Tippy

No, I wish . Life changes happened......

Dharn55

Another one bites the dust. Mine happened in September, oil in the coolant, and coolant in the oil. It ran fine for awhile, and I changed both the coolant and oil to see how long till it showed up again. Wasn't long, and after only a few miles it started missing badly.

As you said, it could be the oil cooler, head gasket or cracked head, but might also be a cracked liner or porous crankcase. No one knows which is more common as Porsche continues to hide any real stats.

The TSB for oil/coolant intermix says to first remove and pressure test the oil cooler, if it doesn't leak, they say the next step is a new engine. Of course this is Porshce, and it was a few years ago. There are some rebuild options now. Lots of threads.

Some says this is a rare problem, but as one who has suffered it, it seems like we see the posting of a failure of a 996 engine at least once each month. Good luck, let us know what your problem is. I am going to remove my engine this spring and have a look.

salayc

Did he just???
Oh boy...

redridge

yeah he did... one a month, Ok lets say 5 a month

60x10=600

600 blown engines... not to bad considering there are 10's of 1000's out there... but Im just saying, I kid

othomasjr

That's the exact same thing that happened to me Doug. I feel your pain. I won't comment any further as that horse has been beaten.

perryinva

Actually, IIRC yours was worse, as wasn't yours an 02, and you pretty much just got it? I don't recall if you got a new engine put in or what, tho......

Doug Donsbach

Finally had some time to do a quick test before I drop the engine. I pulled all the plugs and found they all looked nearly identical with no signs of coolant. Then I pressurized the cooling system to ~20 PSI and listened in the oil filler and in each plug hole with with a stethoscope. I could hear escaping air and bubbles in the oil filler but nothing from the plug holes.

Of course, this doesn't rule out some other form of block failure but it does seem to indicate that a cylinder hasn't actually let go.

The fact that this happened immediately after the car had sat outside in 16 degrees F weather for a few hours the night before gives me some hope that either the oil cooler seals have failed or a freeze plug has let go inside the engine. Of course a clean coolant sample tested at about -35 degrees F, so if a freeze plug did let go, it wasn't due to the coolant actually freezing.

Anyhoo, I'll know in the next day or so what the problem is as I've bought a nice ATV jack to assist with the engine drop. Let the fun begin!

gota911

Doug,

Good to hear some preliminary good news. I hope for the best.

Meister Fahrer

Good attitude Doug!

Hope you learn more about the car, and that you don't find anything major.

Keep us posted?

Doug Donsbach

Well, things are moving a little more slowly than I would like, but working by myself and without a lift a certain amount of extra planning and care was needed to get the engine out. But it's finally out, albeit still attached to the transmission. I'll part those later today and begin disassembly of the engine after I move the car around in the garage to give me a little more working space.

It's not a difficult job at all to drop the engine on one of these. Much easier than doing a clutch on a 944 turbo, for example.

SH || NC

No lift? By yourself? Wow. Nice work. *subscribed*

Doug Donsbach

Before beginning disassembly of the engine, I pulled and pressure tested the oil cooler with 90 PSI of shop air. And of course there were no leaks. Due to the design of the oil cooler and the 4 o-rings that seal it to the engine, there really is no conceivable way that any of those o-rings could fail and cause oil and coolant to intermix inside the engine (unlike some other heat exchanger implementations I've seen in the past, for example the Porsche 944 and the GM 3.0L V6). Worst case, failure of all of the o-rings would simply cover the rear of the 4-6 bank with oil and coolant.

So it's something much more serious.

Dharn55

I'm not sure I am happy to hear your take on the oil cooler as I was hoping my intermix might only be a bad oil cooler (wishful thinking). I know that the TSB for intermix says the first thing to check in the oil cooler (pressure test). But from what you say it seems I am probably going to be disappointed. However, I am still going to pull the oil cooler and test it before I drop the engine.

Did you drain the coolant before you dropped the engine? I have tried to remove the drain plug on my engine but is is stripped. Do you know what size the tools is and whether it is hex, torqx or what?

phaphaphooey

Impressive work so far. Your positive outlook is refreshing. Best of luck.

Doug Donsbach

I'd encourage you to go ahead and pull the cooler, as it doesn't seem that difficult to do with the engine in the car (once you get that stinking A/C compressor out of the way, that is).

I hope you find yours leaking!

I did drain the coolant before removing the coolant hoses. But if you are dropping the engine you'll empty most of what you might get out of the drain when you disconnect the coolant hoses, so you can deal with the stripped plug later.

The plug is definitely a hex, and I believe it is 5mm.

BTW, if you do end up dropping your engine, I've answered your "How High do you have to raise car to remove engine?" thread over on Renntech.org with some pictures showing jack stand and rear clearance heights.