Coolant overheating

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Dano41
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Coolant overheating

Post by Dano41 » Fri May 25, 2018 8:11 am

Hi my 1999 406 diesel has started overheating at times 95c and when I turn the heater to warm air it progressively got cooler and cooler until now only cool air comes out.I have had to top up the coolant regularly recently because there is a small leak at water pump.Any ideas what it might be,could the water pump have failed completely,how do I test that the water pump is working?

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steve_earwig
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Re: Coolant overheating

Post by steve_earwig » Fri May 25, 2018 9:05 am

You'll have to investigate the water pump leak, it may be finished, it may just need a gasket (although it would be silly not to replace the pump while it's off. And timing belt, obv.)

The overheating/cold heater is almost certainly air locks in the system, caused by the drop in coolant due to the leak. You could bleed the coolant but it'd only be bailing out the leaky canoe.
Talking bollocks sin©e 2007

2004 D9 2.0 HDi 110 Estate lhd VF38ERHZF81657352 - sold but being very well looked after.
1991 Yamaha TDM850 - fuel leaks galore!
2008 Toyota Recall4 2.0 VVTI ATM LHD JTMBH31V90D007261 - flimsy piece of crap.
1953 Matchless G3LS - Can somebody stand by with an extinguisher?

PeterN
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Re: Coolant overheating

Post by PeterN » Fri May 25, 2018 10:40 am

Not wishing to be pessimistic but the low water level could have caused the head gasket to fail unless you have always kept it topped right up, this will cause the system to pressurise and blow the coolant out of the filler/overflow pipe. If its been running for any length of time without antifreeze this can corrode the gasket and also cause it to fail.

Peter

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mjb
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Re: Coolant overheating

Post by mjb » Mon May 28, 2018 11:32 am

Could also be a failed thermostat
<steve_earwig> I think this forum is more about keeping our cars going with minimal outlay than giving our cars more reason to go bang

Dano41
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Re: Coolant overheating

Post by Dano41 » Fri Jun 01, 2018 9:49 am

Thank you for the replies.The problem was the thermostat.

PeterN
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Re: Coolant overheating

Post by PeterN » Fri Jun 01, 2018 10:49 am

Good, pleased for you.

Peter

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steve_earwig
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Re: Coolant overheating

Post by steve_earwig » Fri Jun 01, 2018 11:54 am

Heavens, so mjb was spot on :shock: And this makes the water pump leak?? :?

Ah well, good news it's fixed without being something major.
Talking bollocks sin©e 2007

2004 D9 2.0 HDi 110 Estate lhd VF38ERHZF81657352 - sold but being very well looked after.
1991 Yamaha TDM850 - fuel leaks galore!
2008 Toyota Recall4 2.0 VVTI ATM LHD JTMBH31V90D007261 - flimsy piece of crap.
1953 Matchless G3LS - Can somebody stand by with an extinguisher?

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