Northstar Engines and System Technical Discussion Discussion, Developed an engine whine... what is it? in Cadillac Engine Technical Discussion; My car (98 Deville base) started making a strange whine from under the hood in the past 2000 miles or ...
My car (98 Deville base) started making a strange whine from under the hood in the past 2000 miles or less, it is present when the engine starts and the pitch of the whine changes with the engine RPM, sort of sounds like people who installed gear drive on a small block to drive their camshafts but not nearly as loud. The car has 218k miles. I took it to a car shop and the guy listened it with a stethoscope and he said the noise is coming from inside the engine. The car runs fine and it didn't change any driving characteristics this whole time, the oil is clean and I don't see any silver particles. Another shop said my power steering pump is going bad but I don't hear any weird noise or have problem turning the wheel while parked. I read about checking the pulleys by taking off the belt but my 1/2" ratchet is too short and there aren't enough room for my hands to move it.
In the past 1000 miles or so I noticed a clacking noise from under the hood when I first start in the morning, it sounds a lot like the engine is knocking but goes away as soon as I drive off. It doesn't do it every time but I've never heard that sound before in the past 8 years, again the engine didn't lose power or anything abnormal when it does make that sound. I read about carbon buildup and I do give it the foot at least once every few days so it shouldn't be carbon.
In any case I'm a little worried since I'm about to go on a 2000-mile round trip to visit my grandmother.
I would take the WP belt off and check again. that little pulley makes a racket when wearing out(seizing more like it) and is very easy to remove using 1/4 inch rachet.
I'm pretty sure it isn't the water pump since the noise isn't coming from that area, but since the car had its water pump replaced almost 100,000 miles ago (AC Delco part) I will check it tomorrow.
Originally Posted by Ranger
Spray some Brakleen or TB cleaner into the tunnel behind the P/S pump. If you have a vacuum leak the RPM will increase.
I sprayed some carb cleaner at the relief valve and the engine rpm didn't change. As far as checking the starter, since electric motors produce electricity while being turned by an external source is there a place in the fusebox or wiring harness where I can hook up a multimeter and see if the starter is producing power?
I don't know about that. I'd just listen in the starter vicinity with a stethoscope. That should pretty much pin point the starter if that's the cause.
I'll get a set of stethoscope tomorrow, I assume ones for medical purposes works just fine? If the starter is really not disengaging at all then wouldn't it be broken after the many WOTs I did in the past 1000 miles? The car still starts just fine and its startup behavior is the same like before. I felt the clacking noise in the gas pedal last night while accelerating, again the car didn't act any different and the noise went away after a few seconds.
Okay will do. I suppose a last ditch effort to see if the starter is not disengaging without taking off the intake manifold is by turning the key to start when the engine's already running? If it makes that awful noise then that should mean it's disengaging correctly.