Squeal in engine

Fan belt slipping ,fit a new one. The service guys are probably just spraying CRC or similar on the belt,ok for a week.

We had an 80 series Landcruiser some years back with a squeal in the motor, turned out to be the fan belt.
To test, start motor then tip some water over the fan belt, if it is the belt the squeal will disappear in a couple of secs.
Can't remember what we did to stop the squeal permanently.
Hope this helps.
Baz

Was thinking it would be fan belt, thanks. Put the post up, to see if anyone may have had any more serious dramas, (blocked oil gallery or something like that) thanks guys. Cheers

Bearing in an idler pulley, the AC compressor or Alternator?????

Take the belt off when cold and turn/spin the pulleys to see what they are like.

And then replace the belt, is the belt worn, cracked or glazed?

There is quite a few things that it could be. It seems that most of the possibles have been mentioned.

The only real clue is that it stops after about 5 minutes. That to me sounds like a pully or aircon pump. Often the bearing in aircons are dry and so to are some pullies. If they get dust, oil or grease in them they will squeal for a few minutes when cold.

As mentioned, water is the best thing to use to find it... You don't want to be spraying lubricant on parts that should not be lubricated.

Fill a small spray bottle with water. Start the engine with the bonnet open. Listen for where the squeal is coming from and give it a squirt of water. If the squeal stops, note where you spayed and repeat the process the next day when the engine is nice and cold. There is always a chance that the squeal stopped by it's self and not from the water. If you repeat it, that will confirm if the water did stop it.

An alternator is driven by a belt, it outputs a fair amount of energy to the battery, but, after it has recharged/replaced the start current used when starting, the load then goes off the alternator pulley and belt. This major charge typically takes around 5 min.
It is likely the belt has worn and is bottoming in the groove and service people don't notice and just tighten it which makes it drive sort of ok for a while and then goes back to slip.
If it is a multi groove belt 3, 5 or 7 groove it may also be hitting the bottom of it's grooves.
Most people don't look, don't see and because it still has grooves and isn't broken it must be ok, not so.

Possibly not AC related as it would happen intermittently as the AC clutch pulls in and out.
Not power steering as the slip will then be as you turn and make it work.
Cheers
Ross M

Odog - You don't say whether your engine belts are regular V-belts or multi-ribbed V-belts - however, I seem to recall the D40 engine uses a serpentine multi-V-ribbed belt, in common with current design.

Belt squeal has been covered pretty well by all the above posters. However, if the belt is a multi-ribbed belt (and particularly a serpentine belt), it's important to remember that these belts need to be tensioned much tighter than a regular V-belt.

The manual should give you the tensioning methods and specs. If the squeal continues to be persistent, you need to examine pulleys for wear and misalignment.
It's not uncommon for alternator mounting bolts to come loose and create pulley misalignment.
Recently-installed belt-driven components may not have been installed properly as well, creating belt squeal.

The Gates website has a lot of good info on troubleshooting belt problems. The search menu will provide more troubleshooting pages.

http://www.gates.com/brochure.cfm?brochure=1026

Cheers - Ron.

Put some water in a spray bottle & spray the belts with the engine running, if it goes away, check the belt tensions.

An old remedy when a belt squealed when starting up was to rub sunlight soap on the belt in the places you can reach, without the motor running of course. Then hit the starter briefly to roll the motor a bit and repeat the process. This lubricates the belt without it loosing grip.

This is after you have done the aformentioned checks and all appears ok.

Thanks to all replies, will narrow it down, maybe next service get new belt put on and see if it stops, in mean time check with the water in the spray bottle. Great feed back. Thanks again, love this site. Cheers

during the week a fellow in Canberra had a squeak in engine bay turned out to be a platypus

Broken manifold stud. Squeal is leaking exhaust gas. As engine heats up differential expansion means leak diminishes.

Bob