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[Brynjaminjones]

I thought I'd start a new topic to save filling up the Morning one with all of my questions about the XJ's noise it started making yesterday.
Obviously it's really hard to describe the kind of noise it's making, but I'm running through some ideas.

I'm now wondering if I have a loose/cracked flexplate, as some of the videos on YouTube sound similar, and the XJ has made some noise for a long time.

This video sounds almost exactly as my engine has sounded for the last couple of years:
You can hear the knocking noise in the background that was apparently a loose flexplate.
The noise it was making yesterday sounds similar to the one this one was making too:

I thought yesterday that I had low oil pressure, but I didn't really drive it for long enough to monitor it properly. It was definitely coming up to the right region when I accelerated.

Has anyone else on here had a flexplate go?

[bgbazz]

Two very different sounds to my old ears...first one sounds a lot like a big end on the way out...second one could easily be the flex plate (sounds more like a loose rattle to me).

[Brynjaminjones]

Hi, my name's Bryn and I'm an idiot.
 
Guess who hadn't tightened the water pump pulley bolts enough, so that they came loose whilst driving...

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[Delk]

To state the obvious you need to determine where the sound is coming from first.

If it is top end as you first thought you can remove the valve cover and have a look around. The rockers are all fixed with no adjustment so anything loose or out of place is bad. The 4.0 and 4.2 are identical and you can run them a short time with the rocker cover off to check it while running. You will make a bit of a mess from drops coming off the rockers but it wont spray anywhere.
Items to look for
Loose rocker arms
Poor adjustment. Adjustment is done by the hydraulic lifter and could be caused by a bad cam, lifter or really low oil pressure.

Cam drive is via chain and if this is going out will make really bad noises. Plenty of picture son the internet.

Rod bearing noise is not common and would be from really bad service and oil change history.

I have manuals so cant give any clue to flex plate issues.

Exhaust manifolds can also crack and make a ticking noise. This is usually noticeable but not scary.

[Delk]

Hi, my name's Bryn and I'm an idiot.
 
Guess who hadn't tightened the water pump pulley bolts enough, so that they came loose whilst driving...

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Sounds like an easy fix if it didn't fall off.

[Brynjaminjones]

It should be back on the road in half an hour

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[bgbazz]

It should be back on the road in half an hour

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....minus the nasty noises I'm hoping. 

[tedthefed]

beer more than likely got in the way during previous repairs

[Brynjaminjones]

You're probably right Ted!
I remember now that I had difficulty putting those bolts in in the first place. I realised when trying to tighten it that I think the bolts are actually a fraction too long. I filed the ends down and it's gone back perfectly 

I've just been for a drive and all is well. It's certainly a relief, I was expecting the worst.

Let's not mention this again



The only thing I'm suspicious of now is a grating kind of noise that it's making all the time. It's been doing it since all the new parts, and it sounds a bit metal-on-metal like to me. The noise wasn't there without the serpentine belt on, but all of the pulleys sounded fine by hand. Could it be that the new water pump is wearing in or something?

[Delk]

My pulley touches just a little on the water pump inlet side. The clearance is really small and I only noticed it when changing my pump the other day. The old pump had a groove worn in it where the pulley ran.

A few miles later and liberal application of grinding paste (mud) and the groove must be back since the noise is gone.

[JamesH]

Result! That £500 you were mentally putting aside for repairs can now be spent on fun stuff 

[Dutch]

beer more than likely got in the way during previous repairs

Emily more like 

Well done Bryn. 

[jay140285]

You plonker Rodney


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[gazjeep]

Easy cheap fixes always my favorite outcome, well done Bryn

[Brynjaminjones]

Thanks guys, used the Jeep for a couple of hours yesterday and she's running nicely and is back to her days of beating chavs from the traffic lights 


Delk, I think you're along the right lines for the grating noise. I'm looking forward to it stopping as it's quite irritating!

[eastryjeep]

Second clip could be a broken flex plate.
Grab a long screwdriver in your fist, put the blade on the bell housing and your thumb in your ear and see if you can isolate where the noise is coming from. If you hear a metal on metal ring that changes with idle speed it could be a flex plate spoke cracked.
To make sure disconnect the battery and remove the starter, then turn the crank till you can get a grip on each of the flex plate (3?) spokes or the ring gear and pull back and forth. If it goes 'twang' that spoke is cracked and you are listening to the ends of the cracked metal rubbing against each other.