I had my SVA this morning which gave my engine its first proper work out. It seemed to be running very hot (around 100C).

My cooling consists of a vauxhall expansion tank mounted on the battery tray (as high as I can get it), filled with 7 pints of water and 3 pints of coolant. Anyone got any idea why it is running so hot?

Also I know that my carb is running quite lean (from SVA readings - 0.17% CO and 107ppm HC), so could this have an effect?

Cheers

Pete

Lean running engines do run hotter, try running it without the stat and see what the temp does then, it shouldn't get too hot as the stat won't be there to restrict the flow ti'll it's given temp

Jason

what rad do you have and do you have a thermo switch for it?

Also it is important to ensure you have enoughspace behind the rad to allow airfolw to take place and not encourage a build up of hot air behind the rad which will restrict airflow even further and further hinder the cooling process

Edit: By thermo switch do you mean the switch that screws into the rad or something else?

The rad is a 1.0 polo which has been used before so I'm sure that should be ok. It has a thermo switch but to be honest I don't know any details about it. However, when i ran the engine for about 20-25 mins in the garage the fan seemed to kick in at about 95-100 and cooled the engine down again. Since then I have moved the expansion tank higher up and can now actually fit more fluid in the system, but it seems to run hotter.

Maybe I'll get the carb sorted out and see how it goes after that - what sort of temperature should I be aiming for?

Pete

[Edited on 27/9/04 by scoobyis2cool]

Would it be worth fitting a cooler switch in the radiator? Looking at a few older posts it seems that some people use switches that cut in quite a bit earlier than mine, maybe I'll take it out and try and figure out exactly what temperature it kicks in at.

Pete

according to the accuracy of my temp guage i run at about 80-85 on a normal run. Crawling up hill ion traffic sees it pop up to the 95-100 mark but it soon comes back down again. If you give it a bit of stick you can see the temp go up a touch but nothing to wory about.

My fan cuts in at 97. When idling on the driveway with the bonet on the fan is not sufficient to actually cool it down (it stops it going higher). With the bonnet off it will cool it down and the fan will shut off then come on again at 97.

I have had all sorts of issues with my cooling. The rad (carpi) used to sit behind the inboard shockers and about 18 inches from the nose entrance! i used to have to run it with a fan on all the time. I used to spend more time with my eye on the temp guage than on the road - now i occasionally think ' oh i havent looked at the temp gauage for a few weeks - lets have a peek lol.

I ditched the capri rad and got a polo one and put it right in the front of the nose cone and put a pusher fan on it and i have never once had a problem with it in the last 2 years.

It sounds like the thermo switch you have in the rad is a bit high, you should be able to get a lower rated one to bring the fan on at a lower temp, the thermostat I was talking about tho is in the front of the block at the top, it stops the flow of water round the engine until it reaches a set temp then it open up and allows the coolent to flow to the rad, it is used to warm the engine up to running temp faster, itshould be in the housing that links the engine to top of radiator

Jason

Mine kicks in at around 95/100 degs so i reckon its normal,as deckman says it is probably a good idea to fit a different thermo switch.

Myself i'm going to fit a manual override so i keep the temp down in traffic.

Do you trust your temp guage? They can be notoriously inaccurate-especially leccy ones. Was the fan constantly on when it was at 100deg?

P.s. I wouldnt advise removing the thermostat-removal can actually cause overheating probs on some engines. At best, the engine might take ages to warm up...

As mentioned I can't guarantee that my gauge is accurate, although I bought the gauge and sender together so I would hope they are a fairly good match.

I think my best bet will be to fit a different switch, a manual override sounds like a good idea as well bob

Thanks for all the help,

Pete

my guage was pretty accurate when i got it and tested it in the pan of boiling water ,

I have fitted a manual override to mine so that i can pop it on if i know im going to be sitting in traffic before it happens.

Daft question, but do you have the flow of the water the right way round?. ie in at the top and out at the bottom?. (or which ever way it should be).

The Thermo switch data should be in the Polo manual if you have one.

You can buy a mechanical (capillary tube) thermostat from Farnel and RS components.
1-120Deg, fully adjustable for about £12.
RS Stock number 561-460
BUT... use it to switch a 30Amp relay and use the relay to switch the Fan, or you will burn out the contacts on the Thermo.
A lot of My Land Rover Mates have used these.

Pacet, Kenlowe and the like want £40 for their version of this. But they do have heavy duty contacts.
So whats an extra relay amongst friends?

Best Regards

Geoffw