The Mitsubishi Pajero Owners Club®

[iam_TJ]

I've been noticing over the last few months what I originally thought was a noisy tappet that is especially noticeable at start-up and idle tick-over.

It has got louder recently and I noticed it seemed to coincide with when the viscous fan is operating so did some reading in the forums about the fan, read the thread about removing it and refilling with silicon oil that also describes that the fan is usually locked up at cold start until the oil has been spun out by centrifugal force:

http://www.pocuk.com/forums/viewtopic.php?t=164411

After having a mechanic friend take a listen and poke around he thinks one or more of the idlers needs a new bearing. Certainly the top-right (looking from front of vehicle) has some forward/backward play.

I would like some advice as to whether my plan to deal with this is correct, if it should be done differently, and if there's anything else I should do whilst at it ?

1. Remove viscous fan and clutch
2. Listen for ticking noise
3. Remove fan belt
4. Listen for ticking noise (do not run engine for more than 2 minutes due to no water pump operating)
5. Test each idler for play (how much is acceptable, if any?)
6. Remove idlers and possibly tensioner
7. Replace idler bearings and service tensioner
8. Refit idlers and tensioner
9. Fit new fan belt
10. Clean and test fan clutch
11. Refill with 100ml silicon oil 10000cSt
12. Refit clutch and fan

Mechanic friend tells me I could either use a local bearing specialist or else possibly find a complete idler (tensioner?)) kit - advice on this please.

Should the fan be freely rotatable when the engine is off (it is currently) ?

[Google]

[radiomike]

You are on the right lines, remove the fan belt and see if the noise has gone. Worn idler bearings tend to whir and grumble rather than tick, spin each one and listen for noise. Don't forget there is a tensioner and idler on the cambelt which could also be worn, when was the cambelt last changed?
The main cause of ticking on the V6 is the hydraulic tappets which tend to be noisy on start up and behave once warm, they don't like dirty oil or the wrong grade.

[iam_TJ]

Thanks. I originally did think it was a noisy tappet but simple audio-location does seem to confirm the source is the very front, lower, area of the engine around the fan or belt. I do regular oil changes including flushing and oil is good and correct specification.

I'm not sure when the cam belt was changed and it has been on my list to do 'just-in-case'. Vehicle is currently on 105k miles; I got it at around 92K in 2020 in extremely good condition. It had done 60k in 1st 3 years (2003-2006) and then  ~33k between 2006 and 2020 and I've done the remaining 12k since.

Whilst on the subject of cam-belt - is it possible to change it on-vehicle after removing fan, fan-belt, etc., without removing the radiators? This has been the only thing making me hesitate.

[radiomike]

[iam_TJ]

[iam_TJ]

I decided to record a video (and audio of course!) to demonstrate the noise. After a few minutes I decided to include some stop-restarts and noticed the noise begins about 10 seconds after starting. I then had the bright idea to switch off the air-conditioning and the noise goes away!

So, different problem to what I thought. I still need to change timing belt and fan belt and possibly the fan-belt top idler that has some sign of movement on its shaft.

So now to discover what is causing the noise and how complicated and expensive it is going to be!

Here's an excerpt from the video; I switch the air-conditioner on at 21 seconds and off then on again at 27 seconds.

https://iam.tj/shogun/Shogun-6G74-GDI-Noisy-AirCon-Compressor.2.mp4

[cheriedavy]

This data is really fruitful.
Thanks!