944S overheating

[Dave L]

My 944S which usually runs a little cool over heated this afternoon during a short trip. I pulled off, had a coffee while it cooled and noticed the coolant was very low. I topped it of and proceeded after looking things over. After 1/2 mile I stopped again when the needle reached into the red. I added more coolant let it sit for an hour and drove the couple of miles home keeping a constant eye of the temp.

I am a novice but intend to find and fix the problem, hopefully with a little help. I am treating this as a learning experience.

What I know so far

Aux fan is not coming on (usually when I park it runs for a minute or 2)
coolant appears to be coming from the rear of the engine and is leaking a lot.
front hoses and water pump seem fine as I see no evidence of leakage

Any tips, encouragement or sarcastic remarks are welcome.

No socks, lamp cord or duct tape will be used in the repair process.

[Tapage]

well I'm not too expert, but, in my case and here my 951 runs cool at the first mark always.

Some day becomes to hot ( second mark on the gauge ) and go with some old men, that know muchh about porshce ( not your case ) but he said, huuumm is air on the system.

Perform a bleed and all come to normal temp ..

Your case .. did you see where the cooland go out of the system ..?

[Dave L]

cant tell yet where it is coming from. I need to get it up on ramps so I can really take a look. From what I can see from the ground is that starter and the passenger side of the underside is covered in coolant.


forgot a few things from before;
My first insticnt was to turn the heater on full to try and disapate the heat. I had no heat.
No Milkshake, oil looks perfect.

[bearone2]

the water lines go into the heater, held on with clamps, difficult to get to.

[ae1969]

Well if you are exhessively leaking coolant the heater will definitely not blow any hot air.

More than likely its is the hoses at the back of the engine. Not fun to get at but if you lay across the engine and look behind with a flashlight it will all become apparent.

[Tapage]

In my case here in Panama we don't need the heater .. to take advantage in replacing process of my evaporator behind the dash .. !!! yes, it's awesome, but you need to put out all dash and related to get access to this heater and evaporator.

[Dave L]

More info! I am making progress.


I found a hose directly off the fire wall that is disconnected where it reaches the head. From what I see at 944Online the hose is the "upper S Hose" as you can see the hose is still attached to a metal collar that fits in to the "other part"

I am assuming that I dont just jam the collar back in, I would like to replace that part. Can some one tell me what I am looking at here?

[Dave L]

I went into a Porsche Mechanic today asking what the part was. He told me that he actually had another person with a 16v come in with the same problem the week before. They fixed it using JBweld which is the good news but I was somewhat troubled by the fact that they didnt know what the part is.

[Tapage]

Originally posted by Dave L
troubled by the fact that they didnt know what the part is.

thats are very bad news .. I thought porsche mechanic need to know how part is this .. and what it do ..

[peterjcb]

Originally posted by Dave L
I went into a Porsche Mechanic today asking what the part was. He told me that he actually had another person with a 16v come in with the same problem the week before. They fixed it using JBweld which is the good news but I was somewhat troubled by the fact that they didnt know what the part is.

Two strikes against him....he didn't know what the part was and he suggested using JB Weld. I wouldn't trust him as a mechanic either for his advice or for service.
That photo looks like some "Micky Mouse" repair that a PO did, I've never seen a hose with a sleeve on it like that.

[Byron T]

I've got a 16V...that doesn't look familiar. I'll take a look at mine 9/22(it's 3:00am right now) a little dark. I wouldn't trust JB weld to last. In my experience if a cooling system gets low enough on coolant the fans don't kick on because the coolant isn't in contact with sensor. Sensors don't read air temp to well.

[Dave L]

here is a view from further away to give an idea as to the location.

I agree that JBweld probably isnt the best solution, however it will get it back up and running untill I can track down the part and fix it.

[Tapage]

where to buy the plastic cover at right side on the pic .. ? ( internet site ) mine is so " tired "

[Dave L]

I used Jb Weld to repair the problem and actually found another very similar connection that was loose. It appears as though these connections were in fact done at the factory with what appears to be epoxy, It certainly wasnt welded.

The car has seen very little use in the past number of years from the previous owner (about 35,000Km in 5 years) I am guessing that the rapid heating and then cooling of the engine durring autoX, age and the gental use of ther previous years led to the failure.

The good news is shes all put together now, holding coolant and running as cool as a cucumber as ussual.

[carsonmx114]

i think lock-tight makes something for locking in bearings and bushings that might be better to use for this application. not that i'm above using whatever will work.