I've had my Begi S5 installed for a while and have had issues with tuning, AF ratio and misfires..etc. I also had an oil leak that I could not find. The leak is small but leaves spots in the garage and I was tired of it and I wanted to make sure things were fine.
So, this weekend, I took things apart a little bit and I found oil in the compressor inlet, outlet and tubing to the intercooler. I did not take all the tubing apart, nor did I completely remove the turbo (pain in the *** to do) and I put everything together to further diagnose the issue.
I did a compression test and leak down tests and took some pictures of the spark plugs.

Cylinder 1: Compression 155psi, Leakage test 8% (1st time), 0% (2nd time, engine cooled).
Cylinder 2: Compression 147psi, Leakage test 15% (1st time), 0% (2nd time, engine cooled).
Cylinder 3: Compression 139psi, Leakage test 0-1% (1st time).
Cylinder 4: Compression 142psi, Leakage test 0-1% (1st time).

Cylinder 3 shows 139psi, which is lower than the minimum suggested by Mazda, but all the cylinders show less than the maximum difference in compression between cylinders allowed by Mazda (28psi) - Maximum difference: 16psi.
I was slow on the leakdown test and it's cold out, so may be the engine temp had dropped for cylinder 3 and 4 before the test explaining the very low readings.
Here are the pictures:








I sent the same information to Stephanie, but it's the weekend I don't expect a reply from her until next week.
Any ideas? I am not mechanically savvy to rebuild my engine and I hope I don't have to.

 

What year is your miata? Typically, the oil in the intake is being pulled from the valve cover if you have a line connecting the two. As far as oil leaks, a lot of times oil leaks from the rear main seal. I don't see anything terribly concerning.

 

It's a 2002 with 1.8L. The oil 'leak' was actually oil dripping from the hose connected to the compressor inlet. It was dripping on everything under it. It was not a lot but enough to leave spots in my garage.
If it's not that bad, would an oil catch can help? I do have to pass emissions here in MO, would the oil catch can still allow me to do that? I did a search and I can't find much about emissions since most of them vent to the atmosphere.
Thanks.

 

Were the compression numbers taken on a warm motor with the throttle at WOT?

A little oil in the intake is normal, but that looks like a little bit extra blow-by. Can you test your PCV with your air compressor? See if it leaks it you apply 10-20psi into it.

How's the rest of your vacuum plumbing look?

 

At face value it looks like you've got excessive blow-by from your low compression numbers which is creating the excessive crankcase pressure to pump that oil into your intake via the vent tube (assuming your vent tube runs to your intake pre turbo). Run your cam cover vent tube to a catch can, make some boosted runs and then look in the can and see what you find.

 

I tried to get the compression on a warm motor, but it's 30-40 degrees outside, and my garage is not too much warmer after having to open the door to avoid CO poisoning. It took a few minutes to remove the coils, plugs..etc but the motor was warm to the touch, not hot.
I will try testing my PCV tonight if I get a chance. I did change that a few months ago to see if it helps, but it didn't.
As far as I could tell, the rest of the plumbing looks OK. I did re-seat and tighten clamps on the tubing to the intercooler.
This morning (35 degrees), my boost gauge was reading 19 vac at idle after the car has been warmed up, if that helps anything.

 

Any catch can? I don't have one, so what should I get? Thanks.

 

If it turns out that everything else is ok, I'd go the catch can route. Oil in the turbo inlet is normal..... That said, soaking thru the turbo hose and dripping on the floor is not normal. First, get accurate leak down numbers. Second, change to an aftermarket PCV valve. Then, make sure the oil drain line is not obstructed (in internally) in any way. If that does not solve the problem, then add the catch can.
Stephanie

 

For your purposes you can use just about anything. There's a bunch of info on catchcans here.

 

Thanks, I will look for the catch can information. The oil that I saw was in the compressor inlet, should I have a catch can on that side and another one on the PCV side? I do not want to vent to the atmosphere if possible.
Stephanie, regarding that turbo application PCV, it says it requires modifications to fit my car (on the FM website). If not too involved, I get one and modify it.

 

For the moment, all you need to do is clean up your intake/turbo. Remove your cam cover vent hose from the intake (pre turbo) and plug that hole. Stick that cam cover vent hose into a can. Go for a spirited drive. Then look in your can. Any oil? Now look in your intake. Any oil?

If you've got oil in your can and none in your intake, then I sincerely think that you've got high crankcase pressure from blow-by under boost. That pressure is sending excessive oil "mist" out the vent tube, through the hose and into your intake.

 

Get a cheapy plastic Fram fuel filter to use for a catch can. Just find one with the nipples the right size with both nipples at the top of the can. You can see through the white ones and they cost about 3 bucks. You'll see if you're accumulating oil in it after a few boosted runs.



Frank

 

I will try to do that as soon as I have time. Hopefully next week if I can. I did clean my intake 2 times before and I had oil in there at that time. It was a pain to do (whining), but if you think it's necessary, I would do it again. That was at least 6 months ago.

 

Thanks. I will look for one that fits.

 

Thats an excellent idea, thanks a bunch

 

I didn't have time to do much this weekend, but took off the PCV, it was bad, replaced it and drove the car today. A much smaller puff of smoke when I boost, let go and get back on the gas. I bought some things for two tiny catch tanks that I will install as soon as I have time... Will update at that time.

 

Update - So, I tried to make my own catch cans using air compressor filters. I connected one to the PCV side and one from to the other side pre-turbo. I didn't bring the camera to work, so I don't have pictures right now, but basically, tried to collect the oil pre-turbo and after intercooler before going to intake. I also changed the PCV to the one that is recommended for 1989 323 GTX Turbo.
Took the car out for a very short drive, and it started smoking - A LOT. Like clouds behind me. Slight boost made that a lot more. The smoke was white, but smelled like burnt oil.
Parked the car, removed the catch cans, reinstalled the hoses as they were previously. Took it out again, same thing, lots of smoke. Parked it. When I got out of the car, I could hear gurgling/bubbling sounds, seemed to be coming from the turbo area, but not sure.
In the process of all of this, I had oil leaks under the car, extending the length of the exhaust. Still have not had a chance from where.
Any thoughts? Am I completely screwed now??

 

I might be mistaken, but I'm pretty sure the catch can is supposed to go on the breather port (turbo side) of the valve cover. I wonder if you accidentally pressurized the crankcase...

Thinking about it now, you really need to put some pictures up. Normally with catch cans, they go in between the current junction. So on the PCV side, the lines would go to the same place, but you would have a catch can in the middle. Same with the other breather on the turbo side of the motor. That one goes from the valve cover to the intake, and you would put a catch can in there.

A major problem I can see is that if you hooked the turbo intake up to the PCV line, then it wouldn't have proper vacuum to release pressure. The PCV needs to see as much vacuum as possible, so it runs after the throttle body. The way you would have had it hooked up, it would only see vacuum when your turbo is sucking air, but when it was sucking air, it was creating pressure and not allowing the crankcase to vent...

 

I will post pictures from the camera tonight, but if I did pressurize the crankcase, did I screw things up pretty bad? I drove the car a total of a mile??

 

Listen. Go to autozone/oreilly/advance. Buy : Two conical crank case filters (look for them in the rice section), 2 5/8"(3/8? I cant remember) rubber caps, and a cheap 90* pcv valve. Remove your stock PCV system and any hoses you have going from the VC to the intake pipe. Cap the nipples on the intake manifold and the intake hose. Replace your PCV valve with the 90* one and put filters on that valve and the vent.

As for screwing things up, you might have blown your VC gasket and front/rear main seals. Nothing 100 bucks and a few hours wont fix.