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jamie924 · Joined: 04 Nov 2006 Posts: 32

not sure if you have checked the valve stem seals out thoroughly but if you are experiancing smoke for the first few minuites of engine running its possible the seals were damaged when replaced and while the vehicle is standing not running oil is driping past the seals into the cylinder or cylinders and when the engine is started this is burnt off causing the smoke lesens the oil is depleated alot of the late 70s early 80s engines suffered with this the uk ford cvh engine in particular does this for a past time so the new head may cure it or it may have perished seals
best of luck

20v924 · Joined: 24 Jan 2007 Posts: 205 Location: Phoenix,AZ

This sounds like a problem I had with a 930 in my shop. The smoke is not water! Believe it or not it is the result of a bad control pressure regulator, also called the warm-up regulator. You might be saying to yourself "but fuel smoke is black", it actually only turns black when it is incompletely burned. in this case it is burning completely because of the cold running situation the car is in. The car needs a richer mixture when it is cold but you're taking advantage of the situation! Check to see if the aux air valve is completely open when it is cold also.

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A person is smart. People are stupid

Lizard · Posted: Sat Jan 27, 2007 1:56 pm Post subject:

good thing he has EFI and doesnt have a WUR then
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3 928s,

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

or an AAV?
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1987 951 - M193 Version for Japan

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

81turbo · Joined: 03 Nov 2002 Posts: 1065 Location: Oakland, CA

leadfoot · Posted: Sat Feb 10, 2007 9:30 pm Post subject:

Good news then nick, loose guide should definately have been picked up by your machinist though... sounds like whoever did the reco didn't do it properly, the head needs to be heated and the guides frozen so that when they are inserted and cooled they form a good bond... it sounds like they were just forced in... Are you getting them all done at the same time?? I would be suspect on the other guides at this point in time... and whilst you machinist is giving free services you might be able to strike a deal getting them all done...
hope it works out for you...
Leadfoot
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1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

Lizard · Posted: Sun Feb 11, 2007 12:06 pm Post subject:

oops forgot the wink after that last comment, though it is helpfull to read all points regarding the car before making your suggestion as they could have already tried that.
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3 928s,

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Is there an update, Nick? I need this story to have a happy ending. . .
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

-nick · Joined: 16 Nov 2002 Posts: 2699 Location: Cambridge, MA

Last few weeks: temp's in the 20's F, Valentine's Day, girlfriend's brithday, out-of-town guests, work deadlines, etc.

Patience grasshopper!

Looks like I should be able to get some work done this week. I'm anxious too.
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1980 931S
15psi boost, MS-II, EDIS, 951 IC, custom intake, Ford 5.0L throttle body, Forge BOV, WB o2, G31 w/LSD, 964 wheels, 968 rear sway, Bilsteins, 200# Welt. springs. A laptop, and a partridge in a pear tree.
1991 964 C4 Cabriolet

-nick · Joined: 16 Nov 2002 Posts: 2699 Location: Cambridge, MA

Sigh...

I started her up again and within a minute I got smoke. I did learn one thing - nondetergent oil smells/burns much differently than regular detergent oil. I switched the straight non-detergent 30wt oil out for valvoline 5w30. There is no doubt it's burning oil.

I took it out for a ~1 hour run around town. Once the oil started to warm, there was no smoke that I could discern. But, at my first long stoplight after starting it from cold, I got a nice smoke cloud while sitting at idle.

I took it out again last night and the smoke seems to have diminished, but it's still there. For now, I'm just going to put some mileage on it and see what happens. Who knows, maybe the rings still haven't seated. The oil control scraper ring doesn't require any seating time does it?

Otherwise, the car runs excellent. Replacing the 1st gear dogteeth made a dramatic change in the trans. I can slide it into 1st at 15mph+ with no grinds and the engagement is much more positive. The box still shifts too notchy at times, but it ain't bad!

In case anyone is wondering, here's the list of what I've done to track down this dumb smoking deal -

latest - new intake & exhaust valve guides & valve stem seals
previous -
surfaced head
surfaced block deck
head pressure tested
bored block to new pistons & rings
compression rings gapped to 0.027"
oil scraper ring left alone
piston-cylinder clearance 0.002-0.003"
new head gasket every time
head studs torqued properly
~100 miles on bottom end
rebuilt turbo - no oil in intake track
crankcase breather vents to atmosphere, no noticeable blow-by

There's not much else, eh?!
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1980 931S
15psi boost, MS-II, EDIS, 951 IC, custom intake, Ford 5.0L throttle body, Forge BOV, WB o2, G31 w/LSD, 964 wheels, 968 rear sway, Bilsteins, 200# Welt. springs. A laptop, and a partridge in a pear tree.
1991 964 C4 Cabriolet

Min · Posted: Thu Mar 15, 2007 8:01 am Post subject:

Smoothie · Posted: Thu Mar 15, 2007 8:59 am Post subject:

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Lizard · Posted: Thu Mar 15, 2007 2:25 pm Post subject:

as well if it isn't that cold there you could switch to a 10 or 15W base instead of a 5 that may actually help your smoke problems too.

But I would inspect the turbos drains as well.
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3 928s,