CJWessing

Hey guys,

I took the Porsche out for a spin tonight, and when I parked it had steam coming from the driver's side engine compartment. Appears the the coolant reservoir cap is leaking and dumping a bunch of coolant out.

I just bought the car a few months ago, and the previous owner told me he had a new reservoir (and I assume cap) put in. Is it possible that a coolant reservoir cap that's less than a year old could have failed already? The attached photo is what my cap looks like, seems like the latest model.

I also broke a coolant line about a month ago while replacing my engine mounts, is it possible that I may have some air trapped in the coolant system somewhere? Am I in jeopardy of damaging the engine at all?

I just ordered a new cap, so I'll try that as a first step to diagnose.

Thanks for the input!
Chris

pfbz

Whats the part number on the cap?

996-106-447-04 ?

Hurdigurdiman

It is also possible that the coolant may have been overfilled and the release valve with the green arrow could have lifted from pressure to relieve the system. Are you sure that the fluid was coming from the cap and not the relief valve? You say you broke a line and asked could it have air in the system. Lift the valve (green arrow) and run the car as normal and the air (should there be any in the system) will find it's way to the relieve valve. Keep an eye on the engine temperature and don't hammer the revs too high when you are doing this procedure. Good luck. This s good check page to see if you have the appropriate cap for the car http://www.pelicanparts.com/support/OEM_FAQ.htm

CJWessing

Now that you mention it, I did add some distiller water last weekend while I was changing my tail light and haven't driven it since, maybe I overfilled it. It looked like it was coming from the cap and pouring out of the drainage hole (red arrow), but could have been coming from the pressure relief valve behind the cap (it was dark). Should I also suck some water out to the min mark? Haven't checked it yet this morning, hopefully haven't lost too much.

Can the pressure valve get stuck open? If it was the valve, I would expect just one session of pressure relief and then be fine after?

CJWessing

Coolant level is a little above minimum this morning, tried removing the cap but it appears I may have put it on a bit too tight last night. Will try again after work today.

DBJoe996

Fill the expansion tank to the MAX level, but not over that. There needs to be a little air in there for expansion. Why would you want it at the MIN level? The relief valve should not be leaking. It is down when cold, and up when the engine is at operating temperature. You can check this first thing in the morning, it should be down. Then drive and when warmed up, the relief valve should be up. If you suspect air in the system, you can use the little wire thing to "prop" up the relief valve to bleed air from the system. Run it like that for a few days and that should "burp" any air from the system. My cap gets stuck as well, just wrap in a rag and put a channel lock on it...gently turn.

fpb111

That cap does not look like a Porsche cap. Does anyone else have a BLACK cap? I have only seen Blue caps. That latest update 996 xxx ends in 04.

Hurdigurdiman

I have the blue one on my 99 cab.

PelicanParts.com

That blue cap is correct, part #996-106-447-04-M100 which you can find in our catalog here.

Also, take a look at our coolant flush article which may provide more detail on this topic especially 3/4 of the way into the content:
Porsche 911 Carrera Coolant Flush

Fire over any questions - Mark/Pelican Parts

CJWessing

Just picked up a blue one from my local Porsche dealer, it's blue and part number ends in 04. I thought the black one was Porsche because in the picture on Automobile Atlanta it was black and said OEM or Porsche genuine. Took it up to temp and everything appears normal, thanks guys!

PelicanParts.com

Glad this worked-out - have a great weekend!

CJWessing

Also was blessed with a Carrera GT sighting at the dealer today...

Hurdigurdiman

That is one sweet looking machine.

fpb111

"Max" is for when the engine is hot. "Min" is for when the engine is cold. If you fill to "Max" when it is cold it will vent some due to expansion when hot.

CJWessing

Looks like I spoke too soon, after a drive tonight came out to my car to find a small puddle underneath the left rear and my coolant level is low. I can't see where the leak is from the rear of the engine, but I can see it dripping from the location in the picture (pic from behind driver's side rear wheel.) Not sure squarish thing is, but is that something that would leak coolant? My guess is that in replacing the reservoir cap, I upset the delicate balance that was my cooling system, maybe by sealing the cap the higher pressure has caused a hose to leak?