Rough running engine
 

I am getting ready to do the secondary chain tensioners at 126K but just encountered another problem. This morning the engine developed a severe miss fire so I pulled the DTC 's and believe I have the problem identified, but would like some info on what I might look for first.

P0116 Engine Coolant Temperature Circuit Range Performance Problem
P0125 Intermittent Coolant Temperature for Closed Loop Fuel Control
P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
P1000 System Check Not Complete Since Last Memory Clear
P1384 Variable Camshaft Timing Solenoid 1 Malfunction
P1396 Variable Valve Timing Solenoid 2 Malfunction

These last two seem to be the problem. I am sure the timing is out of whack if I am getting these two codes. Is it likely the solenoid(s) or should I look elsewhere first.

Thanks for your help.

Nope, replace the coolant sensor first, clear all codes and see where you are at. The last two are quite possibly phantoms.

Where do you live in Cali? There's an old Can Am car near Salinas I'm trying to get, if you can go photograph the pieces for me it's worth a free sunroof motor.

By the way, on your previous post: it's always possible that you had a critter chewing on your wiring harness while the car was sitting. Coolant temp sensor and VVT solenoid wiring is in close proximity. Take of the plastic beauty covers atop the engine and look around up front.

If you find a rat in the garage, plug in the code reader and see if he spits out any evidence. It used to happen all the time on V12's, they loved the soft insulation on the distributor pickup wires. One rat=no spark on those.

They still like the wiring insulation, and use glue boards. Never use poison cause it makes them die of thirst and theyll chew through anything with water, including coolant hoses...been there, done that

I don't think it is critter related, but I did read on another forum (Diesel related) that a couple guys swear that using a bar of "Irish Spring" soap will keep rodents away. They shave a small piece away every once in a while to renew the aroma. No kidding, it may even work.

The car is driven regularly usually by my Wife and we have never had a rodent problem before (10 years). I have the Beauty covers off since last night. I looked over the top of the engine and it looks fine. With the exception of the o-rings for the what look like cam sensors on the top / front of the cam covers leaking a bit more than normal. I thought I read where the intake cam would be fully retarded under a P1384 condition. Would that show up as a very rough running engine even at speed?

I am going to replace the coolant temp sensor today and see what happens.

Pat

Maybe next week. I work close enough that I may be able to get down there during the evening. I live about 195 miles outside of Sacramento. Salinas is down by Monterey. I work in South Bay so Monterey from there is close enough for me to swing by in the early evening if it is possible. Let me know if next week is good for you.

Pat

So I replaced the coolant temp sensor filled it up with new coolant and still no change. Missing on at least 2 cylinders. So it was due for an oil change so I changed oil and filter hoping that 10W40 would do the trick, but nothing still runs terrible. Got the check engine light to come on and pulled the following codes.

P0300 Random/Multiple Cylinder Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0303 Cylinder 3 Misfire Detected

I am going to take a look at the spark plugs. Any other ideas??

have you checked secondary tensioners? I had a problem that felt like misfire, the codes showed that vvt solenoid is "dead" bought that one and guess what....yea... nothing.. :)
finaly I took over the cam covers and it was easy to see that the chain is loose and skiped one teeth. still the car starts perfectly but shales like hell, when I accelarate between 40 and 60 km/h looks like everythings ok.... anyway now its in the garage i'm whaiting for the parts to arive and changing all timing things.

I pulled the Cam Covers off and here is what I found on the LH.

http://thumb0.webshots.net/t/62/662/...0UhUMfG_th.jpg

Looks amazingly close to catastrophe. The chain is a bit slack and the flats don't seem to line up... But the car still runs and it seems like I might get away with lining things back up and replacing the secondary chain tensioners.

Any insight as to what I should do from here.

Pat

Rough Running
 

Whoa ! Well, at least you found the problem before it was too late. The chain definitely jumped at least a tooth. You were going to do those secondary tensioners anyway, right ? There are several ways to go on that. It would be nice if you could just lift the chain up and stick new tensioners under it and line everything up, but from what I've read, you've got to get the chain (and sprocket) off the cam to replace the tensioners. There was a recent write up with pictures on here from a guy that just did the job. I'm going to be doing it soon myself on my 01 VDP.

don't start the engine again under ANY circumstances until you've changed out the tensioner (s)....if it skips another tooth on start up you'll be reconditioning the head and changing out a bunch of bent valves. Several ebay vendors selling kits to change out the secondary chain/tensioners. ..one with a removable link that avoids you removing the front cover etc etc.

Broken Chain Tensioner has skipped a tooth on the intake CAM
 

I already have the cam covers off and I have new tensioners ready to go. I am machining a cam lock down tool that is similar to the one being sold. Since I have a mill and lathe I tend to make one off tooling when needed. The lockdown tool is identical to the one sold so I know it will work well.

I am planning on doing the drivers side first since it is still intact. I am then planning on tackling the passenger side which has skipped. I am planning on centering the exhaust cam and setting the lockdown tool in place and loosely bolting it in place. I am then going to mark the position on the intake cam / sprocket. Once it is marked I am going to try to remove the broken tensioner and reposition the sprocket one tooth at at a time in order to get the timing correct.

I am looking for advice in getting the timing setup correctly on the "skipped" Cam. I am pretty sure it is only one tooth that has skipped and I know I can get the lockdown tool in place and tight enough so as to keep the skipped cam from movving any further while I work to get it back in place. Any advice from those who have done this before would be greatly appreciated. I also plan on rotating the entire crank/cams/pistons manually clockwise after I am done to make sure the valves are not bottoming out on the pistons.

Again, any advice is greatly appreciated.

Hi,

if I remember correctly, the intake and primary chain gears come in one unit, so the intake cam timing in relation to crank is ok(assuming the primary chain is ok). In my opinion you can just loosen/remove the exhaust cam sprocket, move the intake cam by turning the crankshaft so that the intake cam flat is lined up with the top of the cyl head. You can now move the exhaust cam to its correct position by clamping down the locking tool(the cam sprockets have no keys). At this point a good insurance is to see the other cyl head cams - they should also have their flats lined up.

If I remember correctly, to remove the old tensioner you have to remove the exhaust cam sprocket(it can stay inside the chain though), then bolt a new tensioner in and bolt back the exhaust cam sprocket. Then remove the tensioner locking pin to release it.
To make the whole process absolutely sure you should have the crank position locating pin in place of the flywheel sensor.

And finally - yes, this is my first post here, own a '99 XJR and have done many things to it during the last 3 years.

- Ari -

JagTechOhio,

I'm in Monterey and go up and or through Salinas every once in awhile. I can't really give you a timeline but, if you haven't gotten your pictures I can try to swing something within the next couple weeks if nobody else has gotten the pics for you yet. Just pass along the info of where the pieces are and some contact info there and I'll see what I can do.

Oh my gosh, I wonder if this is what I am in for as well? I just got P1396 with engine roughness at times. At first I thought it was going to be an ignition problem, then I scanned it. I do need to change out the VC gaskets anyway. This would be a great time to check out my tensioners as well.
-Rob

Taking that cam cover off was the best thing you ever did, you were on the edge of disaster !

I was not aware the chain had to come off to put the tensioner in, but if it has jumped a tooth, that is what you will have to do, as the cam timing has been lost. I would suggest you don't do anything more unless you have the correct Jaguar procedure to follow. You can, of course, buy the replacement tensioners which have an aluminium body. These have a little securing pin, (like the pin on a hand grenade) to tie the tensioner spring down whilst you install it, following which you pull the pin out, but hopefully no bang afterwards !

XJ8 timing chain tensioners - etc.
 

Apparently, one cannot edit a posting to make it more readable (such as lining up columns) so the valve clearances might be somewhat tedious to read.

I came into possession of a 1999 XJ8, with 188K miles on it, that didn't run (well, I think it was because the previous owner had taken it to a Jag mechanic and was told it had something to do with the timing and would cost an arm, leg and maybe a lock of hair to get fixed, and the previous owner didn't want to spend that much money).

The Valve covers were off and all wiring disconnected when I got it, so I didn't know what was the problem.

I changed out the primary and secondary tensioners. The chain guides were ok and so were the primary tensioners. Put it back together, started the engine and it was jumping and shaking like there was no tomorrow, and of course, zilch point nada power.

So, I pulled the spark plugs and tested the compression. Four cylinders had 0 compression, the others had 150-155 psi. That was odd, to me since there was no indication that the pistons had collided with the valves (I turned it over by hand several times and it was smoothe).

I got the idea to use a borescope to look inside the cylinders, but couldn't find one for rent around here, so I went on EBay and bought one ($45.00) from China. It will take a week or two to get here.

In the meantime, I checked the clearances between the cam lobes and the valve shims, here is what I found.
JTIS specs:
Intake - .18-0.22mm
Exhaust - 0.22-0.27mm

My Jag...
Bank 1
cyl 1 In - .20/.20 Exh - .28/.28
cyl 2 .20/.20 .28/.28
cyl 3 .20/.20 .28/.28
cyl 4 >.63/.20 .28/.28

Bank 2
In - .20/.20 Exh - .20/.20
>.63/.20 .25/.25
.20/>.63 .25/.25
.20/>.63 .20/.25

So, it seems that it is the valves that are the culprits. Just don't know right now why they aren't closing. Also notice that all the culprits are intake valves (only one per bad cylinder), where in the scheme of things, the firing order is 1-1, 2-1, 1-4*, 1-2, 2-2*, 1-3, 2-3*, 2-4* (where * designates misbehaving intake valves).

Since it is only one intake valve per bad cylinder, that seems to rule out a collision with the pistons.

To be continued..........

Mick

rough idling motor
 

Well, I have bad news. The bore scope came in and I looked at all the pistons as far as I could (the spark plug hole was too small to get the head of the bore scope through, so I had to see what the pistons looked like from the top of the spark plug hole).

I found curved scars on the pistons that had 0 compression. Very peculiar, I guess since when I got the car, the camshafts all lined up to receive the locking tools - that is why I didn't think the secondary chains had skipped any teeth. Three of the pistons with scars were on Bank 2, and one was on Bank 1. Wouldn't that mean that both secondary chains had skipped teeth?

I am now thinking that the guy from whom I got the Jag, got it from someone else who took it to a mechanic and had the motor checked (without changing out the secondary tensioners?) and the timing reset, and when it still wouldn't run good, unloaded it on the guy from whom I got the Jag, who then took it to his mechanic who told him that it was the timing, and the money figure didn't look good so he gave it to me. He did, in all fairness, say the car was just the body (since the motor and trans were unknown factors).

Now here is another mystery: When I start the car, it idles roughly, but when it gets up over 1000 rpm, it is really smoothe. What's THAT all about?

I don't know how to resize the pics I took of the pistons in order to upload them here. Can anybody help? Thanks

If its close to the maximum size, the software will resize and compress, but it must be close. If not, sign up for a free flickr or photobucket account, and use that to host your pics. Then just copy/paste the links here (using the insert image icon above https://www.jaguarforums.com/forum/i...nsertimage.gif)

good luck

ysgeye, how did you come out?