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Discussion Starter #1
Hi all,

I've got a 1990 se with 30,000 miles on the odo. Car runs great, but if it has sat for more than a few days I get blue smoke.

Weird thing is that I fire it up, starts and runs great, no smoke, then after about 30 seconds of running it starts pushing blue for about 20 seconds then stops. That is the only time there is any smoke. No smoke ever while driving and none the same day as a drive.

Leads me to believe it's either oil in the intake that takes a little time to reach the combustion chamber, or oil in the exhaust that needs a little time to heat up. This tends to make me think that it may be a seal in the turbo.

I haven't done any disassembly, but I'm planning on removing the charge cooler first to check for any oil downstream of the turbo.

Any thoughts or recommendations before I start digging in?

Thanks in advance,

Jeff
 

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Cal H
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Don't take off the chargecooler yet first just check the inside of the hose from the turbo for oil. Do the easy stuff first. Couple of hose clamps. Might as well check the crankcase vent if you think it is on the intake side. What weight oil are you using? most of us use 20-50w or 15-50w. Some of the synthetics start out pretty thin and can seep in to things. At 30K I don't think the bearings of the turbo should be worn but I suppose oil could seep in past the bearings of the turbo especially if you are using something like 5-50w. If the seal of the turbo was leaking oil while it was sitting I would think it was more likely leaking on the exhaust side.
 

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It could also be a bad intake valve seal. Pull the plugs and inspect them to see if any are dark. It also can't hurt to pull the hose to the turbo. Not only should you see if the inside of the hose is oily, feel and turn the impeller to see that it turns freely and has no play.
David Teitelbaum
 

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Cal H
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There is certain amount of oil that goes by the valve guides as that is the way they are lubed. Excessive play in the guides will suck oil but if that were the case I would think it would likely cause a puff smoke fairly regularly like on pedal lift off from high rpm. I suppose they could seep while sitting pooling a bit then pump it into the exhaust header at start up. If that is the case just drive it more often LOL.

Actually there is a certain amount of free play in the turbo bearing and it is a design feature of the turbo unit so do not be alarmed unless there is evidence of the compressor or turbine wheel contacting the surface of the housing
 

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Discussion Starter #5
Yeah, my first thought was valve guide seal, but I would think the puff of blue would come almost immediately after start up, not after half a minute or so. And there is never any smoke during driving, regardless of driving behaviour (of course always well behaved!).

I am going to do two things this weekend. First will be an oil change with 20-50 valvoline racing (no we aren't starting an oil debate!) and second will be removal of the hose between the turbo and charge cooler for inspection. Last oil change was 15-40 Mobil 1..

I will report back. Thanks for all the replies!

Jeff
 

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Cal H
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Last oil change was 15-40 Mobil 1..

Jeff
Curious I have never known anyone that used 15-40 before. I have never used it myself because I never run my car in winter. That is what is listed for use below 0 C or 32 F. Although it does list 5-50 along with usual 20-50 for above 0 C use. For below -15 C or 5 F they say use 10-40. Even then the people I know that have run cars in colder climates have used the 5-50. I'm sure this is going to set off a flurry of comments as happens any time the subject goes oil. LOL
 

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Discussion Starter #8
Ok, had this thing on the back burner for a while, finally got back into the garage. I did an oil change with 15-50 Mobil 1, removed the crank case breather from the intake as recommended by L.E.W. and re-routed it to a K&N filter underneath. Put in a new air filter.

Fired it up and it belched out a cloud of blue smoke as usual.

So. Took out the plugs and found that plugs 2, 3, 4 were clean, dry with a hint of white all over. Plug 1 (front) smelled and looked oily.

Just so you don't need to go back up and read the original post, the car starts fine, runs clean for 10 seconds or so, then starts smoking for 30 seconds or so. Stops smoking and then nothing until you fire it up after sitting for a little while.

Next thing on the list is a compression check. Until then, any ideas???

(Car has 30K Documented miles on the clock.)

Thanks in advance!
 

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(Snip)... removed the crank case breather from the intake as recommended by L.E.W. and re-routed it to a K&N filter underneath. (Snip)...
Took out the plugs and found that plugs 2, 3, 4 were clean, dry with a hint of white all over. Plug 1 (front) smelled and looked oily.
Disconnecting the crankcase breather from the airbox might discontinue a symptom, but it doesn't fix anything. If the engine has severe blowby, it needs to be fixed. If you elect to run for an extended period with the breather disconnected, then it's better to plumb in an oil separator/ catch tank, then direct the outlet from it to the airbox. Simply dumping the breather overboard, even with an outlet filter, is just going to make an oily mess.

The results of the compression/ leak down test will be interesting. We should probably just wait for that, but not being particularly patient...

If oil was entering through the inlet, (breather blow-by or leaky turbo) then I would expect it to affect all cylinders nearly equally. That fact that only the #1 plug is oily, and the rest are pretty clean, makes me doubt that's where the oil is coming from.

If the rings in #1 cylinder are worn or broken, I would expect to see smoking whenever you step on the throttle hard, and not just after start-up. Also, there would probably be excessive blow-by and a related belching of oil from the breather hose (disconnect while the engine is running, but not hot... you don't want to get sprayed with hot oil). Since the engine only blows smoke shortly after start-up, and not when driven, I doubt that it's the rings.

The 9XX engines do not use valve stem/ guide seals, so they're not the problem. No need looking for what's not there.

If the valve guides or stems are worn, oil pooled in the head could seep past them when the engine is off, and collect in the #1 intake port. The engine should smoke right away after start-up, so I don't know how to account for the 10 sec delay. If you get the car up to speed, then coast for a while with closed throttle, does the engine puff smoke when you get back on the throttle? That's the typical sign of worn valve guides/ stems.

Do the compression/ leak down test. That will tell us more than guessing away on the keyboard.

Good luck,
Tim Engel
 

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...while sitting, the oil from the turbine seal.....drip, drip, drip, drip - 30 seconds after start - exhaust is hot - blue smokes comes and done.

next day .....drip, drip, drip, & more drips same shyte different days.
 

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Discussion Starter #12
Thanks guys,

Definitely no smoke any time except after startup following sitting. I did a little more looking after I posted that last one...

Took the hose off between the chargecooler and the turbo and found a bunch of oil in there. Also took a light and looked down all of the spark plug holes. All looked similar, a bit oily and a bit of black sooty crap on the top of the pistons. Nothing noticeably different in 1, 2, 3, or 4. (3 was pretty tough to see in though).

Checked into leaking turbos on the inter web and found an interesting article about what makes turbos leak. Main culprits are dirty air filter causing low pressure on the inlet side which draws oil from the bushings, and can also draw excess oil through the crank case vent if it's struggling to draw through the restricted air filter. I was guilty of a dirty filter. Second was running a turbo car at idle which has a similar effect to the dirty filter issue by creating low pressure in the intake side when running at no boost. Guilty again.

I also noticed after reading the manual that there are no seals, and with a well maintained car I would be surprised if it had worn guides.

So I think I am going to hold off on anything drastic until I can take it out for a few spirited drives. I'll still do the compression test and report back.

As for the single dirty plug, I bought four new ones (the old ones were wrong anyways) and I'll check the wires. Could be an unrelated issue.

I will report back with my findings.....

Thanks again for taking the time to reply, always helpful!

Jeff
 

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If you found oil in the hose coming out of the turbo that means the turbo seals are worn allowing oil to get out. Worn seals usually mean the bearings are worn in the turbo. It can't hurt to replace the air filter. I would also make sure you have the correct oil and it has been changed recently in the motor. If you still get oil out of the turbo it will need to be rebuilt.
David Teitelbaum
 

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It could also be a bad intake valve seal. Pull the plugs and inspect them to see if any are dark. It also can't hurt to pull the hose to the turbo. Not only should you see if the inside of the hose is oily, feel and turn the impeller to see that it turns freely and has no play.
David Teitelbaum
I thought these engines didn't have any valve stem seals?????
 

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another thing you can check is to open the valve cover oil fill cap while the engine is running. It is normal to see some smoke (blow by in the crank case.) If you see excessive smoke like a smoke stack off a choo choo train, then you likely have a ring seal issue or cracked ring lands on a piston. I don't know if those are typical issues on these engines, though.
 

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Discussion Starter #18
If you found oil in the hose coming out of the turbo that means the turbo seals are worn allowing oil to get out. Worn seals usually mean the bearings are worn in the turbo. It can't hurt to replace the air filter. I would also make sure you have the correct oil and it has been changed recently in the motor. If you still get oil out of the turbo it will need to be rebuilt.
David Teitelbaum
Yes, filter has been replaced. Just did an oil change with Mobil 1 15/50 as well. Thinking that maybe the dirty filter etc. caused some residual oil in the intake end of things and maybe a good run will clean it up.

That is my hope (wishful thinking!) and I am going to do that after I change the plugs and I am confident that I have the ignition system working properly across all four cylinders.

Speaking of plugs, anybody know of any "good" reason that the car would be running BPR5EY plugs instead of the BPR6EKN? I guess it's a hotter plug and has a single electrode instead of the double...wondering if they would be in there for a reason.

Thanks,

Jeff
 

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Discussion Starter #19
another thing you can check is to open the valve cover oil fill cap while the engine is running. It is normal to see some smoke (blow by in the crank case.) If you see excessive smoke like a smoke stack off a choo choo train, then you likely have a ring seal issue or cracked ring lands on a piston. I don't know if those are typical issues on these engines, though.
This has got to be the easiest 'diagnostic check' ever, but it makes sense. I would be a fool not to try this!

Thanks for the tip.

Jeff
 

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Wingless Wonder
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If you found oil in the hose coming out of the turbo that means the turbo seals are worn allowing oil to get out. David Teitelbaum
Don't fret about SOME oil. After all, on the 4 cyl engines, the crankcase breather dumps into the air filter housing AFTER the filter itself.

So don't panic if its a bit oily in there.
 
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