Hi guys. I’ve got a strange problem. I just replaced the plugs,wires, cap and rotor.The rotor had a heavy high tension burn and the car was running on 6 cylinders. After replacing the parts I started the car and was surprised to hear a loud knocking sound, kind of like a rod or stuck lifter. The car was very smooth and quiet before the rotor issue. I triple checked my wire placement and it seems good. I also checked my coil wires and all the low voltage wires in the valley which seem to be ok. I really don’t know where to go from here. I don’t want to let the engine run much as I’m not sure where the noise originates but I don’t know how to look for a noise problem without running the car.

Any ideas?

 

Make a video and share it on YouTube, google plus, Facebook etc so we can hear what you do.

 

Is it possible your parts are defective? I'd imagine it is an aftermarket distro right. Might be one in ten thousand that are failed right out of the box.

 

 

 

I recall a TSB at one time regarding a change to plug lead layout due to a cross fire issue or similar. Can you run your car for short period in dark place to see if you have an under bonnet/hood lightshow.

 

Odd, I've only ever had something slightly similar once or twice, an incident which sounds similar was when I left a metal rod on top of the engine and it shorted something out while driving. If your certain the parts are good perhaps after consuming several drinks go back and look over every electrical connection? Jiggle them all while its running if necessary, thats how I narrowed down my marelli harness issue to a shitty wire that broke inside the plug that fits into one of the coils which caused another half-bank failure.

I'm sure your aware but if it runs on 6 cly only that is just asking for a fire to start, so plan accordingly if doing more tests with the engine on.

 

 

 

Can you bring it back to the way it was before you replaced the dizzy? Meaning can you replicate the engine behavior where you didn't hear the knocking sound when it was running only on six cylinders? Pull the plug wire either from the dizzy or the plug itself of one of the six cylinders that came alive with the new dizzy and see if the knocking goes away. The addition of the other cylinders may have introduced firing on a bad cylinder on that bank. There are explosions in a working cylinder. If you can remove the ignition from that one particular cylinder, you may be able to silence a problem with that cylinder, rod bearing etc. Once you introduce proper firing as you did by fixing the dizzy, the working cylinder now brings out the sound of a possible worn piston/rod problem. Remove the ignition of that cylinder and the engine will just carry the bad rod which you shouldn't and didn't hear before. With the plug wire removed, the engine will run on11 cylinders but the knock may go away exposing the bad noisy cylinder. Then you'll know the extra ignition explosions have accentuated the sound of the wear play of worn parts of that cylinder...if that is what it is.
Hope you get what I mean

 

So long as the dissy is not modified it is not possible to install the rotor backwards.

When you replaced all the plug leads on the dissy did you follow the numbering on the cap or in the book? the Lucas and Marelli have the wires in different places on the cap.

 

 

https://www.jaguarforums.com/forum/x...-order-169643/

 

Very nice! Thanks

One thing I noticed on the Marelli was the Number 1a wire post is 90 degrees from the front and pointing to the A bank. If this is correct I think my problem is I have my cap configured to look like the Lucas cap with 1a pointing to the front. What do you think?

 

Yes, A is UK driver's side.

 

If you treat the cap as a clock face with 12 o clock pointing toward the front, 1A (right front) is at about 12:30 and 1B is just to it's left at 11:30. In the photo below, front of the car is to the right.

 

 

Sounds like a rotational noise, but not necessarily internal to the engine. You probably already have.....
checked all rotating pulleys, belts fans etc. up front, as well as shielding on torque converter. Just hoping for you.

 

Definitely sounds mechanical to me. I don't like the idea that it was running on 6 cylinders before, I wonder if the catalytic converter has melted? It might be worth lifting the cap and having a look, maybe the rotor is making contact with the terminals?

Can you tell approximately where the sound is coming from? I know it's a pain, but it might be worth doing a compression test.

 

Hi Treborefir

I don't want to send you down the wrong track but since you've tried everything else

When you were replacing the Rotor etc, could there have been a possibility that you 'may' have accidentally turned the engine in the wrong direction and either broken or upset the Timing Chain Tensioner

Very easy to do as I've done it myself and got a very similar sort of ticking noise but 'The Jaguar Gods' were on my side and I got away with it and the noise went away

Maybe worth undoing the Oil Filler Cap to see if the Chain has gone loose

Only a bit of a long shot but you never know