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I know the weather is hot but...

PostPosted: Thu Jul 20, 2006 10:46 am
by Robbie693
... I'm sure my last car never ran this hot.

Temperature gauge never goes below 90 (or whatever the tick mark on the gauge is between 85 and 120) and if I'm held up it goes up to just below the red.

The fan doesn't cut in till about 100-110 deg. and even with it running it doesn't cool to less than about 100 deg. What temp should it begin to operate?

More importantly, why is it running so hot? I fitted a new thermostat, replaced the 7psi rad cap with a 10psi, flushed out the cooling system with the garden hose - all to no avail. The rad is a 3 row unit, standard (small) size for a late '72 Plus 2.

I have heard all the recommendations for fitting a bigger rad but can't afford it at the moment and would have thought that I could at least get this one to run at the same temp as my old car which also had a standard system.

Any ideas folks?

Re: I know the weather is hot but...

PostPosted: Thu Jul 20, 2006 12:01 pm
by tdafforn
Check the Gauge is reading correctly!
Tim

Re: I know the weather is hot but...

PostPosted: Thu Jul 20, 2006 12:05 pm
by Robbie693
Thanks Tim, how can I do that?

Re: I know the weather is hot but...

PostPosted: Thu Jul 20, 2006 1:06 pm
by john.p.clegg
Robbie,

All you need to do is nip down to your local B & Q or plumbers merchants and pick up a central heating thermometer (which should be spring fixing) and slap this on your thermostat holder, this should then give you a good reading of your engine temperature, which you can check against your gauge.

John :wink:

Re: I know the weather is hot but...

PostPosted: Thu Jul 20, 2006 1:25 pm
by Robbie693
Cool 8) , (or maybe not in this case!)

Thanks John

Re: I know the weather is hot but...

PostPosted: Thu Jul 20, 2006 6:00 pm
by Matt
Hi Robbie

If you have a three core rad, standard size, then that should be fine. I have had the same problem as you in the hot weather so I added a ajustable thermostat and set it to kick in at 80 deg, my car never gets hotter than 85 deg now.

Matt

Re: I know the weather is hot but...

PostPosted: Fri Jul 21, 2006 3:48 pm
by chicagojeff
also, make sure you are getting circulation throughout the radiator. Feel to make sure the send and return hoses are hot, and the whole radiator is warm. I had some high temp running that was caused by a blocked heater valve, and a less than adequate water pump.

Re: I know the weather is hot but...

PostPosted: Fri Jul 21, 2006 5:05 pm
by Robbie693
Thanks guys,

The system is uniformly hot so I think my circulation is ok, the incorrect gauge could the problem as the fan cuts in so late (or appears to), so I'm off to buy a thermometer and see what it tells me.

Let you know what happens.

Re: I know the weather is hot but...

PostPosted: Fri Jul 21, 2006 8:22 pm
by Roy Gillett
Also check that the fan is blowing the right way. I had some overheating on a Rally in early June and found that the fan was moving air in the wrong direction! Not really a problem if it cuts in in stop / start traffic but I boiled on the rally after 4 minutes high revs in second on a hill climb. In these circumstances the fan was acting as a buffer to natural air circulation. I just had to reverse two wires on the fan to get it spinning the right way.

Roy