Edward Larson

When I leave for work in the morning the car starts perfectly fine no cloud(6:45am), but when go for lunch (12:00am) there will be about 3-5 seconds of medium white smoke from the tail pipe and from the rear passengers hood gap near the coolant tank but not from said tank. And when I finally get off (3:15) a huge cloud just from the tail pipe but for 2-3 seconds. And every so often there will be a slight blue tinge after the smoke cloud. I can try to get a video of it tomorrow.
Thanks,
Ed
P.S. the rpm dips down to 500 from the normal 750-800 area and it will die some of the time during the 3-5 second area.

Mrmerlin

sounds like a head gasket, or your getting oil into the combustion chamber and its burning in the cats.
First are you loosing oil or coolant?>
I would pull the plugs and see if any look like the tips are rusted and or if any of them look like they are very clean,
or better yet post a picture of them.

928 GT R

Head gasket or crack in one of the heads.

Check your oil for milkiness or a chocolate shake look.

Strosek Ultra

You can always try a bottle of Rislone Head Gasket Fix which will stop any internal coolant leak at least for a period of time. It has worked in my old BMW 635CSI for four years using two bottles but soon she will be up for a cylinder head replacement.
https://rislone.com/ca/product/head-gasket-fix/
Åke

cali4sun

Best of luck. Please post your outcome.

'89 928S4 GP White/Black

Edward Larson

Here is the pictures of the spark plugs, and the oil is not a milkshake
All the plugs look the same but I didnt have time to get the 8th plug off

DeWolf

Mrmerlin

how old /how many miles on the plugs

docmirror

Have you added coolant or water to the exp tank? Mark the coolant level on the side with a grease pen at cool temp, before start. Keep track of the level each day at the same temp.

Remove the oil dipstick. Look on the stick above where the oil level is for foam, or condensation, or creamy deposit.

Check the cam cover vents are not clogged by removing the hoses from the vent pipes and start the car. Also, blow into the hoses and make sure they aren't blocked.

We need to see all 8 spark plug tips, not the body of the plug, but the tips.

Edward Larson

docmirror

I doubt this is water ingestion to the cyls. Sounds more like a oil crankcase breather is allowing some amount of oil vapor to get into the combustion area. The breather setup on the 928 is pretty complicated. Plenty of ways to go wrong. Usually torn or cracked hose(s).

Edward Larson

So I took the car to Werkstatt here in Rochester, MN the guy who owns the shop is an awesome dude.He's got an 82' that is manual w/ 88k miles.
While sitting there talking to him with the car running after about a minute of idling he revved it and a cloud of blue and black smoke came out.
Then he opened the hood and poked around the head with a screwdriver and found a small pool of oil.
He said could be too much oil in the pan to valve seat to the engine needs a rebuild.

Thanks again to everyone trying to help me!
Ed

P.S. I'll update you all when I get the diagnostic completed.

Mrmerlin

if your not loosing coolant and the compression is good remove the MAF and open the throttle plate and wipe out the oil,
Then go drive the car for more than 60 miles

PS if thats what the mechanic said then I would get a second opinion from a 928 specific mechanic

docmirror

A 928 engine that isn't abused will last 500k miles or so before needing rebuild. Your plugs do not show oil fouling or water ingestion.

If you have an oil leak, find out where, and fix it. Do a compression test with a leakdown compression tester. Run the tester at 80PSI, and listen for leaks from the cylinders at the intake with the throttle open and the air cleaner off, and also at the exhaust.

Readings of 60PSI on leakdown compression test or better would indicate that your engine is doing fine. It is not a trivial test method, but will indicate the need for overhaul very clearly.

SteveG

Just curious, do you apply the cocaine to the hoses in a paste or dry? I try to think outside the box, but I've never seen this particular "solution" -- as it were.