My son has a 2003 Jag S 3.0 manual.

About 3 years and 20k ago, he developed a rod knock from poor maintenance. We checked the engine did a compression test and decided to do the crank and bearings.

Cam chains were tricky. hand rotating it showed we were off a tooth, made the correction, and I thought we got it right.

Since he has intermittently gotten the dreaded restricted performance. We have gotten general emissions codes, consistent misfires on 2 4 6 so I have been concentrating on that side. once in a while a "lean" code on that side.

The condition is now much worse on the highway and otherwise happens on coasting.


As cyl 2, 4 spark plug insulators were a dark tan and 6 was pretty white (the normal lean I see)

I removed the injectors, cleaned them and did replace # 6, which did seem OK in my barn Job cleaning.

I decided to do a compression test.

Interesting that Bank one is consistently Much higher, like 40 lbs and pumps up much more quickly, leading me to question if the cam timing is off, or a weak tensioner, or advance.

Oil in the cylinder cause a small jump in all tested.

This all is a bit new to me. I have more ***** than brains when it comes to this.

With that said any hopefully smart comments from the more capable than me Crowd?

I would hate to pull it all down, if its the advance or something.

Help would be greatly appreciated.

Son has a new baby, and would love to get more use out of this ride.

Thanks,

Gil

 

When you reassembled the engine, did you refer to the procedure outlined in JTIS? If not, it is possible the camshaft timing is incorrect.

JTIS is available as a download at no charge in the 'sticky' section of this forum.

It would also be helpful if you post the DTCs present in the system.

 

I did not record the #s as the same thing came up so many times
excessive emissions fault
Excessive emissions bank 2

rarely lean condition bank 2

multiple cylinder misfire
misfire cylinder 2
misfire cylinder 4
Misfire cylinder 6

I thought I carefully re assembled the engine. We printed the various pages from the JTIS. I think I can check it just from the valve covers, but any suggestion would help.

Also concern about the cam advance and any way to test that.

It is wild that one bank cylinger pressure is so much higher than the other, consistently. the only thing I can think of is one side is not getting enough intake or the other is getting too much.

thanks for the get back

 

Remove the cam cover, rotate the engine and inspect the timing marks on the cam sprockets to see if they are consistent with JTIS.

 

That was my thinking

will do.

Do you agree that the timing could cause the discrepancy in compression, bank to bank?

 

It is possible if the valves are not fully closed on the compression stroke.

 

thanks next chance I'll pull the covers

 

I uploaded my copy of the Jaguar Engine Repair Course 168 and it includes the V6. My copy of Jaguar Engine Repair Course 180 is for the V8 engine ONLY.

It should be somewhere on the internet (GUS has a copy) as well here on the forum.

It is probably more detailed than the JTIS info.

bob

 

Here is a link to the course:

http://www.jagrepair.com/images/Auto...Code%20168.pdf

 

I'm struggling to find the 180 - maybe a typo?

 

Here is an illustration of the location of the timing marks.

Note this engine does not have a mark for TDC, so a dial gauge must be used to determine TDC on the number one piston.

 

Having recently installed 2 new heads on my 3.0l the issue of correct timing was a worry?
I ended up researching and consensus was that JTIS was unclear or possibly wrong so used the method in link attached: I used original chains no coloured links,

https://www.jaguarforums.com/forum/x...q-11448/page2/

 

I NEVER uploaded my Jaguar Engine Repair Course 180 because the 168 has ALL the V8 plus the V6.

In fact I never took my paper issued 180 to the copy shop to have it converted to .pdf. (no point) Just the 168.

bob

 

OK - no problem.

 

thanks for the help!

I wish I was more careful when I did the engine. Been running the tires off my rover, and I need some me time to go back to the Jag.

So I will remove the valve covers, do my best to determine tdc and check my valve time, using the additional info I have gotten. It sounds like the most realistic reason for my problem.

If the timing the appears to be off, I will pull the front of the car apart, remove the timing cover and try my best to do it correctly this time.

 

Assuming I have to pull the timing cover, and mess with the chains, anything else I should address?

 

If you have not done so already, inspect the condition of the cooling system hoses as they should be replaced, along with the thermostat, given the age of the vehicle.

When you begin working on the timing chains, work slowly and double check your work. Ask questions if you feel unsure about something.

 

Well thanks for the help. Not out of the woods yet. The training manual helped me remove some of the timing questions. End of the story My drivers side bank is off by one tooth on both the intake and exhaust side. I did remove the cooling hoses, serpentine belt, fan to give me greater access, and I assumed it was off. Grandson came over so the time was limited. I have to pull the accessories, etc, to remove the cover next.

 

I am surprised how well it ran, aside from the intermittent restricted performance!!!

 

Am I correct, there are two bolts under the oil pan attached to the timing cover. This means I have to pull the pan, which also means I have to pull the engine???