hmm...me thinks that is not a good idea...

Silly question: what coolant are you using and what concentration of coolant?

Do you have your undertray fitted? fans working properly etc..

The coolant has been swapped so many times i've no idea. Have tried every variable of coolant though. Right up to nearly 100percent. Fans are fine, no undertray.

100% Coolant, bizarrely, *can* cause overheating. Far better at standard mix: 40% water/coolant, or 50% if you expect a really harsh winter.

Water wetter can help with high rev temperatures, although I suspect you still have an issue somewhere else, the main reason for asking is in case you were just using water which is pretty poor at reducing under-bonnet temperatures.

Mike - as said, try again to clean out using the hose but make sure the water uses the reverse path. There's no use in flushing it out through the 'normal' way as if something is blocking a pipe or hole, you'll only 'squash' it against the narrowing pipe.

Also make sure to 'test' as many separate circuits as possible - just the radiator, the engine block, the heater matrix,... and definately bypass the thermostat.

what pipe would you have to stick the hose in to make the water flow in reverse??

Not done it on the Coupe (didn't do too much really on the Coupe), but did it on the HGT where someone recommended that to me as there was a blockage there. Waterpump: inlet is in the center, so I inserted the hose down that pipe and also disconnected the inlet of the radiator. Didn't go further as it turned out to be 'stuff' near the inlet of the radiator.

Just thinking further (or 'back' really)... the reason why the waterpump vanes got torn off. Might just have been dirt / ... in there or extra resistance because of the decreased flow.

Did a bit of a search on Google and it comes up with loads of descriptions how to flush, most of them pretty much the same. Which probably means the common parts are pretty 'okay'.

http://www.merkurencyclopedia.com/Cooling_System/cooling_sys_clean.html
http://www.econofix.com/radiator.html
http://peugeot.mainspot.net/tips/cooling_ff.shtml
http://pontiacbonnevilleclub.com/forum/viewtopic.php?f=45&p=157920
http://www.automotiveforums.com/t461426-best_way_to_flush_the_coolant_system_.html

Matt are you 100% sure all the water hoses are OK ?

One of them could be collapsing (even partially) at very high temps causing a flow restriction.

Good luck sorting this out mate.

You may have something there Mike. But surely with all the work thats been done to the car in the last, what? 10 months the hoses must be quite new.

Good shout Mike. The coolant hose of death is new but the others are old so they might be worth replacing. I also have a 2 part coolant system cleaner which i'm going to try, but i need to bypass the thermostat somehow (can i just use a t piece??) I could do with getting hold of a silicone hose set if anyone has one they don't want!-

Matt, the club has some sets of silicone hoses for sale. Talk to Porkypaul.

Many many moons ago, I had a similar problem which turned out to be a radiator hose which had delaminated internally - at low revs (and therefore flow) it was fine, but once the flow rate increased it folded into itself and everything overheated.

How did you diagnose it barnacle?

Don't recall; it was my father's car and thirty years ago. It may have been as simple as finally noticing that one of the pipes went floppy when hot.

Ok thankyou. Might be a good idea to replace them all as a matter of course anyway.

fairly cheapish fix matt - at least then you can eliminate them as the issue

I took my turbo coolent feed of today,it was on its way out.Thats on a 53,000 coupe.Thats a very busy area up there by the stat etc.

Whats the latest then guys?

Matt is staying at my house next friday and wont be leaving until i sort it .

Brand new Intercooler installed;



While at John's, it's also going to get a new oil cooler, radiator, engine flush and a new silicone water hose kit.

If that doesn't cure it, nothing will

Ah if that don't cure it, fit some snow chains and it's off to Lapland. Problem cured

gentlemen,it will be sorted.

Just incase anyone is still interested;

I went down to Midlands Car Servicing on Friday and had a new radiator, silicone hose set and oil cooler installed. (And Aux belt)

The coolant hose of death was very soft, and could quite easily collapse under suction. (Despite being brand new from Fiat 6 months ago)

I have also noticed that recently my temperature gauge has been bouncing round allover the place, as if there was air in the line. It has now started acting as normal again.

Also, when left idling, with the expansion tank cap off, the coolant would boil over and spill out the tank.
Now these jobs have been done, the coolant no-longer boils over on idle, which can only be a good thing.

At this point i have a suspicion that the coolant hose of death was to blame, it may possibly have been kinked or bent, or collapsing under load.

I have also installed another water temp sensor in the coolant hose of death, which gives a very accurate account of whats going on.



Only thing left to do now is get on a track day and test it.

good luck with it Matt, if anyone deserves a good run you do

Haven't had a fully working car in nearly a year now Steve!

Fingers crossed, I am still aiming to get us all on track for the battle royale

Your going down Flea!