Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

Oil smoking 931..rings, guides, separator?

 
Post new topic   Reply to topic    924Board.org Forum Index -> 931 Tech.
View previous topic :: View next topic  
Author Message
stored&stock  
Guest





PostPosted: Fri Oct 26, 2001 7:06 am    Post subject: Reply with quote

First off... This forum and its cathexis is beyond special and touches on inspired. So hats off to thoose that tend it with integrity..
Now secondly...Speaking of something that needs touching I will bring up the ailments of my 1980 924 Turbo in the hope that it sees the open road once again.(All help is appreciated)..The car has been in storage for 10 years. Yes you heard me correct...10 years!!
Keeping said car behind closed doors while it is down and out may sound depriving to the world but something in me wants to protect it from attacks by motor hacks and from the horses hooves in the back pasture. And that is not to say that it has not seen that abuse already. Until such a time that it can run from them on its own merits of being healthy I plan to keep paying the $70 a month storage bill with a protecting heart... Yes the story of this car is a long depressing one yet I am able to accept the steadfast intention of my own that it is going to run, run well, and $@!$@! LIVE!! Well I hopes anyway...
The car came to me from a druggy relative. I thought the relative better off with a Camaro & a Suzuki motorcycle and that such a thing of precision as the 931 should be treasured by someone such as myself. So I indeed traded a Camaro and a Motorcycle for this 80' Turbo that was supposedly in good mechanical order. Not that white trash uses such english but that was the implication made as two headaches were rolling out of my driveway. Camaro was a Bondomobile and the cycle was getting shakey and out of tune so I considered it a fair deal and I was consolidating and moving up (yea, Porsche baby!!), etc... The depressing part came when I noticed a oil smoking problem immediately after receiving the car. I heard the car run maybe a few weeks prior and it seemed to be in decent shape so why distrust a relative?, Cause they are druggies and motor hacks, and your a nieve young newbie is why.... Ok , so the car had the hose from the top of the valve cover routed to the back of the car so that one does not notice perhaps the smoke as much. I was told around that time by another relative that the guy might have been underneith doing a bearing job or something on it just prior to trading it to me. I can't figure out how he might have made it smoke unless he changed the oil rings but yet wouldn't he have had to remove the head or taken out the whole crank on the bottom to do such? I don't think he took the head off to get the pistons out the top and I don't think he had the clutch /flywheel off to lower the crank. I don't see how one could get the pistons out any other way in order to do such a job, right? So what is actually bad on this car?.. If my memory serves me right (I don't think it did a few days ago when I posted for turbo rebuild kit) the smoke is literaly pumped out in the form of oil vapors from any crankcase opening in massive amounts particularly that hose that runs from the top of valve cover down to the turbo (oil/air separator?) I am not sure (memory)at this point as to what direction the flow of all this polution is or what the separator does exactly, or what condition it is capable of causing, or if it can even go bad or get clogged or such. What size wrench I need for that?,geez(All help appreciated:))..I believe the situation was that I had to take ALL the spark plugs out and clean them of oil every time the car was ran or it would not start. The car ran with lots of power the first few days of having it and, back to the depressing part, I have only driven it maybe 50-100 miles total and maybe ran engine another 5 hours beyond that at idle for testing. I believe strongly that my results of a compression test showed good even compression with a good first jump of the reading in all cylinders.(but my memory might be wrong)I was unable to do a leak down test to further a prognosis along and so I filed away the information in my brain back then as the car having real bad valve guides. This idea was then thankfully shattered years later when people kept offering up the idea that the turbo could be bad and was pumping oil straight to the intake. I thought this to be the case until yesterday when I yanked the intake tube and found it to be absolutely pristine and never ever having had a trace of oil in it. The other side of turbo was checked years ago when I changed the clutch and was found to be clear also. Can the turbo leak air only internally to where oil is vaporized up through the "T" in the oil separator and hence something in the actual engine seems to be of blame? The current situation on the car is that I put it on stands, sprayed penetrating oil on the cam and in the cylinders, and then found that a freeze plug had blown out over the years even though I drained the water out way back when and I live in mild and sunny Ca. So but obviously I can't actually try and start car until that is fixed but perhaps could run another compression test. Is that going to be able to rule out piston oil rings or not? What strikes me as weird on this situation is that I am pretty sure again that ALL the plugs come out oily. What in the world can cause that?..All the rings or guides bad? or could it be due to a combination of crankcase vapor/turbo pressurizing them vapors into cylinders when valves open?..Enough said and posed. I await eagerly all your helpful comments.

Sincerely,

Kevin
Back to top
Zuffen  



Joined: 31 Jul 2001
Posts: 1426
Location: Owasso, Oklahoma 74055

PostPosted: Sat Oct 27, 2001 12:44 am    Post subject: Reply with quote

Nice long post.

Do the same routine of checks prior to the below advice and get the engine ready for running.

Your going to to have to be prepared for the worst. I would drain the oil and add an engine oil cleaner one or two quarts to the rest of the oil. In the meantime spray some aerosol liquid wrench into the cylinders, use it up if you feel comfortable. With a breaker bar first slowly turn the crank. If it moves freely feel free to use the starter. You might remove the coil wire to keep the animal from starting or trying to start.

We want to lube and try to free up the sticky or stickin parts.

Then let it set for two weeks soaking.

Also make note of oil presure if you get the engine to crank very fast.

While the engine is sitting work out the fuel system by cleaning, flushing and making sure it will work.

Ok post what you find before going to far.

The original smoking could be from anything.

The mains can't be replaced without pulling the crank and that requires removing the belts, cross member. The rods bearings can be but neither one will cause smoking. So I don't think the crawling under the engine story makes sense.

The turbo has some seals on the pop off valve that can be replaced while the turbo is on the car, if they are bad and leaking you can have oil splattering back onto the turbo and exhaust. That oil is from the turbo seals though so it may not apply.

If the trubo is stuck, well that is what we are trying to do is see if we can unstick it.

Keep in mind though that if the intake is clean the compressor side of the turbo seal is good or plugged. If the turbo is still smoking then it could be dumping oil into the turbine side into the exhaust.

If the turbo is fine internally then the valve guide seals may be bad. They can be replaced without removing the head.

If the rings are bad then you will have fuel in the oil, low compression, and excessive leak down. And you will be havinf alot of blowby into the crankcase.

The 80 turbo did have a vent problem concerning the turbo. It could build up positive pressure and blow oil into the air breather and engine via the oil seperator and also by forcing oil past the valve seals. It can happen to 81 and 82 in certain situations. I still don't what the fix is for sure. As it has always been a problem on somone elses car.

So if you get the car running do a vacuum check, you should check all the lines and hoses before trying to get the engine to run by the way. I'm sure they are cracked out and bad.

Also how much oil and which cylinder when you check the plugs. Another thing is return the plugs and crank the engine to force the penetrent into the ring area.

When you get ready to try and fire the engine. Use the starter to blow the excess oil out of the cylinders. Use ether to start as that will help burn the left over penetrent and you will need it anyway.

Let us know what you find

_________________
Bob Dodd - 924turbo@cox.net
931 1982, 944 1982 euro, 924S 1988SE, 93 968 tip 06 Silver Cayenne S, 06 Black Cayenne S

I have Way too many cars, parts for the 931,944 and 951
Back to top
View user's profile Send private message Send e-mail
larso  
Guest





PostPosted: Sat Oct 27, 2001 4:09 pm    Post subject: Reply with quote

hey i didn't read the posts but first thing might be to take tranny out, then gas tank and clean it.
Back to top
stored&stock  
Guest





PostPosted: Wed Nov 07, 2001 11:01 am    Post subject: Reply with quote

Ok, I had put penetrating oil on the cam and in each cylinder and then tried circulating a quart of engine cleaner through engine via starter/jumper cable power. This did not result in very fast cranking and I did not even see any oil pressure. So since last posting I let car sit with some of this fluid hopefully getting into the tight spots and hopefully freeing up some of the sticking parts in preparation for a startup.
Went down this morning to run a compression check and I think I have discovered blown head gasket or messed head. Please read on to varify that I am thinking correctly.....
I did the testing with a slow cranking engine and with all the plugs out. So first off,can that cause very low overall readings?..
#1 jumped to 15 psi on first compression stroke and then topped out at 30 psi, adding oil to cylinder results in maybe only 5 psi boost and a barely notable bit of the oil leaking over and being vaporized out of #2 spark plug hole..
#2 jumped to 15 psi on first compression stroke and then topped out a little lower at 27 psi, adding oil to cylinder changes reading little if any and/but vaporizes a lot of the added oil right out the #1, I think anyway. (can't really see much while cranking key)..
#3 jumps to 50 psi on first compression stroke and then on up to 60 psi. I didn't note much change with adding oil to cylinder.
#4 does a 25 to 30 psi reading without oil but goes 50 to 60 psi reading with oil...
Questions:
Now since there was never oil in the water or water in the oil does this mean a probable blown gasket between the #1 & #2 cylinders only? And but still where is the oil problem coming from? Valve seals or from maybe a section of the head gasket between only a cylinder and oil jacket? I probably have a combination of unburned gas/oil leaking right out #2 into #1 and then out the #1 valve guide/seals to the top of the valve cover situation? Does that sound about right?... I would hate to change the head gasket to only find a situation of bad rings also... If I yank the head to change gasket should I go with a copper gasket. I have been reading the other posts and it seems like I will just be changing it again real soon if I go with stock gaskets. With head out or in should I go ahead and change them valve seals? Any special equipment other then torque wrench needed?
I still need the size of the freeze plug above the oil filter. All helpful comments greatly appreciated...

Kevin
Back to top
larso  
Guest





PostPosted: Sat Nov 10, 2001 1:08 pm    Post subject: Reply with quote

when does the car smoke, is it purple, white, or black.

Lars.
Back to top
stored&stock  
Guest





PostPosted: Sat Nov 10, 2001 2:37 pm    Post subject: Reply with quote

Smoked all the time from in the engine. Been awhile but pretty sure it was purple-gray. So with all that I have done does verdict sway toward it being time time to yank the head or should I still be thinking rings and/or valve seals?.... What size is them freeze plugs and should I go copper head gasket?

Kevin
Back to top
TroyDest  
Guest





PostPosted: Tue Nov 13, 2001 6:37 am    Post subject: Reply with quote

Kevin,
Your compression is way low! It does sound like a bad head gasket to me and maybe worn guides. Just to eliminate posibilities though you should remove the cam cover and make sure the valves aren't overadjusted. There should be about .006" space between the cam and the tappets when the lobe is pointing away from the valve. If the valves were overadjusted by your relative, they could be partially open all the time giving you low compression. Though that doesn't explain the oil problem, it's a quick check for the compression problem.
If you deem that the gasket is bad, you can either use the custom copper ones on this site or the factory gasket. If you use the factory gasket, you must use the Turbo gasket (expensive). The non-turbo gasket will not work. I drive my factory-gasketed '82 931 pretty hard and have not had a gasket issue. You might consider using Raceware head studs (expensive) if you replace your gasket - they seem pretty good. As long as you don't let your engine overheat, the factory gasket should be fine.
For the freeze plug, just order it from the dealer.
Back to top
larso  
Guest





PostPosted: Thu Nov 15, 2001 3:39 pm    Post subject: Reply with quote

If you are having head gasket troubles, try to figure out why. I had troubles with my old 931, put a gasket on, idled the car, and blew a head gasket. Put another one on after changing the Coolant cap on the tank and checkign the radiator, blew another one.

The bleeder was leaking as the aluminum had gone a little porous/rough where the bleeder seals. I never use bleeder screws with holes close to the sealing point any more. I use normal bolts or hollow bolts with the holes down low. The leak was so small that it was not to be noticed, but since it is the highest point in the system, air can suck in.
Back to top
stored&stock  
Guest





PostPosted: Thu Nov 15, 2001 5:56 pm    Post subject: Reply with quote

Who thinks compression will change if I stick an actual battery in car and recheck the compression or if I start car for a few minutes and then recheck? Car did run with plenty of power (JUST SMOKED)just prior to storing and clutching it so I question my compression readings even on the highest cylindrs..... How about some more oppinions on this here issue of low compression vs. varying compression....& copper or not to copper? Are you serious Lars with the multiple orgazm%#@#@, I mean blown gasket?
..Bob?

thanx Kevin
Back to top
TroyDest  
Guest





PostPosted: Thu Nov 15, 2001 7:37 pm    Post subject: Reply with quote

Kevin,

Something else I realized as I was thinking about your compression problem: Check the cam timing. If your timing belt has slipped or is installed wrong, the valves will be open at the wrong time - hence giving you low compression. Just rotate (by hand) your motor until your cam sprocket dot lines up with the cam cover pointer. There is another pointer on the oil pump behind the crankshaft pulley that should line up with a notch on the crank pulley in this position. If the upper pulley and lower pulley don't both line up at the same time, your belt is out of whack.

Another way to check timing marks is on the flywheel. Line up the cam sprocket first. Look down from the driver side with a flashlight behind the intake manifold. There is an inspection hole in the bellhousing where you can see the flywheel. You should see a mark on the flywheel at the bottom of the hole when the cam and crank are at TDC.

Good luck. -Troy
Back to top
larso  
Guest





PostPosted: Sat Nov 17, 2001 4:11 pm    Post subject: Reply with quote

I think you should check your compression gauge...there is no way a car can run on 15 PSI compression.

Maybe buy a new one or something, are you sure the hose isn't leaking at a joint? I've bought the cheap 30-50 dollar gauges and the hose joints suck. I haven't found a good one yet, still looking, probably will cost a hundred or more.

Back to top
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> 931 Tech. All times are GMT + 10 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group