[mooltjie]

Hi Everyone...

Thought I come back and throw one more question on to the forum since you were of such help with my previous issue.

I had my truck taken into a "stealer" for a master/slave clutch cylinder replacement (I still cant sit straight upright ) and while there all the filters + oil. Went to get it yesterday...all was fine, especially the clutch felt "new" and "crisp".
This morning, not even 2 blocks from home heard a high-pitched whine coming from engine bay..., best way to describe would be almost like the sound of a cheap supercharger.
This only occurs when revs is between aprox 1200-2000, over 2000 and the whine/squeal goes away... same on idling, no noise.

At work I popped the hood to try and find the source of the noise and it seems to be coming from front of engine block, but I cant be sure.

I've have tried in vain to find a solution to this on the interwebs... similar issues mention cooling-fan viscous clutch, fanbelt-pulley, alternator, water-pump, steering-pump, type of oiled used and some folk advising just to ignore the issue.
I know its not the chains as its definitely not a grinding noise, and it goes away at higher revs.

If anybody has had a similar experience or have any ideas as to what it might be I will be truly grateful.

Regards

[mooltjie]

Just a quick update on the status of my "squeal".
On the way home yesterday evening still with the annoying whining from the engine bay... Swung by a friends house to pick up a visiting swambo, at this stage the whine started becoming more a constant "not-that-high-pitch" whine at all rev speeds.
About five blocks from home I notice that the squeal is all but gone. On the driveway and I cant get the engine to reproduce the same whine/squeal.
This morning I had all the windows open and actually playing a bit with the revs to see if I cant get the engine to start the whining again but with no luck. I would say that she is purring like a kitten, but I would be lying... she is growling like a lioness in heat!

If anybody has any theories as to what might have caused this please let me know... I always feel better knowing what the problem is, rather than waiting for something to go seriously wrong.

Regards

[eldirko]

Hi,
I had the same noise and couldn't find the cause of it and I decided to see what would happen. A few days later the chain broke, so don't wait till that! Something is really wrong, but till now I haven't found the answer to it.
I have this engine waiting for time to check what went wrong, we just put another second hand engine in.
I would love to know though before we start spending money on the old engine...

[mooltjie]

Thanks for the warning, but I think in my case it might be something else... As I said the sound went away completely, did yours do the same, or did it become worse ?

I took the truck on a "man-drive" just to see what it would do in the higher revs... no sound whatsoever!
Anybody with some knowledge of the inside of the 4M40 please correct me if I am just babbling... could it be that some of the bearings are lubricated by the engine oil, and maybe it got "dry-ish" if the change took to long ?

[eldirko]

Hi Mooltjie,

The sound was exactly stopping at 2000 revs, never got worse.
We drove with it for a few months and checked everything and found nothing till it broke. Never was gone though.....

I am glad your sound stopped. Some engines sound more metallic if the oil level is too low and lubrication will get bad if you wait too long with changing the oil.

[mooltjie]

Ja... I guess the best thing to do is get a quote and open up the engine and change the bearings on the camshaft...
Thing is I just picked it up from the authorized dealers for a master/slave clutch cylinder replacement and oil and filter change (all original) so I am a bit pressed on the budget...

Regards

[Chriswm]

Two things to mention:
Firstly, my 4M40 had a similar whine-problem, fortunately with a low-tech solution. The whine would be audible around 1,500 to 2,500 rpm, and especially when the engine was cold, less so when hot.

Almost any 4m40 repair will require the removal of the inter-cooler and it turned out that a pipe was loosely fastened afterwards causing a tiny bit of air and turbo noise to bleed through. After removing all the turbo pipes and refitting them properly, the whine went away.

Secondly, I can perhaps also mention a strange rpm-related "engine noise" in my 4m40 that we could not pin point, but resulting in my aircon fan belt tensioner bearing failing (disintegrating) about a 1,000km later. Fortunately with no resultant damage.

[mooltjie]

Hi guys... sorry for the late response, I kind of fell off the earth for a little while.

The whining from the engine turned out to be the front bearing of the camshaft... After the squeal returned (about 15,000 km later) I had all the bearings changed on camshaft as a preventative-measure ... when I got it back from the shop only the front bearing had a little play, not so much as to fail, but still glad I had it changed, makes me sleep I little bit better at night.

Aswell added LiquiMolly's Ceratec to engine oil... no sure if anybody has some experience with this ?

Regards

[Brianrapson]

Hi Guys, I also had a high pitched squeal coming from the front of the engine, we thought it might be the V belt tensioner our mechanic confirmed it was not this and after tightening the belts VERY tight the noise reduced for a while the returned and got worse the next option was to take it to an aircon specialist who tested everything and declared nothing wrong with the aircon compressor. We then took it to a different mechanic recommended who discovered that the front crank shaft pulley was rubbing against the timing chain cover. The pulley has a rubber insert in it as a damper this had become detached and caused the pulley to rub against the cover. We got a second hand pulley from PartsHunt who were very helpful. After fitting the pulley no more noise and I have fallen in love with my Pajero again. I hope that this will be a useful experience to other owners when trying to identify mysterious squealing noises at the front of the engine.

[Lawrence Woollam]

Before you do anything change the oil filter or check that it is a dealer approved one.

Lawrence