Burning Oil?

[dontfeedphils]

I'm glad that I've got a good new job now because I think I'm going to be buying a new shortblock for my '90 GSX. The problem I'm having is every time I get into the boost I smoke out anyone thats behind me. I'm 99% positive that I'm burning oil because it always seems to go somewhere while at the same time I have no leaks.

So I guess I'm asking is if there are any other possibilities as far as my problem goes? Also I'm going to start saving up for a new short-block from SBR, and when I get that I plan on having the head gone through and throwing it all in.

If anyone has any input or any ideas on what else I should do please let me know, just looking for opinions. Thanks guys.

 

[diablos991]

This could easily be a number of problems ranging from your turbocharger, to the valve seals in your head, or even a faulty pcv valve.

Your first step should be to check the turbocharger for shaft-play (some up and down is ok as long as your compressor blades aren't rubbing against the compressor housing, but there should be no in and out)and the lower intercooler pipe for oil. Either of these could mean that you have a blow turbocharger.

You also need to do a compression test on your engine. If those results come up low, then you should perform a leakdown test to pinpoint the area where you are losing compression.

EDIT: Also, are you sure that the smoke is oil? You could have a boost leak that would cause your car to run rich.
White smoke that smells sweet is coolant.
Blue or gray smoke that smells bitter like burning oil would be an indication of oil burning.

Link for compression test
Link for leakdown test

 

[dontfeedphils]

Well I'm pretty sure that is not the turbo, because it's a big 16G thats maybe 6 months old. And yeah I'm sure that it's oil I start the week at the top mark on the dipstick, and end the week on the bottom mark.

I do a ton of work on my other car, ranging from just electrical to swapping heads, but its a Hurst/Olds with a 307, so I still haven't learned all the different possibilities and symptoms that are associated with turbo cars.

But I will check my lower IC pipe for oil, and I'll pick up a screw-in compression tester, and run some tests. I suppose it could be running a tad rich, my last tank I got about 23 mpg, but that still doesnt explain the dissaperence of oil. Thanks for the help.

 

[diablos991]

I wouldn't rule out the turbo until it is checked. I have seen a few turbos fail before 1k miles.
It is possible that something could have been sucked into the compressor housing and did some damage or that the seals are bad.

Keep us informed on your numbers and the results of your tests.

 

[95CarbonEclipse]

+1 for the PCV valve. I would double check this, as boosting the VC will cause a TON of smoke out the tailpipe.

 

[dontfeedphils]

So if the PCV Valve is bad will it actually pressurize the valve cover? So will that cause enough pressure to actually blow by some oil and eat it up? Well either way it's a cheap try so I'll try it.

And I'll try and pick up a compression tester. Should I use a screw in tester or just a hold in tester?

Thanks for the help, because if it ends up being a PCV valve I will bow down to you.

 

[diablos991]

Definitely a screw in compression tester. They are not too expensive and some automotive stores will even let you borrow one for free.

 

[kenamond]

So if the PCV Valve is bad will it actually pressurize the valve cover? So will that cause enough pressure to actually blow by some oil and eat it up? Well either way it's a cheap try so I'll try it.

And I'll try and pick up a compression tester. Should I use a screw in tester or just a hold in tester?

Thanks for the help, because if it ends up being a PCV valve I will bow down to you.

The PCV valve is supposed to close when the intake manifold pressure is higher than the valve cover pressure (like when you're boosting). The PCV valves on these DSMs don't last forever (they die quickly). So when you boost, the IM is under pressure, and the PCV valve lets that air pressurize/boost your VC and crankcase. Autozone/Carquest PCV valves don't work; you need an OEM valve or a check valve (search for the thread, "Stupid PCV Question" for more info on check valves - long thread, but lots of good info about what to do and not do with the PCV system).

I use the screw-in compression tester. http://www.geocities.com/dsmgrrrl/FAQs/compression.htm gives the DSM test procedure.

If you smoke mostly under boost, I'd suspect the turbo first as the other folks suggested.

Looks like you're on the right track, though.