Hi folks,
My celebrations on replacing the lower vacuum hose on my V6 were short-lived as the Christmas drive to my mums house in Swansea was 75 miles of misfires and flashing check engine light. I have gone from a car that ran well but wouldn't idle smoothly to a car that idles smoothly and doesn't run well grrr... so I would welcome some advice.
What I have done:

• Replaced lower vacuum elbow hose
• the three coils under the manifold
• three spark plugs
• upper and lower plenum/manifold gaskets

When I discovered all wasn't well I replaced the three spark plugs from the non-manifold side and found one plug well had lots of water in it so I thought that was the problem. I also at the same time swapped the three coil-packs that I had taken from under the manifold as I assumed these to be working as I had only changed them as a precaution.

I have checked for fault codes but can't see any, I'm using a wireless OBD plug and can connect to the car and get readings from some sensors but no error codes are seen at all.

I must admit to buying cheap coil packs and spent Christmas day/boxing day at my mums reading about the perils and "DOA's" that have occurred with these so ordered a set of six new coil packs.

In the mean-time I have stripped off the manifold (again) and have noticed that one of the three coils that I replaced has a slightly exposed wire and the connector is a little wobbly. I'm hoping that this will fix the problem.

But... as I have it all apart, is there anything else I should check or look at ?

Thanks in advance for any and all advice.

Regards

Steve

 

You've probably got the cause but I think there's another hose that's prone to fail on that era car (not under the manifold - at the engine rear maybe). It'll be in many threads.

 

I agree.

There is a rubber adaptor on the vertical pipe at the rear, and attached to the LH cylinder head rear face.

Easy to see, get at, with the manifold off, but barely accessable with the manifold in place.

Follow the pipe from the throttle body to the vertical pipe, and the joiner/adaptor is the one in question.

 

jokeruk,

I just replaced the second rubber hose adapter at the firewall yesterday. Good news, it's only $5 at the Jaguar dealer. Part # CS250039 - Rubber Connector. It was very difficult to find this part number, I hope it helps. This did not solve my misfire and I am replacing coilpack for cylinder 4. Best of luck!

 

Jokeruk,

I just replaced the #4 coil and test drove the Jag. Runs like a champ! After owning this S-Type for 6 years, if you are experiencing the severe misfire/chugging syndrome it is almost always the coil. The rubber connector fixed the codes P1587, P0171 and P0174 codes.

 

Good news, thanks for the update.

For future reference, what brand coil gave you trouble? What brand coil fixed it?

 

The coil that failed had only one identifiable feature: printed on the side it said "Eesten Industry K11" I don't recall if It was on the car when I purchased it or not.
I bought the replacement from AutoZone, Duralast $49.99 lifetime warranty.

 

 

Steve,

I also tested resistance between the old and new coils, but both tested within range, making it a real head-scratcher. With nothing to lose, I installed the new coil just to rule it out. I'm no electrician, and I was using a brand new meter I got for Christmas, so maybe it was Pilot Error (no plane crashes itself!).

One thing I highly recommend is using Ox-Guard (made by Gardner Bender) on the spark plug terminal and dielectric grease on the insulator. The Ox-Guard prevents corrosion and is conductive, making a better connection. I've added the Ox-Guard to spark plugs on cars I've purchased and the before and after results are very noticable.

Just prior to the coil repair, my son and I replaced all the front ball joints. What an improvement! Now I believe it needs the lower strut bushing. I don't like to throw money at something that's not broken, but after the results of the ball joint repair, I'm going to replace all the bushings, front to back. At 140,000 it's been a great car and deserves a refresh!

Happy Motoring!

 

Heat may have been a factor. In operation, a coil will be moderately warm, both from current flow and radiant heat from the engine. Certain types of electrical faults can appear to heal themselves once everything cools off, if that is when you took your readings.

 

kr98664,

Great point! Heat can affect the components electrical properties. I was checking them cool, of course.

 

Or they may be breaking down under the internal high voltage the coil produces but your meter cannot produce.

There are testers, but they're not cheap.

 

OK, for the top rear hose part I can't seem to track down the part you have listed: Part # CS250039 - Rubber Connector.

I *can* find this part rubber connector XR819733 on the JEPC which on the exploded diagram looks correct. I'm just waiting for my local dealers parts department to call me back, maybe they can confirm.

Steve

 

Steve,

Sorry, I posted the number wrong. When I found it, it was identified with the number I posted making it impossible to find. The correct number is C2S50039

Connector slightly bent after pulling during removal. Failure on right side.
Firewall area. 90 deg elbow removed.

 

Hi, yes, thanks for the pics, I took my pipe off - had to use a sharp knife,,,,, but it was a good call as the inside was perished and although possibly not leaking it was also not long for the world!

Collecting a new one tomorrow along with the elbow that fits into it and the top plastic vacuum pipe as that was a very slack fit and at £6.00 seems well worth it.