Advice for resetting skipped secondary chain
#1
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I am trying to determine the best route to restore the correct timing on the LH Cams. One question: When one set of cams has their flats up in proper position to be locked down, should the other set of cams opposite side have their flats up as well? When my right side cams are lcoked the opposite side flats are both off center. This Photo shows what I mean. The opposite side is locked in place.
![](http://thumb0.webshots.net/t/66/766/4/90/39/2252490390100698880WvtoBR_th.jpg)
Any info is appreciated.
![](http://thumb0.webshots.net/t/66/766/4/90/39/2252490390100698880WvtoBR_th.jpg)
Any info is appreciated.
#2
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Is that a piece of plastic from a tensioner under the chain !!? and the flats.... hmm .. I think flats should be parralel or at least "looking one way" but your are looking diferent ways
how does your car idle? does it start at all? anyhow to set the timing correctly you'll have to lock cams on both sides so yea they have to be same on both sides..
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#3
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Yes that is the bottom plastic tensioner guide that has somehow ridden up over the exhaust cam sprocket. Car started and idled but very rough. I did the LH (Drivers side) and it went smooth. The RH (Pass Side) is my problem. The plastic must have ridden up over the intake cam sprocket and lodged under the top of the chain tensioner.
I have replaced both sides, but I am not sure about the RH (Pass side) It seems it is too slack for it to run correctly. I am gong by the write ups on this site and instructions on AllData. Also, Once I had replaced the RH side I turned the engine over a couple times using a 24mm 1/2inch to make sure nothing was hitting. Took all the plugs out to make it easier and listened for any noise or clashing sound and it was clean
I really want to know for sure if all four flats should be in proper lockdown position in order for timing to be correct. Or for someone to turn me on to a "How to set the valve timing correctly on your 2001 XJ8" That would be great.
One thing I noticed is that on the RH (pass side) If I turn the crank counter clockwise a small amount the valve train moves in that direction, but the intake cam does not move. Which is another question of mine regarding the VVT setup. How much play is attribute, if any, to the VVT mechanism. Once the motor is running will it adjust itself?
For now I have new secondary tensioners installed, but I am waiting to understand and make sure I have the valve timing correct.
Thanks for everyone's help and opinions
I have replaced both sides, but I am not sure about the RH (Pass side) It seems it is too slack for it to run correctly. I am gong by the write ups on this site and instructions on AllData. Also, Once I had replaced the RH side I turned the engine over a couple times using a 24mm 1/2inch to make sure nothing was hitting. Took all the plugs out to make it easier and listened for any noise or clashing sound and it was clean
I really want to know for sure if all four flats should be in proper lockdown position in order for timing to be correct. Or for someone to turn me on to a "How to set the valve timing correctly on your 2001 XJ8" That would be great.
One thing I noticed is that on the RH (pass side) If I turn the crank counter clockwise a small amount the valve train moves in that direction, but the intake cam does not move. Which is another question of mine regarding the VVT setup. How much play is attribute, if any, to the VVT mechanism. Once the motor is running will it adjust itself?
For now I have new secondary tensioners installed, but I am waiting to understand and make sure I have the valve timing correct.
Thanks for everyone's help and opinions
#4
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Well, Got it finished and back on the road. I went over setting the valve timing on both sides a second time and it fired up first try. It was running a bit rough initially, but once I got it over 35 mph it smoothed out and is running good. I am still thinking I might have to adjust the valve timing once again because it is not velvet smooth, but I want to understand a few things first. So if anyone cares to comment on the questions below, please feel free to add your $0.02
When the RH Tensioner broke and the plastic runner rode up and over the exhaust cam sprocket. Did the VVT mechanism try to adjust timing to overcome the now incorrect exhaust cam timing?
Did driving the car after it was repaired set the VVT back to a normal position? I ask becasue the RH side had a lot of play in the chain and the intake cam did not move for about 10 degrees while the exhaust cam moved. This was after I replaced the tensioner and was moving the rotating assembly via the crank bolt. While moving the valve train in a clockwise motion it seemed like the RH had some slack. When moving only a few degrees in a counter clockwise motion the slack was taken up, but the intake cam did not move until the exhaust cam moved about 10 degrees.
Any help and suggestions or advice is greatly appreciated.
Thanks,
Pat
When the RH Tensioner broke and the plastic runner rode up and over the exhaust cam sprocket. Did the VVT mechanism try to adjust timing to overcome the now incorrect exhaust cam timing?
Did driving the car after it was repaired set the VVT back to a normal position? I ask becasue the RH side had a lot of play in the chain and the intake cam did not move for about 10 degrees while the exhaust cam moved. This was after I replaced the tensioner and was moving the rotating assembly via the crank bolt. While moving the valve train in a clockwise motion it seemed like the RH had some slack. When moving only a few degrees in a counter clockwise motion the slack was taken up, but the intake cam did not move until the exhaust cam moved about 10 degrees.
Any help and suggestions or advice is greatly appreciated.
Thanks,
Pat
#5
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1. With the flywheel locked off at TDC with the special timing tool all cam "flats should face directly upward.
2. The VVT unit is spring loaded to return to idle timing position. You need to use the timing tools to apply correct timing chain tension as you tighten the machine screws that lock the timing sprockets to the cam shafts. Otherwise the VVT or lax chain will allow the intake cam to rotate.
3. A stern warning: replace all 1st or 2nd generation plastic timing chain tensioners NOW with the newer all metal ones.
4. Timing chain tension loss and movement of more than one tooth means exhaust valves hitting pistons. This means pulling the head and replacing bent valves, new gaskets and all new head bolts.
2. The VVT unit is spring loaded to return to idle timing position. You need to use the timing tools to apply correct timing chain tension as you tighten the machine screws that lock the timing sprockets to the cam shafts. Otherwise the VVT or lax chain will allow the intake cam to rotate.
3. A stern warning: replace all 1st or 2nd generation plastic timing chain tensioners NOW with the newer all metal ones.
4. Timing chain tension loss and movement of more than one tooth means exhaust valves hitting pistons. This means pulling the head and replacing bent valves, new gaskets and all new head bolts.
#7
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I think the tensioner problem was fixed in the '02 MY. How many miles? Do you hear what sounds like valve noise or ticking when started cold that goes away once it warms up?
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#8
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No noise as of yet. The vehicle was always dealer serviced and has a 3 month 3000 mile warranty on the engine,transmission etc.. The car has 95K on it currently. The color is Anthracite with Cashmere interior and has the Alpine premium sound upgrade. Body is perfect and cost only $6,300. I have the steel liner engine which was verified,I just don't know about the tensioners,which now concern me. I read another thread about replacing them and I have the mechanical skills to attempt. I would just have to purchase the special tools needed. I was just hoping there was a way to tell without removing the valve covers.
#9
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In the absence of any noise when cold, you would have to remove the valve covers to visually inspect the secondary tensioners.
Since your car was dealer serviced you could try asking the dealer to give you the service history or at least confirm or deny the tensioner repair. Some dealers will furnish this info and others may not, seems to be some type of legal CYA measure.
I would pull one side off and have a look. Your looking for a metal contact surface between the chain and the tensioner. Originally they should have been white, but with heat and oil they are most likely a shade of burnt orange. Just make sure the surface is metal.
If you have no ticking noise from the engine when cold then you should be ok for now.
I may be able to help with the tools, PM me if interested.
Since your car was dealer serviced you could try asking the dealer to give you the service history or at least confirm or deny the tensioner repair. Some dealers will furnish this info and others may not, seems to be some type of legal CYA measure.
I would pull one side off and have a look. Your looking for a metal contact surface between the chain and the tensioner. Originally they should have been white, but with heat and oil they are most likely a shade of burnt orange. Just make sure the surface is metal.
If you have no ticking noise from the engine when cold then you should be ok for now.
I may be able to help with the tools, PM me if interested.
Last edited by NorCalDiesel; 07-08-2009 at 11:08 AM.
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