Oil leak

vwmike911 · 11-23-2009, 01:00 PM

Hi all Ive just removed my engine from my 81 3L SC as it had a oil leak from above or beside cylinder 6 i cant locate the leak yet but i haven't removed the oil cooler what i would like to know is there any thing under the alternator shroud that could cause the leak before i remove all the intake and injection to check?
Regards
Mike

BoxsterGT · 11-23-2009, 01:56 PM

This is a common location for oil leaks.

They usually come from the oil pressure switch, the thermostat O-rings, and the lower end of the breather hose when it gets hard/brittle from age.

All three can be corrected without pulling the engine.

Often, we replace all three components, and seldom have further problems.

Good luck in your quest for that "Dry" engine.

Len

vwmike911 · 11-23-2009, 10:40 PM

Hi Len
Thanks for the reply the engine is out now and wanted to know was there anything under the alternator shroud that may leak i would rather not rip the fuel and air intake off to check but again want to make sure its right before replacing engine? anyone????????
Regards
Mike

BoxsterGT · 11-24-2009, 07:04 AM

Nothing under the shroud itself.

The common leaks described above are all accessible from the top. The good part is that it's much easier to fix w the motor out.

Len

yelcab1 · 11-24-2009, 07:18 AM

and the breather housing gasket, that makes 4

vwmike911 · 11-24-2009, 08:09 AM

Cheers gents
Regards
Mike

Gunter · Gunter's Garage

+1 to the above

Since the engine is out and you want to be sure, sometimes the 3 seals in the oil cooler get worn. The leak would the show up on the bottom, not on top.

If the top of the engine shows oil, the 4 items mentioned are suspect.

A clamp on the end of the breather hose to the breather cap is recommended.

vwmike911 · 12-01-2009, 11:38 AM

Hi Gents
Ive now replaced all the suggested items
oil pressure switch
breather gasket
thermostat seal
breather hose
oil cooler seals
i still have a leak any one with any other suggestions?
Regards
Mike

dshepp806 · dshepp806's Garage

any pics?

vwmike911 · 12-01-2009, 10:28 PM

Quote:

Originally Posted by dshepp806

any pics?

Hi will try and put one up later can any one see anything wrong with removing the injection unit and removing all the top covers then refit the injection unit and run it up to check the top for leakage i know i cant run it for too long due to no cooling but hopefully will be able to locate the leak????????
Regards
Mike

Superman · 12-02-2009, 06:36 AM

Quote:

Originally Posted by vwmike911

Hi Gents
Ive now replaced all the suggested items
oil pressure switch
breather gasket
thermostat seal
breather hose
oil cooler seals
i still have a leak any one with any other suggestions?
Regards
Mike

Volume-wise, the big culprit is the o-ring that seals the thermostat body. Under the grey plastic air deflector thingie located above #6 is a thermostat that is inserted into the case. Pull that thermostat body out of the case and replace the o-ring in there. About 2" in diameter. When this thing fails, it spews mass quantities of oil down the rear of the oil cooler. Use the green o-ring and lube it with silicon grease such as Dow Corning 111 or 112.

Gunter · Gunter's Garage

Quote:

Originally Posted by vwmike911

Hi will try and put one up later can any one see anything wrong with removing the injection unit and removing all the top covers then refit the injection unit and run it up to check the top for leakage i know i cant run it for too long due to no cooling but hopefully will be able to locate the leak????????
Regards
Mike

Not recommended because it would take a while to get the oil hot enough to leak out wherever it does. The cylinders get hot almost instantly and need cooling right away.

Instead, use the special dye that some shops add to the oil to find leaks.
Clean the area as best you can, add the dye, start and let it get hot, observe.

I take it that by thermostat seal you mean the O-ring inside?
And you have a clamp around the breather hose were it meets the breather cap?

How and where do you see the leak? On top mostly and/or running down the sides? Between which cylinders?

vwmike911 · 12-02-2009, 08:36 AM

Quote:

Originally Posted by Gunter

Not recommended because it would take a while to get the oil hot enough to leak out wherever it does. The cylinders get hot almost instantly and need cooling right away.

Instead, use the special dye that some shops add to the oil to find leaks.
Clean the area as best you can, add the dye, start and let it get hot, observe.

I take it that by thermostat seal you mean the O-ring inside?
And you have a clamp around the breather hose were it meets the breather cap?

How and where do you see the leak? On top mostly and/or running down the sides? Between which cylinders?

Hi yes oring replaced and clamp on hose, dye would not really help as i can observe the oil leaking from below running around cylinder 6 oil cooler side but cant find any leak above with the main cooling cover on??
Regards
Mike

Gunter · Gunter's Garage

Could it be the cooler itself?
They can be pressure-tested.

Have you checked the torque on the head studs? Long 10 mm Allen with a calibrated 3/8-drive torque wrench set at 23-24 ft-lbs and going cross-wise.
I made up a tool by getting a LONG 10 mm Allen L-wrench, cut off the short end, insert the long end into a 10 mm 3/8-drive cocket etc....................

Many possibilities for leaks on these engines. Rocker shafts, cam towers................

Superman · 12-02-2009, 08:55 AM

I'd agree that removing the engine shroud will likely not be illuminating. Running the engine without cooling air is not recommended but if it's just idling, it will be okay for a while. But not long enough to warm up the oil.

If the thermostat o-ring is not leaking and neither is the stuff around the breather plate, then the leak is either a rocker shaft or the oil cooler or oil cooler seals (3). Or, as Gunter says, a failed oil cooler.

vwmike911 · 12-02-2009, 12:00 PM

Hi Gents
Heres some photos hopefully, the oil seems to leak under pressure rather than temp as it leaks almost as soon as the engine is fired?
Regards
Mike

Gunter · Gunter's Garage

Wow.........that's some leak.

Running that heavy should make it easier to locate.

I assume that after replacing the usual suspects on top that there is no more oil now right by the breather cap, pressure switch etc. ??? Top is clean??

Can't think of anything on top of #6 that could leak so bad.

Oil cooler???
Hose connection to oil cooler?
Through bolts???

I would send an email to John Walker's Workshop with pictures and an explanation of what you have replaced so far. Hopefully, JW will chime in.

Admire your patience because this is really frustrating.

vwmike911 · 12-03-2009, 08:37 AM

Quote:

Originally Posted by Gunter

Wow.........that's some leak.

Running that heavy should make it easier to locate.

I assume that after replacing the usual suspects on top that there is no more oil now right by the breather cap, pressure switch etc. ??? Top is clean??

Can't think of anything on top of #6 that could leak so bad.

Oil cooler???
Hose connection to oil cooler?
Through bolts???

I would send an email to John Walker's Workshop with pictures and an explanation of what you have replaced so far. Hopefully, JW will chime in.

Admire your patience because this is really frustrating.

Hi Mate emailed john thanks do through bolts leak? how do you seal them?
Cheers
Mike

Flat6pac · 12-03-2009, 03:57 PM

Looks like you might have stud problems as the only thing there is a base gasket. The heads on an SC torque to 25 Ft#. If you dont have a broken stud something is falling apart because you dont have enough pressure to keep the cylinder set.
Dont torque the bottom, just look for loose nut, its got to be there. Reason being the dilivars cant take any strain with their age.
Bruce

E Sully · E Sully's Garage

You could also check for a loose rocker shaft.