My 2002 XK8 with 115,000 miles has started trowing VVT codes p1396 and p1384. Engine runs smoothly and quietly, no rattles. When energized the solenoids emit an audible click, and when running, the voltage to the solenoids is only 10.5 volts, what should the voltage be?

 

The voltage, measured on an AC setting, at the solenoids will (or should) vary with engine RPM. The two tests you report indicate that the solenoids are at least actuating and the engine management is at least trying.

Has any work been done recently - tensioner replacement, for example?

Low oil pressure is one possible cause.

There are two or three recent fairly long threads on addressing these codes. While no conclusive resolution has yet been reached, you will find lots of guidance on how to troubleshoot. Do a forum search on '1384 1396' to get you started.

Good luck and please report back on progress.

Mike

 

Thanks for your reply. Yes, tensioners have been done, the pan removed and all debris removed, I tried. I thought I had solved the problem when I cleaned the connection to the crank position sensor, and had no ce light after a few short trips, but after the next longer trip the ce light was back making me think it's low oil pressure related. So, my next plan is to change the oil with a heavier grade, say, 10-40, see what happens, if no good, maybe change the oil pump? Unfortunately I'm due for smog test soon!

 

Agreed on doing the simple stuff first.

Your quickest route to getting a true oil pressure reading would be to tee off the pressure switch and hang a proper gauge off it, as the OE gauge is worse than useless.

I don't know if it would affect a smog test; from what I've read, CVVT doesn't really add much for the extra complexity, and the older motors without it pass the tests. Would your testing rules mean a fail just because the codes were present?

 

Mike, here in CA you will fail smog with a CEL no matter what the reason even if you had 75% nitrogen and 25% oxygen comming out the tail pipe.
My daughter has an old Honda Accord with a CEL for torque converter lockup, nothing to do with emissions, and it failed smog.

 

Thanks for the enlightenment BobRoy.
The universal problem of rules and their (mis)interpretation.

Thankfully no periodic testing here yet so don't have to deal with this type of nonsense.

 

OK, changed oil to 10/40 Mobil one and added a bottle of Lucas oil enhancer, (thick goo) drove quite a long distance in hot weather, very varied driving conditions, some highway, some stops, and so far no light! Fingers and toes crossed!!

 

Bobroy, you have a lot of Jags, you must be a glutton for punishment! I know we love our cars, but I think I'll love mine one at a time! Though the wife loves the Vanden Plas!

 

I find my cars with mechanical issues. Usally A drum or tensioners. I get them for a low price because sometimes the only offers are from wreckers. I only deal with X100 or X308 so the engine and transmission are the same, only difference is AJ26 and AJ27. I found 3 XK8s that were totaled but the engine and transmission were good. I also have an XJ8 for parts. So if I'm working on a car I usally have the parts available from the parts cars. I have 2 AJ26 and 1 AJ27 along with 2 ZF5HP24 transmissions on the shop floor. I have been selling parts and I use that money to purchase new parts when needed. So far I've got 2 XK8s and 2 XJ8s back on the road. The plan was to do the repairs and resell, but everytime I get one back on the road someone in the family wants it. So this is not a profit base opetation, it's a hobby. I have sold 1 XJ8.
I enjoy working on and learning about the cars and the interaction on the forum. Hopefully I have made a few friends.

 

If switching the oil to a thicker grade, then this sounds just like the early 3.0L v6 S-Type issue that would throw vvt codes, but its a internal mechanical fault of the VVT, not the solenoid itself. I've taken the VVT's apart before on the V8's, and changed the seals, to prevent leak down of oil ( knocking noise occurs till you rev engine to get oil pressure up, noise goes away) other than that, its 2 springs inside. I have some pictures of one taken apart on the laptop at home. I'll try to post. There's several S-Types running around doing that, instead of replacing the VVT units, just run thicker oil.

 

Thanks for the update, phobman. I hope it turns out to be that simple.

Thinking about it, if you do want to pursue the true oil pressure, it would be easier still just to remove the oil pressure switch temporarily and plug the gauge in its place.
The electronics won't mind other than to give you the 'low oil pressure' warning light and a zero reading on the OE 'gauge'

 

I've just been examining the parts books and searching for the 2 seals that connect the vvt solenoid carrier to the vvt mechanism they call the magnet, that bolts to the camshaft. If those seals were worn the oil could loose a lot of pressure at that connection and prevent the operation?? What do you think??

 

Any leaking oil seal is going to cause a reduction in oil pressure. The items you mention are, if I understand correctly, marked 11 here:



I notice there's also a filter on the carrier oil feed. That may have accumulated debris - 21 here:


JEPC doesn't show the internals of the CVVT unit so I imagine it's a case of 'buy a complete unit' rather than replace internal seals. JBzXJ40's practical experience of R&R will be of much more value here than my conjecture.

All very good in theory, but it's not exactly a trivial task to get to the CVVTs. I'd follow your plan A and confirm oil pressure before delving into the internals.

If you're interested, section 9 of this manual on Gus' excellent site will give an insight into how all this is supposed to work:

http://www.jagrepair.com/images/Trai...ual-9-5-01.pdf

Mike

 

Yes, that's it, I hadn't noticed the filter, thanks! I'm confident that the oil pressure has been healthy enough, never noticed any low pressure symptoms, but could imagine these seals getting old and hard and not doing their job!

 

Agreed. Seals are not forever.

Please do report back on outcome if you decide to replace them.

Mike

 

Two days of driving now in hot weather on the new oil and no further ce light, looks like it's fixed for now, until the seals get progressively worse, maybe i'll do them next year!

 

i removed my tensioner now my engine knocks as if driverside needs more oil. The car seat for 3 weeks too.

 

Hi Terry,
Youre' in the wrong forum -should be X308:
https://www.jaguarforums.com/forum/xj-xj8-xjr-x308-27/

Although the motors are similar, I'd suggest that you start a new thread over there and include some more details of what work has been done, any codes thrown, etc.

Mike