Originally Posted by razorboy

Certainly, a valid consideration in the process but the oil pressure does arrive a second or so after initial startup.
MY feeling is that there must be some sort of check valve arrangement that holds the oil pressure once the engine is shut off.
Like many others, if I start the car again withing a short period of time (like 10-20 minutes), there is no chatter on the start. If it is left for a hour or longer, it chatters again for a second. The common wisdom is that the oil pressure is lost to the chain tension assembly (oil pressure controlled) and the system has to basically reset when oil pressure finally arrives. This is the chatter that is first heard as the chains on the VVT are essentially loose when you start the car and then suddenly tension up.
Ove the years, I have heard and seen many folks saying that is just an annoyance and is not detrimental to the car (not like the camchain tensioner issues of the 4.0 engines). I can confirm that after 4+ years of ownership with the issue, the engine is fine, and the chatter has neither increased nor decreased over the years.

Originally Posted by JayJagJay

Interesting... The fiasco I mentioned in (was it this thread) an earlier post was where one of the two bolts in my plastic pick up snapped off waaaay up on the underside of the engine in the area above the sump pan. I took a few pictures of the area and posted them. In that was what looked like a cap of sorts, a housing, that some of the other gurus here rightly (I'm pretty sure) ID'd as a sort of pressure check valve. I'll go back and look. I definitely have the photo but am not sure if this is the same from 97 to 04...

At the time, I was wondering what it was, almost wanted to open it, was interested in whether or not it was a wear item, and whether or not we all need to be thinking about em...?

I'm going to look for the thread and see what others explained to me.

It's this:

Originally Posted by xjrwithproblems

I have received a lot of help here on the boards and thought I would contribute a writeup on a subject that is not really discussed into detail. From this writeup, you should attain a good understanding on how the VVT unit works, how to assemble and dissassemble the unit, and even how to repair it. Keep in mind I am writing this at 3am, so i appologize beforehand for the run-on sentences and grammatical/spelling errors that you may have to deal with.

If you plan on using my information to repair your VVT, I advise that you only do this if you are sure your vvt is faulty. This is not a maintenance step! Work at your own risk, I am in no way responsible for what happens to your car, or how you apply my information.

First off, I will say that there is NO WAY to remove the VVT solenoid without removing the front timing chain cover so it is a bit of work. I have read that it is possible to remove the VVT with just the removal of the valve covers but I assure you this information is false.


Now, the reason I had to take apart my VVT will most likely differ from why you may tackle this job. While doing the tensioners, I for some reason removed the 5 torx bolts holding the vvt to the sprocket. When i removed the last bolt, the spring loaded vvt popped off the sprocket and fell to the floor. Not thinking anything of it, upon completion of the tensioners, I just screwed the VVT back on. Once I assembled everything, i started the car up and the car idled horribly (lots of shaking). I figured it had to be the VVT. I started
reading up on the VVT, and couldn't find much info, so i decided to take it apart and see how it worked, giving me an understanding of how to fix my situation. THis is what I found.

Attachment 172260

As you can see, there are 4 parts that make up this solenoid. I don't know the correct terminology but heres a description.
1. Housing
2. Spring
3. Small Gear
4. Big Gear

When people say that the VVT has failed, I honestly don't see how this piece could fail. All the pieces are solid, and I would be surprised to see any of these pieces break. Mine did have a lot of sludge in it, which could be the problem for those whose vvt's are not properly advancing/retarding. If you hear the VVT clicking, it is most likely the o-rings in the VVT Bush carrier (the piece that looks like the mount for the VVT). As we go on, you will see how the vvt works and how it moves internally.

The picture you see below is the gear from the top view. As you can see, there are two small holes (these holes are for adjusting the vvt to the "full retarded position". Jaguar has a special tool for this, but i rigged something up as we will see further.

Attachment 172261

After cleaning all the parts, I soaked them in wd40 and then put them back together. First, I took the small gear with the 2 adjusting holes and fit it into the larger gear. The larger gear has two of it's sides that are not fixed, in that they move very slightly. you will need to move these two pieces slightly to get the small gear to fit in (once you have it apart, you will know what I am talking about. Once this piece is fitted, you then take the big gear with the small gear installed and assemble it into the housing. Make sure the teeth
are all lined up. I spent about an hour trying to figure out how to put this piece back. I almost gave up which is when i pulled out my hammer and tried to bang it in there. Turns out it went in. Just to make sure i didn't damage anything, I pulled it out and inspected everything. No damage. As far as I am concerned, this is the only way to get it back together. Don't bang too hard, just light taps. You should have something that looks like this. I hammered the center of the small gear with the adjustment holes.

Attachment 172262


Now, i flipped the housing over and with my thumb slightly pushed in the hole where the bush carrier fits into to slightly push the small gear up. You want to push this gear very slowly to make sure it doesn't pop out of place. THis gear needs to be pushed up so the big gear can be properly seated in the housing (IF YOU DO NOT PUSH THIS LITTLE GEAR UP, THE BIG GEAR WILL NOT, I REPEAT WILL NOT BE PROPERLY SEATED). Now, if you look at the picture above, you will see that i have a socket with an extension on the big gear. This is what i used to gently hammer the big gear down. In this step, you are not hammering the small gear with the 2 adjustment holes, you are Hammering the big gear (the location where the socket is standing). When the gear is fully seated, you should have something that looks like this.


Attachment 172263


As you can see, the big gear went down and the small gear came up. I believe this to be the FULLY RETARDED POSITION. The big gear that is seated down will move up with oil pressure, thus advancing timing. THe big spring seen below will keep this in the retarded position when installed. As seen below, make sure the larger diameter of the spring is rested on the big gear, and the smaller goes to the cam sprocket.


Attachment 172264

Once you have the spring on, bolt down the vvt to the intake cam with the 5 torx bolts. VVT installed will look like this (but you probably already knew that)

Attachment 172265

Now, at this point, I was pretty sure this piece was in the fully retarded setting. just to double check, I got two very small torx bits that i can fit into the two adjustment holes and twisted them with a vise grip. As i suspected, they would not twist in the counter clockwise position (retarded), but they would twist in the clockwise position (advanced). This reaffirmed my belief that it was in the fully retarded position. I twisted the two bits back to the fully retarded position by twisting counter clockwise. Keep in mind that spinning the vvt with these two bits was a huge pain in my ****, but is possible. I'm sure the tool would have made this a ten second job instead of 2 minutes of frustration and aggravation.

Attachment 172266


When i was sure I had everything set properly, I tightened my intake cam bolt, and then installed the bush carrier. The bush carrier has 3 different lenght 10mm bolts. Before you install the bush carrier, take the bolts and put them in their holes just to make sure you know which length bolt goes in which hole. I put everything back together, and voila!!!! I have a purring kitty.

If you have any questions, feel free to PM me.