184k on the clock was running fine before I replaced the hose under the manifold.
I had to loosen and lift manifold to replace the hose some dirt may have fall in the block, after i connected everything started it and now there'e a pronounced knock. Almost like a lifter clacking got a p037 code but I just don't think that s it.
Any ideas.

Thanks

 

Is it possible that when you lifted the manifold something may have fallen into one of the ports and dropped into a cylinder?I wouldnt think dirt would create a noise but a bolt or whatever sitting on top of the piston could.You may have to get a boroscope and look into each cylinder.

 

When you cleaned the mating surfaces for the intake, did you use something other than a rag and brake clean?

if you scraped or used scotch brite or anything similar you may have gotten metal particles into the engine which are now chewing up things.

 

I don’t think anything very large could get past an intake valve. A small screw, maybe? A very good chance of knocking dirt loose though. I think tThe valve lift on the 4.2 is 9.33mm so I would be surprised if something slipped by a valve and didn’t actually get wedged between the intake valve and its seat. (That would have become instantly noticed.)

I would get a stethoscope (or substitute a long screwdriver, metal shaft or something similar) to localize the sound. It will help if you can determine where the sound is emanating from. Does it change as you speed up the engine or put it in gear? You can get a borescope that hooks up to a laptop or smart phone pretty cheap and they can come in handy for just looking in all of the hard to see areas like between the engine and the firewall. If you search the forum I believe I read some internal ticking sounds can be related to the lifter (tappet) components. With that code is it possible the exhaust heat shield near the O2 sensors has been bumped and is touching something? It could be caused by a loose connection. How many miles are on the oil (and car), how clean is it and what weight oil are you using? How long did your car sit and how cold has it been where it is?
Good luck. I hate tracking down new sounds.

 

I have read on this forum that some of the oil additives for lifter noise work.

Maybe do some research on that.

 

I wondered about something getting past the valve. Oil i 5w-30 changed every 5k.
The clacking starts as soon as engine turns over starts loud then lessens, clacking increase as engine revs. I tried Seafoam in the oil, no help. If a nut fell in would it rattle around the top of the valve? As much as I hate it I may have to pull off the manifold and look.
Thanks all let me know if you have any other ideas.

 

A nut would not last very long. I use Seafoam in my motorcycles, mainly the gasoline. I believe it would take a while to loosen anything stuck in the valve train. In my personal experience with stuck hydraulic lifters on Ford and Pontiac engines it can take a few miles of driving for them to loosen up. Those were almost always caused by a low oil condition. Have you cleared the codes and or listened to confirm where the noise is coming from?? If it isn't shaking or vibrating you may need to drive it a few miles to loosen a stuck shim and to give the Seafoam a chance to work with the engine hot.
Good luck.

 

I lost the engine in my Vauxhall Zafira, when the Manicat cracked, couldn't get the old one off, had to break it up, and a little piece must have slipped down past the valve and into the combustion chamber, made a real nasty rattle, and when i stripped the head off, I found this...20170630_051959[1].jpg 20170630_052022[1].jpg