I’m usually a chipper fellow, give me a beer and an episode of Top Gear (past seasons not the new rubbish) and all is well.

The latest with my 2000 XJ8 has me exhausted and clueless. I acquired her in December and she seemed well, but definitely needed some proper maintenance.

I don’t have the luxury of a garage to work in where the car is currently parked (in a community parking lot for a section of townhouses). But if I can get her rolling and out of the current restricted performance, I can get her to a garage to work on her over weekends.

Three months ago, I turned the x308 on and heard the telltale thumping from the passenger side. Thankfully because of this wonderful forum, I turned the engine off immediately over concern the tensioners had failed. Since it was winter in New Jersey, I knew I couldn’t tackle the problem right away.
I put some Sta-bil preservative in the tank. Ordered the parts and read the DIY directions.

Two weeks ago I changed the secondary tensioners (zip tie method – one had failed), installed new NGK spark plugs, replaced all the gaskets, and installed a new battery. I also had the misfortune to break the Bleeder Tube, MNC4583AC, but easily replaced. I filled the reservoir with distilled water to replace the little bit that had leaked (a future flush is scheduled soon).

After a significant amount of bore wash, I was able to start the car by holding the accelerator down.

When it started it was rough (no thumping, just aggressive). I took off the valve covers and everything looked very good, secondary timing chains were aligned and no oil in the spark plugs. I double checked to make sure that everything had been torqued to spec.

I started her again and let her idle, still rough. I looked for leaks, no drips of oil or of coolant. I looked for air leaks in the plastic breather hoses on top of the valve cover and the intake tube. Nothing that I could detect. I cleaned the MAF with CRC electrical cleaner and most of the electrical connections around the engine. I did not unplug those around the throttle body – they were tightly sealed. I only cleaned the outside of them. I cleaned the throttle body throat with a towel and some carb cleaner.

And when I went to drive after a hundred yards, restricted mode. I parked and got these codes, p0455, p1642, and p1797. The dash had failsafe engine mode, trac not available, asc not available, check engine light, and brake light.

The next day I went back to examine the gas cap (seemed to be a tight seal), I fruitlessly looked for anything I may have forgotten to reconnect, and did a hard reset. When I started the car, she ran smoother, took her for a test drive and three miles later, restricted mode and a rough idle. I was unable to pull codes with the OBD2 sensor this time and idled her for at least twenty minutes. She ran ok, but still a little rough.

I have ordered an ELM327 reader to perhaps give me access to more information. I don’t want to throw parts at her with my ignorance. There is still a lot left to do outside of this current problem and I do miss driving her.
I humbly ask for any guidance and advice.

 

The 455 is an EVAP code, gas cap is first cheap fix, but not always a cure. Can be the purge valve and/or hose on EVAP canisters or the breather off them could be clogged.
1642 is a CAN circuit failure, check the crankshaft sensor. It will also cause a rough running motor.
1797 is a CAN circuit also and may be related to 1642, so check the crank sensor first and see if it clears and it may clear the 1797.

 

P1797 is a TCM to ECM communications error, I've had the same code on its own for a while. I don't have a fix yet, was planning to take it to a shop when I've got time and find a shop equipped to talk to the TCM.

 

I do wonder... what abbout the primary chain tensioners? Since you had one secondary tensioner that actually had failed.. its quite likely that the primary ones are made of plasic as well.. and are abbout to give up too...

I read somewhere that if a camchain jumps one teeth.. --> rough running engine. Two theeths --> God bye and thanks for he coffie..

 

Thank you all for the help.

The first thing I thought was the timing sequence was incorrect, but I did reinspect the camshafts and both sets are aligned.

I have the full intention of doing the primaries, updating the water pump, thermostat and housing as well.

The secondaries were done out of necessity in a common area parking lot for the townhouses I live in. If I can get her road worthy, I have a garage 20 minutes away that I can work in over weekends.

Here is my update from today:

I went through the entire evap system hoping to find a cracked hose. I cleaned off all the electrical contacts and checked each hose. I did not have a multimeter with me, so I was not able to check the valves.

The car still had the codes, so I cleared them and restarted the car. This is what happened:

5:02 Car idles at 600, sounds ok, but there is a squeak from the serpentine belt. This concerns me because I successfully changed the belt, idler and tensioner pulley three months ago.

After three minutes, squeaking stops, and temperature gauge casually rises to the center of the gauge. Car is chugging, but not alarmingly so. I continue to let her idle.

5:09 car starts to roughly idle hits failsafe engine mode and the temp gauge falls to zero. The code being given is 1642.

5:14 the car really starts to bear down and seems to be struggling. The code 1797 is added.

Without the temp gauge showing me what is going on, I don’t want to overheat so I turn the car off.

I leave the key position in ignition so I can get the codes and there is a whine from the engine compartment.

I have attached two videos (for the sound). The first is the engine struggling and the second is the whine.

I will replace the camshaft sensor. Does this new information, bring any other possibilities to mind?

Thank you for your help.

 

That sounds like an intake leak on the rough idle or the primary guides/tensioners?
The whining sounds like a bleed off as vacuum decreases.

 

Hmm..


Without any deeper analysis...


1) Have you checked that the water temperature sensor is not at fault.. older cars could have up to Three of them.. one for sensing and presenting the temp, one to light up the hi temp warning lamp and one to engage/disengage the cold start fuel/air cirquit. The X308 Jags have one (from what i have been able to figure out). If the water temp sensor are at fault i can imagen all sorts of misbehaviour... Loosing the water temp indication on the dash can never be good..


2) Blocked vents on valvecovers; since i just recently read the bulentin on the possible blocked restrictor hole on rh valvecover and what that could cause.. check that too.


3) Old fuel; The fuel we use today has a best before date that is worse than the best before date on milk... if the car has been sitting for a long time with less than a half tank, you should be happy the car starts at all.. (atleast this goes for the terrible fuel we buy in Sweden) starting cold, the eingine will run on a somewhat fatter air/fuel mixture in order to compensate for the higher internal friction inside (cold oil).. when temp goes up and engine shifts back to a leaner mixture.. --> if fuel bad, rough running..


Anyway.. shooting from the hip here..


I do wonder, when you start engine cold and it runs nicely, how does it rew? Does the rpm raise nicely without hesitation or interruptions too? How does it perform in this regard when engine is hot... does it rev as it should or does it tend to die off?


/E

 

The primaries are not subjected to as high a temp. and there have been very few reports of them actually failing. Apparently, when you hear a rattle upon startup from them it's time for a change, but it won't result in a timing jump.

 

Mine were trashed when I got to them, the one guide even fell apart as I was trying to remove it, the other was split....but timing was still good to say. Once I got the new chains on, she was much more responsive, eliminated that slack in the chain. They sound like a chain being pulled over a pvc pipe when the guides go, similar to that video, but that sounds courser.

 

I actually got mine because of a primary tensioner failure. Here's a clip of the noise https://drive.google.com/open?id=0B5...2FjQkEyZnE2V0E

 

Oh man, that sounds like a tank.

 

All is clear, my XJ8 is doing well...yet I don't understand.

I got rained out last weekend, so yesterday I was finally able to do some more diagnostics.

I installed the charged battery (it was fully charged last time as well).

I started the car which ran pretty smooth, and sprayed water (from a squirt bottle) all over the intake, breather hoses, throttle body, etc trying to find a leak causing the previous rough idle. I used water as the first step and not starter fluid because of the venerability and unknown nature of the wires.

She seemed to choke then smooth out a little more when I sprayed the part load breather hose coming out of the valve/camshaft cover. So I tried to repeat using starter fluid and nothing came of it. She continued to run smooth but no changes in the idle.

The check engine light was on but when I went to check the codes, none were found. I hit erase codes and the check light engine vanished.

Tentavily but with a little hope, I took the XJ8 out for a drive, ended up going thirty miles and no problems.

I wish I could explain what happened. The battery was always new and fully charged... Perhaps the evap or CCV was stuck and cleared. Maybe my elderly MS300 OBD2 sensor was not playing well with the CAN.

I will see what the near future holds and look forward to driving her some more this afternoon.

Thank you to everyone for your help, both on this thread and the numerous previous threads I have read.

Easy Like Sunday Morning,
Tom

 

Sometimes a reset does wonders, but I would be weary nonetheless. Have you lost that bleeder sound?

 

I had a wedding to attend this weekend and what a great occasion to drive a Jaguar. The car performed well.

A very slight hesitation starting from an idle, but there were no noticeable or untoward sounds either when the engine was on or immediately after being switched off.

The vehicle is now mobile and I can take it to a more suitable work environment. In the near future, I will be completing the primary timing upgrades (water pump & thermostat included), flushing the transmission fluid and adding the Transgo valve, and maintainign the electric wires by retaping the wires (the original electric wrap is dry and brittle) and using dielectric grease.

I am also contemplating replacing a bunch of the hoses as a preventive measure.

By replacing the various gaskets (torqueing them to the proper spec), hoses, and maintaining the electric system, I hope to prevent the reappearance of these faults.

As a side note, I know from the previous owner all work had been done at the Jag dealership. The spark plugs were vastly under torqued and the spark plug covers were overtorqued (cracks in both sides). There were twist ties in random spots and a few of the bolts were none OEM (philips head and not flanged).

I am understanding how good it feels to do the work yourself and not skipping any corners.

 

Glad to hear she's performing for you Tyr, but I seriously doubt (as a matter of fact I'm at the guarantee level), a Jag dealer used twist ties, incorrect plug torques, non OEM items and other wrongly torqued items. This sounds like the neighborhood Joe stuck his head under there, so be cautious of what else you may find.....just saying.