Boiling my head

Boiling my head

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Discussion

richardmadden

Original Poster:

26 posts

24 months

Wednesday 2nd January
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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

9,124 posts

107 months

Wednesday 2nd January
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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

2,491 posts

214 months

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

phazed

18,238 posts

150 months

Wednesday 2nd January
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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:

26 posts

24 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...

Classic Chim

9,455 posts

95 months

Wednesday 2nd January
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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:

26 posts

24 months

Friday 4th January
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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

9,455 posts

95 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

233 posts

114 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

9,455 posts

95 months

Friday 4th January
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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

3,647 posts

116 months

Friday 4th January
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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

1,412 posts

40 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:

26 posts

24 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?


richardmadden

Original Poster:

26 posts

24 months

Sunday 17th March
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An update:

The car is now back from X-Works better than ever.

Turns out that at some point in the past, the head bolts hadn't been torqued to the right setting. Also, according to Heath, the bolts looked like they'd been re-used.

While the heads were off, the dreaded premature camshaft wear was also spotted. It was replaced and everything returned to factory spec. I now have a used camshaft as a bookcase ornament.

And, a couple of Mr. Lucas's electrical gremlins aside, a very nice summer's motoring ahead. Touch wood...




wat51901

12 posts

3 months

Saturday 13th July
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Hoping for some advise on a similar issue with my Griff 500 just recently bought as a project car. Replaced the leaking radiator and fitted a new water pump and high flow thermostat as matter of course refilled the coolant system from the swirl pot and filled the expansion bottle up to about half way. Ran the engine up but noticed a lot of air/bubbles coming up through the expansion bottle to the point that it starts to overflow so fitted the cap back on and continued to run the engine the car gets upto 100°c on the gauge fans cut in and heaters inside the car blow really hot then the temp climbs to 110°c, then I start to panic and decide to turn it off. Does this sound like head gasket issues or am I not bleeding it up right?

richardmadden

Original Poster:

26 posts

24 months

Saturday 13th July
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I'm by no means an expert, but I did a lot of reading when I had my issue.

There's a quick check any garage can do. It's a chemical test for hydrocarbons in the water. If they're present, the gasket's likely shot. It's pretty cheap and easy. A leak-down test will then tell you for sure.

Needless to say, if the heads do need to come off, you're best having the work done by a respected TVR or Rover V8 specialist. There are many worse things that can happen and you'll have much more confidence in the car afterwards.


Andav469

924 posts

83 months

Saturday 13th July
quotequote all
richardmadden said:
I'm by no means an expert, but I did a lot of reading when I had my issue.

There's a quick check any garage can do. It's a chemical test for hydrocarbons in the water. If they're present, the gasket's likely shot. It's pretty cheap and easy. A leak-down test will then tell you for sure.

Needless to say, if the heads do need to come off, you're best having the work done by a respected TVR or Rover V8 specialist. There are many worse things that can happen and you'll have much more confidence in the car afterwards.
I used the same kit to diagnose a head gasket failure, very easy to use, the fluid in the pic was blue, it turned yellow in seconds, confirming there were hydrocarbons in the coolant I.e. headgasket failure


Hedgehopper

1,412 posts

190 months

Saturday 13th July
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You don't mention whether or not you have bled the system via the radiator bleed screw. You can also bleed the system via the blanked off hose adjacent to the oil filler cap. I have found in the past that repeating the bleeding of the system after a few hundred miles can help.

Colin RedGriff

2,420 posts

203 months

Saturday 13th July
quotequote all
wat51901 said:
Hoping for some advise on a similar issue with my Griff 500 just recently bought as a project car. Replaced the leaking radiator and fitted a new water pump and high flow thermostat as matter of course refilled the coolant system from the swirl pot and filled the expansion bottle up to about half way. Ran the engine up but noticed a lot of air/bubbles coming up through the expansion bottle to the point that it starts to overflow so fitted the cap back on and continued to run the engine the car gets upto 100°c on the gauge fans cut in and heaters inside the car blow really hot then the temp climbs to 110°c, then I start to panic and decide to turn it off. Does this sound like head gasket issues or am I not bleeding it up right?
Did you bleed the radiator? There should be a bolt in the top of the rad you can remove to allow the air to escape while you fill the system. Usually on the offside top corner.

Also it can take a few attempts to get all the air out of the engine due to the height of the swirl pot in relation to the engine. On the nearside of the engine, tucked under the plenum there should be a pipe with a bolt stuffed in the end which can be used to allow air to be bled from the engine.

Another tip is to put a large funnel in the swirl pot so that as the engine warms it can expand into the funnel and that lets the air bubble out, you might need to top it up a few times.

Steve_D

12,538 posts

204 months

Sunday 14th July
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Bubbles coming out is why you are bleeding the system so in itself is not an issue.

You say the temp went to 110 but you do not say if you had both caps on.
Water boils at a higher temp when under pressure so on a car cooling system the pressure cap is around 13psi which will allow the coolant to go to 118 degrees C before boiling. If you had one of the caps off then your coolant would be boiling and producing bubbles.

Steve