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Diagnosing unusual noises in your Land Rover

As with most other articles on this website, this is not a substitute for professional diagnosis of faults that may occur with your Land Rover. It is, however, a guide to some of the more common problems with suggestions on what to look for. Another benefit is that by being able to explain the nature of the problem in simple and succinct terms to the mechanic, it can save a lot of time and therefore money.

Rolls Royce used to claim that at 100 MPH, the loudest sound was the ticking of the clock. They fixed that minor irritation by changing to a digital clock.

Actually, the subject itself is not at all funny. Being aware of the noises made by your vehicle can alert you to problems before they become expensive, dangerous or both. This is one reason to drive occasionally with the sound system off, preferably in a variety of conditions, meaning on quiet back streets, over speed bumps, on highways and off-road. Even with “normal” ambient sounds, the ear can actually be trained to focus on various parts of the vehicle with surprising ease. Here are some suggestions:

The Land Rover exhaust system

It is fairly simple to pick a faulty exhaust. The noise might be caused by any of the following:

  • A hole in the muffler - easily detected by getting close to the muffler itself to listen for a rumbling sound.
  • A dropped supporting bracket causing rattling or scraping sounds
  • A leaking exhaust gasket usually starting with a piston-like “ppfft” then getting progressively louder. Over time, it will damage the manifold if not fixed. The illustration shows a broken exhaust stud that was probably a result of the vibration caused by a defective gasket

broken exhaust stud
image source: http://4.bp.blogspot.com/-cR9CFIVZ6rw/UB96v3P5H9I/AAAAAAAAEJg/kGdhKX02wbw/s1600/HPIM6055.jpg

Sounds from the Land Rover engine compartment

Try to distinguish between the exhaust note and other sounds coming from the engine bay:

  • Squeals will most likely come from a loose drive belt. This must not be ignored. Older vehicles may have manual tightening systems but there is more likely to be a self-adjusting serpentine belt. Inspect all belts carefully and if there is obvious wear, have them replaced promptly.
  • A growl, grumble and/or a high pitched squeal is usually caused by a faulty water pump bearing. The pump should be replaced before real damage is done. Get the fan coupling checked at the same time.
  • Hissing sounds may come from a faulty pressure cap or leaking cooling hose.
  • Whistling noises may be vacuum leaks. Try to identify the source as a guide to your mechanic.
  • Serious rattles from around the engine could be caused by a loose component but if the rattle seems to come from inside the engine, get professional advise fast before you get stranded. For example, a “clacking” sound from inside the engine could be tappets, but it also could be far more serious.
  • A growling or grinding noise is frequently caused by a leaking steering pump seal If refilling the reservoir does not fix this (most are self-priming), the hoses and/or the pump must be changed.

worn drive belts
image source: http://static.pepboys.com/images/uploads/belts_wornbelts.gif

Land Rover Brakes

Problems are common to all modern vehicles fitted with disk brakes. Sounds to beware include:

  • Excessive squealing is probably (but not always) due to worn brake pads.
  • Grinding noise may mean the pads have worn to the stage where the disks (rotators) are being scored and/or a calliper has broken. Obviously such conditions are potentially dangerous.

new and worn brake pads
image source: http://cf.ltkcdn.net/cars/images/std/154560-325x216-worn-and-new-brakes.jpg

Tyres on your Land Rover

The choice of tyres is important though some compromise is to be expected. They are graded for the percentage of running on and off road - typically 70/30 or 50/50 etc. Having too agressive a tyre will mean more tyre noise without necessarily improving performance. Conversely a tyre designed just for sealed roads will probebly not provide sufficient grip off-road, Regardless:

  • A clicking sound, variable with speed may mean rubber peeling off the tyre and catching on the wheel arch. Change it immediately before it blows out.
The Land Rover Drive train

This is a complex arrangement of moving parts and ANY noise MUST be investigated.

  • A metallic clicking sound is most likely a faulty CV joint, and may be accompanied by difficulty in turning the vehicle one way or the other.
  • A ticking/clicking sound may also be caused by a loose or defective universal joint in a drive shaft, If the joint fails the result is potentially deadly. There have been cases of vehicles flipping over if the shaft digs into the road surface.
  • A defective wheel bearing may also click or make a grinding noise before it seizes. Noises from worn bearings can be tricky because the noise can carry along the chassis and appear to be coming from a different component.
  • Loud whines from the back or front may be coming from the diff centres. Check the oil levels immediately and if OK, consider changing the centres.
  • Whines from the centre of the vehicle, audible through the cabin are probably from the gearbox and/or transfer case. Such noise is not to be ignored.
  • A clanging noise on takeoff may be a faulty auto transmission and/or worn thrust bearings.

These illustrations are (left) a defective universal (centre) worn and new axle half-shafts and (right) a defective hub bearing


images sources: http://farm5.static.flickr.com/4050/4445328061_7ff426afd4.jpg / http://www.discovery2.co.uk/images/fronthub/hub12.jpg

Noises inside the cabin

Other than annoying rattles from the tailgate, doors or windows locks and regulators, the most common noises are caused by leaking dust seals. The problem is that unless they are fixed, they may prevent the driver hearing other more serious noises. The teeth are worn on this regulator causing a grinding sound when the window is raised. Soone, it will fail completely

Please see the other articles on dust and water seals

This article is one of many written by ASPAC Consulting,in collaboration with the technical experts at Graeme Cooper Automotive. To download it in PDF format, click Unusual noises.pdf

Please CONTACT US for help with your particular vehicle OR post a question on the forum.

 

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