Almost there part 342.5

Hey folks I’m sure everyone has been wondering what I’ve been up to so here goes.

  1. My project (Dolly) had an ecu (standalone Omex 710) issue. My laptop could not communicate with ecu to remove or install calibrations. So sent ecu back to the mother land for trouble shooting.
    While I had some jag down time, I thought I would tackle some garage organization stuff (didn’t happen).
  2. In my limited travels around here, I had noticed a house with a xjs in their garage. Then one day it disappeared. I had to stop and find out. I found the owner home an English gentleman and he told me it was at the shop. It was probably about 1100 so he asked if I wanted a beer (got to love it). Anyway, we talked about getting things done on these cars and how difficult it can be. I offered to give her a look when he got it back.
  3. Well, it’s in my garage/shop now. 1989 xjs v12 convertible 32500 miles this car is very nice. No rust no damage. It has been Dis repaired by folks with good intentions.
  4. Repairs so far:
    A) Throttle shaft bushings (not there)
    B) Transmission mount (new original but better than what was there)
    C) Oil and filter (was 10w 30) change too 20w50.
    D) Rear main oil leak (excessive). New ME Wagner pcv added to system. Accessed through cam tensioner plug (really cool and discreate) (And is working as designed).
    E) Cruise control still working, but thanks to Kirby and the folks that added their info to THE BOOK (the little rubber washers on the solenoids were gone). Ran tests from BOOK to verify and not bad.
    F) air conditioning still working, Many hands in here over the years. More to come.
    Thanks to all more to come.
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Wow! That’s great! There’s no way that car would’ve gotten this attention to detail at the local wrench.

Thanks. And sad to say your right. Most shops can’t spend this amount of time. I see so many cars of lesser style selling for so much more. A real shame, someday these cats will come around.

I had never heard of the Wagner PCV system, so I googled it. Very interesting! I would very much like to see how the plumbing is hooked up to the timing chain plug. Photo?

I installed one of these valves on my project and was very satisfied with the reduction in oil leakage from the rear main. The stock pcv system relies on positive pressure in the crank case to vent to back side of filter. Not the best system.
To install the ME Wagner on this 89 I wanted to make as few modifications as I could. So, to verify all would work this is the system as it currently sits. The clear vacuum hose is to verify no oil carry over into intake plenums. Triangle plates on end of plenums were spares from my 86 project. So far, I have only driven 30 miles and no carry over. Rear main oil leak is near nonexistent. Plans are to route plumbing as hidden as possible.
I used the v12 from a parts car to mockup system.





In the perfect world it would be nice to have the valve on one cam cover and the air inlet on the other diagonal across the motor. I had looked at the half moon seals but that will take a little more time to design. The timing chain area has lot of oil droplets flying around so I tried to keep the valve as high as possible. Air is drawn into crank case from the original pcv location on the back of the air filter. No changes needed to this area.

Nib, Thanks for the quick reply. Now I have to go out and start to tear things apart. I am surprised that a 3/4 elbow fits behind the belt tensioner- looking at things with a mirror on a stick I thought I would have to go smaller. It is supposed to be stormy here for a few days, so now I have something to “improve”!

The elbow is 5/8" then 5/8" heater hose to 3/4x5/8 reducer. 3/4 hose to Valve base. Drilled and Dremel new timing plug for tight fit. Pressed plug into cover first then fight with elbow. Just a pain because no room to work. But all pressed in tight.

I am trying an approach using the OE PCV valve. (Which works ok.) Now I have to wait for a delivery from MCM.I ordered a brass elbow for the TC cover plug. If this works then I can spend more money!

I’m confused. Please explain your plans if you would.

I’m assuming MCM might be ME Wagner

Brass parts available at ace hardware or Lowes/ Home Depot. cheap and work well to test. Then once satisfied with performance contact me. I’m in the process of designing a cleaner appearance (so not to look like you went to HD for parts lol) to this valve addition.

Sure. The usual oil leaks my engine had were fixed years ago. There are no oil droplets on the garage floor. I remember the "road draft tube " approach the old side-valve flathead engines had, and the Jaguar version of a “PVC” system is maybe one step above that.
I have thought that it would not be difficult to make a “real” PCV - one that would actually be "positive ventilation " for the crankcase, and your post got me going.
The hard line above and connecting the intake manifolds has been shortened, and is now connected to a piece of 3/8 tubing, which is then attached to my remote old PCV valve. I made a small chamber for the valve. The 3/8 tubing continues and drops down as yours does, to the timing chain cover plug.
My plug is actually a hard rubber solid bung, and not OE. It has a 3/8 hole drilled through it, into which a brass elbow will be inserted, similar to what you did, just smaller.
For me to go to Lowes or any hardware store means two gallons of gas, and a restaurant meal should my wife decide to go with me, so I often buy from McMaster-Carr instead.(MCM) Works out much cheaper!
The hole where the PCV valve used to be is now occupied by a spare PCV valve that has been capped .
The end result should be slight negative pressure in the crankcase, as it should be. Photos will follow, of course!

Another version of the improved PCV modification.

(Installing A PCV Air/Oil Separator Filter)

I finished the plumbing today. It might get modified slightly, as things are so tight under the hood. The clear test tubing lasted about five minutes before collapsing. No surprise there.
I started the car and found that the fast idle speed was slower than usual. About 100RPM. The engine warmed up and dropped down to normal idle, and it too was 100 or so RPM slower. My AAV does not control fast idle and does not enter into things.
As the new PCV plumbing now pulls air through the crankcase in the reverse direction from before, it seemed to me that the oil screen below the “pig snout” rubber cap was causing some restriction, so I dismantled the pipe and rubber cap going to behind “B” bank air cleaner, and removed the oil screen.
After putting things back together, I started the engine and the idle speed returned to normal, proving that there was some restriction in the oil screen. As the PCV is now getting “clean” air from the air cleaner on “B” bank, the oil screen is not needed.
I took the car for a short drive, and it ran well. I’ll keep an eye on the inside of the “B” bank air cleaner, in case there is any build-up of oil, but so far so good.


Nice job. I have a question that probably can only be answered by Wagner. Basically, your system is under unobstructed vacuum. Whatever the plenum vacuum is the crank case sees. Yes, I relies the air flow is now back through the original air filter penetration which is good. But this unregulated flow could be an issue.
Now I am not in any way affiliated with the Wagners. But I do know they designed this valve to have an idle circuit and a cruise circuit for a reason. At this point you basically have a 3/8" hole in your intake. which the ecu will try to compensate for. I would call them and discuss the differences between what you have and what they offer.
PS. nice clean motor. I know where to go for zip Tyes when the apocalypse hits.

Unobstructed?
The flow through the crankcase is regulated by the PCV valve and if I disconnect the vacuum tubing from the valve the RPM’s rise dramatically, just as if I really did have a 3/8 hole in the intake. As the crankcase is simply a passageway for airflow to the PCV, but in a reverse direction, I don’t think the ECU would know the difference. Idle speed is exactly the same as before. PCV valve is regulating airflow just as it did before I made the change.
The Wagner PCV is impressive, and I am not comparing what I did to their invention at all. Your original post made me think that my very basic idea would work, and I am happy with the result so far.
Yeah, the zip-ties. It was either them or duct tape. Fuel stays cooler so that’s ok

I noticed during my short test drive that the car seemed more responsive. I think that by eliminating the pressure in the crankcase the piston rings have a better seal, so more power as a result!

My mistake I see your pcv valve now. I didn’t notice it in the line.

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Final picture of revised plumbing on modified PCV, for anyone interested. Filtered air is drawn into the crankcase through the “B” bank air cleaner. It passes through a metal tube into the rubber capped “pig snout”. Air is pulled out of the crankcase through a fitting in the timing chain tensioner access hole, then through the OE PCV vale and finally into both intake manifolds, through the original metal tubing.
Should any positive pressure build up in the engine, it will pass into the “B” bank air cleaner, just as before.
Stay tuned.


The PCV valve is contained in the housing beside the low pressure A/C port.

Ooo, you should not use heater hose. I made that mistake modding my pcv system with 5/8" heater hose on my Volvo. A few years later, hose was spongy and collapsed at bends. Heater hose is not designed for oil vapor.

I switched it to 5/8" fuel hose, and its been fine ever since.

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Thanks Greg
Yes, I agree. This was just for a test to make sure the layout would work. So far, the Wagner is performing as expected. I need to connect the vacuum gauge to the Wagner and verify the cruise and idle circuits are set properly. Two different levels of flow. (I commandeered this one from my car so should be pretty close). Then I will plumb with proper hose.

We termed such creations. Plumber’s Nightmares!!!

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