hey guys,

going nuts with this issue , my serpertine belt keeps slipping off the alternator !!! so I replaced pulley just above the alternator , the tensioner , the water pump , retorque the crankshaft balancer and STILL
belt half way off the alternator , what gives !! has anybody experienced this issue or any good suggestions ?

 

I think this cropped up before. There are a few different lengths available and all listed for the 4.0 V8 by different vendors. Not all are correct. Maybe you have one of the slightly longer ones. Worth a check.

Have a look here: https://parts.jaguarlandroverclassic.../brand/jaguar/

TO VIN M44199 XR82811 ↳XR830447
FROM VIN M44200 - TO VIN M45254 XR830447

Maybe getting the correct length from these part numbers will shed some light ...

 

neilr my is a 3.0
however like you said its worth looking into it.. also i forgot to mention i had a coolant leak wondering if that could have contributed to that problem

 

Per Barratt's parts catalogue there were three different serpentine belts for the V6 over the production run, so you may well have an incorrect belt installed. I personally would always replace a belt that has been saturated with coolant from a leak, but that is just me...

Good luck in getting this sorted.

 

Look on the belt tensioner. You should see a set of indicator marks, typically cast in the main body and pulley arm. As the belt stretches in normal use, the indicator marks move out of alignment. This tells you the belt is now too long for use. It would also let you know if the belt you've installed is not the proper length. I have an excerpt from the manual showing this, but I can't find it right now.

Also, loosen or remove the belt to take the tension off the pulleys. Shake each pulley to see if any of them have play. If so, those bearings have failed and need to be replaced. A wobbly pulley could throw the belt like you've been experiencing.

 

Found the details of the drive belt tensioner. I think this is for an early V6, but there should be something similar on all models:

 

In addition to what Karl suggests, check the pulleys for correct alignment by rotating the engine by hand.

 

thanks guys appreciate all your help,

tomorrow morning I 'm going to check the marks on the tensioner, the belt and also the pulleys I dont know about rotating the engine by hand hard enough to get in there to check pulleys and tensioner ...

 

so I I got home early today , decided to start working on it checked tensioner unable to see any marks on it .. HOWEVER I did paid close attention to the pulleys and alternator pulley It did looked kind of crook it it TURNS out I left the top bolt out of the alternator after reinstalling it which I had removed before.. installed top bolt drove back and forth to gym belt still there no problem
only thing I keep getting the " restricted performance " warning and check engine light

 

Cool!

Now that the alignment issues are sorted..

Pull the codes for the restricted performance and start a new thread on what they are.

 

Glad to hear you got the belt issue fixed. Thanks for the update.

Some more details please, for the restricted performance and check engine light. Is this a new problem, only present after your recent work? Or is this an on-going problem that precedes that?

First things first, if the check engine light is flashing, do NOT drive the car. A flashing light signifies a problem bad enough to damage the catalytic converters. Correct the problem before continuing to drive.

Please read out any fault codes and post them. Please post the 5-digit alphanumeric code such as P0306, etc. Many code readers give generic definitions, but the actual code is much more helpful for troubleshooting.

Also, please make sure your battery is fully charged. With your recent serpentine belt trouble, I wonder if the alternator pulley had been slipping, and the battery was not getting a full charge. A low battery can cause all sorts of weird problems. I recommend hooking up an automatic charger overnight to be sure. You'll want a charger with at least a 10-amp output. A trickle charger won't cut it.

 

I was having the restricted performance and check engine along with belt issue so it is not a new issue.!
I m using the Icarsoft1930 to pull codes or any info the only I keep getting is:

fault in communications with vehicle ECU
please confirm
1. this vehicle is armed with system
2. this system is an electrical control system.
3. the diagnostics connector is ok
4.the ignition switch is on

it does feel abit rought idleing too not when im at a stop ..specially when im driving ??

wondering if the battery its causing issues and is there a way to verify that ..

 

If your scanner will not connect..Can you visit a parts store like Advanced or Autozone and see if they can pull the codes?

As Karl brilliantly (as usual) posted above...We need tot P0xxx codes to have a place to start.

 

Is that happening with the key in position II & the engine off ? I use an i930 & this happens with my STR. If I start the engine, it then communicates with the module.

 

thanks guys ,

I opened another thread where I explained codes I m getting ..also work history on the car I have done...

 

Hi All,

I bought an I930 a couple of years back and played hell with the supplier because of this problem "Fault in Comm with ECU..." which in effect let me see everything but the engine codes. However, if you use the OBD2 Diagnostics function rather than the general Diagnostics function - which takes you through Make, Model and Year Selection before the reader scans all the cars computers - the I930 takes slightly different route and asks you to select Manufacture before initiating the scan and then reports back on any DTCs it finds for the Engine.

It looks like an unintentional design feature in the software to me though some might simply call it a Design **** Up!

If my explanation is not clear let me know and I'lll add a complete explanation with some photos.

Cheers,
Cubist

 

yes Cubist appreciate the help ,
i have used it that way i was able to pull the codes that I listed in the other thread.