Burning oil like it's a tank of gas
 

So my car has been taking oil for quite some time now, but lately it's really eatin it up. I'm pretty certain it's my rings, but I didn't do a comp / leakdown test yet. Today I went up a pretty big hill, and then when I came down, I was off the gas, and my car was pulling like 24-26inHG vacuum. I arrived near the bottom of the hill and pressed the gas a little bit, and looked in the rear view mirror to see a HUGE cloud of white and blue smoke. I got home and parked it. A few minutes later I started it up to take it out for a beat, and it ran really lean. I drove it pretty hard for about a mile and then it seemed to run fine. Could it be possible that this this burns so much oil than it F's with the O2 sensor? I got in boost for like 1/4 mile and it seems to blow it out. It burns about 1 quart every 700 miles! It's awesome! (I am using Castrol GTX 10W-40)

yeah you'll toast your O2 sensor(s) with oil like that.

PCV? My car drank oil before my turbo install. Now its got the 323gtx pcv and isn't burning shit for oil so far (knock on wood).

How does that vacuum measurement translate to kpa? I get like 17kpa vacuum (3k mile engine). If you're burning oil in vacuum, its likely valve stem seals.

Similar to what's happening to me, except i'm at 1qt. every 100 miles.
If it's not your rings it is going to be your valve guides.

Artie? Shouldn't you be chiming in?

I burn lots of oil too. =( I think I'm just about at what you are. 1 quart every 700 miles. I think I'm gonna drive the car to work tomorrow, then come home and check my plugs. I was working on a Toyota today and it was smoking like crazy. It actually turned out that one of the injectors was stuck open. I was running my 550's over 90% DC before so I'm thinking this might be the case with mine too. I run stupid rich while idle (12s, but mostly 13s now). And the damm car backfires quite often too. I mainly notice it after I start moving from a light and I shift. After the shift I get a backfire ( no load). Also, I notice that my AFR's spike rich every time I let off the gas ( in gear or out).

/ thread hijack.

so stuck injector = use of oil?

I tested my PCV and it seems fine, especially since it's brand new. I should run the 323GTX one though instead of the stock 99 one. I have a compression tester and I pulled my plugs out when I got home this morning. Once the wife gets home, I'll have her turn the key while I check the gauge. Should have my answer around 4PM.

you cant turn the key, wait a few seconds then get out and check the gauge?

Yeah, I guess it would work that way, but she likes to get involved. Plus I don't feel like getting in and out of the car that many times. Ok, I'll admit it...I am a lazy POS.

i hear you... :giggle:

Napa sells a tool w/ two aligator clips and a push button.

One clip to the starter solenoid, one clip to negative terminal on battery, hold button and engine cranks.

I can't think of what it's called but it's like $15 and routinely saves me tons of time/energy/needing someone else.

IDK about my miata because it doesn't run.... haha but my Saturn gulps up 2 quarts every 300 miles. Gotta love pistons w/ no oil relief holes. OEM FTW.

- Harbor Freight Tools - Quality Tools at the Lowest Prices

http://www.harborfreight.com/cpi/pho...5499/35448.gif

I just bought my compression tester at Garbage Freight. So today I did the test. My Haynes Manual says on a 1.8 liter, standard compression is 182psi. Minimum is 128psi. I tested each cylinder twice, turning the engine over for about 7 compression strokes, and this is what I got.
Cylinder 1: 170psi
Cylinder 2: 160psi
Cylinder 3: 170psi
Cylinder 4: 150psi

I didn't squirt oil in the cylinders and compression test it that way yet, should I? What do you guys think about those numbers/

You are getting close to the differential limit between cylinders, 28psi. you are at 20.


Did you warm up the engine first?
Did you pull all the plugs in the beginning before starting test?
Did you hold the throttle open?
Did you disconnect the CAS(so you don't get fuel/spark)?


I think your numbers are a little low for a 9.5:1 99 motor. My numbers were ~195 on both my 99 engines. That 182psi sounds like a 94 8.8:1 motor.

Yeah, my '00 motor had ~205-210 on all cylinders when I checked it.

The engine wasn't warm when I tested it. I forgot to hold the throttle open. I did disconnect the CAS though, and all the plugs were out when I did the test. I guess I'll warm it up first, and hold the throttle open while testing. I'll get back to you guys in a day or so.

So I re-did it. I took the car to get inspected, went to the store, then came home. I pulled it in the garage and popped the CAS plug, the injector fuse, and the plugs. Then I retested the compression in each cylinder twice, while holding the throttle flat to the floor, and listening for at least 7 compression strokes. Here's what I ended up with.
Cylinder 1: 160psi
Cylinder 2: 140psi
Cylinder 3: 160psi
Cylinder 4: 175psi

Paul, the part where you said "That 182psi sounds like a 94 8.8:1 motor." I got those numbers from my Haynes manual which is for a 90-97 miata, that's probably why it's so low. So I should actually have 195psi? If that's the case, it looks like I need rings. What are my options? Bored it out +1mm and put turbo pistons in it? Hone it and re-ring it? I don't know what to do. I need to buy someones shortblock assembly so I can have something to build on to swap in. It's nice weather now, so I need as little downtime as possible and of course for the cheapest amount of cash from my wallet.

now do it wet with a tsp of oil on each....

depending on the results after the tsp of oil you may need the bottom end or head refurbed.

the way i roll is just to throw a low mileage stock bottom back in. I'm ain't baller like Artie.