Topic: 2.5 Diesel Cherokee whining noise when I accelerate (Read 4523 times)

bengingle · « **on:** July 18, 2011, 10:00:49 AM »

Hi All,

I think I have bought the car version of the filem 'The Money Pit' with my P-Reg Cherokee.

Having had the head done, it's now got a new noise and problem for me.

Basically when I accelerate in pretty much any gear it's whining/screaching... almost sounds like a belt, but can't put my finger on it. The noise only happens when in gear/motion not if i rev it when in neutral.

it doesn't do it if I'm gentle on the throttle, but under 'normal' acceleration is whines from I think the back of the engine. when i'm in cruise control and it's holding a steady speed, it seems fine, but if i then go up hill or put any pressure on the throttle, it whines/rattles?

As I say, sounds a bit like a belt or fan, have had a look on the net and have the following suggestions:

A wheel bearing
Drive shaft U-Joint
A 'fan' in the engine rubbing something
Brakes rubbing

The car drive fine to be honest, and as it doesn't do it in idle its got to be something thats affected when in motion.

Any thoughts or suggestions guys?

tim_aka_tim · « **Reply #1 on:** July 18, 2011, 02:41:22 PM »

Rear diff?

bengingle · « **Reply #2 on:** July 18, 2011, 02:53:38 PM »

It's not constant enough to be the diff I don't think and it sounds like it's coming from the front of the vehicle not the back. If it was the Diff, it would be more of a grind and vibration wouldn't it? This sounds like a belt screaching/whining and as i say, only when the pedal is being pushed down, not when it's cruising at speed...

The Smiths · « **Reply #3 on:** July 18, 2011, 04:54:55 PM »

sounds like a leaking turbo pipe, check the clamps (or better still change them for some good ones), and see if you have any holes - most likely down near the steering box

bengingle · « **Reply #4 on:** July 18, 2011, 05:50:24 PM »

OK I'll check that one then... can i see it all from under the engine or can i look through the bonnet?

MOCAJ · « **Reply #5 on:** July 18, 2011, 06:06:34 PM »

clutch thrust bearing or bearing on the idler pulleys for the serpentine belt

if it makes no noise when you depress the clutch then prob the latter, take off the belt and look for tightness, also inspect belt for glazing and cracking

Mike Pavelin · « **Reply #6 on:** July 18, 2011, 06:55:49 PM »

Split turbo hose or intercooler.

Dave69 · « **Reply #7 on:** July 18, 2011, 09:26:38 PM »

does the jeep lose power above 2k as this is when the turbo kicks in, as Mike says split hose on to and from the turbo would be worth looking at.

bengingle · « **Reply #8 on:** July 19, 2011, 09:22:50 AM »

Cheers for the suggestions guys, feel free to keep 'em coming.

It doesn't loose any power when driving, having just had number 4 head replaced it drives fine, no noticable loss of power. As I say, it only makes the noise when you put your foot down and put load on the engine (doesn't make the noise in neutral no matter how hard you rev it). When the engine is working at a constant rate (ie. you're not accelerating, just cruising) the noise isn't there or noticable, it only kicks in (and it's very audiable) when you give it some gas (as the yanks would say). Some one did say to me ages ago the fan belt looks a bit worn... could that be a culprit?

The clutch does nothing (other than what a clutch should do), the noise isn't affected by the using the clutch at all... only giving the engine some power makes it happen.

If you're in first and you 'gently accelerate' it's also fine, it's only when you give it decent throttle (and I don't mean flooring it, basically normal driving working up through the gears) it screams and whines.

jay140285 · « **Reply #9 on:** July 19, 2011, 12:58:36 PM »

Fan belt most probably then,

Change it as its a cheap fix first.

If that doesn't cure it at least you haven't spent lots of money.

bengingle · « **Reply #10 on:** July 19, 2011, 01:46:01 PM »

Not wishing to sound too stupid, but does the fan belt work harder (go faster) as I put my foot down then?

jay140285 · « **Reply #11 on:** July 19, 2011, 01:50:36 PM »

Yes it does, faster the rpm faster things spin.

bengingle · « **Reply #12 on:** July 19, 2011, 02:21:21 PM »

That being the case though would it not spin at the same faster rate when I'm in neutral reving the engine up - which doesn't make the noise, it's only when I'm driving/moving?

UKJeeper · « **Reply #13 on:** July 19, 2011, 02:47:53 PM »

Quote from: Mike Pavelin on July 18, 2011, 06:55:49 PM

Split turbo hose or intercooler.

(Mike's a Jeep mechanic. I'd be looking at his suggestion).

bengingle · « **Reply #14 on:** July 19, 2011, 02:53:12 PM »

Lovely stuff!

Panic mechanic! · « **Reply #15 on:** July 19, 2011, 03:16:20 PM »

belts can make a lot of noise, when driving the engine is under more load, every switch you flick on can make a difference, power steering pumps etc all put extra load on the belt and if its worn and cracked it will slip.

bengingle · « **Reply #16 on:** July 19, 2011, 03:42:24 PM »

Thanks Guys much appreciated as always... it's actually going to go in to my local garage but I like to give them a bit of a heads up (and get some knowledge myself) so when it's done I'll post the diagnosis. fingers crossed it is something unexpensive like a belt.

jay140285 · « **Reply #17 on:** July 19, 2011, 03:45:51 PM »

Quote from: Panic mechanic! on July 19, 2011, 03:16:20 PM

belts can make a lot of noise, when driving the engine is under more load, every switch you flick on can make a difference, power steering pumps etc all put extra load on the belt and if its worn and cracked it will slip.

The Smiths · « **Reply #18 on:** July 19, 2011, 10:18:32 PM »

Quote from: The Smiths on July 18, 2011, 04:54:55 PM

sounds like a leaking turbo pipe, check the clamps (or better still change them for some good ones), and see if you have any holes - most likely down near the steering box

Quote from: UKJeeper on July 19, 2011, 02:47:53 PM

Quote from: Mike Pavelin on July 18, 2011, 06:55:49 PM
Split turbo hose or intercooler.

(Mike's a Jeep mechanic. I'd be looking at his suggestion).

Listen to Mike - but I also drive a 2.5TD and have had this happen

donk498 · « **Reply #19 on:** July 20, 2011, 05:57:17 PM »

Definatly sounds like a boost leak. Inlet manifold gasket maybe as the heads been off.

Dave69 · « **Reply #20 on:** July 20, 2011, 09:33:15 PM »

a long5mm hose pipe put one end to your ear and move the other end round the areas you might think there is a leak. what you should hear is the whistle but obviously louder. this is just a simplified doctors stethascope (sp)

bengingle · « **Reply #21 on:** July 21, 2011, 08:29:02 AM »

Dave thats a quality suggestion, I'm now thinking tin can telephones!

Dave69 · « **Reply #22 on:** July 21, 2011, 09:04:38 PM »

not sure whether you are being sarcastic or not but it's a genuine piece of diagnostic equipment albeit simple just like a long screwdriver which amplies the sound of bearings etc

mechanics stethascope with a tube and solid rod attachments

Author Topic: 2.5 Diesel Cherokee whining noise when I accelerate (Read 4523 times)

bengingle

bengingle

bengingle

Mike Pavelin

bengingle

jay140285

bengingle

jay140285

bengingle

UKJeeper

bengingle

Panic mechanic!

bengingle

jay140285

donk498

bengingle