Squeaky/chirping noise from engine

[Timpg251109]

Hi all.
Iv had a dry squeaking/ chirping noise coming from my 64 plate a-class 1.6 blue efficiency sport.
it’s gone in the garage 3 times now and no one can figure out what causes it!!
I thought it is the water pump bearing is failing as that’s where the noise comes from, plus there’s a smell of burnt coolant.
the issue is though, it doesn’t make the noise all the time and the smell isn’t there all the time either. only when the engine is hot and the car has to be parked in a certain position for the noise to start, which makes diagnosis very difficult. It’s just come back from a garage after they could only suspect it being the auxiliary belt slipping, this has been changed, the pump has been pressure tested and there’s no visible sign of a coolant leak.
has anyone experienced anything like this asI’m at a loose end at the moment!!!https://youtu.be/WOC-frKLE6c

 

[alexanderfoti]

Does sound like a worn waterpump bearing. Could be an idler bearing starting to fail early?

There should be signs of coolant near the bottom of the pump if it's failing and leaking.

 

[Timpg251109]

Does sound like a worn waterpump bearing. Could be an idler bearing starting to fail early?

There should be signs of coolant near the bottom of the pump if it's failing and leaking.

hi mate
That was my immediate thought, but the pump has been pressure tested on 3 occasions now and hasn’t given any indication that it’s failing?! Iv also had a look underneath when it was on a ramp, and the engine is as dry as a bone.
On another forum it has been suggested that the noise could be coming from a crank shaft seal rubbing on the crank pulley? This would coincide with the noise not always being there and only representing itself once the engine is hot.

 

[alexanderfoti]

hi mate
That was my immediate thought, but the pump has been pressure tested on 3 occasions now and hasn’t given any indication that it’s failing?! Iv also had a look underneath when it was on a ramp, and the engine is as dry as a bone.
On another forum it has been suggested that the noise could be coming from a crank shaft seal rubbing on the crank pulley? This would coincide with the noise not always being there and only representing itself once the engine is hot.

Could be, but if it is that, it would be leaking pretty soon!

I think it's more likely that the pump only leaks a small amount and then it evaporates.

Ideally, run it with the belt off, if it stops, it's something on the belt train. If not, then crank/chain etc

 

[Timpg251109]

Could be, but if it is that, it would be leaking pretty soon!

I think it's more likely that the pump only leaks a small amount and then it evaporates.

Ideally, run it with the belt off, if it stops, it's something on the belt train. If not, then crank/chain etc

to be honest I think your correct, my only thought was though. If it’s the water pump bearing... it doesn’t do it all the time, even when hot. plus the car has to be positioned in a certain way for the noise to start. Like when car is bumped up on a kirb or not parked on dead flat ground.
issue is, that garage workshops tend to be flat lol!!! So I end up looking rather silly when the car decides to behave itself when being diagnosed lol!!!

 

[davemercedes]

The purists would scream at this...

I bought a caravanette from my then neighbour about twenty years ago - it was conversion he did on a Peugeot J3 van (typical French trader's van of the time) - the engine was halfway into the front cabin with a big clip-on cover. He had had the same chirping noise problem and was sure it came from the fan belt or pulley.

He showed me that once every year or so he gave the fan and top pulley the tiniest spray of WD40!

Well, honestly - a year later I heard the chirping noise - just before we were due to go off to France. So I did the same and gave it a tiny squirt of the magic WD40 and the noise went almost instantly!

If you decide to try this - do remember to only give it the tiniest spray and point it so that it gets the inside of the belt and the pulley.

Purists reading this will be apoplectic now but so long as you do really restrict it to a tiny spray, it will bed in within a couple of hours of use.