Whining sound and vibration

(Ilkka Suppanen) #1

Hi
I have xj12 series 3 1991. About moth ago the engine started to “whine” between 1500 - 3000 rpm. Inside of car you can hear the strong"whine". Outside in engine compartment whining sound is bit damped because of all the other noises engine makes. There is also notable vibration outside of the car near engine.
The whining sound is there with gear(s) on, whiteout gear, and reverse.
Here is the link to the video from inside of the car, where you can hear the whine.
https://www.dropbox.com/s/st3gz6r6rb79fv2/xj12_whining.mp4?dl=0

  • The jaguar specialist changed all the engine mounts to new ones. Whine is still there.
  • He also all belts away and the sound/vibration was still there when running the engine.

What this could be? We are baffled
Sincerely, Ilkka

(Maynard) #2

A couple of suggestions. Remove all the belt from the engine and start it up. See if the whine is still there. If not, it is one of the ancillaries (i.e. alternator, ps pump). If it is still there, it is an internal engine problem.

You might want to try (before removing the belts) using a mechanics stethoscope and try to isolate the sound that way.

(Ilkka Suppanen) #3

Thank you Maynard. Yes, we did that and the whine was still there. So it is not the ancillaries.

Sincerely, Ilkka

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #4

Some have reported whines due to the timing chain tensioner being too tight. The fix is easy: Remove the access plug, insert a lever and “trip” the latch.

I dunno how it would have gotten overtight, though. Previous reports were following work on the engine where the assembly left the tensioner too tight.

(Mark Eaton) #5

It doesn’t appear to be changing in frequency with engine RPM. It perhaps gets stronger (louder) at higher RPM. It is also quite a low frequency. And doesn’t sound very “mechanical”. ie. tapping or knocking. Sounds very much like a belt or something rubbing. Which makes Kirbert’s diagnosis sound like something worth checking.

A stethoscope (or long screwdriver) might help locate it to front or rear of engine.
I wonder if turning the engine over by hand shows up anything?

I would expect most engine noises (knocking etc) to change with RPM. But a belt rubbing, doesn’t really do that. Maybe the power steering pump causing the belt to slip. But that’s usually a high pitched noise, not a low pitched howl. As is the alternator belt. Does it change when you load up the steering? Does it change with Air Cond engagement? Is it there from cold, or only when hot?

Actually, listening to it again it sounds very much like wind, sucking (blowing) through a flap. I wonder if there could be a problem with the air filters - not fitted correctly. There is no sound on idle, just when air flow picks up. Or, a leaking vacuum valve in the air conditioning (flap motor).

Cheers
Mark

(Ilkka Suppanen) #6

Hi

We found a cause and solved the sound / vibration problem.

The car mechanic Marco found that the source of sound was around oil filter and oil filter assembly.

By changing engine oil from 20W-50 to 20W-60 and changing the oil filter we solved the problem of sound and vibration. It was about 6000 km since the last oil change.

It is still bit unclear exactly what caused the whine: Was it: the oil filter, oil itself or the valve on the oil filter assembly? At least we know where to to look if whine returns.

Thank you all for profound and good help to narrow down the problem.

Sincerely, Ilkka

1 Like
(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #7

If it was the oil itself you are in real trouble, especially since 20W-50 is the correct oil. I can sorta see it being the filter, though. Those things have a backflow prevention flap and a pressure relief valve inside, either of which I suppose could be making racket.

Definitely a new one, though. I’d kinda like to see that old filter cut open. I’d also kinda like to know the brand.