Belt or Pulley Noise

[Delray]

I was driving today, going around a curve with a good amount of acceleration/force being put on the motor. I got a intermittent, fairly loud low whining/squealing sound coming from the engine. It stopped then came back a few times within the next mile.

I parked it at home and lifted the hood. It would intermittently start and stop and also change pitch with RMP. It seems to be coming from one of the pulleys. I don't know if a bearing went out or what...tensioners, fan, crank, power steering, alternator, water pump, idler?

So far I found a diagram of the primary and secondary drive/belts/pulleys and pumps. I guess from here I will get a piece of tubing and try to isolate where the sound is coming from exactly?

 

[Delray]

Listening the best I could, it sounds like it is coming from the primary tensioner pulley.

 

[bbyer]

Belt deflection pulley, or perhaps spring tension?

My guess is that the noise will be from an idler pulley/belt deflection or one of the two belt tension pulleys. It seems that group of bearings go out more often than anything else.

Well that is not really correct but when a generator or other pulley is the problem, it seizes, and one of the belts rips off.

Some guys just replace the bearings however in the case of the deflection pulley, there is an updated idler pulley design now for the V8, part number PQR500350 per the link below. You might consider replacing it as well once you have everything torn apart.

http://bit.ly/1dGASsf

Nothing is straight forward on a 3.

 

[Delray]

So, should I just go ahead and replace both primary and secondary belts, both primary and secondary tensioners, and replace idler pulley with updated idler pulley while I have it apart...or is this overkill?

Thanks!

 

[tlt]

I would just replace all, if you haven't put belts on. Typically this is suggested at 95k.

You can check with your supplier for updated part numbers, most of the time, they automatically flag when new part numbers are available.

PQR500330 Serpentine belt, primary belt, lr3, 4.4l 1 $19.64
PQS500221 Ac belt, range rover sport, 4.4l 2006 - 2009 1 $13.93
PQG500030 Belt tensioner, serpentine belt, range rover 2006 - 2009 1 $48.09
PQG500220 Belt tensioner, ac belt, range rover sport, from 7a113766 2007 - 2009 1 $66.03
PQR500350 Idler pulley, lr3, 4.4l 2006 - 2009 1 $17.42

 

[bbyer]

Probably overkill.

Replacing all would most likely be overkill. It is more of a case of how much you have to remove to fix the problem. If you have to pull something off, then one should at least look at it with the idea of replacement as labour and time are the real costs, not the parts.

In your case, if it is that "first" spring tensioner, then that is about all I would replace unless I had the presses and or knowledge to replace bearings only and then where the labour is free, the costs are very low.

I would however remove both belts and spin/rock all the pulleys to see if anything seems out of place. If the belts are old, I would replace both and of course keep the old ones; as such, I would know the "spares" fit and that needing a new belt thru breakage would be unlikely.

Incidentally, the long belt is I think 6 grooves and the shorter "fan" belt, 8 grooves. As such, watch what you are replacing and make certain the pulleys and belts have the appropriate number of grooves/ribs.

 

[tlt]

I did all of mine, and kept the old ones for spares.

 

[Delray]

Completed this project successfully . I was a little intimidated considering the number of items to replace, but they are all bolt on/off once you get things taken a part for the belt replacement. The link I found for 'LR3 Belt replacement' had lots of good pics and instructions for the belt replacement.

A couple of things to note.

1. The new / updated idler pulley requires you grind down a portion of the support plastic (plastic arms that radiate from the center). Grind down the area just outside the inner plastic ring. Otherwise it binds against the metal collar on the vehicle. This could be really bad if you installed/tightened it without doing it (probably have bad noises burnt plastic smell as soon as you ran the vehicle).

2. Removing the hose attached to the air intake resonator was not intuitive (at least for me). You have to squeeze the open area of the circular collar and it pops off.

3. I noted another person on that thread complained about their fan nut must not really 36mm, as the spanner slipped/stripped across the nut. This happened to me also. I figured out the rented tools spread a bit with all the abuse, so the span is more like 38-40+. I used a 5 lb hammer to pound it back into square/36mm.