Squeal when accelerating

[dgbalfour]

The car is a well-cared-for 1991 240 SE 2.0L. The clutch was changed at 140,000 miles (now has 160,000). Ever since the clutch change there has been a small squeal as I bring the clutch up to get the car going from a standstill.

This initially only happened when I was being a bit vigorous in 1st gear, and often when I was towing. Now it's becoming more frequent, it nearly always happens in 1st unless I'm being very gentle and now has started happening as I change from 1st to 2nd.

I'm guessing it's a bearing somewhere running dry. Does anybody have any pointers on what I need to investigate and how I might do this?

Many thanks,
David

[migrator]

Is this only happening during a gear change?

If it is happening on any hard acceleration, it may be that the fanbelt(s) need tightening. If the belt(s) is(are) slack, the crankshaft pulley may be spinning too fast for the belt(s) to keep firm contact and the result is the screeching noise.

[dgbalfour]

That was my first guess too, but the noise only happens when the clutch is in the 'transitional' phase - not fully out nor fully in.

[migrator]

Hi David,

Sorry to persevere but this was happening on on old 240 estate that I once had. Because the screeching was happening even when changing gear, I was thinking about all sorts of expensive 'clutchy' things. I even got a mate out to listen to the noises and he was of the belt opinion.

I tightened up the belts and the result was no more noises. I am not saying that yours is definitely the same but if you have not tried checking/tightening up the belts then that is a good cheap place to start.

[Erling]

When you had the clutch replaced, did you also replace the throw-out bearing?

replaced fan belt 1 year ago had a screehing noise since then every time change thru the lower gears unless very gentle sounds like a belt sliiping to me will have it checked when i get timing belt replaced at 80000 miles and 7yrs old have a s40 2 .0 cd

[Engineer]

If it’s not auxiliary belt slip, then it could be the torsion (red) or dampen (green) springs in the clutch disc. Common at high mileage, if disc was poorly fitted (gearbox hang) or if the disc is budget spec.

[Clifford Pope]

It's the clutch release bearing getting dry. They seem prone to this, even when newly replaced.
If you pull back the rubber cover on the operating lever you can insert an oil can with a length of extension pipe and give it a few drops.
Mine started doing it soon after I renewed the clutch and bearing. After living with it for 100,000 miles I discovered the oil can trick. It's been virtually quiet for a further 50,000 miles. Once it did came back a bit, so I gave another squirt of oil.
It's easier than taking the gearbox off!

[Erling]

Clifford;
That's a great trick, I wasn't aware of this. I'm sure this would save a few gearbox-out jobs! Here's a picture of the interior, to illustrate Clifford's hint:



Edit: I should add that this is the M46 (4 speed + overdrive). Your 1991 should have the 5 speed M47. I believe, but cannot confirm, that the clutch design is similar.

[dgbalfour]

Thanks for all your replies - I'm pretty sure it isn't the belt tensions, I did those first but I will have another look now I know it can cause similar symptoms. It wouldn't be the first time I'd have disregarded something that I shouldn't have on this car.

If that fails I shall try the oil can into the clutch release arm. I haven't really ever had a good look at my gearbox, what sort of length of tube will I need on this oil can?

Thanks again,
David