93 Integra Engine Using Too Much Oil, But Why?

ASSISTANCE Stock Engine-Bay Components
1

Okay, quick overview. 1993 Integra RS, 200,000 miles. Loosing 1Q oil every 300 miles. No blue smoke. No carbon around valve stems seals. No obvious leakage splatter on engine. Where the hell is it going? No leakage on garage floor or on parking lots.

Is there some way it could be leaking oil while driving / under pressure and blowing downwards onto the pavement that wouldn’t be obvious?

Here’s the compression test:

#1 - 145 PSI
#2 - 145 PSI
#3 - 105 PSI
#4 - 125 PSI

Since nominal PSI is 199, none of those is great, but #1 and #2 are within tolerances. #4 is below minimum pressure tolerances (suggested 135 PSI) and #3 is below min pressure and maximum variance.

What’s my next step? I love this car. I’d normally just keep tossing in oil, but it’s using it (or leaking it) so fast that I’m concerned I’ll be busy doing something else and it will loose too much and I’ll destroy the engine anyway.

Also, I suspected a ring issue and asked the mechanic to do a leak down test. He did a compression test, looked for leaks and valve stem seal issues, and told me he had no idea where the oil was going and suggested nothing else. (I suspect a bad mechanic here.)

So really 2 questions:

  1. Any idea what’s going on?
  2. How to identify a good honda/integra mechanic (not a dealer). I live in Ft. Collins where we don’t have a huge selection of non-dealer honda mechanics. Nearest highly experienced honda mechanic (that I know of) is in Boulder.
2

i would check the pcv valve
also, you could run a wet compression test and compare numbers to identify a ring problem.
but it’s more likely your pcv, as you’ve indicated no blue smoke

3

Thanks, welfare. I had heard rumors that the PCV is the likely culprit in these cases. I’ll have it checked out and post back.

4

how does a bad PCV cause you to burn oil… I’m burning a lot of oil, so maybe thats my problem.

5

if it’s stuck open vacuum will pull oil from the crank case and coat the intake. it may not always “burn” oil. but oil will be consumed through the intake.