300 Tdi Discovery noises???

Disco as sig. getting some whiney, whistley noises from it when accelerating, and on over-run, particularly under load. Lifted bonnet and had a looksee/listen and it appears to be the waterpump ... ish area.

Is it likely to be the waterpump as a whole or is there a replaceable bearing that might produce the same symptoms? I'm about to have a longer look, well, in an hour or so, when i intend taking the aux. drivebelt off and turning it by hand to see how hard (oo-er missus) it is. Can anyone give me a clue as to how hard or easy it should turn? I mean, like a normal nut freely rotating on a bolt or a nyloc nut, rotates by hand with a lot of force?

I'll also want to check the fan/viscous coupling. AIUI if the engines/water temp is warm/hot the fan should be hard to turn, when it's all cold it should turn easily ... Is this the right way round???

Cheers.

Reply to
Paul - xxx
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Check all the things driven by the belt(s) - water pump, alternator, power steering pump, fan, a/c compressor (if fitted) and idler pulley. All should rotate freely and noiselessly. If any are wrong you'll recognise it - noisy, ratchety, stiff, wobbly etc..

The water temperature doesn't come into it directly. The viscous fan senses the temperature of air exiting the rear of the radiator. You can have a cooking engine, blocked radiator and the fan thinking the engine is cold!

Reply to
Dougal

Thanks, 'swot I figured, but wanted to check first.

Heh, now that's an arse-about way of doing it .. but then it's a Landrover ... ;)

Reply to
Paul - xxx

Triple check the water pump mate, if it goes, it goes!

Also check the tensioner.

Reply to
Nige

Yep :)

It should turn smoothly with no play whatsoever.

The aux belt tensioner is another whiny place. The tensioner is about £40, but the bearing in the middle presses out, and a new one in for about £5.

I took mine out, and took it to a bearing shop.

Only issue with doing it is that its a bit tight for space on the 90 at the front with the rad in.

Reply to
Mark Solesbury

On or around 30 Aug 2008 15:07:49 GMT, "Paul - xxx" enlightened us thusly:

I've had 2 alternators go on 300 TDis.

Basically:

Start the engine from cold, speed it up to about 2000 revs. Fan should run noisily for 20-30 seconds then slow down, while running, it should pull lots of air through the rad.

The second check is harder as you need to get the engine hot. Presuming the fan ran down as described above, run it at about 3000 revs on a warm day with it stationary, til the temp gauge gets above normal. At some point above normal but before the red, the fan should come back in and spin noisily for a while.

The other way is to drive slowly up a long steep hill on a hot day.

It's not easy to get a TDi up to fan cut-in temperature.

Reply to
Austin Shackles

Take the belt off, which is dead easy, and examine each pulley and the water pump. Almost awlays a failing water pump will feel "squidge , squidge" as you turn it - they don'y usually squeal until very near the end....

The sound you describe could well be just the "300 squeal" - put a spot of talcnum powder on the belt - does it go away? If so, changing the belt may make it go a away, or you can just live with it.

It could also be the alternator bearings. There are 4 types fitted to 300 Discovery I's - makesure you get the right one, they are interchangeable to an extent, but differing pulley sizes will make the belt tension wrong, leading to premature bearing failures.

The viscous unit should be slack when the engine is cold, locking up as the temperature rises. Occasionaly they fail "unlocked" which can lead to over heating, but mostly they fail "locked" and will bo nothing other than over-cool.

Cheers Richard

Reply to
beamendsltd

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