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The oil in the spark plug tubes is coming from the O-ring gaskets under the cam covers. When you remove them to check the tensioners you can change those then. In 98 they switched from using 2 O-rings connected for each pair of cylinders to a separate O-ring for each plug tube. They also changed to different cam cover gaskets sometime in 98. The older ones cost more of course. I've had good luck buying from Christophers Foreign Auto Parts. They have a kit with the gasket kit, upper tensioners, new tensioner bolts and upper chains for cheaper than just the gaskets and tensioners separately. And with the mileage on your car the chains should be replaced also.
My car started idling rough after I accidentally spilled coolant on the coil cover and some leaked in. The coils didn't like that for some reason. So I am driving it around with the cover off until it dries out and its getting better.
The oil is from a leaking valve cover gasket. Please stop running the engine and remove the valve covers. It is very likely a failed tensioner has resulted in one of the exhaust cams skipping a tooth. One more tooth and you are in for major repairs.
I have the cam covers off both sides and the tensioners are orange. I've got some pictures and one video, if I can upload it. The tensioner on the right( facing the front of the engine) is very loose as is the chain which runs between the two cam shafts. The video shows this. The one picture shows two small screw drivers. They are lying flat against the flat sections on each cam shaft. I believe they should be parallel. Is that correct? How do I tell which one jumped a cog? I am going to order the parts package tonight and hopefully have them by the weekend.
To check the cam alignment, rotate the engine clockwise (from front) using the crankshaft bolt, until you can lay a straightedge across the flats. This takes the slack out of the chain.
I am almost certain I can see from the photo that the chain is riding on the metal backing plate on the tensioner....it is supposed to be on a plastic shoe that has likely fallen off. A smoking gun.
What Steve was saying about the shoes is the tensioner has a plastic cap that the chain glides across, it's not unusual for older ones to have this cap 'break off' then there is a bit more slack and possible tooth jump. Once you sorted out the cam timing you will need to pull your oil pan and clean the plastic pieces from the cap out, they will eventually clog the oil pickup and you'll have oil pressure issues. Note in the photo the top of this is plastic, yours is metal where the plastic broke off.
BTW I asked you about Ohio once, do you know a Lovejoy from Warren/Champion?
Last edited by jamdmyers; Apr 28, 2015 at 05:40 AM.
Plastic guide gone off tensioner, found part of remains when cover came off!
Ready to start replacing parts. Got the full kit from Christopher's Foriegn Car Parts. What an incredibly well put together parts kit! All parts packaged separately and labeled, all gaskets, a tube of RTV AND a package of buttered popcorn!
I went to the extra trouble of taking the radiator out so I could get my impact wrench in on the crank shaft bolt. I held the harmonic balancer with a rubber strap wrench and it took a 2 second blast with the wrench and it was out. Definitely the way to go.
One question. The new primary tensioners come in a package that says to discard the old backing plates before installing new tensioners. It says the new tensioners work on internal spring, not oil pressure. I've read so much about being careful to orient the backing plates correctly, I'm kinda spooked to be told to throw them away. Any thoughts? It this correct? Thanks a bunch for everybody's help, I would never have got this far without this forum! Heck, I probably wouldn't have even tried it. But, so far, I'm really enjoying this.
When I removed the radiator I had to disconnect the transmission oil cooler lines from the left side of the radiator. I lost about a hundred cc of AT fluid. Where is the refill port? Is it accessible with the car on the ground?
Unfortunately no, you have the ZF5HP24 transmission I believe. There is not a fill tube as you might be familiar with the fill port is on the side of the transmission casing and it's a bit convoluted on how it's filled. Check out the DIY sticky there are a number of articles or a search, there's been alot of information posted.
I test drove a 1998 xj8l s my 1998 Vanden plas has lost 2nd gear. The engine is a replaced engine and I the owner gave up on the car. I had to show the dealer what it should sound like. Anyway, it runs really odd. Doesn't stall. Runs nothing like a throttle body being dirty. It does die and at 2000 rpm comes to life with more power than my VP. I can hear clicking clacking sounds on the driver's side valve cover. I can get the car cheap and swap my motor if this doesn't work out. So I am interested in how this comes out. Runs really odd though. Does yours sound like it has an aggressive can in it? Real lumpy. Not like one misfire?
I test drove a 1998 xj8l s my 1998 Vanden plas has lost 2nd gear. The engine is a replaced engine and I the owner gave up on the car. I had to show the dealer what it should sound like. Anyway, it runs really odd. Doesn't stall. Runs nothing like a throttle body being dirty. It does die and at 2000 rpm comes to life with more power than my VP. I can hear clicking clacking sounds on the driver's side valve cover. I can get the car cheap and swap my motor if this doesn't work out. So I am interested in how this comes out. Runs really odd though. Does yours sound like it has an aggressive can in it? Real lumpy. Not like one misfire?
It would be better to open a new thread in the XJ8 X308 forum if you proceed with this car. The symptoms are probably caused by a failed tensioner causing the exhaust cam to skip a tooth or even two. It's likely there is valve damage, even pistons.
I put it all back together, turned it over with the fuel pump fuse out for a minute, put the fuse back in and it cranked right up!!!! I'll have to take it up to the transmission shop in town, because I couldn't get the fill plug out of the transmission to top it off. I thought I had it, but I think I may have boogered up the hex hole in the plug. Trying to find a hefty, strong 8mm, 6 point box end wrench can be a challenge. All I could find was an offset and it didn't fit in the space that well and when I put the pressure on the hex wrench slipped out and then I couldn't get it back in place. It only lost about a 100 ml when I disconnected the transmission cooler lines from the radiator, so I hope it will get to the shop.
