I have an 03 S-Type 4.2l.......it's been spitting 171 and 174 codes at me for a couple of weeks. I've ruled out the easy vac leaks.

I removed the intake manifold bolts to find the back 2 very corroded and rusty. I also removed the throttle body to see into the intake, very oily and black. I suspect at the least, a faulty intake manifold gasket.

Problem.....I've removed everything I can see to get the manifold out, it is loose, however something at the back of the mani is holding it in place, feels like a wiring harness, but I can't see or feel anything, I'm at a loss.

Any idea what on the back of the manifold is holding it in place? Any help would be appreciated.

 

Also worth reading previous threads especially to see what LTFTs do.

 

There is a bolt under the front between the manifold and bracket attached to the rh head and another on the rh side on the bracket attached to the valve cover.

 

Once the bracket is removed, as per Tony 1963's post, you have the MAP connection and the vacuum hose to the brake servo.

Once you have the bracket removed x 2 ,10mm bolts, you should have enough room to lift the manifold up and get better access to the MAP connection for removal.

some photos attached which may help.

The vacuum line has a connection hidden under the silver heat insulation, if you slide it back you can see the connection about 4" from the back of the inlet manifold. So should not be an issue.


Since you have got this far, I would suggest you change the Throttle Body coolant line AJ 811763 it is about $10. and much easier to change out now with the inlet manifold removed.

 

Great help guys, came right out.

Now what I found......the passenger side intake manifold gasket is covered in oil. There was some oil on the driver side gasket as well. I looked in the intake, and there is oil pooling at the bottom. I attached some pictures.

This may be getting above my pay grade.

Any thoughts?

 

Crap......just realized the pics I attached are upside down, sorry, amateur.

 

bgiff,

I don't see anything really wrong!

I would say you rocker cover seals are leaking, and oil is running down. Now would be a good time to replace these and the VVT oil seals.

The air inlet manifold seals looks like they were sealing from what I can see in the photos.

I attach a couple of photos of mine when I took it out, and it looks the same.

There was about an egg cup full of engine oil in the air inlet manifold, which just gets sucked in from the rocker cover vents.

I would suggest you replace the inlet manifold metallic gaskets. AJ85392 x 2 to vin 13088, and AJ 89062 thereafter.


How is the green air inlet gasket, to throttle body air inlet manifold, still soft and proud off the manifold?

How many miles on you cat?

 

Bydand.....she's got 180,000 miles. I bought it with less than 20k, so I know 90% of the history.

The green air inlet gasket looks totally fine to me, so I think I'll leave it.

I will replace everything else that you suggested though.


I did order a new intake gasket, which I assumed was an issue considering the rusty and corroded intake bolts. I also am hoping that my lean condition is a result of a faulty gasket.

I am concerned that even after a new intake gasket, and I button her back up that I continue to get the 171 and 174 codes, along with the dreaded restricted performance message.


We shall see.....I will post once I get her running again.

 

I fear you may be correct?

Have you seen the post below and others, on P0171,P0174?

https://www.jaguarforums.com/forum/s...nk-1-a-110023/

https://www.jaguarforums.com/forum/x...solved-117387/

Change Fuel filter, clean MAF, O2 sensors. etc etc....

180K is good going.

Now, may be the time for O2 sensor change out, if not done already done, due to age.

Once you get it back together try taking live data and see what it looks like.

Or you could be just throwing more bits at it.

Good Luck.

 

Update....I replaced the intake manifold gasket and re-assembled everything. I tried to take my time so as to not damage anything.

Good news, after 50 miles or so, no lean engine codes or restricted performance, seams to be running just fine.

Bad news, upon start-up I immediately get 2 new codes, p0193 and p1108.

P0193....I looked at the fuel rail and connectors and don't see anything obviously wrong, so not sure what the deal is here.

P1108....the only thing I did with the map sensor was to unplug it when I removed the intake. I was certain to make sure the connector snapped back into place when I re-assembled, so again not sure what the deal is here.

 

Maybe they share some harness and it's chafed.

 

Maybe Nixon is taping too.

 

How do you remove the intake manifold on an 05 s type 4.2 to replace knock sensors