seized at what RPM was your engine spinning? That lead doesn't come from cylinder head/heads rebuild. When engine piston and valve hit each other on lower RPMs usually only valves get bent, but with higher RPM bottom end gets impact too, and I'm afraid Subaru bottom end is quite fragile. I would advise you to drop the oil pan and to inspect main and conrod bearings.

 

[Lubener]

The addition of your 3 quarts of make up oil has made this report appear better than it actually was.A couple shorter oil changes and an air filter change and another analysis are in order.

 

[CT8]

Originally Posted By: chrisri

When your tensioner seized at what RPM was your engine spinning? That lead doesn't come from cylinder head/heads rebuild. When engine piston and valve hit each other on lower RPMs usually only valves get bent, but with higher RPM bottom end gets impact too, and I'm afraid Subaru bottom end is quite fragile. I would advise you to drop the oil pan and to inspect main and conrod bearings.

It pounds the Bearings.

 

[Edison]

Originally Posted By: Bigdaddyeasy

Maybe do a couple shorter ocis to get the metals from failure and rebuild under control

How short?

 

[Lubener]

I would try 2500-3000 miles.Go with a lower end filter and change it out at the same time.

 

[fdcg27]

FWIU, silver in a UOA typically signals the kiss of death for these engines. We see no evidence of silver in this UOA. Lead and copper do look a little high, but this could be episodic. As others noted above, it's too early to get really worried based upon a single UOA. Knocking at engine start is not usually main bearing knock either.

 

[bluesubie]

Subaru used lead bearings in the early WRX's.

 

[JFK]

Your bearings took a hit when your timing belt broke. This does not mean your engine is going to implode. It will shed lead until the gouge in the bearing is worn down. Keep an eye on oil pressure, listen for any knocking and keep an eye on UOA for trending. Silicon was awfully high for such a short OCI. Check air filtration. Paper is best for the engine.

 

[Edison]

Thank you guys, looks like I need to install an oil pressure gauge. When the heads were removed, there were barely any marks on the pistons from the valves. The belt snapped while I was cruising at 3k RPMS and I quickly pressed the clutch and never cranked the engine. The air filter is paper and has less than 5k miles. I did notice that the top of the air box has a broken tab, maybe is not fully sealing.

 

[Edison]

Here is the follow-up analysis. This time I tried Mobil1 High Mileage 10W-40. Seems like the car liked it better than Rotella T6.

 

[Brons2]

holy magnesium Batman!