Well, being a British car freak, I finally "moth balled" the old 1987 XJ6, and picked up a "new" daily driver a couple of years ago. One owner, Jag serviced since new. Quite the machine, until here of late.

Since December, have had the fuel pumps replaced, after leaving me stranded, as well as the "Octopus" of the cooling system.

All seemed well until this week... on Monday, the car started idling roughly at a stop light, and continued to get worse as the week has gone on.

Code readings of:
P0300
P0305
P0306
P0307
P0308
P1316
P1000

and today, a new one...
P0358

I changed the spark plugs last night on the offending bank. Upon removal of the cover, all was nice and tidy inside, very clean, no oil or water present. Uneventful, no problems, just a normal change of plugs.

After changing the plugs, restarted, and still a rough idle. This morning, cleared codes, restarted until engine light came on again, then read codes again... same as the first list. So, cleared codes, restarted, sat in car waiting for the check engine light to come on. It never did. Code reading was just P1000.

Road tested this afternoon... 1/4 mile up the road, the Limited Performance light came on. Returned to shop, checked codes, same as before. Cleared codes, restarted, another road test. Car ran fine... filled car with premium, drove 6 miles, came back to shop, letting car idle for awhile.

Went back out to check status after a few minutes... Limited Performance warning again. Ran codes again... the "usual suspects" PLUS a P0358 this time, and the car is once again idling poorly...

2001 Jaguar XJR
1987 Jaguar XJ6
1967 MGB GT
1959 Austin Healey "Bugeye" Sprite
1971 MGB
1972 Austin Marina (wife's car)
1978 Chevy Siverado (the beater... bought new)
And many numerous projects...

 

I'm a bit puzzled. Did you try looking up the codes? They are there to tell you what is wrong, you know.

You have a random misfire code, and specific codes for cylinders 5,6,7 and 8 misfires, and a code for a bad coil on 8!

I wonder if you have a wiring fault? Either that, or a faulty ignition control module, the unit that drives the coils. I had one fail on my A6. Similar symptoms. Check everything is plugged in. Not sure about the AJ26, but it is common to use one control module for each bank, which would explain why all your problems are with one bank.

 

Mark, yes, I've read every post I can find regarding this, and have looked up all the codes detected by my code reader. Yesterday, the code indicated random misfire, and on 6, 7, and 8, in addition to code 1316 (injector circuit IDM codes detected). Today, the P1316 didn't show up after clearing the codes (I was trying to find an isolated cylinder code), but, now I've added the 5 cylinder code, and the P0358 as well... The plugs were replaced, and I can't imagine all 4 ignition coils going down all at once...

The ICM is a good place to start...

Thanks...

 

If it were mine, since the codes are on one bank, I would make damned sure my timing had not jumped on that side!

 

We have seen this before: plastic secondary tensioners failed causing a jump in timing. Classic when all cylinders failed on one bank.

Still, over on the XK8 forum there is a case where all four codes on the right bank; I was sure it was tensioners, yet the owner cleaned the coils and fixed the issue . . .

https://www.jaguarforums.com/forum/x...4-idle-132835/

 

Man, I'm sure missing my 67 MGB GT right now... wrecked it a few years ago... bought one to replace it, but in need of some body work and paint... when nothing else would go, it would... no computer, nothing too complicated to work on... but... the "new" Jag is taking away from the GT budget at present... arghhh... I actually drove it more than my '87 XJ6, which I bought from the original owner with only 20,000 miles in 1999... most of my "new" cars seem to beckon me at about 12 years of age, (but, were much more expensive when new than I pay for them now)... oh well, it's been a fun ride for the last couple of years... just a new "learning curve" I suppose... before I bought this one, my newest car was the '87 XJ6... My plan is to purchase a "new" XJF in about 12 years... Hopefully the original owner will have had all the problems corrected by then... ~8^)

BTW, sorry, but, I'm new here... a long time "Jag Lovers" member though... I'm liking the "forum" format of this site quite well though...

Right now, I'm not quite sure where to start, or, to just take it to my trusted mechanic. We're 200 miles from the nearest Jag dealer... and my mechanic is also the President of the British Car Club I started 15 years ago here in SW Missouri... DIY, or... pay the bux, and have it fixed???

 

Rod:
If you are not sure of the history of the secondary chain tensioners, I would sure get the valve covers of and have this inspected. Check the archives for the very sad tales of engines wrecked by valve crashes. Time, not mileage seems to be the culprit for failure of the earlier plastic tensioners.
BTW, I learned from a Jaguar service writer that the new 5.0 liter engines are also supposedy having chain failures Oh well.

 

Spark: Ow! Thinking of trading the cat in for a 2012/2013 LR4 or RRS with the 5.0L, need to check this out (arthritic knees making the very low X308 problematic).

As for Rod's problem: checking the tensioners is a must, unless you have iron clad proof they have been upgraded. Do not take the easy route and expect good results. We have seen too many examples on the X308 forum where misfire codes on one bank are timing issues caused by tears in the plastic tensioners. By the way, the repairs are easy for anybody with half a wit, a power screwdriver, a 1/4' ratchet with 10mm, 5/16 or 8mm, 7mm sockets and a plug socket, some extensions and a willingness to read every written word on replacing the tensioners and cleaning plug-on-coils. Total cost in the neighborhood of $160 to $200 DIY and four hours or so; ten times that for a pro. Once you open up the cam covers you can tell if there is damage to the primaries -- then a pay for tow to a pro. IMHO

 

I search some old posts, and it seems early XJ8s did the coil control directly from the ECU, and later ones had separate Denso ICMs. There should be two. According to the info I found, though, each ICM supplies 2 cylinders on each bank, so that doesn't really explain your problem.

 

Jim:
Check out this thread.
https://www.jaguarforums.com/forum/x...ngines-133846/
Like someone else on there, I was ready to call BS on the 5.0 issues reported, but then I looked at JgaXkr's profile and I am ready to take him at his word. BTW, I have 36,000 miles on mine and all is well, so far

 

This isn't going to help you, but I had to comment - 1972 Austin Marina??? Say it isn't so! I just hope it isn't brown

 

Got to be a coupe - they didn't look bad. Our neighbour had a orange 1.8TC coupe that was quite fun.

 

????? Quite fun? I know there were some funny herbs in SF in the 70s, were you using any ?


Bad brakes, axle tramp, and terminal understeer, to name just a few of their vices.


Then again you don't really do winding country roads in the USA , would have thought the freeway was out of a Marinas comfort zone as well.

 

Thanks for all the suggestion/comments thus far. At this point, have changed spark plugs on the left bank... old plugs weren't oily or black... nice tan color on all four. Today, pulled the cover again, and checked with a spark tester. Each plug is firing (at least visually) so, I assume the coils and plugs should be working.

So, what to do next??? As my next newest auto is a 1987 XJ6, I'm not so used to working on these modern monstrosities with all the electronics and computerization.

I am not sure as to whether the 2001 XJR has separate ICM's, or, if that's all controlled by the ECM. I do have the workshop manual covering many cars of the era, but can't find anything definitive for my particular car.

Or, should I just pull the valve covers and check out the tensioners first??? Would rather eliminate any other suspects prior to tearing into the tensioner problems...

Rod

 

Yes, it is so... my wife does own an Austin Marina sedan... all four doors of it... it's lovingly known by our car club as the "red brick" (at least it's maroon, and not brown). The problem is, that in order for me to keep accumulating British rust over the years, I had to let her have her own LBC as well. But, she will NOT drive a stick... so, when she found an LBC with an automatic, she was sold... purchased it on the spot. The plus side, same 1800 as my MGB's... negative side, practically everything else about the car. But, she does so love it, and gets angry everytime the guys on Top Gear blow one up or drop a grand piano on one... to each his/her own... as for the Marina, it is in the "Book of Lemons", and it's only claim to fame other than Top Gear is that Ed Asner drove one during the first season of the Mary Tyler Moore Show... ~8^)

 

Here in "Hillbilly Country" of the Missouri Ozarks, we have LOTS of winding country roads... which is what first endeared me to these quirky little cars back in the 70's... Have driven thes backroads in several cars over the years, but none have been as fun as in my Austin Healeys, MG's, Triumphs, and an RX7 I had for a brief time period in my life...

 

Thanks for all the suggestion/comments thus far. At this point, have changed spark plugs on the left bank... old plugs weren't oily or black... nice tan color on all four. Today, pulled the cover again, and checked with a spark tester. Each plug is firing (at least visually) so, I assume the coils and plugs should be working.

So, what to do next??? As my next newest auto is a 1987 XJ6, I'm not so used to working on these modern monstrosities with all the electronics and computerization.

I am not sure as to whether the 2001 XJR has separate ICM's, or, if that's all controlled by the ECM. I do have the workshop manual covering many cars of the era, but can't find anything definitive for my particular car.

Or, should I just pull the valve covers and check out the tensioners first??? Would rather eliminate any other suspects prior to tearing into the tensioner problems...

Rod

 

Rod:
The likelihood of it being the tensioners is quite high. Other than grounding, there really is no single component that would cause misfires on one bank without an accompanying code like "knock sensor failure". There is a good possibility you might have not yet crashed the valves, but if the chain jumps another tooth, you will. And that is BAD!
So barring some valid alternate diagnosis, you really should not run the engine until you have this sorted.

With even limited tools, and working slowly, you can check both sides in less than two hours. And, for now, you will probably not need new gaskets as the ones on there are the rubber, reusable type. Just be careful on removing the covers. A 10 mm deep socket on a 1/4"socket wrench with a short extension is about the extent of the tools required.

Since you need to check your tensioners anyway, this is really the only valid next step in my opinion.

 

Well, after exhausting every other possible cause, my best friend who's a master machinist came over yesterday. We ran a compression check on 5 - 8, and found 150, 150, 155, 155. So, left bank is still working. However, his keen ear on the stethoscope indicates excessive noise in the front of the cam cover on the left bank. Thus, looks like a tensioner/timing chain job if probably in order here.

Does anyone have the tools to do this job??? If so, anyone willing to loan, rent, or sell them? I know I can buy/rent from Motorcars LTD or Christophers.

 

Rod... had exactly the same symptoms and codes on my 01' XJR. It was a failed secondary tensioner on the left cam bank. I replaced all tensioners and chains. Unplugging the battery or clearing the ECU with an OBD device will clear the universal codes, but not the Jaguar codes. I have an associate that let me borrow his Windows based Matco Interface that has the specific Jaguar interface and I found 26 error codes that didn't present on the OBD reader. Once cleared the car starts and runs perfectly and fuel mileage is up 2.5 mpg.