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Cloud of Steam from under bonnet..

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avante101

New member
Hi
I have an 87 2.5 NA 944. As I was pulling into the drive something under the bonnet seemed to vent steam quite violently. It seemed to be coming from the front of the engine on the drivers sidenear the top, afterwards there was a very small puddle of coolant under the car. Revs were just above tickover when it happened and I had been poottling around before hand so the engine was not especially hot or stressed. Temp and oil pressure were all normal before hand and it was running fine. Started up again ok afterwards.
I had a good poke around and could not find any split hoses or anything else obvious. Did not loose much coolant either.

Is there any sort coolant pressure relief valve which could have operated?

I am a bit stumped as to what happened, and slightly concerned that this could be head gasket issue.

Any advice would be greatly appreciated!
Thanks
Barnaby
 
I had a similar thing and it turned out to be the cam cover gasket leaking and dripping oil onto the exhaust, when sat on tick-over you would get a sudden plume of white smoke pour out every 2-3 minutes which was very embaressing when stuck in a traffic jam!
 
Could have been coolant escaping from the header tank. Had you recently topped it up?

(In terms of traffic jam embarassment, I had a number of Mk1 Golf GTi's, and lost the idle bleed screw from one of them once. It meant it idled far too fast, but made a noise akin to a football referee blowing his whistle as hard as humanly possible ... and was loudest at idle! Driving that through central London traffic jams got quite a number of odd looks!)


Oli.
 
when that happened to my Lux it turned out to be a tiny split on the underside of a small hose pipe near the top front of the head which goes to the pump/thermostat housing. I think it may be the return off the cylinder head ? . It is about 4" long and has is 3/4" one end and 1" dia the other. Its the highest part of the coolant system.

Might be worth doing a leakdown test on the coolant system in case you have the start of a small head gasket failure and the coolant system is being pressurized by compression gasses. Also check that your fan is switching on after a long run and you switch the engine off
 

ORIGINAL: avante101

Hi
I have an 87 2.5 NA 944. As I was pulling into the drive something under the bonnet seemed to vent steam quite violently. It seemed to be coming from the front of the engine on the drivers sidenear the top, afterwards there was a very small puddle of coolant under the car. Revs were just above tickover when it happened and I had been poottling around before hand so the engine was not especially hot or stressed. Temp and oil pressure were all normal before hand and it was running fine. Started up again ok afterwards.
I had a good poke around and could not find any split hoses or anything else obvious. Did not loose much coolant either.

Is there any sort coolant pressure relief valve which could have operated?

I am a bit stumped as to what happened, and slightly concerned that this could be head gasket issue.

Any advice would be greatly appreciated!
Thanks
Barnaby
Click to expand...
have a look at the cooling system bleed nut as this can come loose over time

its on the thermostat housing i think

its in the manual in the "renewing your coolant" section if its not on that housing
 
Nice one, I think it is the hose which peanut mentions. It looks a bit tatty and is probably the original.
Won't be able to change it untile
next weekend.
 
Mine failed once in the middle of nowhere. I just popped into a local garage and they scrounged up a short piece of used hose which was one size it worked fine with jubilee clips till I got a replacement months later. It may be a bit tight on one end or a bit loose on the other depending on what you scrounge .
The original has a slightly different dia each end
 
Could be a crack in the radiator where the plastic end tanks meet the core. That happened to me once. You could only see the steam when the car was hot.

Not expensive or difficult to replace though. I think I went with a euro car parts one for about £90. I fitted it in an hour on the driveway with no previous experience and a pretty poor selection of tools.
 
Have had this happen to a couple of cars and neither have been coolant related.

I had an MGB V8 that used to spit oil past the dipstick tube onto the exhaust manifold. Cured that by re-sealing the dipstick tube with a new rubber seal.
Also had a jag with a pin hole in a the power steering pipe - when under load it would fire a fine jet of PAS fluid at the exhaust.
 
Is there a pdf somewhere on here which has exploded dwgs and part numbers? I can remember seeing one, but I can't find it now.
Going to take the small piece of hose off to check for a split and might as well put a new one in regardless.
Had a quick look and coolant level seems a little low. Wifey was nagging so couldn't run for long enough to get hot and presurise system to really locate any leeks.
 
There is a parts breakdown on the Porsche website - search for classic models.
Other than that you want to watch them leeks - they keep putting soil and all sorts in your engine [;)]
 
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