MM951

So I'm driving home from work this afternoon when I smell oil burning and notice smoke coming out of my hood. Thinking the worst, I grabbed the fire extinguisher and checked it out.

Well, right over the "E" in "Porsche" on the cam tower there is a 2-3finger wide chunk blown out of my cam tower! There doesn't seem to be any damage to the cam lobe that is exposed and I can't think of anything that would get loose in there. Anyone have any ideas on how the hell this happened?


Luckily I have a few spare cam towers, but I am having trouble sourcing a cam tower gasket quickly -autozone no longer has them available and advance auto is a 3+ day wait....kinda a PITA as it is finals week here at school but I'll manage.

anyone have any ideas on what caused this ?

Mike

Mark944na86

You could probably make-do with RTV make-a-gasket type stuff as a temporary gasket, but I'd really try to figure out what punched a hole in your cam tower before driving (or even starting) it again.

And sorry, but I have no idea what that might be. Checked your timing belt? If that looks OK, maybe start by taking off the cam tower and turning the crank over slowly by hand and watching what happens with your cams...

Clint's 944

The only thing I can think of that could do that would be if one of the internal allen bolts backed out. However, I would imagine there would be considerably more damage done, not to mention a hell of a racket it would make.

Needless to say...we need pics!

Oddjob

That would be my guess too, or some other foreign object that was got left inside the tower. That damage sounds typical of having one of those bolts picked up by the cam and punched through the cam tower - unfortunately I know what it looks like when that happens.....

V2Rocket

yea those are some pretty big bolts that would take a while to back out.

something got dropped in there

lee101315

That is definately a loose bolt in there. Either it backed out on its own, or it was left in there from the last time it was removed.

Same thing happened to me. I glued it back in place with silicone, I had class the next evening so there was no time for me to rip the cam tower off. In fact, its been like that for 6 months so far. Here's a pic of my "E" that I glued back in place

Just find the bolt before you seal it up.

V2Rocket

yea i dont think gluing your engine back together is the best idea for long term reliability.

just get a new cam cover its like $50.

944obscene

Wow, that's reasuring.

Legoland951

I know exactly what happened. It happened to me and the oil had enough gas in it that when it leaked from the hole in the cam tower to the header it actually caught on fire while I drove the car to the nearest water hose (the previous owner ran the car rich so the oil was full of gas). It was one of the 2 locator dowel pins left in the cam tower and its the only thing small enough to fit and not get hit by a cam lobe. I drove the car for a few hundred miles before that one fateful bump I hit and sure enough it took the P out of the Porsche and set the oil on fire. The engine ran perfectly fine with the hole other than the big oil leak. Just change the camtower and you are good to go.

Do not leave it alone as the dowel pin broke the cam tower and still remained in the cam tower. Mine could not be glued since I was WOT relined when the cam tower blew apart. Even then, the dowel pin remained in the cam housing for me to find when I change the cam tower out.

theiceman

WOW that is interesting I would be curious as to what the OP finds in there. The oil will ignite regardless of gas contamination if it hits a hot enough surface. lots of 911s have been toasted due to oil dripping on the collector area of the heat exchanger.

944obscene

It's nice to know that my motor is closely related to a hand grenade.

choinga

I have a cam tower I'll sell you for cheap. I had my head gasket done recently and put a new red powder coated cam on.

lee101315

I was lucky enough to find the culprit right next to the cam when I looked in the hole with a light. As long as you find it, its ok to glue it in place until you have time to change the cam tower...its just a cover, after all.

chris_v

Your oil has gas in it? Is this another infamous rennlist mod?

Legoland951

Lee, the camtower is not just a cover. Its the entire cam housing assembly with many load bearing parts and oil passages along with hydraulic lifters.

Chris, the previous owner of my 1st 944 was a jackass who misadjusted the fuel switch INSIDE the DME and the car ran rich forever. There is some gas in all oil as it blows by the combustion chamber but very rich mixture will contaminate the oil and thin it out. This is the same owner who installed the lobster rib hood scoop and left the dowel pin in the camtower along with cracking the top of the gas tank so the interior of the car is like a gas chamber.