85 944 losing oil with no signs of a leak

[peejay90]

I recently purchased an 85 944 as a project car. I resealed the oil cooler, flushed out the cooling system and changed the oil. I have not driven it yet but while idling in my driveway for 20-30 minutes at a time it appears to be losing about 1-2 quarts (according to the dipstick). I allowed ample time for the oil to drain back to the sump and have verified this 3 times. There is no sign of a visible leak, no oil in the coolant, no smoke in the exhaust, and the engine compression is well within the healthy range.
Where could it possibly be going?

[pfarah]

Either you're leaking it, burning it, or it's commingling with the coolant. OR, there's a sneaky devil stealing it...

Verify there's no blue smoke coming out of the exhaust. You may want to remove the plugs and verify they're not gummed up with oil. The oil is going somewhere. I know that my car has to sit for a good 10 minutes, after shut off, prior to checking oil level.

[peejay90]

Pfarah,
The spark plugs look clean and there is no blue smoke in the exhaust. There is some evedince of oil in the coolant, suggesting that I did not properly install the seals on the oil cooler, but not enough to explain the loss of 7 quarts of oil.
When resealing the oil cooler I followed directions found on Clark's garage and used a basic cheap aftermarket kit. Is there a preferred kit and/or a better method of installation?

[tamathumper]

Just to clarify, you're saying you've lost 1-2 quarts of oil in 30 minutes, 3 times, so 3-6 quarts of oil lost in an hour and a half of idling? And no blue smoke?

[VirginiaF1]

Originally Posted by peejay90

I recently purchased an 85 944 as a project car. I resealed the oil cooler, flushed out the cooling system and changed the oil. I have not driven it yet but while idling in my driveway for 20-30 minutes at a time it appears to be losing about 1-2 quarts (according to the dipstick). I allowed ample time for the oil to drain back to the sump and have verified this 3 times. There is no sign of a visible leak, no oil in the coolant, no smoke in the exhaust, and the engine compression is well within the healthy range.
Where could it possibly be going?

Welcome to the forum..
Respectfully, your findings can not be wholly accurate.

The dipstick Hi/Lo marks represent ~1.5 quarts difference.
Does the following describe your exact measuring method (times 3 no less)?
"Car on level ground, check dipstick which shows full oil mark, start car and run for 20 mins, no white or blue smoke from exhaust or engine bay, no fluid leaks under car.
Shut car off, wait 10 mins for oil drainback, oil dipstick shows below Low mark now."
Repeat above steps. Repeat again?

1. No oil intermixing into the coolant system?
(ie: no milkshake on dipstick or in coolant reservior?)

2. No fluids pooling under engine bay?

3. How many oil quarts were initially put in after the oil cooler job?
4. Which oil brand & viscosity?
5. Which oil filter? (Mahle OC142?)

Can't wait to help you resolve this unprecedented first forum post mate..
Again, Welcome.
Mike

[peejay90]

Originally Posted by VirginiaF1

Welcome to the forum..
Respectfully, your findings can not be wholly accurate.

The dipstick Hi/Lo marks represent ~1.5 quarts difference.
Does the following describe your exact measuring method (times 3 no less)?
"Car on level ground, check dipstick which shows full oil mark, start car and run for 20 mins, no white or blue smoke from exhaust or engine bay, no fluid leaks under car.
Shut car off, wait 10 mins for oil drainback, oil dipstick shows below Low mark now."
Repeat above steps. Repeat again?

1. No oil intermixing into the coolant system?
(ie: no milkshake on dipstick or in coolant reservior?)

2. No fluids pooling under engine bay?

3. How many oil quarts were initially put in after the oil cooler job?
4. Which oil brand & viscosity?
5. Which oil filter? (Mahle OC142?)

Can't wait to help you resolve this unprecedented first forum post mate..
Again, Welcome.
Mike

I added nearly 6 quarts 10w-30 after the cooler change witha purolator filter.
There is no blue smoke. And the coolant looks clean after 4 flushes.
After running the engine (at idle, no driving) I waited 15 minutes and checked the dipstick and added nearly 2 quarts till the dipstick read correct. Ran the engine again and found the oil level had dropped again. Repeated this a couple times with consistent results. Drained the oil and found only about 1 quart was left in the sump. Drained the coolant and found very little oil, possibly left over from the flush, but bot enough to explain the loss of 7 qts of oil.
Tested engine compression, 210 psi and holding across the board.
I see no external leakage othe than the power steering pump which drips when under pressure.

[VirginiaF1]

Originally Posted by peejay90

I added nearly 6 quarts 10w-30 after the cooler change witha purolator filter.
There is no blue smoke. And the coolant looks clean after 4 flushes.
After running the engine (at idle, no driving) I waited 15 minutes and checked the dipstick and added nearly 2 quarts till the dipstick read correct. Ran the engine again and found the oil level had dropped again. Repeated this a couple times with consistent results. Drained the oil and found only about 1 quart was left in the sump. Drained the coolant and found very little oil, possibly left over from the flush, but bot enough to explain the loss of 7 qts of oil.
Tested engine compression, 210 psi and holding across the board.
I see no external leakage othe than the power steering pump which drips when under pressure.

Is this 944 on Earth?
Is your gravity the same as here on our planet ?
Your planet's atmospheric pressure at 14.7 psi?


Seriously though, where are you located?
(Please update your signature line with year, model, mileage and location;
Makes it way easier for members to help diagnose and suggest )

Being only a 2 year owner, my expertise has been exceeded by your issue.
I will wait for the big guns to weigh in ...

[VirginiaF1]

Originally Posted by peejay90

Pfarah,
The spark plugs look clean and there is no blue smoke in the exhaust. There is some evedince of oil in the coolant, suggesting that I did not properly install the seals on the oil cooler, but not enough to explain the loss of 7 quarts of oil.
When resealing the oil cooler I followed directions found on Clark's garage and used a basic cheap aftermarket kit. Is there a preferred kit and/or a better method of installation?

Forum sponsor's kit is what I used last year and so far so good:
Pelican Parts - Product Information: 10-0914-165-M30
(Includes OPRV gaskets and shims)

What was the oil pressure gauge showing during your 20 minute idle?

[peejay90]

Originally Posted by VirginiaF1

Forum sponsor's kit is what I used last year and so far so good:
Pelican Parts - Product Information: 10-0914-165-M30
(Includes OPRV gaskets and shims)

What was the oil pressure gauge showing during your 20 minute idle?

Thanks I'll check out that kit. My oil pressure sender has failed and am currently pricing a new one. The gauge reads high, maxed out.

Los Angeles, ca
1985 Porsche 944
260,xxx miles

[AKCJ]

This is indeed a mystery.

So, thinking outside the box, where could we hide that much oil? What if it leaked out the rear main and was somehow still in there with the clutch? As far as I know the clutch housing would not hold oil - it would leak out.

I don't see how that much oil could get in to or hide in the AOS/intake manifold/rubber boot/air filter housing. The engine probably wouldn't run if it did.

How did you drain the coolant? Possibly the oil could be in the coolant passages or radiator?

Last idea - oil pan. Possibly something is preventing the oil from getting to the oil drain plug? Possibly the dip stick is not consistently accurate?

[mytrplseven]

Just doing a normal oil change on my '87 N/A with filter I end up putting a little over 7 qts back in. With what you've done to your car, is it possible that you still need to add a little more until the entire system has it's fill?

[Slam]

!!! Keeping an eye on this.

I agree with the RMS theory, but the BH would leak out. So... It's gotta be in the water jacket or the rad. If the car is in fact doing this.

[pfarah]

I thought these cars hold 5.8 qts. There's something fishy going on here if you don't see oil in the coolant, the plugs are clear, and no blue smoke being emitted out of the tail pipe. With that much oil loss over your estimated engine run time, the car would look like a good ole country smokehouse. I'll take a side of black-eyed peas and collard greens with that BBQ!!
Seriously, the problem is likely staring right at you.

[tamathumper]

If your oil pressure gauge is pegged all the time, make sure the wires aren't reversed on it.

There just simply isn't anywhere to stuff 7 quarts of oil... Maybe the drain holes from the top of the engine back into the sump are all plugged, in which case it's swimming around in the top end. I've seen dumber things done by previous owners... including the reversed oil sender and the plugging of drain holes - with finish nails, no less.

[thumbdoctor]

If your engine has only been idling, perhaps the oil is going into the exhaust system and there's not enough exhaust heat / pressure to burn it like a drive cycle would. I have seen turbo exhaust side seals fail that weren't apparent until the vehicle was driven.

[John_AZ]

Originally Posted by peejay90

I added nearly 6 quarts 10w-30 after the cooler change with a purolator filter.

You might be using the wrong Purolator oil filter.
This style could cause oil leakage.




You should not use a Purolator oil filter at all!

It does not have the proper "anti drain back valve" to prevent the oil filter from draining---causing bearing damage on start up.

Use only an OEM Porsche, Mahle, or K&N oil filter to protect your engine on startup.

J_AZ

[jhowell371]

That much oil loss amounts to 1 or more oz of oil per minute. The one quart left in the sump puzzles me, shouldn't the oil pressure drop with so little oil? If so then shouldn't it get noisy? Like lifters collapsing and ticking, maybe bearings starting to knock? If the cooling system was full there's no way you could force all that oil in there with out shoving the coolant out the overflow. If it is leaking past the rear main seal it has to drip out somewhere. All that oil sucked into the intake system would have filled everything up causing smoke or worst case a hydro lock and even unburned oil would soon be blown out the exhaust pipe leaving evidence. Other then just keep topping it off and waiting for it to show up somewhere I'm stumped.

[VirginiaF1]

I've PM'd V2rocket in Riverside, CA to see if he has time/inclination to review this new member's amazing issue in person..

If anyone else is in the L.A. area, an experienced lookover would be invaluable for sure..

[VirginiaF1]

Originally Posted by sjyfjydyjyzhuan

The spark plugs look clean and there is no blue smoke in the exhaust.

Really? Plugs are clean?
Please return to the Land o' Spam..

Reported.

[pfarah]

Spam sandwich...