XJ6 S2 - new purchase troubleshooting
 

After a couple of years without I will be collecting an XJ6 again this weekend. It is a solid car, minimal wear and tear inside and out, and reportedly still yet to clock over 100,000km (hard to believe after 37 years but from the condition I doubt it has passed 200,000, so maybe 100,000 is possible)

The car has sat a bit in the last couple of years, and as a result number 2 (second cylinder from the rear of the engine) doesn't appear to have compression according to the current owner. I had it running when viewing it, no nasty noises, no mess in the oil, definitely running lumpy. Reportedly this has happened to the car before from sitting and a fresh plug temporarily improved things. The current owner had it diagnosed by a mechanic friend as a sticky valve but has not investigated further. The symptoms I can see are:

• Rough idle
• no exhaust smoke
• no large rattle
• no oil contamination

My current intention is to assume it is something minor, pop some fluid in it to try and loosen up the valve, pop in some new sparkplugs, clean the contacts on the dizzy cap and replace the lead on that cylinder for good measure then drive carefully home and see what loosens up. Any suggestions based on this very minimally described list of symptoms would be greatly appreciated.

That sounds like a plan, albeit an optimistic one. It would be great if the only problem is a sticky valve, and it frees up, and all is sweetness and light from there on. But I would not bet my life on it. Good luck.

The head may need the valve retainer plates.
The valves can get jammed, without them.
Most engine rebuilds, these are included.

Attachment 155862

I completely agree it is an optimistic idea Dleit53 but as long as there is a low risk of harm driving it carefully home then if it is still happening when I get home I will start pulling things apart and investigating further if it is still occurring then.

congrats on the purchase, hope it goes well

I agree it is a plan.

Where is it coming from?????.

You are in Victoria, so not far from anything in any given direction, so plenty of pubs to assist the trip.

I would be at least giving it some fresh oil and a filter prior to the excursion.

Remember that at highway speed that engine will be sitting on about 2600RPM, so if something lets go it will land in SA.

In 1992 I bought an HR holden ute from Winton,Qld(well before being able to see pics on the internet). I saw it in the Trading post(paper), the bloke told me on the phone it ran rough and it kept stalling, but it had new paint, HQ susp and disc brakes, twin battery set up and LPG. I jumped on an overnight Greyhound to buy it.

It ran pretty rough most of the way home(833 miles), until I got close enough to Brisbane to buy LPG then it ran sweet as. Turns out it was tuned to run 100% lpg. A mate tweaked it and I did 320,000 miles without a single breakdown until I sold it to buy my first Jeep in 1997.

Not saying you should drive it home, but I would give it a go.

And as Grant says, there is always a Pub nearby to ease the pain should a complication arise.

I like the way you guys think!:icon_lol:

I agree with the plan. I'd add some good ol' Marvel Mystery Oil or maybe Seafoam to oil and gasoline. It wouldn't surprise me at all if you had a sweet running engine when you arrive home.

Good luck!
Retro

Thanks guys, I've got an oil additive and will grab a fuel one as well for the drive, take it easy and hope for the best. Fingers crossed the worst case is that the car will arrive home needing the same work as it needs at the moment :)

Not the best of starts. Checked all the fluids and jumped in the jag this morning for the big drive home. Engine was running well, felt sluggish under acceleration but actually sounds like it is running on all 6 when it is over 2000rpm. Stopped 10km down the road for fuel and there was smoke pouring out the rear end. Rear brakes were both half seized on, getting things hot enough to make the diff bleed a little oil and cook the brake fluid. Thankfully we found a mechanic who was open on a Saturday. As soon as it was on the hoist you could feel the brakes stuck, so he will rebuild the rear calipers for me during the week, then we will attempt the drive again next weekend.

Good save, I wasn't so lucky. There is valid reason Her indoors named the XJ6 "Fireball"

https://www.jaguarforums.com/forum/x...m-fire-115245/

Wow, looks like we stopped just in time from reading your story. We were probably not too far off ignition, will be taking an extinguisher for the next journey. Fingers crossed when the calipers come off there wil not be many issues arising

So, both rear calipers were stripped and rebuilt by a mechanic during the week making Ivy good to go again. We picked her up this morning and headed home. She was rolling far better but still pulled to the left slightly when backing off the throttle. Oil pressure was down, possibly due to old oil/old filter, never read above 40. About 20km from home i started to smell burning rubber. Pulled over and the front left brake had stuck on, getting hot enough to cook the wheel bearing grease. By this time Ivy sounded closer to running on 6 but had a rattle at idle, so we popped her on a truck for the last 20km home. Will start playing next week and see how much of a project I have bought

Told ya it would be sweet.

OK, some hiccups, but thats motoring.

The 40psi is normal, and I would spend no more time on it, really.

If the rear calipers were sad, the fronts will be also. Cast iron calipers tend to do that.

The rattle at idle could be anything, and new oil/filter would be the first step, and then stethoscope around until the general area is found, then sort it. They can be a rather "tappety" engine at times.

Thanks. Filter and oil was definitely my first step with pressure. Considering pulling the pump too just to see what condition it is in as i was dropping below 20 at idle when the car was hot. Will pop the cam covers off and see that everything is looking and moving as it should in there, then if that is all good go back through the fuel system cleaning out the carbies, filter, and checking the wiring to the pumps. Did the internal pumps run any sort of in-tank filter? I'm more familiar with the earlier external SU units

The timing chain dampeners can wear out and cause a clacking sound.
Been there, done that.

Some good news, had a play this evening, a giggle of the wires at the headlight fuses and how have all 4 front lights working. I have removed the aftermarket fuelpump that was jerry-rigged into the front of the car due to issues with the factory pumps and as soon as I did that the car ran perfectly smoothly on 6 cylinders until it ran out of fuel in the carbies. Going back out to take a look at the fuel tank switch now.

Neither fuel pump working, fuel gauge not budging on either tank, where is the fuel system supplied with power? I am thinking my issue may lie there.

The fuel pump/s are powered via the fuel pump relay, near the centre bolt that secures the cross braces at the bulkhead, basically alongside the starter relay. The EARTH of that relay is sorted by a reverse oil switch in the oil gallery on the RH side of the engine. Soooooo, NO oil pressure = NO earth = NO pump activity. Most of us down here simply earth that wire, so the pumps work with ign ON.

The second problem is the "Inertia switch" on the LH front pillar, below the dash trim. Usually covered with a "plastic" cover thingy. Again, if suspect, join the 2 wires for now, and sort the switch later. It is required as a safety feature eventually.

The in tank pumps are very suspect, due to age. MEMORY, HAHAHA, they have a sock thing over the intake.

awesome. is the reverse oil switch also the oil switch which runs the oil warning light? Because that is the one warning light not working on my dash.