Screeching noise help!!

[Porkchop]

Originally Posted by Stephen Edwin

PorkChop - have you tried adding a water pump lubricant to the cooling system? "In the olde days" that additive was cheap and readily available and it might still be available now.

Thanks for the tip, I've had a bit of a look around and the general consensus is that if the coolant (carrying the lubricant) is able to come into contact with the bearing then your pump is knackered. They are apparently "sealed for life" bearings and therefore can't be lubricated post-manufacture, that doesn't mean that it ISN"T the bearing that's ruined of course....I'll try Clifford's isolation test and hopefully get to the bottom of this!

[Derek UK]

"I wonder if the rear bush in the alternator could be dry although I seem to remember giving it a fill with WD40 whilst on the bench."

WD-40 isn't a lubricant. It quickly dries out and thereafter is no use at all.

[Porkchop]

Originally Posted by Derek UK

"I wonder if the rear bush in the alternator could be dry although I seem to remember giving it a fill with WD40 whilst on the bench."

WD-40 isn't a lubricant. It quickly dries out and thereafter is no use at all.

Be that as it may (I might have used light machine oil can't remember) the noise was unabated immediately after fitment to the vehicle, even WD40 doesn't evaporate quite that quickly....

[Porkchop]

Originally Posted by Porkchop

Thanks Clifford, I'll try the isolation method once I've had breakfast. I replaced the brushes in the alternator myself a few months ago as it was starting to fail and had the local auto electrician do the rest of the work as I couldn't source the correct bearings hoping that it might have been the source of the noise but again after reassembly zero result/change.
I haven't checked out the water pump but am intending to do a timing belt change asap as it's interval has come around. I've got a good quality Hepu pump sitting around ready to fit including new seals plus new oil seals (haven't done a timing belt before so slightly nervous!)

I wonder if the rear bush in the alternator could be dry although I seem to remember giving it a fill with WD40 whilst on the bench.

Will report back....

Ok, I've removed the PS belt and zero change so at least I've eliminated it from the equation. I've now removed the two matched belts from the water pump and alternator and hey presto no more noise! I'm not sure how to isolate the individual components (alt and water pump) i.e. run them off the crankshaft pulley individually, I do have an adjustable (linked) v-belt at work that I can bring home and attempt to connect directly bypassing each component as it's length is adjustable. Is there an alternative way to determine which one is at fault, thanks for everyone's replies!

[dingov70]

Here goes with an old trick , ask your beloved one for her tights / nylons / pantyhose . Remove the rubber belts and simply loop the nylon jobs around the crank pulley & the water pump pulley , tie them as tight as you can . Start & run the engine for a few minutes , there should be enough friction to drive the pump & fan and eliminate that as your squeal source .

Simply repeat for alternator , missing out water pump pulley . A few minutes running will not be detrimental to the engine

[Porkchop]

Originally Posted by dingov70

Here goes with an old trick , ask your beloved one for her tights / nylons / pantyhose . Remove the rubber belts and simply loop the nylon jobs around the crank pulley & the water pump pulley , tie them as tight as you can . Start & run the engine for a few minutes , there should be enough friction to drive the pump & fan and eliminate that as your squeal source .

Simply repeat for alternator , missing out water pump pulley . A few minutes running will not be detrimental to the engine

Thanks for the old trick, certainly good for the Nullabor Plain between water-holes but I've got one of these luckily so I might not need to wrench the undergarments from my beloved...

[Porkchop]

Anyway back with an update as promised, I removed all belts from all accessories and naturally - no noise. I then reconnected the alternator using the adjustable linked v-belt from it to the crank pulley and still no noise! This made me think that 1) there's nothing wrong wit the alternator and 2) obviously if I hooked up the water pump on it's own using the same technique then I would hear the screeching sound again, and nothing, zip, nada. It was hard to get the tension up to the same level with the WP as I couldn't adjust the pulleys but it was spinning the fan around quite ok and there was no obvious slippage. I then put the two matched Contitech belts on and the noise was back! Got my younger son to turn the car over and alter the revs whilst I squirted the belts with a spray bottle but it made absolutely no difference to the noise level - it was just as bad as before. I'm still not convinced that the belts themselves are the culprits as the water spray should have had some effect.
I've now taken the water pump off as I've had a Hepu one sitting around waiting for a moment like this but now I've run into a snag. the steel coolant-return pipe is completely corroded at the flange where it goes into the pump and is basically unrepairable, I've contacted a local supplier with the intention of sourcing a new one but for some reason I have a gut feeling that this might be one of those difficult to obtain parts at least in Oz.....will report back.

[Clifford Pope]

Looking at a spare pipe and water pump, it would appear that the size is just standard 15mm plumbing pipe.
I tried a bit of old pipe that had a compression olive on it from a plumbing joiner and it was a perfect fit. You could braze on a bracket and bend a length of copper pipe to the right profile.
Just a thought.

[Porkchop]

Originally Posted by Clifford Pope

Looking at a spare pipe and water pump, it would appear that the size is just standard 15mm plumbing pipe.
I tried a bit of old pipe that had a compression olive on it from a plumbing joiner and it was a perfect fit. You could braze on a bracket and bend a length of copper pipe to the right profile.
Just a thought.

You know it's a funny thing Clifford but you read my mind exactly! I've got a pipe bending spring (external) so thought I might use some hard-drawn copper and anneal it where it bends to create a replica, including brazing on the brackets. I'll whip the old one off as I haven't done so yet and give it some thought....cheers!

[Porkchop]

Another update on the on-going saga with the water pump/screeching sound etc, have finally managed to track down a 2nd hand coolant pipe that matches my 23E motor and will hopefully fit it tomorrow,. This will allow me to put the replacement water pump and associated gear back on the motor and see if anything has changed, I doubt that it is the genuine Volvo WP I've taken off as it still seems as tight as a drum and was probably changed when the timing belt was last done. On that front, has anyone got any tips when flushing and refilling the cooling system on a 240?