Author Topic: TDI Blowing Oil Smoke 115k miles (Read 7975 times)

myke_w · « **on:** August 27, 2007, 11:14:12 am »

So I got a sweet deal on a 98 Jetta tdi the other day
I'm noticing that it's blowing a bit of oild smoke, some on start up and some on acceleration.

I'm fearing that the turbo is heading south, but have to wonder if it could be valve seals. Is there any definitive way to tell?

Also, I've never seen a tdi this young eat a set of rings yet, is that even a possibility?

Thanks in advanace.

Myke

subsonic · « **Reply #1 on:** August 27, 2007, 02:28:03 pm »

Do you know anything about the past owner? Some peoples idea of an oil change is doing it when the low oil light comes on. I guess really dirty oil/ wrong oil run for a long time could shorten some life span.

RabbitGTDguy · « **Reply #2 on:** August 27, 2007, 04:16:23 pm »

More than likely, i'm willing to bet the seals on the turbo are headed south. My brand new motor smokes a bit because of the "used' nature of the turbo *final selection still to be determined*, but next in line would be the valve stem seals.
As already suggested, maintenence records or knowledge about how meticulous the PO was helps out alot as I've heard of people really neglecting oil changes, etc. etc.
Compression test could help you decide on rings though...if oil changes were kept up though, I doubt it could be them *unless oil changes were regular...but the grade of oil was wrong*.
I can vouch for the OEM rings. On the Mk1's motor, it was a 126k mile motor when I got it...when I checked the rings they were well within spec. I also knew the PO had been friendly to the motor as well. Found an AMSOIL filter on it when I got it as well as amsoil in the crankcase

Joe

myke_w · « **Reply #3 on:** August 27, 2007, 06:45:31 pm »

Well I tore the intake off tonight (filthy inside btw) and had a chance to wobble the turbo shaft a bit, doesn't seem to have excessive play but I guess that probably doesn't mean the seal rings aren't bad. As far as I know the car was dealer serviced (doesn't mean ***) but I'm told they did have good service intervals. I haven't done compression test, I guess that's next. Does anybody have a trick for changing valve seals with the head on? Isn't there a compressor tool for that? IE bring piston to top depress valve unload keepers springs retainers, replace seal reverse?

Is there any really good way to determine if it's the valve seals or the turbo without replacing one or the other?

RabbitGTDguy · « **Reply #4 on:** August 27, 2007, 07:34:38 pm »

yeah....
Removed injector and use an air compressor to keep air in the cylinder for changing them out...if you can rig a way to do that with your compressor...keeps the valve from dropping into the cylinder.

There are some other methods out there as well.

Joe

lord_verminaard · « **Reply #5 on:** August 28, 2007, 07:23:10 am »

I dunno if I have ever seen a TDI with leaky valve seals..... turbo seal on the other hand, maybe a dozen times......

Brendan

myke_w · « **Reply #6 on:** August 28, 2007, 08:40:49 am »

I was also thinking 115k was pretty young to have eaten valve seals or rings.

I took the intake off an it's full of crap, also pulled the intercooler lower hose off and it looks clean, could just the exhaust side of the turbo seals be leaking? If I pull of the down pipe will my question be answered? I've only ever seen turbos fail so badly that oil is both in the compressor and turbine side.

RabbitGTDguy · « **Reply #7 on:** August 28, 2007, 01:36:09 pm »

Well...turbos can leak on either side. Into the intake side of the turbo (which you'd find more than the lovely pool of oil provided by the CCV system in your intake track) which you might see by pulling the inlet hose from the airbox-turbo off or by pulling one of the intercooler hoses and seeing how much is "pooling" in there. Also...they can leak on the exhaust side...causes a "coughing" smoke your talking about on cold start and occassionally during shifting, etc. If they are REALLY bad...you'll notice use of oil and quite a bit of "coughing", almost choking through the exhaust and lots o' smoke out it. Checking the dp could tell you. Best would be to remove the dp from the turbo just to quickly see.

Unfortunately..only way to really tell with the valve stems is to pull the head and see if oil is coming down from the stem of the valve itself...which I'd doubt on that mileage...but then...goes back to that PO stuff.

My .02

Joe

myke_w · « **Reply #8 on:** August 28, 2007, 01:43:57 pm »

luckily I have the intake off.. perhaps yanking the exhaust mani and looking at the valves through the ports will give me a clue... i guess seeing a pool of black *** would give me a clue...

RabbitGTDguy · « **Reply #9 on:** August 28, 2007, 06:37:06 pm »

yeap...it would be a good indicator...
i think you'd see alot more smoke, alot more often if it was the stem seals...but then...maybe not.

Joe

vman858 · « **Reply #10 on:** August 28, 2007, 07:17:22 pm »

I picked up a 1998 3 weeks ago and mine bucked and smoked very bad. I found a busted intercooler hose and that cut down on the massive cloud but it smoked pretty good on start up and 3/4 to WOT. I replaced all the vacuum / pressure lines( don't forget the one inside ECM) the N75 relay and cleaned the intake. Also mine did have some oil in the intercooler and all the intercooler lines had oil in them. Oh yea, new air filter, now smokes very small puff at startup and a small amount at WOT between gear shifts. Its got 243000 miles on it but good maint history. Runs great.

myke_w · « **Reply #11 on:** August 29, 2007, 09:26:36 pm »

thing is, this car runs great, no oil in the intercooler at all.. planning to tear the snail off tomorrow hopefully that gives me some answers

vman858 · « **Reply #12 on:** August 30, 2007, 07:06:05 pm »

Well I am NO EXPERT but mine did run fine after the intercooler repair. Just smoked more. It might be worth checking those vacuum/pressure lines to / from N75. Mine was setting a CEL from N75 though for what its worth.

myke_w · « **Reply #13 on:** August 30, 2007, 09:22:43 pm »

Well, took the down pipe off, exhaust side looks great, intake looks great no radial or axial play all vacuum hoses are in good shape. :x

Cleaned the intake that was packed with ***e.

The turbo is definitely fine.

Did a compression test, 500 +- 25 on all cylinders cold, about as good as it gets..

I guess that either means I have a cracked oil ring or some bad guides / seals.

I'm just gonna drive the damn thing and monitor oil consumption, what else can I do?

Any further suggestions are most welcome.

I'll keep the board posted on the consumption thing.

jtanguay · « **Reply #14 on:** August 31, 2007, 01:32:20 pm »

with the oil cap off while running the engine do you get much smoke coming out? maybe its time for some totalseal rings :twisted: