The local dealership wants $1100 usd to install an outlet pipe assembly and to put in a new coolant reservoir on my 2004 XJ8 to fix my small leak (70000 miles). They said it was a 5.5 hour job.


I found a new "THERMOSTAT HOUSING Assembly 100% GENUINE JAGUAR *no aftermarket copy 4.2L ENGINE" for $119 on eBay that had the thermostat inside. I also found a new coolant reservoir tank bottle (with a new sensor) for $47.

My mechanic charged me $240 to install the 2 new parts and to perform a coolant flush on the system. They work on all cars, but mostly American car owners frequent the shop.

Now let me back up.

After conducting some research on the forum, I found how to take off the outlet pipe assembly. I also found the corresponding section in the x350 workshop manual (I downloaded the full manual on this site). I printed off both sections for my mechanic.

On one of the sections that I printed off from the forum, a contributor suggested to take off the throttle body to make the "process so much easier."

I made it home but now my Jag is now on "limp mode" and I am getting the P1229 code. This code is from Electronic throttle control issues. In addition to it being in this mode, I noticed that some white smoke that wasn't present before now comes out the muffler at times...

I talked to the mechanic, and he said he did not have to even remove the throttle body to install the outlet pipe assembly.

I also asked him does he have the Jaguar/Land Rover specific diagnostic tool, and he informed me that he does not own that particular device.


What I have done so far to remedy this problem:

- Clear out the codes with my OBDII Reader
- Disconnect both battery terminals for 3 hours
- Turn the key on, but do not start the engine. Slowly push the throttle to the floor over a 3-5 second interval and then slowly release the pedal. Do this 3 times. This action recalibrates the throttle body TPS.

Turn the key off and then start the car normally.


Please let me know how I can get my baby on the road.

Thanks in advanced for all the help.

 

P1229 indicates TB motor problem.

eg https://www.jaguarforums.com/forum/x...-relays-74733/

 

Yes, a TB problem. It has never had any issues before this repair. What way do you suggest to get my cat off limp mode?

 

Did you not read the link I sent?

It is possible that limp mode is NOT related to your recent repair.

Unplug and plug in supply wires (ie clean) to the TB motor and check wires to TB motor

for possible damage, corrrosion etc.

Check fuse to motor and the relay in the circuit.

Is there 12volt supply to the motor?

Failure of TB motor itself is rare but possible.

Failure of TPS is possible but code does not indicate TPS.

 

I am not sure what the "outlet pipe assembly" is that you refer to.

If removing the throttle body makes access easier and your mechanic did not do that then it is possible that he loosened/damaged something connected to the throttle body and there are several "things" going in and out of the TB to loosen or damage.

 

The plastic bypass/return pipe rear fasteners mounted on the top of the cylinder block cannot be accessed without removing the throttle and induction elbow. I just did 2 in the past few weeks.

Maybe just the thermostat crossover/outlet pipe was replaced and the angled bypass pipe was left in place????

I have seen people pull that 'shortcut' to save some time but still charge for the full repair. I hope they at least replaced the 'O'ring for the thermostat-to-bypass-pipe housing.

Check that the throttle harness connectors are fully plugged-in.

bob

 

I will try those suggestions.

This is a pic of one of the items he installed.

I saw the old one with the bad O rings.

Silly question but where is the fuse to motor and the relay in the circuit located?

Thanks for all the help thus far!!!

I will keep everyone posted on my progress.

 

The fuse to the TB motor is F24 in the under bonnet fuse box.

The relay is the non servicable type so forget that for the time being.

It means that the relay is not the plug in type.

The most likely fault IMO is the two pin plug to the TB motor.( It may

be part of a bigger connector on the TB.

 

The mount holes circled in RED have fasteners that cannot be accessed with the throttle elbow in situ.

That is why I question the statement that the throttle was NOT removed to change the pipe.

bob

 

My feline is purring again!!!

I want to thank everyone that contributed their time, effort, and energy to get my baby on the road again!!!!

It was the two pin plug to the TB motor barely hanging on for dear life.

This was due to the plug not being a self-clinching fastener.

It is missing the little plastic piece to keep the plug in place.

I am thinking about taping it up with black electrical tape, unless someone has a better idea, or can point me where to get that little plastic part.

After that, I took my $15 OBDII Reader and cleared the codes.

This forum has helped me tremendou$ly throughout the year$ with my XJ6, XJR, and now my XJ8!

Thanks again team!!!

 

Black tape tends to not do well where you have significant heat.

Can you use a zip tie? On mine I would use wire looped around the base of the female piece and then loop and twist around the male when in place.

 

" On the Road Again" Wille Nelson

Cue for a song? LOL

 

I dont know whether yours looks the same as mine. In this picture you see two electrical sockets both of which would lend themselves to a wire loop or zip tie to keep the two halves together.

 

jackra_1, I just looped a zip tie to connect the two halves together. After looped, I cut off the excess part of the tie.

Thanks for the idea!!!

 

You are welcome.

After I posted last time I realized I had the same problem with my MAP sensor and I will use a zip tie on that. It was not loose but over time I am sure it would disconnect.