D22 Navara - whirring noise while cruising

[smithbro]

Hey guys!
I have a 2004 ZD30 D22 and am experiencing a weird whirring noise when cruising. Particularly at around 60kph in 4th gear and using minimal throttle and it is also fairly constant when cruising at 100kph in 5th gear. Seems to be coming from the drivers side of the engine bay or wheel area, not 100% sure. The sound is similar to road noise from big mud tyres. Definitely not my tyres though.

Done plenty of searching online and have checked the following;
EGR - this is blocked off and swirl mod done. I've pulled off and resealed the blocking point as it was weeping some oil.
Checked front wheel bearings - seem fine, no noise or movement.
Checked hubs are not locked in.
Checked drive belt tension - seems fine.
Checked for boost leaks - truck has a FMIC setup, all clamps are tight and silicones are not blown etc.

Has anyone experienced this? What else can I look at to try and eliminate this annoying noise!?!

Cheers!
Alex

 

[Old.Tony]

Do you notice it at 60km/h in 5th gear? Is it at the same frequency (rate) as it occurs at 60km/h in 4th gear? If the frequency is the same in both gears, it's on your drive train. If the frequency changes, it's related to the engine.

First thing I'd do is check your wheel locking hub and make sure they're off. I'd then jump underneath and give the drive shafts a wiggle, there shouldn't be any movement apart from rotation. The front drive shaft should rotate freely when you've selected 2WD and the front hubs are unlocked, that's worth checking in case one of the hubs has an issue and isn't unlocking.

If it's the engine, it could be an exhaust leak, particularly around the turbocharger. I had an issue where the gasket in the join between the turbocharger and exhaust manifold had become thin and acted like a reed in a clarinet (played rather poorly, I might add).

Try the 60km/h speed in both gears and let us know what happens to the frequency of the sound. That will help pinpoint the issue better!

 

[smithbro]

Hey Tony,

Thanks for the reply! Yes it does seem to be the same frequency at 60kph in both 4th and 5th gear. It seems to be from the drivers front wheel area. I checked that wheel bearing yesterday arvo and it was slightly loose, tightened it up so there is no play but sadly the noise still occured on the trip to work this morning.

 

[Horatius]

Yes it does seem to be the same frequency at 60kph in both 4th and 5th gear. It seems to be from the drivers front wheel area. I checked that wheel bearing yesterday arvo and it was slightly loose, tightened it up so there is no play but sadly the noise still occured on the trip to work this morning.

Have you tried slipping it in neutral when it's making the noise? If it makes no difference that should rule out anything in the motor.

When you say "checked the wheel bearings", how did you do this? Was there enough grease and was it ok, not all dried out? The races smooth, no pitting?When was the last time they were packed?

Wheel bearings don't need to have lots of play to be stuffed. Tightening it won't do anything much if it's had the sword. Sometimes with bearings it can not only be difficult to find which wheel is making the noise, but if a wheel itself is the cause of the noise.

They don't necessarily make an obvious rumbling when when you lift it up and spin the wheels either, have had it happen.

It might be worth having a good look, at worst it will give you a chance to repack them if they need it.

 

[Horatius]

ps. As Tony says, it's also worth checking the hubs are fully out. They can make a racket if not (but it's usually very obvious).

 

[Horatius]

pps^

In 2wd with hubs out, if you get under and spin the axle to each front wheel, they should spin easily. You should hear and feel it if one of them is catching in the hub somewhere.

 

[smithbro]

Admittedly it was a quick inspection of the fronts - jacked up and spun the wheels (no resistance/noises) and then checked for play by jiggling the wheel while holding at 12 and 6. Drivers front had a small amount of movement, so I tightened that side. There was plenty of grease but it did seem old. I've got a new front bearing kit here so will be pulling them down this weekend to inspect/repack or replace

The noise itself occurs when I am cruising in 4th/5th at 60kph-100kph when only a minute amount of throttle is applied. If I let off the throttle, the noise stops.

Appreciate the help guys! Will update if I find anything over the weekend

 

[fuzzylogic]

This probably isn't it, but I had a strange one once on my D40, ended up being the alternator belt, which had stripped the inside rib only, the loose bit left on the belt would flick against something just at a certain engine load...made a clicking tapping noise which had me stumped for a while...worth checking

 

[[email protected]]

does it have a clutch pulley on alternator , remove belt carefully jam the armatuer with a screw driver , the pulley should spin freely one way

 

[[email protected]]

does it have a clutch pulley on alternator , remove belt carefully jam the armatuer with a screw driver , the pulley should spin freely one way watch youtube

Testing Alternator Pulley Clutch

 

[Horatius]

The noise itself occurs when I am cruising in 4th/5th at 60kph-100kph when only a minute amount of throttle is applied. If I let off the throttle, the noise stops.

So the noise only happens under load/with some accelerator? That makes it less likely to be a front wheel bearing then as that shouldn't make any difference.

 

[smithbro]

Okay so I'm still looking into this issue...

Pulled the belt off last night to inspect the alternator clutch pulley & tensioner/idler. Tensioner/idler seem to be working fine, bearing in the idler is smooth but it all looks very old so I will probably replace that. I was more concerned about the alternator clutch pulley - with the alternator jammed the pulley was locked in one direction and would spin in the other, but when spinning it feels gritty and not easy to spin. There is also a few mm of movement forwards/backwards? Seems easy enough to replace. Another symptom that makes me think this is alternator clutch pulley related is the battery light stays on the dash upon starting, until I give it a slight rev and then it goes away. Truck has always done this for the last year that I've owned it.

 

[[email protected]]

change the pulley before it seizes you will get rid of those noises

 

[Rera86]

Any update on this issue as its exactly what my nav is doing….

 

[Boogieboots]

I will also look into these suggestions. I have had what sounds like muddie road noise but no change in tyres. I did get the diff oils changed a little before it started and the hubs are definitely unlocked

 

[Rera86]

If i push the clutch in while driving the noise stops so im thinking its gearbox related.
Possibly thrust bearing.

 

[pmackie67]

I have same and mechanic said if it’s not that loud and you change gearbox oil ( I use Castrol 80 vmx gear oil )
I do it every 30000 ks and it silky smooth.
He also said nice gentle gearchanges and should be ok .
It’s gear selector that problem in mine .
Regards peter