Giant blue cloud behind car-towed home-massive oil leak

[Chris Morse]

I don't want to do this again.


Fully warmed up, hit 6k rpm and the giant blue cloud bloomed behind my 74. Shut it off before i could think to check the pressure and coasted to the side of the road, with a massive oil trail behind the car back up the road.

It is in the engine compartment, on both brakes and the entire underside of the engine - $15.00 per quart, hour and a half waiting for the tow, not happy.

Started it up with a friend this evening and a lot of oil was coming down the right front side of the engine, shut it off.

Looking back through my dad's service records, i see two coolers replaced within the last year. one ********** aftermarket copy and one factory cooler.

My friend and just replaced the oil lines, installed a carrera cooler, brass lines and the factory thermostat - no problem with the new stuff.

Is this likely a sticking pressure relief set up killing the stock cooler???

Do I need to drop the engine to find the leak.

What should i look for besides the obvious chaffed cross over line or a blown out blown cooler seal.

Do we have a sticking bypass plunger???

Should i plan on doing the new plungers & springs as a precautionary measure???

Just got through replacing two rear axles, all of the injector holders and seals, plugs, oil and filter,installing the carreara cooler set up, factory quick shift and am about to order a set of Dunlop Direzzionales.

Is my dad's car possessed????

Mired in ignorance,
chris

You don't want to se the pictures....

[crustychief]

We want to see the pictures. There are a lot of trained eyes on this board that can identify problems very quickly with pictures. Besides, you didn't type a thousand words.

[djpateman]

Did you just do an oil change? Do you know how to correctly check the oil level in the tank; engine running, warmed up, level, etc? If you overfill, the oil will find a way to escape.

[Chris Morse]

I have about 1000 miles on an oil change. After installing the carrera cooler and brass lines, i added two more quarts and have about 200 miles on the car with the new cooler.

I pulled the air filter and looked under the filter and it is clean in there.

The car had been running for about 20 minutes. The temp was about 190 F and pressure was reading about 50 psi at about 3200 rpm, cruising down the road behind a slow poke. She turned off and i punched it up to 6000 rpm, car sounded good no noises and whammo giant blue white cloud behind the car. I shut it off and coasted to a stop, still smoking.

I got out and opened the engine lid and there was oil everywhere, especially the front of the engine compartment, (by the transaxle) oil was everywhere, the underside of the engine was dripping oil from everything and there wa a back trail about 2 feet wide of oil leading up to the back of the car.

Pulled the dipstick and the tank was empty.

Later, last night, with a cold engine,i grounded the coil wire and cranked the engine for about 3-4 seconds and oil started dumping on the right center - right front of the engine. I did not see the pressure gauge move.

I have, recently, (300 miles or so), been noticing occasionally inconsistent pressure readings, sometimes staying at 60 psi after a bit of high rpm work, then it would drop to 40, then back up to 55 With a constant engine speed. I put this down to a possible bad sending unit or loose wiring going to the gauge. This didn't change after i pulled the sender wire, cleand and reconnected the wire.



not happy,
chris

[Grady Clay]

Chris,

Reading all this, the cause is not clear to me (yet) either.

The proximate cause of the oil leak may be the failure of the engine oil cooler or seals.
It can be other.
Is it possible you replaced the oil pipe under the transmission and the clutch parts are (or had prior) touching - causing a hole?

I would remove the cooler and inspect it and the two upper seals.
If everything appears OK, have the cooler pressure tested.

What is the history of the engine?
Replacement, rebuild, service, etc?
Tell us more about the front cooler installation.
Was the oil change a change in oil type?

I am very suspicious of the two prior cooler replacements within the past year.
I would want to very carefully inspect and measure the two oil pressure systems: one regulating and one safety.
There are many different parts to these systems and it is easy to have an incorrect combination of parts.


We want to see pictures … and see you happy again.

Best,
Grady

[Vin-barrett]

Under the cooler I have seen some kind of sealant goop that looks pretty mickey mouse...
I have seen this on a few engines and believe it's put there from the factory?
Could that stuff have sprung a leak?

[Wil Ferch]

I don't see the model year of your car posted. I believe Porsche updated the internal pressure relief valves and by-pass valve pressure settings on the very earliest SC's (?). Accessed via horizontal and vertical plugs on the external engine casing. Often manifests itelf with loss of oil pressure/foaming under spirited driving or track conditions. Could this be a probable cause? Others may have more to chime in.

[Grady Clay]

Originally Posted by Vin-barrett

Under the cooler I have seen some kind of sealant goop that looks pretty mickey mouse...
I have seen this on a few engines and believe it's put there from the factory?
Could that stuff have sprung a leak?

Vinny,

Not Factory and should not be there.
Replace the three cooler seals, check the cooler and the other ‘normal leak’ items – breather gasket, oil pressure sender/switch and thermostat O-ring.
This is straightforward DIY covered elsewhere.

“Sealant goop” seems to be common with low-rank MM (Mickey Mouse and certain other) hack ‘mechanics’.

Chris’ ‘leak’ is in a pressurized system: either the main oil pressure that the cooler sees or in the early part of the scavenge system (which is supposed to have 100 psi protection at the thermostat/pressure relief valve assembly).


Wil, it is a ’74 (I assume 2.7 but could be other).

I have never seen a perfect description of all the oil pressure relief/safety pistons, springs, spacers, plugs and other. BA has a good description and there are a couple of Factory bulitans but we need actual dimension measurements, spring lengths and spring rates.

These are very reliable parts.
The problems arise when incorrect combinations are used to ‘update’. I suspect this is particularly true with the ‘oil bypass mod’ that would be on a ’74 2.7.

A good subject for a through search and another thread.

Best,
Grady

[Wil Ferch]

Sounds either like an internal blockage at some critical point....or the engine-mounted oil cooler itself broke ...and/or... its connections to the engine block failed.

[Vin-barrett]

I think the sealant goop ive seen may be from this repair.
I found this pic on another thread....

[Head416]

I'm a novice here, but I'm thinking:
Oil on ground -> external oil leak (hose, connection, etc)
Blue smoke -> internal oil leak (rings, valve guides, etc)

What would cause oil to burn and leak on the ground? Seems like two different problems to me. But obviously there's some common connection.

[Joe Bob]

Oil dropping onto hot heat exchangers.....

[Vin-barrett]

Originally Posted by Head416

What would cause oil to burn and leak on the ground?

The leaking oil cooler area is right above the exhaust, so its drippin out and burning off

[Chris Morse]

I cannot get the car up in the air for several days to assess the source of the leak - I am seriously involved with a new house construction, a rental rehab of mine and a few minor jobs for some good clients, so cannot give you any meaningfull info at this point, but as time permits, i will do photos, get the car up in the air and pull the cooler/lines to assess the situation.

My major fear, at this point, is that i have an intermittant, sticking pressure relief that might have killed three coolers. but this is premature untill i get the cooler off and assess the situation, it could be a backed out relief plunger base screw or a split line.

To answer some of the prior questions, I installed a set of used brass factory oil lines, a new carera cooler from Elephant, a new factory thermostat with pressure relief and new/rehabed flex lines. Oil has changed from 20-50 castrol to 20-50 Redline synthetic.

I am still very interested in identifying the "Best"pressure relief/controll plungers and springs for this recently rebuilt 74 2.7, ($11,500).

This car is my dad's pride and joy, my 4th Porsche and i want to do it right

thanks for the advice and concern,
chris