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MG Midget and Sprite Technical - 4Life

Having a slight overheating problem so after checking the usual suspects and finding no problems, drained the system and filled up with 4Life hoping this would cure it. Seemed to work OK with the temperature staying lower than previously but developed a screech from the water pump. Tried everything to cure it and decided the only change I'd made was to use 4Life. Drained the system and refilled with water.The screech has now gone and the temperature problem has disappeared.

If I refill with 4life(I don't want to waste it, it was expensive) and the screech returns can I add a water pump lubricant to the radiator to cure the screech or should I be thinking of replacing the water pump.







J Cowley

Hi JC,

Don't know but would be helpful if you stated either model, year or engine.

I am a 1500 guy for instance.
Dave Squire

I remember hearing about something like this a few years back, albeit in the context of marine diesels which started squealing after they had been switched to a waterless coolant.

The eventual consensus was that it wasn't lack of lubrication causing the noise from the pump. Water is a poor lubricant after all and the pump bearings are sealed "lubricated for life" items. So the general view seemed to be that it was most likely caused by cavitation in the pump, owing to the different characteristics of the new coolant.

Evidence of this was seen as micro-pitting at the vane roots of the pump rotors, which is a sure sign of cavitation.

JC I can't say for sure if this is the cause of your problem; it's just a possibility. As you have reverted to water and the screech has gone away it seems to argue that the pump is okay and that lubrication is not likely to be the issue.

As for additives I'd suggest consulting the manufacturer of 4life.

But as the cooling is good and there's no undue noise, I'd leave well eanough alone personally.

Good luck.
Greybeard

4Life isn't a waterless coolant. It just comes ready prepared. I have used it for years in my MGB V8 and I have no complaints. The frost protection is fine and the high boiling point is a definite advantage in a V8! Also the indicator in it gives an indication of impending problems like head gasket failure. If it changes from red to yellow you need to find out why. I've not encountered any water pump problems over 24000 miles.
Mike Howlett

JC
Interesting. Just a thought. When you originally drained down the system to load up the 4life, could that have unsettled a blockage in the water jacket, so that there was the some sludge catching with the water pump when you loaded the 4life, making the noise? And when you flushed it all out again, that got rid of it for good?

Personally my view is (as others have rightly told me) if you have an underlying overheating problem you need to resolve that rather than mask the problem with some other "solution". And maybe, if the first para above is right, you have now done that?

Good luck , Graham
Graham V

It's a 1974 Mk 3 1275. Did a longish run yesterday with no sign of a screech until I was about to put it away, I revved the engine while stationary the screech returned.
I suspect the water pump bearing. The 4life was a red herring.(No pun intended)
J Cowley

It isn't the fan belt being a bit slack is it? They can screech mightily if they slip.
Mike Howlett

Beat me to it Mike. It's a good possibility. Even when they're tight they can still squeal when they get old and worn, when the vee profile gets shiny. One way to check is to run the engine with every electrical load on you can. High beams, hazard lamps, wipers, radio, the lot. If it starts squealing like that (even if you have to rev it to provoke the squeal) you've probably hit on the problem.

I agree though that checking the pump bearings is a good move, as is having a good feel of the alternator bearings while the belt is off.
Greybeard

Thanks for your help guys. Bought a replacement fan belt , measured it and found it was 4mm wider than the one fitted. I don't know why it didn't occur to me, that although looking perfect, fan belts wear and therefore sink further into the pulleys. This, coupled with the fan belt having very shiny sides caused it to slip and screech.
J Cowley

Well done, JC. Better than buying a new pump :-)
Greybeard

This thread was discussed between 17/07/2015 and 20/07/2015

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