strange noise in 3ltr patrol

Hard diagnosing a noise over the internet. I had a squealing noise which was worse when cold and gradyually disappeared as the engine got warm. it sounded exactly like a belt slipping or a bearing letting go.. It turned out to be a leak from the EGR valve, fairly common as I found out after a bit of research. Might be worth looking at, mine was covered by warranty but it was a fairly lengthy repair job.

Thanks for the reply navaraman the noise increases in speed as the engine speed is increased this is why I think it must be a bearing but which one and why does it disappear when grease or spray is applied.

If the noise went away when the mechanic put grease on the belt then the belt will be the problem, to check if this is still the problem either spray plenty of CRC, WD40 or whatever (Belt Conditioner is best but people usually don't have that laying around) onto the belts with the engine running if the noise stops its obviously the belt so would be best to replace it. This is an easy first step to diagnosing the problem.
Chris

Suprised to hear "goingplatnium" hasn't pop'ed his daft head into this post yet!! Don't worry the master of all things 3lt Nissan will be along soon I am sure!!
Have a good day

Cheers Stefan

If you have the room without cutting your hand I just use good old soap (bar of soap) and hold it against the belt as the engine is running and will shut it up if thats the problem. By doing it this way there is no chance of over spray onto your bearings etc making it easier to eliminate the problem. I have used so many of those belt sprays to stop the belts on the old hilux from sqeaking I just went back to the hand soap and worked a treat. Regards Steve M

Hi joeblogs
Just read your problem in regard to the 3ltr Nissan motor with noise coming from the belt drive area. I notice that you have already had your belt drive tensioner checked and remedied, however, there is another problem that occured with the belt drive on the 3ltr motor, which was recognised by Nissan and a bulletin from Nissan was sent to all Nissan dealers to cover this problem under warranty. Also the belt drive tensioner was also a problem Nissan identified and covered under warranty.
1. The fan belt tensioner had a problem which you have apparently had seen to and
2. also, there is a problem with the alignment with the belt pulleys. As I said earlier this was recognised by Nissan as a problem and covered under warranty. So any Nissan dealer would be aware of these problems with the ZD motor.

You have to be very careful as not all of them are honest and will try and suck the last $ out of you.
If you give the Nissan Technical Service section a ring in Melbourne on phone 03-97974111 they will be aware of this problem and be able to advise you accordingly. You haven't mentioned whether your vehicle is still under the warranty period or not, however, if not and because it has been an established recognised problem you may be lucky. Who know, but what do you have to lose. I have found that there was a lot of problems with the ZD30 motor but the Nissan Technical Branch were reasonably honest but some dealers were still out for a quick buck.
Good luck and hope you fix the problem.
The Major

I would find another mechanic or tell him to go ahead with the crankshaft replacement on a no fix ,no pay basis LOL. See what he says then.

Normally when there is a noise in the belt areas you remove them one at a time until the noise disappears.
When all the belts are removed ,turn the alternator and water pump by hand by hand and feel for roughness.