Sentinelist

So there I am an hour ago in my 951, sitting at my bank's drive-thru in front of the tellers, coincidentally feeling thankful for a properly sorted old Porsche after several months. It's running like a top. I just got my new Becker CD stereo working with an AUX input for my iPhone and am streaming Internet radio. I just washed it last night. The sun is out but not baking yet. It's going to be a good day.

"Thank you for your business, Chris!" I smile and wave, and disengage the clutch to pull out, idling down the driveway without giving it any gas. 1mph, maybe. *POOF!* *SCRAKLTCHPHETCHPHHH!* A cloud of steam and a bad scraping sound suddenly bring my fine morning to a blinding halt. Bloody hell. The temp gauge went up a full notch, but wasn't overheating or giving me a red lamp. The engine was running perfectly fine otherwise. Ok, home is a mile away- I'm limping this thing home ASAP, slowly. And it made it just fine, drove almost completely normal even, never getting into the red area on the temp gauge. I even tried a little boost to check that system. Most is well! I got into the garage, popped the hood, was still steaming a bit. Green coolant traces all over the back of the engine where the steam was eminating from, even some on top of the intake manifold. Pretty sure I left a gallon or two on my bank's driveway.

So thankfully, I assume, my engine is not shot. It seems to run fine. Is this indeed my head gasket? I plan on repairing this myself, hopefully with a sturdy gasket (metal?) that will get this back on the road for near-daily duty soon. Been there/done that advice, tips and recommendations welcome.

For now, Porsche keys in, Audi keys out. Headed back to the office...

Seattle944

damn that sucks. I hate that feeling. As I'm sure you know..check your oil for the white substance.

Tedro951

That would be a big time head gasket blow to blast coolant externally. Time for a pressure test..

87944turbo

sounds like the hose at the back of the head if it is on top of the manifold like that.

Sentinelist

I hope this is the answer to my prayers! I actually noticed some bubbling around that a couple months ago once after hearing a fizzing sound. It went away and I forgot about it, so that could be the weakness. If that were to have blown (was pretty violent, got steam out both sides of the hood, definitely green coolant on top of the intake manifold), could my head gasket be fine (since I didn't note any power loss)?

?

divil

Check your this

Heater control valve - it's between the back of the engine and the firewall, a little below the intake manifold. When it happened to me (last week) I thought it was something catastrophic too. Apparently it's a very common failure.

hardtail15

+1 happened to me last month

86 951 Driver

Heater control valve. Go ahead and replace the hoses while you are back there.

Sentinelist

Wow, how often does a problem with these cars turn out to be far less worse than what it seems? Sure hope you guys are right- it seems like it now that I'm looking at this component. I'll get this and the hoses this week and report back soon.

It's now a good day again (I think).

Van

That's my bet, too.

A head gasket is usually between the combustion chamber and the water jacket - so all coolant goes out the exhaust pipe.

divil

Well you have 14 separate coolant hoses and they're probably all the same age Personally I'm capping it at 2, and replacing all my hoses + clamps..I worked it out and it's cheaper than calling a tow truck 14 times!

dillon410021

heater valve would be my guess

Sentinelist

No doubt. The only thing that bugs me is that - supposedly - all the hoses were replaced including the heater hoses at the time I had the PPI done in Nashville last October by a well respected tech before I flew out to pick the car up. However, I don't recall that this heater control valve was replaced. I took one last glance before leaving this afternoon and the hoses themselves looked fine. For the money, I'll go ahead and buy new ones- it looks like I need 2 around this assy? Or 3?

catamount

Another vote for the heater control valve. It happened to me pretty much just like that. The good news, the back of the engine, firewall, etc will be extremely clean. So, you won't get dirty (much). The bad news is you'll probably be replacing the HCV, the cycle valve and there's a sensor too. That sensor (why can't I recall it's exact name, old age maybe?) as a Porsche part is expensive. But it's a stock Bosch part that is used on BMWs as well. The BMW part is much cheaper.

divil

Well if they were replaced that recently you're probably fine with just changing the valve (assuming that turns out to be it)...I think there are just 2 hoses - at the top right in this diagram

I think the easiest way is going to be to pull the hoses and the valve out as a single assembly...that's how I plan on removing mine anyway. So then you can take a good look at the hoses and see if you think they're OK. The lower one connects to the firewall over on the passenger side behind the cam tower.