Hello everybody,

Firstly i'd like to introduce myself, my name is Tom (as you may have guessed from my username) and I have very recently entered Jaguar ownership. I bought an LPG converted 1996 XJ6 with 144000 miles three weeks ago, so far I'm very impressed with the amount of car that I bought for less than a grand! It's in beautiful condition too, polished and waxed it yesterday, I must say that this is the most beautiful car I have ever owned.

Onto the problems,

1. It has always idled a little rough, either revs oscillating up and down less than a hundred revs, or just sounding rough at a steady idle, there seems to be no rule as to which happens when, but for 10 seconds or so after start up (cold) it idles beautifully.

2. It has gone through two auxiliary belts so far, the first time was during the MOT emissions test two weeks ago, and the second yesterday - I have put a third belt on and tightened it borderline overtight - I still get some squeal when it's cold and wet and I have any load on the alternator (just dipped beam will do it, sidelights very slightly) the voltage gauge drops when squealing, as expected.

3. Yesterday when the belt snapped (due to slipping and squealing, it had worn so thin it just snapped!) I couldn't stop as I was on a dual carriageway, but managed to stop before the temp gauge was in the red (turned engine off when it was on the mark before the red section), i left the fans running and turned the water pump by hand to help it cool down. After this, the fuel computer is telling me its averaging 15mpg at best, whereas before I could get upto and above 30 on a dual carriageway and 25 mixed town/dual carriageway. This doesn't differ if I am running it on petrol or LPG. Doesn't sound any different and still pulls well. Worth noting after this, the expansion tank was empty enough that the radiator light came on on the dash - topped it up and ran to check for bubbles/airlocks.

After reading up on here I had a look at things on Tuesday, I took off all the air intake pipework and cleaned it (lots of oily sludge in inlet manifold bellows) from air filter box to the TB (carb cleaned it - didn't remove and clean), I couldn't find any splits or holes, and put it all back on and tightened. I also cleaned the MAF with special cleaning spray (this made a difference on responsiveness and it's a little quicker). Spark plugs all look fine (will be changing them back to champions though when they arrive, have NGK R's in there atm). I attempted to see if the exhaust manifold was cracked, but couldn't get the heat shield off - the bolts are already rounded off.

I'd really like to get it running spot on, and there seems to be such a wealth of knowledge on this forum - I hope some of that could be shared with me.

Thanks.

 

Welcome to the forum Tom,

I'm surprised that anyone in Somerset is thinking about car buying at the moment. I'd have thought a boat would be the priority! You are certainly getting a relentless pounding.

You are obviously getting to grips with the issues. Be very careful about overheating. The sixes aren't as easily damaged as the V8's by this but it's still something to be avoided.

You can also visit the UK Region forum by following this link UK - Jaguar Forums - Jaguar Enthusiasts Forum to find other members in this country.

Enjoy the forums.

Graham

 

Welcome Tom and congrats on your new purchase. Agreed, these cars give an awful lot of bang for your buck.

So, if you found the usual deposit of gunk in the intake bellows, it's probable that the throttle body is due a good cleaning. This can only be done properly by removing it. Simple job, undo the cable/s, couple of bolts and no gasket.

The butterfly flap inside tends to stick and doesn't close fully with the build up of gunk in the barrel, leading to high idles, by the way. A good carb cleaner and soft cloth will do the job.

While you're at it, you might also take a look at the idle control valve, the small cylindrical device fitted to the top of the carb body, with an electrical plug attached. It can be removed and the plunger inside cleaned up also. Check/ clean electrical connection at the plug also.

You have the added "complication" of having LPG fitted, which is a mystery to me, but others will have an input.

Hop this helps and happy motoring.

 

Thanks for the replies guys.

GGG, my previous car (that i'm still selling) is a Freelander with all terrain tyres on it, it's been a godsend these last few months and several times i've given lifts to and from work for friends and family. But it has been outclassed now, my Jag has Michelin winter tyres on it so that should help matters (I certainly don't intend to go wading in this car!). We've certainly had our share of the rain, although Yeovil hasn't been affected too badly.

sogood, thanks. I'm really enjoying her. I get plenty of startled looks when I pull upto places, or when people see the face behind this wheel (people don't seem to expect to see a fresh faced 24 year old behind the wheel of a big jag). I have cleaned the outside of the butterfly valve and TB but didn't go any further, i'll have a go at this and the ICV when it's not heaving down with rain! Lets hope that will be sometime soon...

Regarding the near overheating, could anything have been damaged? It runs as it did before this incident, the only change being what the fuel computer is telling me.
It's worth noting that all the problems stated in the first post are present whilst on petrol AND LPG, however the idle is ever so slightly worse on LPG.

On another note, do the sixes suffer from the chain tensioner issue as per the early V8's? I have a ticking noise that can be felt when touching the inlet manifold and LPG injectors, the frequency rises with revs - not noticeable when the engine is cold.

Many thanks.

 

If you haven't already done so, I'd check the alternator bearings to make sure they are not binding and causing the slippage/wear.

 

welcome and enjoy the board

 

Welcome to the forum, Tom. You may want to mark your crank-damper pulley to determine if it is perhaps delaminating. When it happens, that can chew up your belt. If it has never been replaced, it may well be on its way out at 144k mi. Does it squeal ONLY on cold-start? Or can you make it squeal well after the car has come to operating temp by loading up the elec. system?

Reset your mpg computer while out on the dual carriageway and see what you get.... Extended idling (as you may be experiencing during troubleshooting) will drive those numbers down quickly.

 

Thanks for the welcomes and replies chaps.

Regarding the aux belt, I checked the water pump and alternator pulleys/bearings and both span as they should - the delaminating of the crank pulley is a new one to me? (although much to do with cars later than the 80's is 'a new one' for me really!)
I re-tensioned the belt this morning, and so far have had no more squealing. I didn't re-tension after fitting the new belt as it seemed tight enough, but perhaps my feel for what is tight enough, wasn't, for this car - it certainly has more electrical toys than my previous cars.

aholbro1 - how would I tell if the crank pulley was delaminating? I hate messing with crank pullies, I recently changed the cambelt of my BX GT and it was a real ***** to undo! Had to use a breaker bar and the starter motor, and even then it lifted the car a couple of inches off the floor before the bolt moved. I have been idling a bit too, will reset it, cheers.

 

No there are no real issues with the chains/tensioners on the 6 cyl. Is your LPG system single point or multi point? If it's a multi point system then the ticking is likely the LPG injectors. They can be very noisy but it's not a problem.

 

You need a tool to ensure you've tensioned it properly. A "Burroughs guage" I believe someone called it? I got something on the order of $10 from Amazon with some good but also some dodgy revieiws, and it worked ok for me. Assuming my tool worked and mine is properly tensioned, I will say, to me, it felt pretty dang tight! If re-tensioned and didn't squeal on cold-start, you may not have to worry about the crank damper. They are pretty reliable to squeak and squeal just a little bit on EVERY cold-start once they start making noise.


There's a link to the tensioner tool in this one: https://www.jaguarforums.com/forum/x...lt-how-102387/




Use white-out or a paint-pen and mark - starting on one of the timing teeth at the back of...come straight forward across both pulleys and make sure your mark extends to the front flange. So you'll hit the timing tooth, the middle pulley and the front pulley. After you fire it up and run a bit...if your marks are still all in a line, you are good. However, if the timing tooth and the mark on the front flange are aligned....but where you marked the middle pulley is MIA...you have a delaminating balancer. Best option is to have it rebuilt, though if you find one in a breaker's yard for cheap you may want to buy it to run while yours is being rebuilt...or have it to send off for rebuild. Starter/breaker-bar has been used by many members here for the removal...didn't work for me..just lifted the left front corner of the car several inches each time I hit the starter, until it broke my breaking bar.


There are links to the marking and also to the damper change...but I'll have to edit back later to post them. Gotta run to a HS Basketball game just now.


Here is some reading on belt noises:


https://www.jaguarforums.com/forum/x...alancer-84531/
https://www.jaguarforums.com/forum/x...nating-102422/
https://www.jaguarforums.com/forum/x...j6-vdp-101088/
https://www.jaguarforums.com/forum/x...rs-shot-99495/
https://www.jaguarforums.com/forum/x...nsioner-72996/
https://www.jaguarforums.com/forum/x...-squeal-87355/
https://www.jaguarforums.com/forum/x...y-helpp-85765/
https://www.jaguarforums.com/forum/x...995-xjr-84032/


Lastly, if it DOES turn out to be your balancer, here's one way to get it off:
https://www.jaguarforums.com/forum/x...roject-100618/
and put it back on:
https://www.jaguarforums.com/forum/x...lancer-101674/

 

I've only had two incidences of belt aquealage since my last post, and they were both on very cold, very early frosty mornings with lights, full fan and rear de-mist on. It hasn't happened any other time, so i've not tensioned it further, and I hope the balancer isn't shot!

Made some progress with the running too. In the last couple of weeks I have put some new champion spark plugs in and installed an Andy bracket. The car feels noticeable quicker now (though still comparatively slow on LPG), so much so that when I feel someone else needs a display of what a real car can do/sound like I switch over to petrol and usually give them a good seeing to! The trip computer reads 25-30 on my work commute now (as opposed to 22-25), same roads and driving. Just a shame you need to subtract 7mpg from that figure to get a LPG MPG figure (average of 16.5, but only had two tanks since sparks/bracket). Must get the system looked at, it's slower on LPG too, no top end.

A question, is there supposed to be an O ring/gasket between the coils and the valve cover? When I replaced the sparks I noticed none of the coils have this, and I'm sure it's been mentioned elsewhere but can't find the post.

Polished it last weekend (beautiful and shiny it was) and meant to get some piccies up, but it got dark and now its covered in road kack again... Spoilers - it's spruce green with oatmeal

Cheers fellas.

 

there are

coil gaskets
spark plug tube seals
valve cover gromments
valve cover

 

Cheers Vandenplas408, what are the spark tube seals? Are these part of the valve cover gasket? I have no oil in the spark tubes, but no seals etc. Could the lack of coil gaskets affect the running of the engine? At the moment the coils sit on the metal of the valve cover.

Next I want to take the throttle body off and give it a clean. Then maybe replace the temp sender and temp sensor (gauge always reads between blue bar and the white line before N), I have a new thermostat to go in, but want to do the sensors first as it blows hot air, and I don't fancy breaking the stat housing - it seems all too easy to do!

Cheers.

 

The coil gaskets are just paper gaskets, I'm not sure they do any good. I have noticed no difference with coil operation with or without gaskets.

 

Welcome aboard Tom!

Actually it's not uncommon for the chain tensioners to cause issues on the 6 cyl, particularly the upper one. Mine was taken up to the maximum of its adjustment about 5,000 km ago, which means should it cause problems in the future, a replacement will be required. The key symptom was a pretty nasty sounding screech for 2-3 secs on firing (cold start only). Sounds like a badly slipping belt (or as I mistakenly thought at the time, a starter motor issue). But no, turned out it was the upper ten. This may not be a culprit in your case, right now, but worth keeping in mind!

All the best from down under..

 

Just to be a bit more accurate re. my previous comment about the TC upper tensioner - It was actually the TC itself that caused my problem. Adjusting the tensioner to max. cured the squeal / screech, but as it is now at max adjustment any future recurrence of the symptom would mean the fitting a new TC.

 

Hello chaps, a couple of little updates. Spent some money at XJK Ltd last week and bought me a temperature sender and sensor, gearbox filter kit (including sump gasket, metal insert thingy etc), thermostat housing gasket and just to make up the free delivery amount (as delivery cost £28) two new rear green badges ('Jaguar' and 'XJ6') oh and I bought a throttle body gasket as that'll be coming off for cleaning soon.

The reason for the new thermostat and temperature sensors is that it's always ran fairly cool, it used to sit around the white bar above the blue cold area, now it sits a smidgen under N. I put the new parts in before going to work, and the gauge temp sender didn't want to budge, so i've left that for now.

I've started to notice a slight gearbox whine when going slow, I guess it's doing it at speed too but you can't hear it. Also the rear diff can sometime whine when you're slowing down, usually only above 60 or after harsh acceleration. So a fluid change in both of these is in order (i've seen the brilliant guides on here, thanks chaps).

Some of you may have seen me in the new members forum, but just in case some haven't, last week saw me cleaning, polishing and waxing the Jag on a lovely sunny morning. I only got rained on once (halfway through polishing) so had to have a coffee break. All in, that's 5 hours of buffing. I'm sure my arms were going to fall off by the end, no machine polishers here!



















It came up really shiny, especially from a couple of feet away. But the paint on the bonnet, roof and boot is quite bad, if you look closely, you'll see that half of the bonnet is dull and one side is scraped off. The roof is starting to orange peel and the boot is hazy and coarse. There are a couple of dings on the doors but the rear wings are very good! Both front wings are bubbling, one very badly and both bumpers are bad. The front bumper looks like the surface of the moon with it's chip craters, the back just has tar and smaller pits/chips. Nearly all of the brightwork is very good, the bootlid top bit is just a bit scratched and worn.
Inside I had no time or energy to clean, so it's as it is - which is pretty good. I would like some new car mats, and there are a couple of carpet bits that need shampooing to remove ingrained dirt or ink or something. The leather is rather good though, as is the dash.

All in all, I love it! So far cost wise (including LPG and petrol usage) it has averaged 31.1 MPG and it isn't running right on LPG either, it's alot slower and has been doing 13-20 MPG. So when I get it running properly, it'll be a rather cheap Jag to run

 

Hi Tom,
Lovely pictures, I am sure your Babe will do you proud after your dedicated attack of TLC and hard work?
Enjoy your Lovely Jag!!!
Regards, Stu

 

Thank you for the complimentary replies ladies and gentlemen

Had a free afternoon today, so whipped off the throttle body. Well, I say whipped off, in reality it took me several hours of fiddling with different sized spanners trying to get things around the LPG condenser that sits just to one side of the intake bellows, the water pipes for the condenser are looped around the post MAF pipework, which makes doing anything here an exercise of removing many different cable and hoses.
Gave the throttle body a good clean, not very dirty at all, just a thin layer of oily film on the walls. Cleaned all the electrical plug contacts with, well, electrical contact cleaner! I even bought a gasket for the TB from XJK.com but it didn't fit, was slightly too long in one direction (was slightly rectangular) whereas the 3.2 TB to inlet manifold joint is square. Used a tiny amount of instant gasket instead.

Unfortunately after all my work, it doesn't seem any different. I only went round the block and down a short national limit lane to wind her up. Will better tell tomorrow when I go to work. I'm starting to think i'll have to bite the bullet and buy a new coil, then at least I could swap it for each current coil to see if anything improves.

Need to get and change my gearbox fluid soon, got the sump gasket and new filter and have found some cheap fully synthetic ATF by Carlube, 47.98 for 9.10L (2x4.55L). Seems to be the cheapest I can find short of buying 25L+ drums.

I'm also on the lookout for a good used bonnet, as the paint man said it would be at least 500 to paint the entire bonnet (which I would want). Wings too, both are bubbling increasingly. The list carries on....!

 

Hi all, I finally got around to getting my new badges on! Bought the boot pair to pad out a parts order a while back to avoid paying £23 delivery :O I have only just realised that I seem to have bought a sport 'Jaguar' badge as it has no chrome around the edge, but I quite like the effect.

Before:







After:







Washed her and had a good buff over, very please to see after several weeks of no cleaning, she's still very shiny. Good old wax, eh!

Really need to get going with new wheels/tyres (as this warm weather will be wearing down the winter tyres very quickly) and a replacement exhaust section (underfloor cat section, before the split into 2 pipes) as she's blowin' like a good un, sounds very nice - but quite drone-ish at 60/70. Also spotted the buibbles on the drivers wing have flaked some paint off, best get them seen to too... Good used wing I reckon, why not make it a pair and get the other side sorted.

Cheers.