I finally tackled the replacement of the fuel filter in our 2006 XK8 Victory Edition convertible. We had been getting periodic lean codes on both banks and sometimes restricted performance messages. But you could clear them and they would usually stay away for quite a while. Still, I knew that was the original fuel filter and at 60K miles, and more importantly a~9 years, it was way overdue to change.

I had tried to do this job several months ago but after jacking up the left rear wheel and seeing how stupid this was put it off. I've been working on cars for 30 years and am with others on this forum who curse the engineer that put the filter where he/she did. But I now have a 4 post lift and it was much more manageable.

In all my years of working on cars I have never seen the gunk that came out of this filter when I dumped it out the reverse flow in my drain pain. All this dark gray sludge just kept pouring out!

I worry that maybe our fuel pump is disintegrating. Yet the gas that was dripping after removing it looked normal and so far the car still runs fine. Another thought was perhaps the previous owner added some sort of fuel additive at one point and it all ended up in the fuel filter?

I guess we'll see what happens next but thought I'd share that with this group and see what the collective experience and wisdom of everyone is.

Thanks,

Doug

 

Very interesting Doug,

As a matter of interest did you ever get a chance to measure the fuel-line pressure before you replaced the filter?
It would be interesting to note the difference after you changed it.

Andrew

 

Andrew,

No, I didn't go to the trouble to try and hook up a fuel pressure gauge, especially since I knew that fuel filter needed to be changed regardless. That said, I couldn't find a port anywhere on the fuel rail of the engine to relieve the pressure, which is also where you would connect the gauge (most cars have a Shraeder valve for this).

Do these engines have one and I just missed it?

Doug

 

I changed the factory fuel filter (dated April 2005) on my wife's 2006 XK8 Victory Edition several weeks ago as part of my 90,000-mile service on her car. It dribbled several ounces of grey, murky gas as well. No doubt that the fuel pump was having to work extra-hard to force gas from the tank to the fuel rails. The car was running fine, though....

I guarantee you I won't wait nearly as long to change the fuel filter next time. Probably a good idea to change it every 30,000 miles or so. I suspect this would help to protect the very-difficult-to-access (and very expensive) fuel pump....

 

I would have thought it would have had a Shraeder valve somewhere. Mine is 2003MY which most definitely does have one, but can't comment on your MY.
I'm sure someone will be along soon with the relevant info.

Andrew

 

Andrew - can you tell me where it is exactly on your car? Extra credit for a picture .

I know my daughter's 2004 Mazda6 3.0 V6 (same engine as Jag V6's and later Fusions) had a Schraeder valve and they were removed by 2006 when they redesigned the fuel rail slightly. Not sure if that was a cost reducing move or what by I suspect that may be the case here. Learned more than I ever want to know about that engine when I had to replace it last year due to pre-cat failure (swapped in a 2008 Fusion engine, after swapping oil pan, front cover, valve covers, etc.). Decent engine (Porsche/Cosworth design) with a flawed exhaust system design by Mazda.

Doug

 

From another post, don't know if it'll help or not but worth a shot?


The Schrader Valve on the 1999 XK8 is at the rear of the Right Fuel Rail:


Attached Thumbnails

 

How many miles do you think the filter had on it?

It's odd that Jaguar uses such small filters on high output engines.

The BMW filter is a bit larger in diameter, but almost a foot long.

 

Were these cars with the dirty filters fueled with Ethanol blend fuel?

The reason I ask is because of the nasty appearance of the filter contents. The usual crud I have seen in fuel filters is rust or sand. I have seen ethanol dissolve fuel lines and plastic fuel tanks, both of which produced a nasty gel when they failed.

 

Some of the very early 4.2L engines have a Schrader valve but most do not. Some nonsense about reducing emissions.

In this case, all you have is the electronic sensor to go by.

 

Here's the Schrader valve on my 2004MY 4.2 (engine cover removed):-





Surprised they did away with it, but then electronic sensors never lie do they?

Andrew

 

https://www.jaguarforums.com/forum/x...crisis-104680/

my horror story