RoninFL

Hey there,

M96/21 - 02 3.2 Boxster S engine question.

So I bought an engine that had intermix & a Non-Porsche specific mechanic said blown head gasket. I figured cracked head & bought with that expectation.

Latte oil / no oil in coolant according to seller who did an engine swap on the car.

Engine turns fine - no issues

After stripping motor, I performed a leak down test with a basic Harbor Freight tester. 3 tests per cylinder & used a dowel in the spark plug hole to get TDC except on 1 / 4 there i used the Cam Lock tool. Obviously cold, but I can't exactly run the engine normal operating temps. Tested @ 98 PSI since the gauge said DON'T GO OVER 100 and wanted to leave a little wiggle room...

Average results:
- 1 - 7 PSI / 7.2%
- 2 - 2 PSI / 2.1%
- 3 - 3.5 PSI / 3.6%
- 4 - 5.5 PSI / 5.6%
- 5 - 2 PSI / 2.1%
- 6 - 7.7 PSI / 7.9%

Engine oil was drained for shipping, so I did put a squirt down each intake stack & 1/2 quart in filler day before I started hand cranking the motor & doing leakdown test.

So those #s look pretty good to me - all within spec according to some quick Googling.

The oil cooler was removed, so I can't pressure test it for a leak. The AOS / Plenum / Intake had Milky oil.

Am I crazy to think the Intermix was a failed Oil Cooler & the previous owner's mechanic completely misdiagnosed the head gasket when really heads are fine based on leakdown numbers??

Thanks for the help!
Ron

jcbeckman

The AOS (air-oil separator) is the more likely culprit.

RoninFL

I figured the AOS was toast given all the milky oil in the AOS tubes.

Forgive my ignorance - new to water-cooled P-cars, but can a failed AOS cause intermix?

jcbeckman

Nah, ignore me, been up too late lately. Thinking of a different issue.

stl_986

I'm thinking oil cooler...if in fact it really did have intermix. It isn't very common for these to blow a headgasket or get a cracked head. It can happen, but it would be the last thing I would think of when doing a diag. Best thing would be to get it back together and get it in a car then flush/fill the fluids. Worse case it is a cracked head and all you have lost is some time & fluid costs. My money though is on oil cooler which would also make me ask why that didn't come with the engine, it usually does but things like AC/Alternator/starter might not. Most dont strip those parts off cause of what it takes to get them off the engine.

ER17

I have one I bought which, when filled with coolant, started pushing oil from the rear main seal. Draining the sump first brought several gallons of coolant. I have torn it down, but see no obvious source of the intermix. The oil cooler was new. Any suggestions where to look?

RoninFL

The Oil cooler was removed by the mechanic when doing the diagnostic. I was also kind of bummed it wasn't on the pallet with the engine.

If the PO is to be believed, the car was running fine & one day while driving he noticed lots of white smoke. Pulled over and had the car towed the mechanic. Mechanic investigated - evidenced by missing oil cooler & spark plugs missing from Cyl 1 & 2. Was told it was Head gasket & PO sold the car rather than spend the $$$. New buyer wanted to put a Honda Turbo motor in the body. I bought the engine.

I've asked for the missing oil cooler & hopefully he will send it so I can try to pressure test.

In the meantime, someone on another board mentioned pressure testing the cooling system. It should hold 20 PSI indefinitely, so I'm going to rent a tester from AutoZone and try to plug up the water lines then pressurize.