Overheating

[adequatespeed]

I have noticed that a few people have talked about overheating problems (ultimaandy), particularly in heavy traffic. The meahanical pumps turn too slowly to give a good flow of water along the long pipe runs and small radiator in an ultima.

One suggestion is to use an electric water pump. (not one of these £80 jobs you can get in demon tweaks)

I am using a CSI pump that will push about 30 gallons per min. I can not say it has cured the overheating problem on my car but up to now it has never overheated. They have the added advantages of looking superb and not robbing any power as they do not need any additional belts and pulleys.

Also you can use them with the engine stopped to avoid heat soak and cool the engine off quickly.

www.csiperformance.com


I did have a problem with the factory expansion bottle though. It is woefully too small and used to hiss like it was going to pop. I have changed it for a 2L ali tank and had no problems since.


Any other views?

[Sieze]

I discussed this Ted last year as using an electric pump made alot of sense to me.

Unfortunately the factory told me that all the problems they have had with cooling on customer cars have had electric watrer pumps fitted. He also questioned their longterm reliability. I suggest contacting them.

[ultimaandy]

I never actually had any overheating problems, however I did see over 100C in heavy traffic on a hot day.

This was before I fitted the oil cooler and since then its behaved quite well.

Also the recommendation is that in hot weather you turn your tickover down to 750rpm.

I must admit though that I have seen high oil temps on the track which strenthened my view to use good oil and change regularly.

[james]

I used to have all sorts of problems with my Mk4 overheating on the track (the Mk4 has the alloy floor extending all the way to the back of the car, which encloses the engine compartment and limits air flow even more than the GTR). I found that the addition of a couple of extra oil coolers, and a high capacity ally rad pretty much cured the problem though.

I understand from Ted that with the GTR having the floor section removed, overheating isn't a problem these days. You just need to make sure that you spec the cooling system up to a level that will cope with your engine. The addition of a couple of hundred extra horsepower will possibly require the addition of an oil cooler to get rid of some of that heat

I've considered removing the rear floor section on my car, but the positioning of various oil pipes (most especially the gearbox cooler take off which sticks out the bottom of the gearbox) prevents me from doing it, as I'd rather have to put on an additional cooler than lose my oil when a foreign body breaks a pipe.

[adequatespeed]

Not heard of any problems with a decent electric water pumps like the CSI one. Mine has been going strong for 18 months and still sounds sweet.

I would have reservations over the cheap plastic things.


Also I have a decent size oil cooler fitted too

I have fitted a water pump fail light as part of the dash system which warns in the event of the fuse going.

Alternatively you could take the route of most production cars and link critical items to things on the dash e.g. water pump & rev counter run from the same fuse. (rev counter has a second fuse of lower rating) so if the pump goes the rev counter does too.


I had this on an old merc where if the cooling fan clutch failed the rev counter stopped working.