Hi guys, still tracking down a slight air leak in the manifold.

This morning, pulled my oil dipstick to see if the new o-ring I installed made a difference, and it was evident it did...I heard this hissing and the engine stumbled as I did it, reseated it, and everything returned to normal. Before this, I could pull my dipstick, and there would be no change. The o-ring was dried out and brittle...it actually broke in half when I tried to roll it out of its notch.

Anyway, after putting it back in its track, I heard another hissing sound, ever so slight. Took off the engine cover, and I am hearing this air leak (vacuum break...not sure) from the right side manifold, and then on the back side of the engine, below the throttle body. Both norma fittings don't seem very tight, the one in the back makes the most air noise and spins easily. After checking all my vehicle parts diagrams and viewing online sources, I cannot for the life of me, determine what that hose is called...considering just replacing it, or if I must, just take it off and find o-ring replacements.

Can you identify this for me gents? Is it part of the emissions system? (I know the engine is more than just a little dusty...its on the to-do list)



Here it is where it reconnects to the rear of the engine, looks like the lower throttle body elbow... i was too lazy to take off the air pipe to get a really good pic.



Heck, I decided to make a quick video,hope you can hear the hissing? Well, I just watched it, that slight hissing isn't auidble over the background noise and sounds like a repetitive microphone thing...like its recording on an old cassette tape..lol

 

Aha! dug through the JTIS one more time, and found out my subject part is the positive crankcase ventilation (PCV) pipe. Both ends sounds like its leaking, the norma connector is not very tight, and wiggling the end increases the air sound. Is there another vacuum hose inside that semi-flexible conduit, or is that the air carrier? I ask, because it also sounds like there is some are exiting at the two 90-degree bends (inside the flexy, not on the elbow itself that connects to the PCV)

Can I rebuild the inner vacuum line if present?

 

The disc looking part is a baffle/breather, and they all sound like a vacuum leak. Used to drive me nuts.

 

Really, I believe it! Ive decided to rebuild the line with same norma connectors, new o-rings. Wish me luck, otherwise im hoofin it to work monday.

 

This thing was brittle, make all kinds of crackling noises as I removed it.



Well, i fabricated my own PCV line. I purchased 36" of 5/8" coolant hose, half dozen o-rings of various sizes, and some worm clamps. I carefully removed the 90-degree elbows without damaging them, fit the new hose onto them, and it was a really snug fit, but worked great. The new o-rings were definitely needed, the new connectors went on tight, they felt good...barely could rotate them.



Without any reset to the computers, I immediately started the car up and started AutoEnginuity to see what changes had occurred. I think might help my cold start condition, that begins with a rough idle, then ramps up the RPM to compensate. This wasn't a cold start, however, but I immediately observed the short term fuel trims were suddenly running rich, where previously, it was almost always in the positive. If I sealed up the PCV line successfully, and the proper amount of exhaust gas is being returned, that would mean less oxygen in the exhaust. long term fuel trims continue to keep dropping closer to 0.

BEFORE

AFTER


The o-ring replacement for the driver side manifold and the throttle body, in addition to that one on the oil dipstick has sealed it back up...hopefully.

 

Looks like it'll last a while.

The autoenginuity display is fascinating. Is that screen only with the Jaguar specific upgrade?

How about a screenshot of "gauge mode"? Or is that already posted somewhere?

 

Had the same problem, with the same pcv pipe on my jag xf v8 sc
I was looking for an air leak and found it cause when Put my hand on this pcv pipe, it just broke down into pieces -__- I was like wow this is cheap

so i did like you did and built my own pipe so no more leak problem.

jaguar land rover know about this particular problem with these type of pipe but don't change it …

 

not to start a hijack, but I am THIS close to buying the autoengenuity SW, since it is IMPOSSIBLE to get any kind of coherent recommendations on the JLR Mongoosie kinda hack ... do you like it? Is is doing everything that you want?

 

It did alot...not as much as the mongoose w/ SDD, but it is much easier to use. I sold it to another member once going SDD.

 

It can basically do everything except program the modules, but Matt is right, it is WAY easier to use.

I have one with the Jag extensions that I have been thinking about selling. If you are interested drop me a PM. I did the same as Matt, got the SDD Mangoose hack thing.

 

I have Autoenginuity with the Jaguar Expansion and a JLR Mongoose clone with SDD. AE runs on anything up to and including Windows 8.1 but SDD only runs on Windows XP Pro. I tried it in a Virtual Machine but performance was slow and I now have it on a dedicated laptop.

My usual approach is to reach for Autoenginuity first as it's faster to get to the answer than stepping though System Driven Diagnostics.

As has been said, the power of SDD is it offers the facility to program modules which AE does not have. However, used incorrectly, this could turn a Jaguar into an expensive garden ornament!

Graham