Whining noise - any ideas?

[nullspace]

Recently whilst driving around in my 1.6 I've noticed a whining noise. It is a low pitched whine, reducing in pitch, noticeable when I lift off the gas to idle (as i'm approaching a junction or roundabout, say). It seems to be coming from the o/s of the car, and only happens when the car is up to temperature. Starting her in the morning and driving around town it isn't noticeable - yet after a short motorway run on a sunny day it sounds like I'm dragging Chewbacca under my bottom end.

 

I figured it was the water pump, or the PAS pump. The belts worried me at first, but the aux belt was changed about 10-20 thousand miles ago and the cam belt has only done ~86,000 (don't think its been changed). There are no repetitive knocking/slapping noises, and the aux belt on quick inspection looks and spins just fine.

 

Today I did a coolant flush using Holts 2-step radflush. This was simply as a matter of course given that I'm cleaning up the front-end/rad area while the bumper is off, and access was easy. (Should have seen the rubbish that came out of it though - 17 years of 'black').

 

Car is on the axle stands, and as I sat in there giving it a 30 minute fast-idle i started to hear that same whining when lifting the throttle; again only once the engine was up to temperature (say, halfway through the needle range - cooling fan fired up). Obviously I wasn't steering, so it can't be related to the PAS pump. Do you think its the water pump? Has anyone had a similar experience before? Once my car is back from welding i'm planning a belt/tensioner change and i'll be swapping out the pump anyway (again, as a matter of course) - so if it's the pump i'm not too bothered for now.

 

Just worried it could be something more sinister, or more disaster-eminent (my worst fear here is a cam belt snap).

 

Advice, as always, mostly appreciated.

 

John

[Ahmotorsport]

Could be belt tensioner area, if you're changing it anyway, change it and try again.

[nullspace]

Could be belt tensioner area, if you're changing it anyway, change it and try again.

 

It needs to do a journey to the bodyshop in the meantime unfortunately - I guess i'll just drive real carefully.

 

After that I'm hoping the belt, pump, tensioner change sorts it out.

[sidrick]

Your PAS pump is still turning even if you're not steering, unless I've forgotten a lot since I last owned an Escort!

 

I wouldn't worry about it. A full belt, tensioner and water pump replacement is on the cards.... if there's a noise after that then you've narrowed it down, but also eliminated the critical items.

 

Had to lol at you saying the aux belt had only covered 20k, so it's unlikely to be that. I think my cam belt will be changed again before it does 20k

 

For what it's worth, in my experience the time between a water pump noise/bearing failure and it leaking water and eventually seizing or breaking up is 100's not 1,00's of miles, so don't let it run too much.

[nullspace]

Your PAS pump is still turning even if you're not steering, unless I've forgotten a lot since I last owned an Escort!

 

I actually wondered this myself after posting. You're right, the pump will be spinning no matter what - even when the hydraulic system is doing no work itself. I think where I was coming from here is that it isn't an effect associated with steering the car. Having experienced it at a standstill and in neutral, it can't possibly be related to steering itself, but could still be the PAS pump. That said, the fact that this whine only occurs when the engine is up to temperature suggests it isn't - unless heat soak of the PAS fluid is having an effect somehow.

 

I wouldn't worry about it. A full belt, tensioner and water pump replacement is on the cards.... if there's a noise after that then you've narrowed it down, but also eliminated the critical items.

 

Had to lol at you saying the aux belt had only covered 20k, so it's unlikely to be that. I think my cam belt will be changed again before it does 20k

 

Christ. Seems you're right. I'd read the cam belts are usually good for 100k or so, but Haynes does say they should be replaced at every 60k. As for the fan belt, I honestly had no idea they perished so quickly. I'll give it a good look over tomorrow.

 

All I know re: the belts on this car, is that one was changed by the RAC shortly before it fell into my hands. I have to assume it was the fan belt as obviously there was no damage to the engine. That and I have a toothed belt sat in my cupboard that I assume came with the new fan belt in a pack. (This must be an unused cam belt - so I've no excuse not to change it!).

 

For what it's worth, in my experience the time between a water pump noise/bearing failure and it leaking water and eventually seizing or breaking up is 100's not 1,00's of miles, so don't let it run too much.

 

Yeah, I'll be doing about 30 miles max before its changed. Just need this welding done before the MOT runs out. I can work on a car in SORN until the cows come home, but I can't drive it to a body shop, you know?

 

Cheers,

 

John

 

 

As an afterthought... When the engine is up to high temperature, the coolant loop is under a lot more pressure. If the bearings on the water pump are screwed, then i imagine any vibration of the impeller would be more forceful under full load. It's probably the pump then (I optimistically hope as I turn the key and head to Liverpool next week, lol)

[cherrybeard]

Take the aux belt off and run the engine. This will narrow it down to either the cam belt system or aux belt system. When you have narrowed it down to one system or the other, spin each pulley by hand to see if any are making any noise. You might not be able to replicate the noise exactly as the pulleys will spin a lot faster with the engine running. It should be obvious when you get to the culprit.

Could be as simple as the aux belt is worn/stretched/slipping. Check the freeplay in the power steering pump pulley by trying to push/pull it in and out of its hub. Anymore than a mm or two and you should get a new one. I checked a lot of steering pumps at the scrappy and some had no freeplay at all whereas some had almost 5mm of in/out movement.