Rumble at rear of car AGAIN!

[podge72]

Ok...so story so far...bough car then within a few weeks of ownership had reconditioned gearbox at a cost of £2500 due to rumbling sound coming from rear. Assumed knackered gearbox, torque converter etc.

Have had the car back for a few weeks now and the rumbling seems to be still there.

Oddly it seems to only be when under light acceleration and between 30-50mph (as before). Also, the rpm seems to go up by approx. 250 rpm then drop back down then go up, then back down etc, etc at the same time as the rumbling noise occurs.

Is there a simple explanation for this or has anyone come across this before.

Any advice would be appreciated.

Thanks

Shaun

[Old Peter]

Hi Shaun,

 

I can't  think of anything without hearing/experiencing a the rumble,  But the first thing that comes to mind is the exhaust is a touch loose.  Maybe the rubber mounts holding it on?

 

Regards,,
 

Peter.

[podge72]

Peter

 

I'll check the exhaust mounts but what about the rpm issue, as this only seems to happen at the same time as the noise?

 

Cheers

[Old Peter]

Hi Shaun,

 

I am afraid I could not put my finger on that as I am not an engineer,  but I have come across situations where vibration occurs at a certain rpm and goes away when the revs increase or decrease.  It is usually something loose.

 

Regards,

 

Peter.

[O.T.H]

Hi Shaun

 

Can I just ask is your car a 4 WD I'm not really  S types but if it is that clears things a little.??????

 

Frank

[Old Peter]

Hi Frank,

 

All S types are rear wheel drive. I have had a whine but never a rumble from an RWD vehicle.

 

Regards,

 

Peter.

[O.T.H]

Hi Peter

 

Yes Peter but if its in the rear and it shows a rev change it must be the dif or something

in the drive line ?????   I would say.???

 

Frank

[Old Peter]

Could be, Frank.

 

Of course, getting the feel of the car on a drive can tell a mechanic quite a lot, but us old drivers can only go by experience.

 

Peter.

[Mike_eng]

Hi Shaun,

 

Please see the following website http://www.thelurch.com/lurching_zf_transmission.htm I think you'll find your answers there.

 

Your car is fitted with the same 6 speed automatic gearbox as mine, am I right? If so you need the firmware upgraded to the latest version.

 

I have attached Jaguars technical bulletin 307-14 which describes the fault and how to rectify it.

 

I would strongly suggest taking it to a Jaguar specialist rather than a dealer. Nene Jags in Peterborough charged me £70.00 to do the work, Guy Salmon Jaguar wouldn't even believe their own bulletin and were convinced "it must be something more serious" surprise surprise!

 

It's been fine for over a year and 16000 miles now.

S307-14UK (1).pdf

[MalW]

Hello Shaun

 

Did you get anywhere with the vibration problem. I have the same issue. After driving the car for about a mile and only travelling at about 40mph  vibrations are felt/heard from the nearside rear, and the revs go up and down over a 250 rev band. After a couple of minutes the vibrations stop, the revs remain constant and I never get another problem no matter how many times I stop and start the car through out the day. The problem re-occours  the next time I use the car, which may be up to a week later.

In my opinion it is not the gearbox or the diff, as the problem would be more consistent and the car suffered from the jag lurch which was remedied when I had the gearbox reprogrammed at a local jag specialist.

The car drives impeccably except for this fault.

 

Is there anyone who has experienced this low speed vibration problem and who can offer some advice on how to resolve the issue.

 

Shaun, in the absence of any replies I will go to my local jag specialist to seek advice and will post their comments in due course.

 

Malcolm  

[Old Peter]

Hi Malcolm and welcome to the Club.

 

I think Mike has probably given the right answer.  I had a couple of guesses, but my S type is one of the last few made so I have not had that experience.

 

Regards,

 

Peter.

[MalW]

Hello Peter

 

Thanks for the welcome.

I have had the jag lurch resolved but the vibration issue persists. The fault only happens during the first mile or so of driving and lasts for only 30 seconds to a minute and it doesn't happen again until after the car has been stood for a while. It feels as if the brake on the nearside is binding but this would be felt as soon as the car was driven if it was related to being stood for a while. I have also had new rear discs and pads fitted less than 3000 miles ago. Will speak to the local jag specialist and post any thing useful in the next few days.

 

Malcolm

[podge72]

Malcolm

Would appreciate your comments on this once you have spoken to the Jag specialist. To be honest I've had nothing but trouble with the car since I bought it so to get this resolved would be a big relief. At the moment I feel like getting rid of it.

Cheers

Shaun

[MalW]

Shaun

 

Visited the Jag specialist today and he has told me it is the torque converter that is causing the problem. To fit a brand new converter will be £1050.

Well sickened off!. Time to looking for a 5 series BMW I think.

 

Regards

Malcolm

[podge72]

Malcolm

 

I had a feeling that it would be the torque converter. As much as I like the S-Type I'm regretting buying the !Removed! thing at the moment.

 

Thanks for letting me know.

 

Cheers

[jampot]

I had a rumble with my S Type so I  jacked the rear of the car up, started engine and put the car in drive then got underneath and put a screw driver on the diff to my ear then to each rear wheel bearings and it was a wheel bearing , I changed it without the use of a press.

[podge72]

I'll get the exhaust mountings checked etc but that wouldn't account for the change in rpm at the same time the rumble occurs. If it was the diff or bearings then the whine would be constant, albeit louder or faster depending on your speed, which it isn't.  

 

This is what makes me think it's the torque converter.

 

Appreciate all of the advice.

 

Cheers

S

[podge72]

Ok - so update from previous.

 

Car went back to gearbox specialist who advise me that to cure the rumble would be a software update. Not convinced to be honest...don't really understand how a software update can cure, what seems to be a mechanical fault?

 

Anyway, a week or so later go and pick car up, apparently all sorted, test driven etc, etc so take it as gospel and drive tentatively away. So get to about 30-40mph and hear the sound again. Thought maybe I'm just being over sensitive and hearing things!  

 

Following day prove to myself I'm not mad as this time hear it clearly and can make it do it again at will.

 

Call garage again who tell me it was fine when it left them, shocker! ...so it's going back again (3rd time) next week and I have asked that the torque converter is looked at again as although they say they have replaced this I think it could be faulty.

 

Lets hope third time lucky!!

[podge72]

I'm sure everyone's getting bored by now but I'll give an update anyway...

Jag back to gearbox specialist who updated all software, test drove etc and confirmed all is well. Caught train over to pick car up, drove 2 miles down the road and surprise, surprise same !Removed! noise again.

Called garage again and told them that nothings changed, who decided to tell me it was fine when it left them. Needless to say that didn't wash so have booked car back in again. Decided to go to lunch with family, came out of eatery to discover a pool of coolant under car! Called mobile mechanic to diagnose what the problems was who quoted me £500 for new radiator (fitted). In the meantime added some Radweld to coolant which seemed to have no effect whatsoever. Decided to get a second opinion from the usual garage I used for my BMW E30 who said they couldn't find a leak so thought it may be the head gasket (x2) being a V6 (£1600-1700 to repair). Although no mayo under the Oil cap as I checked??

So, to summarise, car still not fixed after 6 month of ownership and I have a radiator that I'm sure will eventually fail and to top it off some little sh*t decided to key the car from front to back just to make my day!

I'm still waiting for the Jag ownership to get better!!!

Shaun

[jampot]

Makes me mad when the garage says "it was ok when we left it" no it wasn't, its their excuse for putting it out in the yard and forgetting about it because they cant fix it, or can be botherd.

[jpvd]

sounds like you need to find a decent mechanic as the one you keep going back to is tugging your chain.....If the sound is at the back, then its not the gearbox....maybe its the diff, a driveshaft, wheel bearing?....also have you tried pulling on the handbrake when you hear the rumble and does the rumble stop when you do?....as it could also be a sticking caliper (all cars with combined handbrake twist piston calipers are a pain for seizing up as they get covered in crap and rust). What about when you break, does the sound stop?...also try costing done a hill in neutral and check for the noise.....get someone to sit in the back and try to pin point the location of the noise.....

 

hope this helps a little......but get it to a good mechanic....

[podge72]

The trouble is the car was initially fixed under warranty from the dealer I bought it from and as he paid for the gearbox refurb he chose where it went to be fixed. It's at a gearbox specialist not a garage too.

The gearbox has had new clutches, torque converter etc but the problem still persists. It onlt occurs when lightly accelerating up an incline between 30-45 mph. The revs surge up and down by approx. 250 rpm and past 45mph and under 30mph it doesn't do it. The hand brake is electric so cant be used when in motion. If it was a wheel bearing it would occur all the time when under load. If it was the diff or driveshaft why would it only ever do it under these particular circumstances?

It's driving me nuts to be honest as no-one (i.e. garages or gearbox specialist) can come up with a definitive answer.

Cheers

Shaun

[StrayCat]

Hi Shaun

 

It's worth checking the history of the replacement gearbox.

 

What does refurb mean?

 

If it's a rebuilt box it won't have been cheap but if it's simply a 'reclaimed' box from stripping down another car there's always the chance that car was abandoned because of, dare I suggest, expensive gearbox problems.

 

Good luck.

 

Jim

[podge72]

Jim,

Refurb...as in original box with any worn/broken parts replaced rather than a recon box from another car.

Anyone want to buy an S-Type (3.0 Sport Plus) I'm joking...I think??

Shaun

[O.T.H]

Hi Shaun

 

I keep thinking about your problem and I seem to remember years ago but on a different make of car

we had a noise simular to yours --after trying everything possible it was found to be the prop-shaft

U/J was seizing and making the centre bearing -[ a bit dodgy ] make the noise .???

 

I suppose its been checked but its just a thought .???

 

Frank