Boiling my head

Boiling my head

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Discussion

richardmadden

Original Poster:

7 posts

15 months

Wednesday 2nd January
quotequote all
Hi,

Apologies in advance if this is a daft question.

I was out in my 500 the other day when I saw the temp gauge had reached 110 degrees.

I immediately pulled over (into a pub car park - the only lucky thing that happened the whole day), popped the bonnet, turned off the engine (but kept the ignition on to keep the fans going).

The fans weren't running and soon steam and coolant started blowing through the expansion tank cap.

The car's in the workshop at the moment with the fault being traced. It runs fine (though I had it trailered there just to be on the safe side).

My question is - will I have done any damage to the head gasket, head and other pricey innards? It can't have been at that temperature for more than ten minutes (including the heat soak once parked up) but I tend to be a pessimist.

Thanks in advance!



baconsarney

8,696 posts

98 months

Wednesday 2nd January
quotequote all
A few years ago my fans failed, middle of summer and stupidly hot day, stuck in traffic in town, temperature rose really quickly and I steam through the bonnet vents (Chimaera 500) before I saw the temp gauge way past the 100... kept her running for another couple of minutes, lights changed and I managed to park up another 100 yards further on.... let her cool completely then did the remaining two miles before temps went mad again.... no damage it seemed, no changes anywhere, still good 5 years on... hopefully yours will be ok too thumbup

ianwayne

1,975 posts

205 months

Wednesday 2nd January
quotequote all
Sounds like otter switch failure. Shorting it out with the ignition on will test if the fans work or not.

phazed

17,064 posts

141 months

Wednesday 2nd January
quotequote all
The fan connection often fails from the wiring loom at the multipin connected to the fans at the bottom of the radiator. Just pull apart, clean and reassemble. Once apart if you have a multimeter you can check if there is power there when the engine heats up.

richardmadden

Original Poster:

7 posts

15 months

Wednesday 2nd January
quotequote all
Thanks all!

Baconsarney - your story is reassuring. I suppose that even though it's a thin-walled alloy engine, it was after all designed in the early sixties with fairly generous tolerances. I'll keep my fingers crossed but keep checking for mayo on the oil cap nonetheless...
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Classic Chim

8,625 posts

86 months

Wednesday 2nd January
quotequote all
Just remember in these lower temps you might get some condensation which will appear as mayo if the engines not running for very long periods, best to check after a good drive to make sure any natural residue has disappeared. If the head gaskets are ok you’ve got away with it id imagine.

richardmadden

Original Poster:

7 posts

15 months

Friday 4th January
quotequote all
Thanks Classic Chim. I'll give it a good run before I check for the dreaded Mayo. I'll also report back for the sake of the collective knowledge bank. Fingers crossed...

Classic Chim

8,625 posts

86 months

Friday 4th January
quotequote all
No worries, I learnt this from a fellow member on here and it’s absolutely correct, I often check for things like this and one morning a small bit of mayo,,, yikes then read what Sardonicus had said about winter driving and short journeys so went out and had a good run, Mayo gone.
That was a relief I can tell you biggrin

theholygrail

211 posts

105 months

Friday 4th January
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My 94 Griff 500 regularly sits at 110 regardless of driving conditions. Probably as much as it does at lower temps. I was reassured by them what services it that it appeared normal for my car. The fans work and nothing "bad" has ever happened so I've tended to ignore it. Having said that I might get them to check it again at its next service! Funny what you put up with in a TVR that you certainly wouldn't in a daily!

Classic Chim

8,625 posts

86 months

Friday 4th January
quotequote all
If you get Rovergauge you can check your dash gauge against the Ecu temp sensor easily enough, if my car sits running for say 1/2 hour stationary or slow traffic the gauge eventually gets over 100 but when I was at Powers having the Mbe checked over I noticed the lap top or Ecu temps were 89-90 the whole time, rock solid with fans coming on/ off every now and then.

Thats really the only way to be sure.

neutral 3

2,874 posts

107 months

Friday 4th January
quotequote all
Check that it isn't using water, I doubt water will get in the oil, if, like my one, it boiled over.
My Griff burst a hose and it boiled over.
It boiled over again the following year due to the rad developing a leak. Fitted another radiator and I noticed that it was using water.
It also boiled over for a third time @ the Dartford crossing due to the fans not cutting in. Still using water and noticed that it was down on power.
A compression test showed that it's down considerably on the two middle pots on the right bank. Will be sorting the head gaskets soon.


Edited by neutral 3 on Friday 4th January 22:23

RogerDodger

627 posts

31 months

Sunday 6th January
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I've taken both my V8s over 110 with otter switch failures. No issues at all as long as you shut down when you see it happen. Imagine how common it is with such dependency on one delicate component.

On my SeIeght , it had a racing water pump pulley that was too small for traffic. Previous owner, and me, frequently hit 110+ (more like 120) before gaining speed and cooling down . I had a new larger pulley made to cure this engine was perfect and revved to 6500 cleanly (4.3 with rodes lifters).

P.s just put a metal screwdriver across the otter switch terminals with igition on . If fans come to life then it's the otter.

richardmadden

Original Poster:

7 posts

15 months

Friday 11th January
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Hi,

I promised the group an update. Well, after an attempt by a local garage to fix the overheating (and another spectacular melt-down), I trailered it up to X-Works in Preston.

Heath from X-Works called today with the bad news. A leak-down test shows a 30% loss in cylinder five. The others are fine.

So it's looking like a head rebuild. Heath reckons the leaking head was the cause of the overheating, not a result: there are no leaks in the system and the thermostat and otter switch are performing fine.

I'm pretty sanguine about it. It's a relief to have the problem diagnosed, and I know X-Works will do a good job, giving me and any future owners peace of mind. The bank manager may not agree, but since when was TVR ownership a rational thing?