Overheating

[Tom1]

I have a 72 and it started overheating today. It goes into the red while I'm at a stop light or driving slowly. The needle starts going down if I rev it at the light or start driving faster. The radiator is full and the heater is blowing hot. where should I start?

Thanks in advance.

[Chamonix72]

How tight is your fan belt? If it's loose, your water pump may not be turning properly at idle. Alternatively, it may be your water pump is bad.

[Tom1]

There has been a new strange metallic sound coming from the front for the last week or so. Belt is on there tight.

[Grover]

So is the fan operating?

[RandyMolson]

There has been a new strange metallic sound coming from the front for the last week or so. Belt is on there tight.

Makes me think mayhap the impeller cracked off inside the water pump.

[Tom1]

radiator fan and cabin fan are both running.

[02for2]

Sorry to say that it sounds like an impending Waterpump failure from either a disintegrating seal, impeller or impeller vanes.

Best to tackle it now because if the impeller is disintegrating by bits, these could lodge in critical passages reducing flow once a new pump is installed.

I'd carefully remove the existing pump, keeping all the little bits of pot metal you may find (these were the impeller), and try to piece together the impeller and it's vanes from the bits, that will tell you if you have any unaccounted for bits still in the block or cooling system.

Cheers!

[Tom1]

Cool, a new project. Funny thing is I've been having cooling problems the the westfalia as well. Guess everything has to happen all at once.

[c.d.iesel]

have your present radiator RECORED

[TobyB]

It's not the radiator. Otherwise, it would heat worse under load.

Here's an odd one from the Nissan camp... The flange for the fan's just

pressed onto the shaft for the pump, and I guess it's possible for it to come

loose. Or the impeller could've come loose.

Otherwise, it SOUNDS like your fan's not working. But that's too easy.

hth

t