# Need help diagnosing oil burning



## warpedhalo (Sep 23, 2010)

Well, the problem is I'm burning oil. Definately oil... white smoke, smells like oil and even potentially oil coming out exhaust. I say potentially because my "rebuilt" gt30 went out like immediately after putting it on and it blew a lot (2 quarts actually... in a hurry) of oil through the exhaust, so it may be that stuff in the exhaust. My oil isn't being lost like that anymore, but it still smokes.

Ok, things I've observed so far are that a WOT run will cause it to clear up, as if maybe the oil pools somewhere and the WOT run's increased airflow blows the sitting oil out maybe? Then, it will stay clear for the rest of the drive usually. However, if I drive increadibly slow (like crazy snowy roads) or ESPECIALLY if I let it sit and idle it will start to smoke. I've contributed this maybe to the increased vacuum that I am getting? Vacuum at idle = a lot more than driving normally, could this cause a problem with the PCV system? I have a new PVC valve thing that connects to the valve cover, because when I tore everything apart the hoses going to it were nasty crusted and looked burnt even inside. Thought maybe it was a bad valve so I replaced it. Could the problem not have been the valve and something else... like maybe (hopefully) something comon? I've seen a DIY for a catch can on a 1.8t (I think a golf though) that had the burnt crusty hoses too, is it normal?

I'm just looking for opinions and experience here to help stop my oil burning. Any input would be appreciated. Thanks guys

Edit: One thing to note is that it's not just that I don't notice it while driving and it still does it. It really does stop, or at least do it significantly less. After a WOT run it will take it a while to start smoking while idling.


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## 20v master (May 7, 2009)

Sounds like valve stem seals to me. Do a compression and a leak down test and inspect the PCV system again, specifically verifying operation of the check valves.


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## warpedhalo (Sep 23, 2010)

Well, I'm getting oil in the intake plumbing too... which is why I thought something pcv related. Would valve stem seals allow oil into the plumbing? I was also thinking that maybe the reason it smokes at idle and not while driving is because of something temperature-related instead of vacuum related. I noticed that the car doesn't get up to temp... ever, like 1/4 of the temp gauge. It is cold here though so I'm not sure if that's normal. If I only let the car run for like 30 seconds before I take off it doesn't smoke, but if it warms up for say 15 minutes it will smoke like crazy for a while.


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## wrparrish (Nov 13, 2008)

Valve Steam seals would allow oil to seep down from the valve train, into the combustion area and or out the exhaust.

Its plausible, But from your description of 2 quarts getting pissed away really quickly, i'd say you definitely have something else going on at the same time. I couldnt say what though.


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## warpedhalo (Sep 23, 2010)

Well, it's not getting rid of it that fast anymore... that was when I had the other turbo and I think it was leaking out of the turbo itself. I had a gt30 that sounded like a supercharger when I put it on, and having never owned a turbo before, I assumed it was a break-in thing. It was supposed to be newly rebuilt. Anyways, about 200 miles later, when I would shut the car down I could hear the turbo making a scraping sound as it spooled down. It was also smoking more and more, so I knew the turbo must be having issues. I tore the intake plumbing off and it had so much shaft play that it had eaten away at both housings. So, I sent it back. Then I got it back and it sounded exactly the same and was smoking again. So I pulled it off again and bought 50 trim to use until this gt30 thing gets worked out. I can tell looking into the compressor housing that the compressor wheel has a wobble in it, which is what I assume makes the sound and will destroy this turbo again. I don't get how it could be balanced but they missed the bent wheel? Don't buy rebuilt turbos from five.star.store or five star store or whatever on ebay.

I'm going to simplify the PCV system later today and make sure every last possible route travels through the catch can before it gets to the TIP. I'll post with the results from that. Also, is there an easy DIY leak down test procedure? I have a compression gauge, but I've never done a leak down. What am I even measuring with a leak down test?


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## Doooglasss (Aug 28, 2009)

White smoke means burning coolant. Oil would be blue. Also some white smoke is normal in cold weather conditions.

I was blowing blue smoke everywhere I went until I disconnected the PCV system from the intake manifold. If I were you I'd have my PCV routed to a catch can not involving the intake manifold or intake piping. If you have oil in your intake piping it's coming from the PCV and sitting there until it gets sucked through and burnt off.

Keep away from Ebay turbos. I literally just had a woman in my office telling me about the 5th time she's been ripped off on ebay. She just never learns...


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## warpedhalo (Sep 23, 2010)

Well today I disabled the "Y" shaped valve under the intake manifold, ran the big 90 bottom PCV and the big top valve cover PVC pipes together and into a inline pcv valve, then into a catch can, and then to the intake. It seems to be smoking normal I guess ha ha. It's been really cold here so it still smokes a bit, but less than before. Now I can replace the front o2 sensor I hope. I'll give it a few days and see if it's consistant, but I let it sit and run and it didn't start smoking like before.


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## warpedhalo (Sep 23, 2010)

Ok, it still burns oil. But the fact that I have oil in the intake pipe makes me want to keep trying stuff before I go tearing the head off and spending the money and time with all that. So, I'm down to 2 possibilities... the suction jet pump (this thing) and whatever the line is that comes from the firewall area and goes to the TIP. 

So first request is for anyone who can tell me what the connections are on the suction jet pump and what it does. I read that it opens under boost to allow the PVC to work, but I read somewhere else that it is to generate a vacuum in the coolant system. I have the hose that forks off blocked right now, I had it running into the TIP and thought that was maybe my problem, and then I blocked it off and still oil... so what is it supposed to be hooked to? Can it be the source of my problem? From what I saw one side is hooked directly to the bottom of the intake manifold with a 90 degree rubber hose and the other end is hooked to a hard line that ultimately goes to the intake manifold too, but there is another hard line spliced into it... but I could be wrong, it's hard to see with the manifold on and the parts store didn't have an intake manifold gasket so I couldn't pull the manifold off to see better. Someone please explain this thing to me, or at least let me know where the hose that forks off goes and if this pump is a possible suspect in my oil problem.

My other request would be what does the line from the firewall do (the one that goes into the TIP)? Can it be my problem? I think this one is a long shot, because it seems like it's not going to be carrying oil or coolant or anything, but it is the only other thing connected to my intake plumbing, so I have to explore it as a possiblity i guess.


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## Doooglasss (Aug 28, 2009)

The suction jet pump is your stock PCV valve. It's job is to ventilate crank case pressure, nothing to do with the coolant system at all. You can refer to the 1.8T FAQ for diagrams of the vacuum system on our cars.

There are two lines that travel across the firewall. One is for the brake booster and the other that goes into the TIP is the EVAP ventilation. Neither have anything to do with this system.

You can pull the intake manifold and reuse the gasket. I would elimiate all connections between the PCV system and your car by completely taking that system out. Vent both the connections to a catch can.

Remember that even after removing this system you're still going to smoke until all the oil has been removed from your charge pipe system.


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## warpedhalo (Sep 23, 2010)

Ok, just to make 100% sure I'm understanding correctly, are you suggesting that I vent the PVC with an air filter instead of running back into the TIP? I am all for this, but I remember reading somewhere not to do this but I think it was because of sludge. I may be wrong, but wasn't the 1.8t sludge problem mostly due to the turbo? Like the turbo cooked the oil and made it sludge up? If so, will a BT stop this? I may be being too optimistic about that, but it seems to make enough sense to ask about ha ha. And the evap system is for fuel vapors correct? So that is ruled out.

So it's down to ventilating the PCV to atmosphere and valve seals. I hope it's PCV... maybe I'll run some sea foam after the turbo to help the excess oil in the intake pipes clear out faster, but if I lose any oil I'll know it's not just oil left over in the intake... I'll keep an eye on it and keep everyone posted (cause I'm sure I'm not the only person who has had this problem or will have this problem).


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## darrenbyrnes (Jan 4, 2005)

DougLoBue said:


> The suction jet pump is your stock PCV valve. It's job is to ventilate crank case pressure, nothing to do with the coolant system at all. You can refer to the 1.8T FAQ for diagrams of the vacuum system on our cars.


I was wondering about that Suction Jet Pump thingy as well and according to the Bentley, I don't think I have one installed (ATC engine). I'll verify tomorrow and should probably take the manifold off anyway to check the vacuum hoses down there...


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## warpedhalo (Sep 23, 2010)

Ok, vented my catch can (an in turn my pcv hoses) to atmosphere and still smoke. I looked up today how to do a leak down test, hopefully advance auto has a tester I can use. I am going to do the compression test and leakdown test, but (keep in mind I'm not expert) won't the valves be sealed and therefore not let me test the valve stem seals which would bo on the other side? this would seem like the case, even more considering that there's no way a rubber seal would take the pressures of the whole combustion process. So is the leak down test just to see if I have leaking through the piston rings? Can oil even come up into the combustion chamber through the piston rings? Wouldn't that be a pretty significant compression leak and the car wouldn't run? I'm new to all of this internal stuff for the most part so bear with me please lol.


Is there a way to test valve stem seals? I would really like to rule them out. I'm not smoking at idle on startup, only when it gets warm, and it's smoking all the time and I was told valve stem seals only do it on first startup and then no smoke the rest of the drive.


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## wrparrish (Nov 13, 2008)

You asked several questions in a stream of consciousness manner, ill try to reply in kind.

In theory yes your valves should be sealed, but they certainly can seal improperly or "not all the way" and you will lose compression there. Your valve stem seals are not meant to handle the pressures of combustion, but mostly prevent oil thats in and around the cams from just running down the valves and puddling in your combustion chambers.

Oil can get by any of your compression rings, or the oil seal rings, on your pistons. Even when new, you may not scape the cylinders completely dry, this gets worse as they get older. You can get a siginificant ammount of oil past the rings ( blow by ) and the car will still run. Albeit you will get oil into your exhaust. The cars you see that smoke heavily ( blue ) while accelerating are usually because theyve been run low on oil and the rings suffered.


I would do the best job you can eliminating pcv or other related **** that puts oil into your intake, or into the combustion process, and from there... suck it up and overhaul the mother****er.


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## warpedhalo (Sep 23, 2010)

Well, I was going to do a leak down test and valve stem seals today, but I'm mad at the car so we are not talking. I had what I thought was a gasket leaking since I put the new turbo on and instantly had an exhaust leak, and I was waiting to get my gasket in the mail, no big deal till then. However, it turns out the custom pipe I made for the wastegate that I had welded on broke off and the wastegate is being held on my the dump tube. It was welded on by a guy who welded for like 30 years as a profession and he told me it would NEVER come off and it's been like 2-3 weeks. OMFG this car is a pain in my a$$. SO, it looks like I'm taking the head off to get the manifold off cause I'm definately not taking the transmission back out, and while the head is out I may as well put in new seals and guides if need be. So, no need to debate anything anymore I'm going to do them.

I'll do a compression test before I pull the head off though to check the rings. I also vented the PVC to atmosphere so I don't think it's PCV-related anymore. I don't think I'm going to leave it to atmosphere, more of a troubleshooting thing. I do have another question though, do 1.8ts by chance run a higher oil pressure than normal that would force oil past turbo seals? I'm thinking of putting a needle valve in line with the turbo oil feed (strictly diagnostic reasons) but I wanted to know if it was an issue with anyone and anybody with an AMU motor... what is your idle vacuum read? I'm getting 10(insert the -psi unit of measure here). That seems pretty low.


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## wrparrish (Nov 13, 2008)

10 is low

Reading the Vacuum on an engine is an extremely helpful diagnosis tool, however it hardly gets done anymore.

One of the ways to test for failed valve guides, or leaking valves is too run your Vacuum test, i dont really know of any other way to do so

A low Vacuum reading during idle usually signifies a leak
A fluctuating / oscilating reading usually signifies valve guides or valves.
If it just goes down and continues to decrease, you have an exhaust restriction ( doesnt happen alot)

A Vacuum gauge is ~$10, they are great to have. It combined with your compression results, should give you an honest picture of your situation.


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## warpedhalo (Sep 23, 2010)

Just to come back and post results (which is easy to forget to do but leaves everyone hanging) my oil burning was either from running lean, too restrictive of a pcv setup, or too thin of oil. It was blowing oil past the exhaust seal in the turbo. 

My pcv line was running upward to the catch can, and it was all going through a 3/8 line with a check valve inline. There turned out to be water being held in the line on the catch can side of the check valve, so my crankcase pressure was trying fight hydraulics and gravity lol. i assume that was my whole problem. But my crankcase pressure is probably higher than normal, because along with my low vacuum, I have have super low compression too so I imagine I have more pressure in the crankcase than normal. Anyhow, I fixed all this by running a 3/4 heater hose from the 90 off the block to under the car, and an additional one from the valve cover vent to under the car. I kill a lot of whales though I'm sure so not for everyone. Just kind of threw out the old pcv setup and catch can. 

The lean problem I attribute to low vacuum since the fuel pressure regulator is vacuum operated. Fixed this with lemmiwinks and an adjustable fuel pressure regulator. Regulator may not be needed but I had one so I added some fuel pressure. Lean makes you ruin seals in a turbo apparently, which will make you leak oil into exhaust obviously.

And I started running 10w-40 full synthetic mobile 1 oil with lucas oil stabilizer. I've read that turbos like to leak thin oil. Even though when up to temp from what I've read 0w-40 and 10w-40 are the same thickness... I don't know. I've also read that I may be getting away with such thick oil cause I have terrible compression, but I don't understand what that would change. i do not have any valvetrain ticks or anything on startup which is what I would expect if the 10w part was a problem... but it hasn't gotten colder than 50 degrees since I put it in.

Oh, also I ran the car for a while with no turbo at all getting this all narrowed down. So terrible compression (like 80 psi per cylinder so BAD) doesn't necessarily make you blow smoke like I had read. No turbo, no smoke. But yeah I got these problems figured out and threw a turbo back on it and no smoke and no ruined turbo! It was a $200 ebay turbo too... that I rebuilt with a staggered gap exhaust oil seal and a loctighted nut on the compressor wheel. But it's time to bust out the Precision now since the ebay turbo is ok! Didn't want to risk blowing up my good turbo lol.

That's all I did that I can remember. I wish anyone running accross this thread luck with finding whatever their oil leak is!


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