Overheating problem - help if you can?

[Scooby P1]

Hi all

Bedford was very hot today and I wasn't the only Noble with an overheating issue.

I recently had the pro alloy header tank fitted by a local garage but today it kept boiling over. By the end of the day after 3-4 laps the temperature gauge would suddenly shoot up to 120 and by the time I nursed it back to the pits the header tank level had gone below the sight glass. This happened at least three times.

I tried to bleed the system by hand squeezing the fat pipe entering the radiator on the drivers side with the header tank cap off. This seemed to get the return pipe in the tank circulating the water, i.e. the air lock had been got rid of but this didn't solve the problem.

Was it simply because it was a hot day or something more sinister?

After driving back to London, temp gauge stayed constant but the tank was fairly empty again.

Any ideas how to solve this problem would be welcome?

Could it be related to an electrical issue? There's certainly a bad earth somewhere as the battery doesn't last longer than two weeks without being on charge and all the dials stopped working briefly this evening but turning off and starting again solved that.

All rather annoying as was lapping very fast but the car kept overheating.

Thanks.

[Scooby P1]

I had to attach a pipe to the overflow to stop it spraying all over the place it was spitting so much out repeatedly!

Regretting fitting it now as never had any heating issues before this......annoyed I left the original header tank at the garage to be thrown away.. Only got the PA one so I could have it on black and it look better!

[Scooby P1]

Anyone got a link on where to get the high pressure cap from?

What a stupid design. Upgraded equipment is worse. Not a fan of that mentality.

Once the cap is upgraded, will that stop the temp suddenly jumping to 120?

Bear in mind this has never, ever happened before this bloody PA tank was fitted!

[Scooby P1]

Standard radiator mate.

But I've never had an overheating problem ever before yesterday.

And I have been on fairly hot track days before. And been stuck in huge traffic jams in 30+ degrees and its never waivered a degree over 85.

The standard expansion tank has no overflow outlet and that's where water pours out of my new PA one. Had to fit a hose to point down so it doesn't spray all over the engine bay!

[Scooby P1]

2.5bluenob said:

this is what i use
http://www.demon-tweeks.co.uk/performance/radiator...

What psi spec do I get?

[Scooby P1]

Totally agree with Jarcy.

I have never had this problem before and remember going on a very hot track day a few years back when I was sweating there and back let alone on track and NO temperature fluctuations at all.

4 laps was my limit by the end and the temp would flash up to 120, I could limp back and find the header tank below the sight glass and then left for 45 mins each time with clam up and in a garage so not even in the sunshine!

My rad is standard, but had new water pipes last August as the old ones were perishing, and now new header tank. Definitely going to try a new cap.

Not going to change the rear mesh as I like not being able to see my black intercooler (Jarcy's is silver before anyone says that's why the car overheated!) but would an oil cooler be a sensible mod? I have no idea what my oil temps were.

Only other car that suffered our problem was a white subaru. Everyone else kept lapping all day.

How do the guys get on in sunny countries with Nobles?!?!

[Scooby P1]

TuxMan said:

I think any std Noble will suffer from the same problems you guys had on Saturday !! the std cooling is very marginal I would suggest you upgrade too :

Pro alloy radiator
heat wrap exhaust complete inc down pipes
front or sidepod mounted oil cooler with M400 pods
removable number plates
high flow Jetstream rear mesh
high pressure cap for expansion tank
if you want too keep std rad Adrian's turbo rad will help
water Meth injection .


I have no problems in very high temps running lots of power !!

have you checked the Rad to make sure its not full of crap ? flies ect .

The rad is quite pricey, but maybe this would be a good idea.
Perhaps Jetstream can wrap the exhaust for me?
Don't like the high flow mesh or the M400 side pods so will avoid these.
High pressure cap being ordered now!

It seems pro alloy themselves fit an extra pipe off the overflow of their header tanks like I had to: http://www.proalloy.co.uk/cgi-bin/sitewise.pl?act=...

Does the coolant make any difference? Not sure what coolant i had in mine.

The good news is everyone is saying it's related to cooling and not a head gasket at the moment.....

[Scooby P1]

Went to check on my car last night and the header tank was very low, below the sight glass.

Filled it to half way up the sight glass, started the car and it instantly seemed to fill the sight glass.

Didn't bother letting the car warm up but mine is definitely behaving strangely.

How does one make sure there are no airlocks in the system? Taking the pipe off the rad or letting the car tickover with the cap off the header tank I have tried but not sure if either is 100% effective.

Should the pipes going into / out of the radiator feel solid or reasonable squishy?

[Scooby P1]

Looking to improve the pressure at which the header tanks throws its toys out of the pram but it seems the 21-25psi version of this will take up to 24 days to deliver:

http://www.demon-tweeks.co.uk/motorsport/radiator-...

Would it make sense to wait for that or would the 19-21psi version be ok?

Also, how much is an oil cooler + fitting?

Thanks guys

[Scooby P1]

I have the 21-25.

But the damage has already been done. Seems my overheating car has cooked the starter motor relay and now it won't even turn over.

Wonder if this race cap would have prevented that?