a high pitched squealing noise coming from inside Motor when we take off the oil cover the squealing goes away and engine runs rough.there's a lot of suction from where oil cover goes on .what do you think?shouldn't be that much suction on the oil cover? the squealing goes away soon as you take the cover off and soon as you put it back on the squeal comes right back.
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2003 Volvo V70 Question: squealing noise coming from motor block
Sounds like the the crankcase vent system is drawing too much vacuum. You will need to service the vent system soon as damage can occur to the engine seals. This system is located under the intake manifold, so the manifold will have to be removed to service. If I can get the first 8 characters of the VIN which lets me know which engine your car has, I can get you more exact information.
Replypushrod, April 10, 2013, 18:54Master
Good answer!! You have seen this before i bet. Actually the engine crankcase breather is plugged. No fresh air comming in so crankcase vent vacuum is pulling in air wherever it can, thus the high pich squeal prob. at rear main seal. Seal lip acts like a reed in a musical instrument vibrates against the crankshaft. Good sign eng. is sealed up tight! You may know if update available.