996 GT3 coolant loss - how soon before engine overheats?
996 GT3 coolant loss - how soon before engine overheats?
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Harris_I

Original Poster:

3,364 posts

289 months

Monday 5th March 2012
quotequote all
OK, dumb question coming up.

Just had an engine rebuild on my 996 GT3 but it appears a couple of coolant hoses were weak. Result: total coolant loss whilst cruising on the highway at gentle revs in relatively cold temps (locally that's about 20C). It took me about a minute or two to find a safe spot to pull over and switch off.

Question is when the coolant low warning light comes on, does that mean the coolant is below minimum, or does it mean total loss? I ask because by the time I'd parked up and checked the level, it looked like it was completely drained. Water temp had stayed normal (say 80+) but I'm not sure I trust the gauge as I don't know what reading it's picking up if the coolant has completely drained.

Bit worried as the car has just spent 5 months being rebuilt and the last thing I want is an overheat.


996ttalot

1,931 posts

205 months

Monday 5th March 2012
quotequote all
Harris_I said:
OK, dumb question coming up.

Just had an engine rebuild on my 996 GT3 but it appears a couple of coolant hoses were weak. Result: total coolant loss whilst cruising on the highway at gentle revs in relatively cold temps (locally that's about 20C). It took me about a minute or two to find a safe spot to pull over and switch off.

Question is when the coolant low warning light comes on, does that mean the coolant is below minimum, or does it mean total loss? I ask because by the time I'd parked up and checked the level, it looked like it was completely drained. Water temp had stayed normal (say 80+) but I'm not sure I trust the gauge as I don't know what reading it's picking up if the coolant has completely drained.

Bit worried as the car has just spent 5 months being rebuilt and the last thing I want is an overheat.
Basically if it dumped all the coolant, then you need to be stopping asap. Not sure from what you described whether it was gradual loss or not. Coolant hoses should be replaced on full rebuild - known issue with dropping engine, especially on the main coolant hose.

Let us know how you get on. Hopefully you will be okay.

fioran0

2,410 posts

202 months

Monday 5th March 2012
quotequote all
below minimum, but how much below is then a guessing game.
if your light came on and you pulled over while you were still getting a temp reading that made sense you should be fine. when the coolant totally empties you see no coolant temp at all, and then a resuming of temp reading as the metal heats up and you are melting the engine.






Harris_I

Original Poster:

3,364 posts

289 months

Monday 5th March 2012
quotequote all
I would hazard a guess that it was a gradual loss since I didn't hear it hiss out as has happened to me in the past. I guess my main concern is whether it's possible for the engine to overheat if the water temp gauge had been reading normal for the journey, and stayed normal when the low level warning came on up to the point the engine was stopped.

Harris_I

Original Poster:

3,364 posts

289 months

Monday 5th March 2012
quotequote all
Ah ok, fioran0. That is actually quite comforting to know.

fioran0

2,410 posts

202 months

Monday 5th March 2012
quotequote all
The cooling system holds quite a bit of fluid, 23L on a cup with no heating so a bit more on the street cars.
The expansion tank thus represents quite a small part of the volume so a loss can empty this, trigger the light and still see you having quite a bit in there going round.
Obviously you don't want to just drive about with it like that but circumstances mean you often can't just stop.

If the gauge didn't start to drop then you should have still had a good volume in there and no probs at all I'm having to drive for a couple of minutes to stop


Harris_I

Original Poster:

3,364 posts

289 months

Tuesday 6th March 2012
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Thanks chaps. Workshop says I'll have the car back tomorrow. (Phew).