I have an 85 Toyota MR2 with 130k on it. When I acquired the car it would burn oil on startup and then once the car would heat up it wouldn't smoke unless I really really pushed it. Procrastinated on checking valve clearance and doing a valve adjustment (major PITA on this car) and burned a valve.
Took off the head had a valve job done (including new valve guide seals) replaced the head still have the same oil burning issues.
Compression is good on all cylinders, oil pressure is good, and oil burning on startup majorly decreases when the oil is on the lower end of safe zone. My understanding is that oil burning on startup tends to be a valve guide seal issue. Is it possible that they weren't installed properly or is it just most likely my rings? Is my next step a leak down test (haven't done it yet because I don't have the equipment) or is there something else I should try?
Thanks

12/12/2010 11:27:22 AM

paging zxappeal

12/12/2010 11:50:03 AM

It's my understanding(and has been my experience) that when you freshen the top end on a high mileage engine compression is restored and the increased engine vacuum will suck oil past the worn rings, even if the rings weren't causing oil consumption before.Th

[Edited on December 12, 2010 at 1:19 PM. Reason : Though I've done several valve jobs at 130,000 that didn't smoke afterwards.]

12/12/2010 1:18:17 PM

You say compression is good...but what are your numbers? Sure sounds like a lot of blowby to me, or at the very least a severely fouled PCV valve, but that won't result in smoking.

Valve guide seals won't do but so good if they were installed incorrectly or your valve guides are worn to shit.

I'd be willing to bet you got some ring wear.

12/12/2010 4:30:46 PM

Numbers were pretty good what they are supposed to be stock I was within 10 of the stock compression numbers on all four cylinders (stock should be 179) I will recheck though before I do a leakdown. It actually doesn't have a PCV valve it is just a straight tube. I put a catchcan on that for about a week to see what I would get and got what amounted to 1 to 2 drops of oil. I would think that the machine shop would have let me know if the valve guides were worn. They were a reputable shop from all accounts (and not cheap) so that is why I was assuming rings.
I was told it was possible to get good compression numbers and still have bad rings and that is why a leakdown test was what I was going to try next.
It was a real shame to start up that car after all that work and have it still blowing out smoke. I am still hoping somehow that it could be valve guide seals but I think I am deluding myself because I don't want to start thinking about engine replacement.

12/12/2010 4:43:41 PM

Who rebuilt your head? When i got a 92 civic head rebuilt every valve guide was out of by a large margin on the exhaust side. I know hondas in particular are hard on valve guides OMG VTEC.

12/12/2010 5:03:56 PM

I had T. Hoff to all my head work.

12/12/2010 6:34:37 PM

ok same place i use. i run 18lbs of boost and dont burn oil. im going to second your opinion on the bottom end.

12/13/2010 10:41:17 AM

just let it burn oil

12/13/2010 7:37:00 PM

Thats what I am doing right now until I can scrape together the cash to start on an engine swap.

12/15/2010 8:26:25 AM