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MGB 73 getting loud squeal with acceleration

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J

jsomersdc10

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Belt treatment helped, noise is intermittent but seems to be getting worse. Afraid it may be a bearing going bad. Any tips on how to figure out which one?
 
if you jack up the car you should hopefully be able to spin the wheels and hear if there is a grinding noise.
 
If belt treatment made things better, seems the wheel bearings wouldn't be in the loop. Does the squealing change as the engine speed changes?

Try this: car parked, engine idling, gearbox in neutral. Rev the engine and see if the squealing changes. If yes - not a wheel bearing problem.

Let us know how it goes.
Tom M.
 
NutmegCT said:
If belt treatment made things better, seems the wheel bearings wouldn't be in the loop. Does the squealing change as the engine speed changes?

Try this: car parked, engine idling, gearbox in neutral. Rev the engine and see if the squealing changes. If yes - not a wheel bearing problem.

Let us know how it goes.
Tom M.
Click to expand...
Sound does increase with higher rpm on engine with transmission in neutral. Appears to be coming from front of engine. Maybe alternator or water pump pulley going bad. Any tips on how to check them or something else that might be making that high squeal sound with increase in rpm? Thanks
 
Quick check: open and close throttle while you lightly spray water on the belt(s).

Would also be helpful if you post a video of the engine while it's running, so we can hear the type of squealing and how changes in rpm change the sound.
Tom M.
 
Get the next smaller fan belt. If it is a bearing, a LONG screwdriver with tip in contact with the different devices (waterpump, alternator, air pump) with engine running and your ear on the handle, it will become evident which one has a bad bearing. Be VERY CAREFUL the screwdriver stays out of moving engine parts!
 
DrEntropy said:
Get the next smaller fan belt. If it is a bearing, a LONG screwdriver with tip in contact with the different devices (waterpump, alternator, air pump) with engine running and your ear on the handle, it will become evident which one has a bad bearing. Be VERY CAREFUL the screwdriver stays out of moving engine parts!
Click to expand...
Before you do that take of the fanbelt and start it up - running for a couple of minutes won't hurt then engine and you will instantly know whether the alternator or the water pump are the problem.

Oh and, - does this B have a fan clutch? If so, it could be that - and there is a cheap and easy fix on youtube.
 
It may be the harmonic balancer. Mark the inner and out rings with chalk or white out. Then after you hear the squeal check to see if the marks are still aligned.
.
 
Hi y’all, most here won’t know me, I have a Healey. But as JPSmit says take the belt off and run the engine. U can run for enough time to ascertain the noise. But also while the belt is off, WITH ENGINE STOPPED, turn and wiggle the pulleys. You may feel them loose or ruff running. Not spinning smoothly.
 
How old are the belts ? They lose their grip over time and my squeel even though perfectly adjusted. I am going through this issue with my 1992 Miata (with original belts).
 
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