replacement engines
 

I was ready to flush my coolant and got this all set up, then noticed coffee colored gunk in the recovery tank. Car never overheated and I checked the fluids 2 days prior and everything was fine. Nothing but oil shows on the dipstick. The check engine light came on briefly a couple of times in the past week, but went out. I will post error codes later today...i hope.
I have a line on a couple of engines for my 145K 2000 boxster s (fear I have a cracked head due to intermix issue) that cost about as much as my repair, plus installation. Question is, I have tiptronic and these are manual. What is involved to use a manual engine and match it to a driving tiptronic? (Meaning I have all the parts for the tiptronic) do I need to switch some stuff over or are the engines just different?
Any help is appreciated.
another question that will help me with diagnostics, how can I test for a cracked head?..I know this could be the oil cooler or o-rings, but feel this is unlikely and hopefully it will be obvious once I tear down into it.

I swapped a manual engine into my '01 tiptronic. Most of it is the same, but there are a few things that you need to keep from the original engine.

*The wiring harness. The tiptronic wiring harness is integrated into the engine harness. It is a lot easier to just swap the harness over than try to separate them.
*The vacuum system. There is a vacuum line from the engine that goes to a change over valve on the tiptronic transmission. The brake booster vacuum line is different, connects to the opposite end of the engine and has a venturi connection.
*The alternator and starter are a little different, but will function fine in either engine.
An old post from when I did the swap: http://986forum.com/forums/426619-post16.html

Do a cylinder leak down test. If the leak down test is ok, then the source of the intermix is probably the oil cooler.

Compression Chart full color from Renntech
 

This is fascinating and useful for those who are visual learners.Courtesy of Renntech. It will help ensure you test each cylinder in the correct position.
https://www.renntech.org/forums/uploads/monthly_04_2014/post-93239-0-35664900-1397384617.png
Here is the Firing order and cylinder i.d./location
http://www.gtsparkplugs.com/firing-order-porsche-boxster.html

Would not bet on that. We have seen a couple of heads crack on the cam sides, which would completely be missed in a leak down. First thing I would do is pressure test the cooling system to confirm that there is a leak, then do a leak down. If the leak down passes, you could have a bad oil cooler (which can be tested separately to confirm or deny), or you could have a leak outside the combustion area.

Yep...I thought of that, the cylinder leak down is only if the crack is in combustion chamber. Pretty sure I have a tight coolant system,, the cap really hisses when I remove it warm (not hot). Tell me if this isn't a valid assumption and I will pressure test the cooling system.
So, I hear the the oil cooler is rare. The only thing I noticed is a couple of flashes from the oil light the night before...just flashed on, then off, then flashed again, little flicker, then off. the level of oil is fine and the oil looks clean, however, I noticed some condensation on the oil filler cap?
If the oil cooler blew out, that would be a huge relief. The orings would just mean lost coolant, correct?

If the Heat Exchanger "O" rings have failed you will see oil &/or coolant pooling on top of the engine underneath the base of the heat x. Note some aftermarket "O" rings are undersize and will leak almost immediately. Ask me how....

another quick question -
I am seeing head assemblies, some say the 2.7 and 3.2 heads are interchangeable and others only have an application for 2.7 and don't list the 3.2 as fitment. Anyone know the real deal on this?

I had a head go on my 2000S, from what I gather the most likely year to fail, biggest giveaway was white smoke from exhaust. Have you had plumes of smoke from exhaust. If not don't panic, may be simpler.

I thought S head was different, possibly different cams.

My understanding is you need head and cam holders as all line bored, but this is what I was told by someone who I am sure knows far more than me.

Thanks for the feedback and I have never had smoke, white or otherwise. No symptoms except intermix (oil in coolant tank) suddenly on Friday. sure do hope its simplier, but nothing has been so far. :+)
I have confirmed that they are different part numbers, but I am hoping for a more authoritative answer from someone on compatibility. Some of the folks on ebay list them as interchangeable and others dont. Once I drop the motor, I need to move fast as it will be at a shop. I gots NO garage.

Good luck, hope it's cheaper, keep us posted.

Before you have brain surgery, try an aspirin :)

Seriously, first you should try to eliminate the simpler probable causes, like the heat exchanger o-rings, the HE by itself, if both are Ok, then can move into a crack head scenario where someone like Len Hoffman can repair for you.

Good luck!

Thanks and no doubt...I'm not dropping the engine or cracking the head until I figure this out. But it will be at a garage with the clock ticking. BTW, if the o rings are leaking, how would oil get in the coolant? Are two of them coolant and 2 of them oil and they cross pollinate when leaking? It will be obvious once I take the intake off if o-rings are bad. I can pressure test the cooler (i think) and see My mechanic is good, I just like knowing what things are and leading him to good decisions.