2006 xterra timing chain noise

[jpeters]

Long story on this one. This engine had lotsa problems. First cats plugged and lost power we fixed that . But engine was burning 2 quarts to 50 miles plus timing chain noisy. My buddies car not mine. He deceided to replace the valve stem seals and all timing components. After that still same issues. This is when I got the car to repair. I pulled the engine and rebuilt the engine with new rings, bearings oil pump etc. Block was checked and honed at machine shop , crank was checked and polished. Heads ground valves and set clearances. Put all back together and still have chain noise. I used the same timing components that were replaced before the rebuild. I checked oil pressure and is a bit low hot at idle but good when rpm is up a bit. I am lost on this one. I pulled the timing cover and spin the engine over and watching the chain and I see the primary tensioneer going in and out about 1\8 to 3\16. It does have a ratcheting mechanism to hold it extended and is working. I was going to try starting it with TC removed but would not start. I have been an auto tech for years, retired now but I can not find the problem. It has been in my shop for 6 months and I am about to throw in the towel. Now I did notice when I had the heads apart some scoring in the front cam journals but the other ones were in good shape. Any good techs out there can help i will dance at your next wedding.

[Niti QX4]

Are you absolutely sure it's timing chain noise and not lifter related?

[jpeters]

Yes it is coming from the timing cover area. I used a long screwdriver as a stethoscope. The lifters a mechanical on these and I set them . I did not order the pucks but was able to grind the valve tips
a bit till I got the desired clearance. Also I pulled the belt and ran it without everything else turning.

[Niti QX4]

I would start with new timing chain components. Get rid of the "new" ones previously installed so you can verify correct fit and timing. New tensioners will remove that possible issue.

While doing that measure CL to CL on the cams, crank and verify proper dimensional correlations.

Weird issue for sure.

[VStar650CL]

Was the water pump changed along with the chains?

[jpeters]

Water pump was replaced with a Bosch one. And yes my thoughts exactly on replacing all the timing components again. Not sure what you mean by CL. And I replaced the primary tensioneer again with an oem one.

[Niti QX4]

CL is the centerline. Make sure all dimensions are to factory specs. CL distance from cams CL to crank CL Check all CLs. Cam to cam, cam to crank, etc. Verify all dimensions meet nominal specs.

Odds are slim, but if the block was decked previously, and if the heads have been milled too much and the head gasket is too thin, you may be at the tolerance limit of the chain tensioner system.

Only way to confirm is to measure CL distances.

Also, any chance it be the CVTC causing the noise?

[jpeters]

Nothing ever done to engine . It was never worked or maintained . That`s why it is in this condition. Can the valve timing control actually cause chain noise? I did notice when i rolled the engine over by hand I can hear a pop in the phaser at least one of then I do not remember on the other one. These are new ones but aftermarket at that.

[Niti QX4]

I would still check the CLs just to make sure and so that can be ruled out. I only use OEM parts on internal engine components, as long as they are available.

I have been bitten more than once by aftermarket parts and now only use aftermarket on easy to change out items. I don't like doing things twice.

[Niti QX4]

Any updates on this project?

[Niti QX4]

"Well, I guess the world will never know"

[jpeters]

Since the owner is not really wanting to spend $1500 on oem timing components , it is off my lift and pushed outside till he can decide what he wants to do with it.

[Niti QX4]

Thank you for letting us know. So many times questions get asked and we never get to find out what happened. Thanks!