J Chen

White Smoke = Water. One should never see white smoke
from the exhaust unless the whether is cold. What is the
condition of the gasket ?

joseph mitro

Doug, glad you came to post. sorry to hear of your misfortune. i think you'll find a lot of us have spent way more than the car is ever worth. i spent $12,000 in two years on my 944 turbo. now i've advanced to rebuilding my engine (it's got 350 miles on it now)

good luck!!!

Doug85.5944na

The gasket was trashed by one my forign exchange workers from Mexico so I didn't get a real good look at. It wasn't in pieces from what I remember. Hmm?? I don't remember it looking that bad...
Dumb of me not to inspect it better. Nothing about it jumped out at me.
(The exchange worker is still with us)

Devia

Sounds like catastrophic piston failure - too many things going on, at the same time. Vibration was the rods & piston, IMHO. Also, minor water leak from head. SHAKE hard, mix suddenly with aluminum block, and BLAM!

IT happens. Sounds like there was a problem with the head coming off before - Legoland951 and I encountered this last Spring, that you MUST remove the camshaft properly, or the idle is NEVER correct. When I feel better, I'll get that up on my site.

I think many small things contributed to this, not just one. No, I don't think it was the injectors, it's just what happens sometimes. Been inside many of these, and seen only 4 thrashed this bad, and 3 were just as bad.

Rebuild a new shortblock, and replace the head, INCLUDING the camshaft - my guess that one wasn't put together right, and made things worse. Idle would NEVER be right, if the pin's worn out, from being pulled wrong.

- Julie

Zero10

Well, it does sound more and more like either a jammed fuel injector, or a bad head gasket. If you got enough fuel in the cylinder, it could blow out a head gasket from the extra pressure. Also, all that gas and coolant would clean the inside of that cylinder pretty well.

I'd say this one is chalked up to either a fuel injector, or a random catacalysmic head gasket failure.

nine-44

I'm still holding onto my other theory of coolant from sitting and damage on startup, maybe just cracked the piston top? It then cam apart when cruising?

My NA had a bad plug wire, split boot, it got wet and I didn't notice the miss until I got into the gas. Just crising I couldn't tell a thing.

Also, my Dad's 951 had a vibration on accel along with my NA too, I replaced the CVs on the 951, fixed, greased the NA, fixed. Not saying that is your problem, but if it's still there with the new motor. It's something to look at. The 951, the CVs started clicking shortly after the vibration, they were dry apon inspection

nine-44

oh, and the " what it is about these cars" Only 944 owners know what it is to accellerate in every corner for some reason, cuz they feel damn good on the road!

jonnybgood

I am out of theorys. white smoke says coolant to me too but unless that cylinder wall was already cracked or something then I would be looking for an explosion more than water pressure.

I have all my expenses in Quicken but I don't look at the 944 catagory anymore.....

I increse my speed on the on cloverleaf ramp after leaving work every day. I am at the limits now and I am sure the other freeway drivers think I am nuts but I am the only one with a big grin on my face. These cars are great. Welcome to the club.

Nice to see you post again Julie.

F18Rep

Oh and BTW...welcome aboard Doug. I think everyone will enjoy reading your updates...Bruce

nine-44

yeah, sorry, Welcome to the list, and sorry about the failure, you'll get it. Good luck with the fix.

Dave951M

The only thing I can think of is a massive, catastrophic headgasket failure.

Dal Heger

I'm sorry, I can't see it as having anything to do with the headgasket. That's the weak part in the engine. Even if the headgasket totally failed, the worst thing that would happen (while the engine was running) is that you'd get a HUGE plume of white smoke and a REALLY sickly sweet smell/taste (yea, you can taste it) from the antifreeze. There is NO WAY that it would either crack the head/cylinder wall/piston from a headgasket leak. The theory about differential expansion of metal from hot spots suddenly getting cooled by a bit of coolant splashing on them doesn't hold water (forgive the pun). The coolant normally vaporizes at the piston wall/coolant interface, that's what takes the majority of heat out of the engine! It takes a LOT more energy to vaporize a liquid than just heating it up to (say 100degC - boiling point).

What is more probable is that the piston top was damaged in some way last time the head was out. A scratch, dropped, etc. Something that would have started a stress crack in the piston. The piston then progressively got worse. How did the workers clean the piston tops? Wire brush? There you go, you just took off a whole lot of aluminum and scratched the hell out of it.

Another option is that there was some foreign object in the cylinder, leading to piston damage and the results follow. It could have even been as small as a washer, it doesn't take much to damage the piston and cause it to fail. The damage from the head really points to FOD. Yes, you can get some damage from the piston pieces whacking about (have seen that), but this looks worse. It looks like there was something bouncing around in there for a long time.

All of those ridges would allow for pre-ignition to occur and that would finish the job.

Just my theory, I could be wrong. I've seen some bad headgasket failures, this really doesn't look like one. You'd have to be totally inept to miss the signs, loss of coolant, sweet smell on startup and running, bubbles in the cooling system, coolant overflowing (being pushed out by the combustion process (gasses)), temp gauge getting pegged, coolant mixing with oil, really rough running, steam cleaned piston, spark plug, and combustion chamber, etc.

Dal.

Doug85.5944na

Well guys thanks for all the Welcomes. Still have the lower end in the car and hopefully will have it out this eve... And by the way what size bolts do I use to hold the engine to engine stand?

joseph mitro

M12 i believe. 70mm for my engine stand

Tom Carson

there another post recently where it was said the 4 bolts are M12 x 120 with a 1.50 thread, and very difficult to find. (the 1.25 and 1.75 threads are more common.)