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johnwalklett · Joined: 17 Nov 2003 Posts: 31 Location: staffs england

After years of owning air cooled Porsches last week I bought a 931. it has only 50,000 miles on it and has stood for the last 2 years only being started to move it in and out of its garage. The turbo had siezed which I have replaced with a reconditioned unit and the car went great for 2 days. But durnig a good blast the car started to smoke badly and no longer goes as fast. The smoke is white and smells oily. A friend has sujested that maybe the head gasket has gone. Can anyone reassure me it is nothing related to the turbo I spend 2 days replacing and no more seriour than a head gasket.
Regards
John

Lizard · Posted: Mon Nov 17, 2003 5:27 am Post subject:

white smoke - water
blue smoke - oil
black smoke - running really rich

try to pull out the spark plugs and crank the engine over and see what comes out, also have you checked out the level of coolant?, also have you a boost guage and know how much boost you are pushing, as if the car has been sitting for awhile then the wastegate daiphram probably has a hole in it and is causing you to get too much boost to the engine and then blowing a head gasket,

also you would be able to perform a compression check to confirm the blown head gasket,

if you really want a smoke screen like James Bond, you are supposed to leak diesel fuel into the exhaust
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3 928s,

MunkPuppy · Posted: Mon Nov 17, 2003 12:13 pm Post subject:

I am experiencing the same problem as you, except I don't have a lack of power as far as I know.
My feelings are that either my self-rebuilt turbo is to blame or there's something wrong with either the head gasket or valve seals. Not looking forward to discovering what it is

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'80 931 FOR SALE

"It's a shame that stupidity isn't painful"
-Anton Szandor LaVey

wdb · Joined: 02 Nov 2002 Posts: 2024

my knowledge of turbos is limited, but I think ,under boost the the valves would not leak oil because the pressure would push the oil up and out ,not draw it in , check your spark plugs, if they are clean your not burning oil in the engine , it would be the turbo leaking oil into the exhaust . check your intake ducts for oil if they are covered in oil your tubo might be leaking into the ducts , if your intake duct is clean and the plugs are oily ,carbon foeled , it could be your head gasket .

johnwalklett · Joined: 17 Nov 2003 Posts: 31 Location: staffs england

Cheers guys,

I'm hoping to have a good look at it this week. But other conversations I have had with people in the know have said the head gasket may have gone. Also I checked the water today and I'm sure it has dropped about 1/4 of an inch since last week. Hoping it will show up when I compression test it.

Just want to drive it again!!

let you Know how I get on,

Regards

John

numbbers · Posted: Tue Nov 18, 2003 10:19 am Post subject:

Well if your coolant has droped only a 1/4 of an inch, it may not be a blown headgasket. But, the compression check will tell.
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1980 924 Turbo

cooper931 · Joined: 13 Nov 2003 Posts: 32 Location: Fayetteville NC

When my turbo went it only smoked when I steped on the gas for some unknown reason. I would recomend checking your engine oil and look if its milky and smell it. if it has a sweet smell to it and not the usual oilly smeel then it is your head gasket. Just some extra advice that might help.

johnwalklett · Joined: 17 Nov 2003 Posts: 31 Location: staffs england

Maybe a change of plan.... Removed the pipes to the inlet side of the turbo today and found 1/2 inch of oil in the bottom. Cleaned it out and ran the engine and no smoke for a short while. Then checked the turbo and oil in it again. Won't be very happy it the turbo is Knackered. The Turbo Technics recon cost me £490 and has only done 30 miles. May there be another problem with the car that has caused this to happen??????

Regards

John

Lizard · Posted: Thu Nov 20, 2003 3:37 am Post subject:

if you took the front of the turbo off and found a puddle of oil, cleaned it out and then ran the car pull it again and there was a nice little puddle again, take the turbo back to the shop as they did not do something right
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3 928s,

Smoothie · Posted: Thu Nov 20, 2003 4:21 am Post subject:

You might also or only have a problem with the turbo-to-oil pan oil return line. Given the amount of oil accumulation you're describing, I'd recommend a look at it. This is more likely to be a problem with earlier 931's due to something in the oil lines' design. They can be more prone to developing a blockage that restricts the return flow of oil.

This wouldn't explain much of a loss of power though and if the turbo had seized, you'd experience more than just a loss of power, but an exteme loss of power as you'd have no help from the turbo - a low compression engine with the frozen turbo blocking airflow at both the intake and exhaust sides. BTFT (been there felt that)

Could be that all the oil burning is fouling the plugs and if it's o2 sensor equipped (not likely) that would be fouled also - one or both possibly loosing you some power.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

johnwalklett · Joined: 17 Nov 2003 Posts: 31 Location: staffs england

I a going to check the oil return pipe tomorrow. If it has become blocked or restricted will this have damaged my turbo?, or will it just be pushing oil past the bushes?. Am I right in thinking that there isn't a seal on the turbo shaft? The turbo hasn't siezed and when I ran it after I cleaned the oil out the car sounded smoother at low revs. I surpose if the inlet turbine was partialy submerged in oil it would cause drag and slow it down?

Regards

John

Smoothie · Posted: Thu Nov 20, 2003 9:37 am Post subject:

numbbers · Posted: Thu Nov 20, 2003 11:03 am Post subject:

I guess all is possible, but my money says that your oil seals in the turbo are not sealing. Probably because the turbo housing has excess wear that the rebuilder did not repair. Take it back.
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1980 924 Turbo

johnwalklett · Joined: 17 Nov 2003 Posts: 31 Location: staffs england

Spoke to my turbo supplier today and they have said that it could well be the return pipe blockage or a crank case beather problem and this shouldn't have damaged the turbo if I can rectify it. If the problem persists they are happy to replaced the turbo if it is faulty.

Really hope I haven't got to take it off again!! It was a pig of a job!!

Wish me luck I hope to get to the bottom of this tomorrow as I have the day off.

Regards

John

jl924t · Joined: 03 Nov 2002 Posts: 214 Location: Surrey, BC Canada

johnwalklett
Did you ever remove the head to check the head gasket? Did you do a compression check? Do you have oil in your air filter box? Just courious.
John L.
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1980 924 turbo