First, i did my secondary tensioners a few months back. i've been in China so i haven't driven the car much. i read up this link

http://www.jag-lovers.org/cjw/#0104a

on the last page 87 of V8 tensioners it explains i can expect from a cam skipping a tooth. one of my cams was off when i used the locking tool so I assume it skipped a tooth.

1) to fix it do i just use the locking tool then loosen the nut to the cam/gear and let the cam turn flush to the locking tool so it parallels the other cam? yes? no? advice, because i'm gonna do that tomorrow.

2) how do i know which cam is the one that skipped a tooth? 3)do i have to pulled the other valve cover to ensure TDC?

Second, while i'm at it i'm gonna take a look at the primary tensioners.

4) is there any way to get that crank off with a normal puller? and how does it get back on? bolt?

5) Lastly, the reason i am looking at my primaries is because i can hear chains at low idle. am i correct to assume thats the primaries?

advice and help is much appreciated. questions are numbered for ease of response.

 

Be carefull here. I had the same thing happen when I replaced my secondary chain tensioners (cam flats didn't line up).

Note that the intake cam will rotate "inside" of the VVT gear. That is, you can grab a "non-important" section of the intake cam with pliers and rotate inside of the VVT gear/valve (this is how it advances the timing of the cam).

I don't know for sure but I think you will need to use the crankshaft locking tool to set the crank then you can set the cam flats.

More expert advice is needed here...

 

Yep, ronmexico is exactly right. What do you mean about skipping a tooth? Was that before when you changed the tensioners? Your chains did not just suddenly skip a tooth without a broken tensioner. As Ron said, the VVT units adjust the phase of the intake cam to the crank, so unless you have moved the VVT to its extreme per the cam assembly instructions, it will not line up with the flat.
So, the answer to,
"1) to fix it do i just use the locking tool then loosen the nut to the cam/gear and let the cam turn flush to the locking tool so it parallels the other cam? yes? no? advice, because i'm gonna do that tomorrow."
is NO! You must repair what caused it to slip. If you have done that, then you do the cam alignment procedure, including the part about tensioning the VVT towards the correct position. I looked at your link and did not see the alignment procedure. If you need the procedure, I recommend JTIS or Alldata.com

Answer to 2 or three is to do the procedure, then not worry about it until you have a tensioner or chain failure.
I do not know the answer to four.
If you have good ears, you can hear most anything. If you hear a rattle, you have a problem.

Good Luck.

 

when the tensioners where bad i heard an abnormal thump on the right side of the motor. that's why i decided to get to work on the secondaries. when i took the cover off on that same side, the cam closest to the intake manifold was about 35-40 degrees offset from the flat cam. i did the procedure with the tool pinned against the offset came and it managed to stay in place and i did the tensioner swap. ( i used a home made tool and it had to bend a little, b/c i tightened it dawn that hard,to keep the cam in place) car runs very smoothly below 50, but after that i have issues.

as for the sound of the motor. it sounds like chains running in a case without strong guide support. i can hear it in traffic when i'm against a highway divider or driving under 10 mph after the car has started. if i am not mistaken, the tensioners are oil pressure driven and they haven't recieved enough pressure right after start and that's why i can hear the sounds. by why i can hear it in traffic after the car is hot is another concern.

thoughts?

 

and the images of the cams from here

https://www.jaguarforums.com/forum/s...t=crank+pulley

aren't even close to what mine look like. i could pull the cover and take a pic.

 

Namor:
Help me understand: When you say " when i took the cover off on that same side, the cam closest to the intake manifold was about 35-40 degrees offset from the flat cam", do you mean the flats on the cams were offset from each other? Did you have the VVT "unwound" by tensioning the cam with the tensioner tool? The factory procedure says ....
5.Install the camshaft sprocket. Install the chain tensioner tool 303-532 to the sprocket holes. Apply force to the tool in an anti-clockwise direction to tension the chain on its drive side. Whilst applying the opposing force to the sprocket and chain, tighten the sprocket securing bolt to 115 - 125 Nm . Remove the chain tensioning tool.
It sounds to me like you didn't use the crank positioning tool, nor did you follow the recommended procedure to unwind the VVT. If you did not, I do not know what to tell you except those procedures are written for a purpose.
Were your tensioners busted?
I sure would not reposition the cam unless you fully understand the factory recommended procedure for alignment. Note: I did not say you had to follow it, just understand it fully so you can be sure whatever method you use will give the same results. If not, you will be very very lucky to not bend the valves as they strike the pistons.


As to yours looking different. That would seem to mean you either have a 3.2 engine, a SC engine, (no VVT) or an engine built after 8/02 (Morse style primary chain).

 

tensioners were busted.

intake cam, right side of the block. yes, the flats were that offset.

didn't use a tensioner tool. i did the project on a whim because i got the car for free and knew the car was about to kick the bucket b/c of tensioners and other issues. i just jumped into it using my brain and a post from this forum.

all i did was remove the valve covers, lock the cams with a tool i made, pulled the exhaust cam gear, swapped the tensioners, put it back together. no instructions. car runs better, but not great.

if you have a guide or instructions that would be nice help.

and i'm in a 2000 XJ8 VP. thats the 4.0

 

OK, gotcha.
Considering everything, I would believe you would be money ahead to get a manual in order to get the details right. There are posts of where to get the JTIS manual online (although I am pretty sure it is in violation of copyrights, so I won't reference it). If you go that route, search for timing chains in the MY'98 since that is the first year.

I use Alldata.com which costs about $30.00 for several years, I believe.

What all that will explain is how to get the VVT, the sprocket assy on the exhaust side, twisted to the right location for the cam flats to line up NAD how to get both cams inline with the crank.

 

thanks. i just got everything put back together. i was going to do the primaries today but i couldn't get the crank pulley off. managed to get the nut off though. i think with the puller the primaries will be an easy job.

after looking at other pics on this forum i found that one of my cams must have definitely have something wrong with it. and... when i had the valve covers off back when i remember thinking it was strange that there was so much chain slack on the side where i am suspicious of the cam jumped. in fact, i had made a tool to keep the chain tight and it wouldn't to any good on the suspected bad side.

thanks for the tip. i may look into the timing tomorrow if i get around to getting a manual. otherwise i'll hold off till next weekend.

 

Using the (a) tensioning tool is definately a requirement. The secondary chain must be tight on the "drive side" of the chain otherwise it can skip teeth. It took me awhile and some help from another member on this forum but I finally understand what the tool was used for.

I am not sure exactly what happend in your situation but in mine I had a similar problem. The flats on the cams on bank "A" did not line up. After thinking about it for awhile (and some expert advice) I simply took a pair of channel locks, grabbed an "unimportant" part of the intake cam and twisted it flat (inside of the VVT gear) with the exhuast cam.

Mind you that everything was still intact. i.e. the exhust cam sprocket had not been removed or loosened, when I "twisted" the cam flat.


I've everything back together and it seems to be running fine. No codes about the VVT at all.

 

mexico,

i think i'm going to do exactly what you did.

my secondary tensioners were in the mail and two days before they arrived i heard a very bad sound from the right side of the motor. a sort of thump single big knock sound. that's the side of the motor my intake cam is out of line. (passenger) when i installed the secondaries there was nothing i could do to make the chains tight on that side. the driver side was good though.

so all i need to do, and i won't blame you if things go wrong, i was going to do it anyway, is:

1) pull valve cover
2) ensure tdc
3) lock the flats (at least on the exhaust cam)/or hold the exhaust came with another lock and use negative resistance against the direction i am going with the intake came?
4) twist the cam so the flats "match up."
5) don't loosen anything?
6) remove locking mechanism or locks
7) assemble cover
8) smile?

 

You should "flatten" the exhaust cam 1st then rotate (by turning the intake cam "inside" the VVT sprocket. Then LOCK the cams down - if they move your screwed.


You will need a tensioning tool or make your own (or find someone on the forum who will loan you one) such that you can hold/twist the exhaust sprocket counterclockwise as you tighten the exhaust sprocket bolt (so yes you will need loosen the exhaust sprocket nut).

I would also recommend using a torque wrench and torquing down to 85 ft/lbs (per spec). Friction is the only thing holding the exhaust sprocket on to the camshaft (no keyway) - so make sure it is tightened properly.

I hope the noise you heard wasn't the chain skipping a tooth or valves hitting the piston!

 

thanks for the response but an issue remains.

if I turn the intake cam to "flat" i have to rotate it to counter clockwise. that would make more slack for the chain as it would move toward the intake gear.

I found that white out is the very best friend when needing to keep things in line. Just make a series of line up marks and it gives confidence in the face of risk.

I think I'm going to pull the cover tomorrow and take a look at things. I'll go from there.

I guess my final bit of information I am after is, when you rotated the cam did you just make it about level in the locking tool or was there some special method? (give or take a couple of degrees) Because anything close to having both cams lined up has to be better than the current situation.

I've put 2k miles on it and it runs. I think the valves and cylinders are fine. I'm not going to bother with any tests. I still get 22mpg and can cruise at 80 without much vibration. 70mph is another story.

i think the sound was a skipped tooth. don't know what else it could be. but there is way to much slack in the chain. i'll post results tomorrow after i open things up.

 

Rotating the intake inside of the VVT should have no effect on the chain tension. One "side" of the chain tensioner is going to be "slack" with the tensioner pushing against it. The other side (as in top or bottom) is going to be tight. Note that the "top" side of the chain will be tight on one bank and it will be tight on the bottom side on the other bank. If that makes sense.

I may not have described this well but here is what I mean....

Take the valve cover off.
Turn *crank* until exhaust cam is "flat"
Do nothing else.
Grab hold of the intake cam (e.g. not lobes!) with channel locks
Turn it flat with the exhaust cam.

I've noticed with mine if I turn the crank back and forth the intake cam will lag behind, turning inside of the VVT.

If you skipped a tooth then all bets are off you will need to re-time everything. I know this happened to NorCalDiesel on this forum so he maybe able to provide some advice on this. This is beyond the level of my shadetree expertise.

It seem like you haven't skipped a tooth because you would notice it with a rough idle (from what I have seen described).

 

oh i have the rough idle. though, some days like today everything runs like a new motor. reeeeeel nice.

turn on the a/c and things roughen up, but not always. the motor can't make up its mind as to how it wants to be.

if i can pull the cover, keep exhaust flat, rotate the intake, move a link in the chain on the exhaust gear so to tighten things up, i will do that.

as is, even with new tensioners on there is a LOT of slack on the top and some tension on the bottom. i know it shouldn't be that way.

i'll think things through tomorrow before i commit to ruining/fixing the motor.