Pajero Bearing noise!!!!

[karllovesmercedes]

Hi there, need a hand diagnosing my bearing noise.

I have a 91 2.5 Turbo Diesel Pajero which is making an odd noise that sounds most definitely like a worn bearing (rattly etc.) Yet it only seems to be noticeable when lightly coming off the throttle under little-to-no load, or lightly back on the throttle under little-to-no load, otherwise it is quickly quiet again.

I had the truck in at Marshall's to sort out an input bearing and fit an HD Clutch (of which they failed to replace the thrust bearing ) The noise seems linear with the engine speed though most noticeable between 2000rpm +, as this is when it is loudest and lasts the longest. Overall the sound is light and the rattling sounds very fast not like the input bearing I had earlier.

Here is what I have thought so far, yet I really can't be sure.
- Thrust bearing
- Rear crank bearing
- Big-End Bearings ???

Would appreciate any input and comments on this as I am really at a loss.

Regards, Karl

[Mehrts]

Had a rear wheel bearing which grumbled when coasting/foot off throttle. Thought it might have been gearbox/diff related due to the different load characteristics. Took a while to figure out that it was in fact a bloody wheel bearing.

[SamLogan]

You could also try a uj in your driveshafts. They can make noises and virbrate on over run and on slight acceleration.

Sam

[churchill]

Is the noise still there when you're not moving but revving the engine?

[karllovesmercedes]

Nah don't think it's a wheel bearing, makes the same noise regardless of the car's speed - only the engine speed affects it.

Is the noise still there when you're not moving but revving the engine?

From memory it still makes the noise when stationary and revving, though you need to come off the throttle quick to hear the sound. Or lightly come onto the throttle at low rpm. Really puzzling as my uni joints are all greased up and all other driveshafts seem to be running fine. The sound is "lightweight" like something light in build.

Any possibility it could be something to do with injectors, tappets or something like that?

[tgaguy1]

Could be the heat shield covering the turbo rattling.

[karllovesmercedes]

Could be the heat shield covering the turbo rattling.

That could very well be, will give that a look and tightening tomorrow morning. Cheers

[SamLogan]

should have read it a bit better. If it builds with engine rpm i would be looking at the thrust(release bearing). That is spinning at engine rpm and would therefore increase linearly. A big end would knock if it was knackered and you don't rear have a rear engine bearing just main bearings which i would think would all have to be stuffed to get a rear knocking noise.

Sam

[karllovesmercedes]

Thanks Sam, thrust bearing seems more plausible at the moment over anything else as it's the only one (as far as I know) which Marshall's didn't replace (they did a shoddy job) just wanted to rule out any other possibilities or get some idea to what it was most likely to be.

Just remembered that I have a video of some startup noise which quietens after depressing the clutch for the first time - a mechanic mate of mine said was the thrust bearing. Would it be any use to upload that? It does sound similar though slightly louder and more solid. I can't capture the actual noise I posted this thread on while driving though as the engine noise overwhelms it

Is there no rear crank bearing that the shaft sits on? Surely there must be something which supports it as it exits out the front of the block for the various ancillaries such as the air-con, power-steering and radiator fan right? Please excuse my low mechanical knowledge on this stuff!

[churchill]

There should be 10 bearings on the crank, 4 big ends, 1 thrust, 5 main bearings on the crankshaft. The main bearings are arranged 1 at the front, 1 at the back and three in the middle.

Sounds like a big end bearing starting to go to me.

[karllovesmercedes]

So if it is a big end bearing, how much worse would it get before being dangerous to drive? It'll start to knock when it get's really bad if I am correct, but has it already caused damage at that stage?

[SamLogan]

If you depress the clutch and it goes away it is going to be the thrust bearing. Have you checked the freeboard of the clutch? If you don't have enough, the bearing will always be in contact with the clutch fingers and will make a noise. This will go away when you put your foot on the clutch as it will make it fully come into contact. Why didn't they change it when they did the clutch?

Sam

[tomsoffroad]

Might be a bit left field but, I've come across one of these motors with a loose crank pulley. Started with a light rattle and got worse, much much worse

[karllovesmercedes]

Sam, that's only the noise which I hear on startup from the thrust bearing. The noise I started this thread on is there regardless of clutch in or out. Just thought they might be related in some way possibly.

Will check the free-play tomorrow morning and compare it to the handbook

Honestly I have no idea. They misaligned the gearbox when they reinstalled it which gave vibrations, a blocked the 4th gear gate, and made impossible to get into low range (literally impossible - once I managed to get it in and try drive, the whole drivetrain felt like it was about to explode it had that much tension in it) and a whole list of problems. They were supposed to replace the stock clutch with a heavy duty kit, machine the flywheel and replace all bearings (Charged me 2,200 for the whole job + replacing the input bearing) Heading back there to get the thrust bearing fixed sometime next week hopefully.

Might be a bit left field but, I've come across one of these motors with a loose crank pulley. Started with a light rattle and got worse, much much worse

oh dear.... had the whole timing belt arrangement and balancing belts replaced about 10,000km ago at Turbo and Diesel, did a brilliant job, but might as well give it a jiggle and see how it sits haha.

Looks like I have a decent checklist to do tomorrow!

[yeti]

take it back

[karllovesmercedes]

If you depress the clutch and it goes away it is going to be the thrust bearing. Have you checked the freeboard of the clutch? If you don't have enough, the bearing will always be in contact with the clutch fingers and will make a noise. This will go away when you put your foot on the clutch as it will make it fully come into contact. Why didn't they change it when they did the clutch?

Sorry, as far as I know the thrust bearing stays quiet at all times apart from this initial startup rattle until I depress the clutch. Is this still indicative of the thrust (release) bearing. Unless of course as you say, it is the thrust bearing causing this noise while driving.

[karllovesmercedes]

take it back

Yea definitely, not accepting it like that

[yeti]

where are ya mate ,someone close by on here might know more if ya could cruise by maybe

[karllovesmercedes]

Located in Hamilton, would be great if someone else could have a look, this week is no good though as I'm full of university papers to finish

Will take it back in to Marshall Transmissions this coming week and get that thrust bearing sorted and see where it goes from there, hopefully it does sort out the rattle. If not then wouldn't mind a keen ear from somewhere around here having a look! In the mean time I will check out the pulley, heat shield and that pedal free-play tomorrow morning first thing.

Cheers to jammysammy, churchill and the rest of you guys for your input and advice too. Much appreciated

[Big]

Might be a bit left field but, I've come across one of these motors with a loose crank pulley. Started with a light rattle and got worse, much much worse

Apparently this is sort of common.. But have you checked the couter balance belt and or shaft..? makes the engine seem more rattly and it seems not as balanced umm hard to explain it but sounds similar to what you are explaining.. If the belt has broken then before replacing it check that the balance shaft turns free.. if not the bearing on that have gone , and not worth replacing, doesn't do any more damage to engine but makes it seem noisier..Balance shaft does what it says.. balance the engine while running.. makes it smoother.. and quieter to the ear..

[karllovesmercedes]

Might be a bit left field but, I've come across one of these motors with a loose crank pulley. Started with a light rattle and got worse, much much worse

Apparently this is sort of common.. But have you checked the couter balance belt and or shaft..? makes the engine seem more rattly and it seems not as balanced umm hard to explain it but sounds similar to what you are explaining.. If the belt has broken then before replacing it check that the balance shaft turns free.. if not the bearing on that have gone , and not worth replacing, doesn't do any more damage to engine but makes it seem noisier..Balance shaft does what it says.. balance the engine while running.. makes it smoother.. and quieter to the ear..

Shouldn't be broken I don't think, was just recently replaced. Though I have noticed the truck vibrates a lot recently when idling (800rpm) Do I just turn the crank pulley to check this??

[Trundle]

is there any way you could put a vid up so we can hear the noise ? may make diagnosis a bit easier !!

[Big]

Might be a bit left field but, I've come across one of these motors with a loose crank pulley. Started with a light rattle and got worse, much much worse

Apparently this is sort of common.. But have you checked the couter balance belt and or shaft..? makes the engine seem more rattly and it seems not as balanced umm hard to explain it but sounds similar to what you are explaining.. If the belt has broken then before replacing it check that the balance shaft turns free.. if not the bearing on that have gone , and not worth replacing, doesn't do any more damage to engine but makes it seem noisier..Balance shaft does what it says.. balance the engine while running.. makes it smoother.. and quieter to the ear..

Shouldn't be broken I don't think, was just recently replaced. Though I have noticed the truck vibrates a lot recently when idling (800rpm) Do I just turn the crank pulley to check this??

Nope take the top cam cover off and you can shine a torch down and see the top pully( it's easier to see it if you take both covers off but this means the crank pully has to come off too).. Even though it's a newish belt I had one fail on wifes truck not long after installing it.. again a common fault ..

[karllovesmercedes]

Thank you, will give that a look at tomorrow as well. Wow haha, that isn't very reassuring Was it the belt that failed or installer-error?

is there any way you could put a vid up so we can hear the noise ? may make diagnosis a bit easier !!

Will give it a go Trundle, over the exhaust and engine noise it's probably a bit hard to hear. I'll give it a go anyway and see what comes out.

Cheers, Karl

[karllovesmercedes]

- The clutch freeplay is fine, checked that today.
- The Turbo heat-shield seems to be bolted on well and not going anywhere, nor is anything touching it.
- Didn't have any time to check the pulley, but will tomorrow.

I recorded this video on the quietest stretch of tarmac I could find, unfortunately the camera strap is hitting the camera and making a clicking sound, but if you listen past that at 720p you can sort of hear the rattle in the background

http://www.youtube.com/watch?v=OLv6SKactj0

[NJV6]

I'd get the harmonic balancer checked as others have said. Its pretty common, especially if its been disturbed.

[karllovesmercedes]

Thanks NJV6, am starting on it now, will let you all know how it goes. Never heard of the balancer issue before this to be honest, surprised it can happen after such a short time from replacement

[karllovesmercedes]

Might be a bit left field but, I've come across one of these motors with a loose crank pulley. Started with a light rattle and got worse, much much worse

Apparently this is sort of common.. But have you checked the couter balance belt and or shaft..? makes the engine seem more rattly and it seems not as balanced umm hard to explain it but sounds similar to what you are explaining.. If the belt has broken then before replacing it check that the balance shaft turns free.. if not the bearing on that have gone , and not worth replacing, doesn't do any more damage to engine but makes it seem noisier..Balance shaft does what it says.. balance the engine while running.. makes it smoother.. and quieter to the ear..

Pulley seems completely fine. The noise is definitely coming from the block somewhere though, probably top end, found a video of EXACTLY what it sounds like

http://www.youtube.com/watch?v=wBfP7lGaUeU

The guy on there said it was dirty injectors, anyone else think it could be that?