Please help Timing issues after rebuild??
#1
Please help Timing issues after rebuild??
Ok guys I have a 98 XJ8 that a spun a rod bearing in we rebuilt the bottom in. Heres the problem im having:
THe heads are on the motor and with no cams bolted down on the heads the motor turns over no problem. When I bolt the cams down to the heads bring the flat sides up, put the locking tool on the cams and put the plug in the flywheel and put all the timing chains on and turn in over its turns for a mintue then a valve hits a piston and of course I stop.
My question is what am I doing wrong I followed the write up that everyone uses and its doesnt seem that compleX. I think Im doing something wrong in the vvt part. Is there a special way to put the vvt. I take the slack out of the chain like im suppose to and then use the tensioner to hold it on the oppsite side and still when I go to turn it over by hand it hits. Does anyone have any advice thanks in advance
THe heads are on the motor and with no cams bolted down on the heads the motor turns over no problem. When I bolt the cams down to the heads bring the flat sides up, put the locking tool on the cams and put the plug in the flywheel and put all the timing chains on and turn in over its turns for a mintue then a valve hits a piston and of course I stop.
My question is what am I doing wrong I followed the write up that everyone uses and its doesnt seem that compleX. I think Im doing something wrong in the vvt part. Is there a special way to put the vvt. I take the slack out of the chain like im suppose to and then use the tensioner to hold it on the oppsite side and still when I go to turn it over by hand it hits. Does anyone have any advice thanks in advance
Last edited by smitty5534; 06-01-2011 at 01:23 PM.
#2
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#6
It sounds like you might not have the crank in the right position when the cams are locked. You are taking out the crank sensor and replacing it with the crank positioning tool and it is falling into place all the way?
Otherwise, I have to wonder if the cams are switched and I can't recall if they are factory marked bank A or B. Or a valve is sticking open and hitting when it should be closed
I don't believe you actually have VVT in a '98. It should be lock the crank, lock the flats, tension the chains, that should have things in sync.
Otherwise, I have to wonder if the cams are switched and I can't recall if they are factory marked bank A or B. Or a valve is sticking open and hitting when it should be closed
I don't believe you actually have VVT in a '98. It should be lock the crank, lock the flats, tension the chains, that should have things in sync.
#7
The VVT's alone are not capable of causing the problem you describe. They operate just fine within their range of movement. And I believe the early engines had VVT's but they were off/on not variable.
Sounds like the primary chains/intake cam may not be correctly timed to the crank.
Sounds like the primary chains/intake cam may not be correctly timed to the crank.
Last edited by test point; 06-01-2011 at 08:36 PM.
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#10
Camshaft Timing
Check that the crankshaft is positioned to 45º ATDC
with a JD 216 drive plate locking pin installed.
Using a JD 215 camshaft locking bar, check that
the camshafts are held with their flats up and
parallel with the top face of the cylinder head.
Check that the VVT units are fully retarded.
Tighten the ‘B’ bank primary chain by inserting 1
or 2 JD 218 timing chain tensioning wedges between
the ‘B’ bank primary chain tensioner and
the tensioner blade.
Fit the JD 217 timing chain tensioner tool to the
‘B’ bank exhaust sprocket and apply 10 – 15 Nm
(7 – 11 lb ft) counter clockwise torque to the
exhaust camshaft sprocket while torquing the
exhaust camshaft sprocket bolt to 110 – 130 Nm
(81 – 96 lb ft). Continue to hold the tension and
torque the intake camshaft sprocket bolt to
110 – 130 Nm (81 – 96 lb ft).
Repeat the procedure for the ‘A’ bank chains.
Remove the JD 216 locking pin from the drive
plate, the JD 215 camshaft locking bars and the
JD 218 timing chain tensioning wedges.
NOTES
JD 218 TIMING CHAIN TENSIONER WEDGE
T180/2.34
JD 217 TIMING CHAIN TENSIONER TOOL
T180/
Check that the crankshaft is positioned to 45º ATDC
with a JD 216 drive plate locking pin installed.
Using a JD 215 camshaft locking bar, check that
the camshafts are held with their flats up and
parallel with the top face of the cylinder head.
Check that the VVT units are fully retarded.
Tighten the ‘B’ bank primary chain by inserting 1
or 2 JD 218 timing chain tensioning wedges between
the ‘B’ bank primary chain tensioner and
the tensioner blade.
Fit the JD 217 timing chain tensioner tool to the
‘B’ bank exhaust sprocket and apply 10 – 15 Nm
(7 – 11 lb ft) counter clockwise torque to the
exhaust camshaft sprocket while torquing the
exhaust camshaft sprocket bolt to 110 – 130 Nm
(81 – 96 lb ft). Continue to hold the tension and
torque the intake camshaft sprocket bolt to
110 – 130 Nm (81 – 96 lb ft).
Repeat the procedure for the ‘A’ bank chains.
Remove the JD 216 locking pin from the drive
plate, the JD 215 camshaft locking bars and the
JD 218 timing chain tensioning wedges.
NOTES
JD 218 TIMING CHAIN TENSIONER WEDGE
T180/2.34
JD 217 TIMING CHAIN TENSIONER TOOL
T180/
#11
Question to Sean B...
I have a question about Sean B's response, and I am familiar with, and agree with all that you have said ... but as I read in the JTIS CD disk service manual, they have the same info and torque valuefor for torquing the bolt on the exhaust cam, but when it comes to the inlet cam, the factory JTIS CD says to first put 30 ft-lb (about 40 n-m) on the inlet cam / VVT bolt, and then to apply additional 90 degree "turn the bolt". I see that your info to torque both cams the same basic 90 ft-lb. Could you please comment on this. I know that torquing by "turn of the bolt" a prescribed number of degrees, is a well established industry practice to assure you actually get the right torque (and preload force), but I am not so sure that the CD has a misprint in there, ... they say 90 degrees more, but that grabs me as an awful lot. I've done engineering calculations (my profession), and knowing the pitch of th bolt (1.5 mm), and the free shank lenght availablt to stretch (about 0.7 inch), at 90 turn, the bolt would be horribly overstressed ( and potentially break). I could believe 9 degrees though, that would put it in th sam ballpark with 90 ft-lb. Anyway, I would like to ask you know of this, if you've heard that's it's a misprint, or whatever you think. I think you've got it right, but am trying to understand what Jaguar's intent was on this really key bolt to make sure pistons dont crunch valves, and really make sur I've got it right as I'm re-assembling my engine now after changing the tensioners on my 99 XK8. Thanks in advance for your time!
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