MINI R50 Cooper - MINI R50 Squeal - not from V-belt!

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Wed 11 Jul 2018 17:37
MINI R50 Cooper - MINI R50 Squeal - not from V-belt! - Canuck

My 2001 Mini (that I've owned since the launch date) has 65000 miles and is well loved. The car has developed a loud squeal from the engine area at 1000 rpm. I thought it may the V-belt so ordered a new one and replaced it. No difference. Thinking it may come from the A/C compressor, I removed the belt and ran the engine briefly. The squeal appeared at 1000 rpm as before so I know it's not the belt or anything driven from it. I'm stumped as to where to go from here.

Any RPM above 1000 and everything is quiet.

Ideas and thoughts greatly appreciated.

Doug Nicholson

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Wed 11 Jul 2018 23:18
MINI R50 Cooper - MINI R50 Squeal - not from V-belt! - elekie&a/c doctor

I wonder if this is an air leak on the induction system. This would be most noticeable when the engine is at idle or just above. Any difference if you push the clutch pedal down?

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Wed 11 Jul 2018 23:31
MINI R50 Cooper - MINI R50 Squeal - not from V-belt! - Canuck

Good thought, will check that tomorrow after I've finished drowning my sorrows. No difference if clutch pressed. Have ordered a new timing belt tensioner as it's cheap and easy to change. Thanks.

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Fri 13 Jul 2018 19:12
MINI R50 Cooper - MINI R50 Squeal - not from V-belt! - John F

Have ordered a new timing belt tensioner as it's cheap and easy to change. Thanks.

That's the first thing I thought of when I read your problem (I had a similar whine from a failing tensioner pulley bearing which I managed to replace before it seized and fried the belt) - but I thought the R50 had a Tritec engine with a chain.

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Wed 11 Jul 2018 23:46
MINI R50 Cooper - MINI R50 Squeal - not from V-belt! - bathtub tom

I wonder if this is an air leak on the induction system. This would be most noticeable when the engine is at idle or just above. Any difference if you push the clutch pedal down?

I was taught an old trick to spray WD40 around inlet systems to detect leaks. The engine note will change if the WD40's injested. Don't know if WD40 will have a deterent effect on O2 sensors and cats!

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Thu 12 Jul 2018 19:19
MINI R50 Cooper - MINI R50 Squeal - not from V-belt! - Oli rag

I know the early Cooper S versions were supercharged rather than turbocharged, not sure about a Cooper? Superchargers can make loud squealing and whining noises.

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Fri 13 Jul 2018 20:33
MINI R50 Cooper - MINI R50 Squeal - not from V-belt! - Canuck

Well it's fixed and I've proved once again that a key skill in life is knowing what to fix.

It was the exhaust heat shield rubbing on the central exhaust support. One of the heat shield fixing nuts had come off and the shield had moved close enough to the support rod to touch it. I guess there is a resonant point at 1000 rpm where the exhaust vibrates a bit. One bolt and washer and quiet reigns. It sounded for all the world like it was something horrible in the engine.

I can rest easy tonight! Thanks for all help and suggestions.

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