Tuesday, March 17, 2015

How to change the tuning valve seals on your Jaguar X-type (P0171 and P0174)

A very common vacuum leak on your X-type is the tuning valve seals. Lucky for you they are easy to change and relatively cheap.

Here is what you'll need:
Here is the procedure:
  • First remove the four 8 mm bolts holding them in place. Two per valve.
  • You can unplug and pull the top one right out. Then with a small pick, pull the seal off.
  • Here is the part number for the seal.
  • Place the new seal in place.
  • Use some silicone spray to lube the seal.
  • Now to do the bottom one, it doesn't come out. So you have to remove the seal right there through the top of the valve. Bit annoying but it works and its quick. The place the new seal in place for this one too and spray with silicone.
  • Push the valves back and catch the four 8 mm bolts by hand first. Then tighten.
  • Just plug them in and that's it, you are done. Make sure you clear the faults of the system.


  1. This is such a great post. It was really informative as well as on to the point and I am glad that I have found it. 3D printed foundry patterns

  2. Hi Daxter, I read your article on Vacuum leaks on Jaguar x types and found it very informative and easy to understand. If you don't mind I have a question for you. Please be advised that I am quite a novice when it comes to working on cars although I have a mechanical background. I purchased a 2005 X type sedan, it had a number of warning lights up, but I was quite happy with the price, so went ahead and bought it, willing to spend money on it to fix the problems. A mechanic installed new plugs for me and a new set of coils, [after diagnostics],plus some other items and all the warning lights were cleared. The car drives very well, however recently the engine warning came on, at first intermittently, but now it is on all the time and the engine hunts on start up, as soon as I'm driving it's fine but the light remains on. I decided to check for a vacuum leak, and was confused when looking at the tuning valves. Majority of the images I have seen show the valves on the left hand side of the manifold as shown in your post. Some images show vertically mounted valves, one on the left one on the right. On the manifold on my 2.0 litre petrol engine I can only see one valve mounted on the left!!!
    Am I missing something here or am I stupid? Would be grateful for your advice. I have checked the Mass Air flow sensor, it is working okay. Sorry for the long post.

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