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803 running hot

Posted: Sat Aug 16, 2014 10:09 pm
by frantam93
Hi,
My 803 is running hot, the engine is running really well even after not having been run for 22 years. Water in rad won't circulate, is there any way I can check if the water pump is serviceable with out removing it. Looking in the rad while the engine is running I can see the water moving from left to right so thinking the pump is ok. I've flushed the rad but after going for a 15 min drive the water in the bottom of the rad is still cold and the top is very hot. I've flushed the rad, it looks to be in good condition and the flushed water was rusty but nothing out of the ordinary so thinking the core is ok. There isn't a heater to worry about so it should be simple also a New thermostat was fitted. Any ideas ?

Re: 803 running hot

Posted: Sat Aug 16, 2014 10:16 pm
by bmcecosse
Rad hot at top and cold below is correct! It's cooling the water..... Is it boiling up ? Most likely is blocked water passages in the rad and block. Keep flushing...... perhaps try some 'Rad Flush' - or some have used drain cleaner with success - but don't leave it in there with (or without!) engine running for more than 10 minutes - then drain and flush very well.

Re: 803 running hot

Posted: Sat Aug 16, 2014 10:48 pm
by frantam93
Rad hot at top and cold below is correct! It's cooling the water..... Is it boiling up ? Most likely is blocked water passages in the rad and block. Keep flushing...... perhaps try some 'Rad Flush' - or some have used drain cleaner with success - but don't leave it in there with (or without!) engine running for more than 10 minutes - then drain and flush very well.
Not boiling just to hot to touch. I'll give it another good flush and see how it goes. Cheers

Re: 803 running hot

Posted: Sun Aug 17, 2014 12:02 am
by mike.perry
If the rad core is blocked flushing it out with a hose may not may not unblock it. Best to get it professionally cleaned and checked especially if it is a tall header tank type which I imagine is difficult to replace

Re: 803 running hot

Posted: Sun Aug 17, 2014 7:09 am
by bmcecosse
Hot to touch is fine then - I don't think there is anything wrong - but more flushing won't do any harm.

Re: 803 running hot

Posted: Sun Aug 17, 2014 10:06 pm
by frantam93
Hot to touch is fine then - I don't think there is anything wrong - but more flushing won't do any harm.

Flushed the rad and block this morning then went for a 25 min run out. All working fine radiator hot at the top and now warm at the bottom.

cheers :D

Re: 803 running hot

Posted: Sun Aug 17, 2014 10:24 pm
by bmcecosse
Great success ! Don't forget to put in some anti-freeze before winter arrives.