Timing Chain Tensioner Replacement

baustin

Well-Known Member
My 06' LSJ engine still has the old style tensioner installed. Not sure if it's original or not but I plan on replacing/upgrading sometime soon since it is the shallow thickness, old style that has been known to fail. As I understand it, I need to buy the new style tensioner (ZZP Link / Amazon Link) but do I need to buy anything else? When I reinstall the valve cover will I need a new gasket (which ones) or just go with squeeze tube of gasket material?

service manual link

Is this the only gasket set I will need? ZZP link for valve cover gasket set
 

JBINTX

Goblin Guru
I just replaced the tensioner bolt recently. Dorman 917-954. Remove the outer bolt, then the inner one. The replacement takes the place of both of them. Takes 5 minutes. Nothing else unless you are getting into the chain itself and the guides inside.
I just did the valve cover gasket as well. No sealant. Got mine from RockAuto. See my post #66 below for some pics. I have TC version, so not sure if there are any differences because of that. Clean the topside BEFORE you remove the cover! Including cleaning the mating surface, it took about 45 minutes.

 

Karter2026

Goblin Guru
My 06' LSJ engine still has the old style tensioner installed. Not sure if it's original or not but I plan on replacing/upgrading sometime soon since it is the shallow thickness, old style that has been known to fail. As I understand it, I need to buy the new style tensioner (ZZP Link / Amazon Link) but do I need to buy anything else? When I reinstall the valve cover will I need a new gasket (which ones) or just go with squeeze tube of gasket material?

service manual link

Is this the only gasket set I will need? ZZP link for valve cover gasket set
How Many miles on the donor?


Chain Kit

Gasket

Valve cover gasket
 

baustin

Well-Known Member
Good info.

My engine only has 76k miles. I did the guide bolt the other week, good thing is the one I removed didn't have any issues yet.

I do know the Carfax report shows on 2014:
Timing belt replaced (just copying the report, I know we have a chain)
Thermostat replaced
Spark plugs replaced
Engine valve guides checked/replaced
intake/exhaust valves replaced

I'm hoping when I open the valve cover up that I don't find bad things inside though the engine isn't (and it seems like it never did) running any tunes or upgrades so I'm not sure what would've caused the valves to need replacement since the tensioner is still original looking.

With such a low mileage donor engine I wouldn't expect to need to replace the entire chain setup yet.
 

Karter2026

Goblin Guru
Good info.

My engine only has 76k miles. I did the guide bolt the other week, good thing is the one I removed didn't have any issues yet.

I do know the Carfax report shows on 2014:
Timing belt replaced (just copying the report, I know we have a chain)
Thermostat replaced
Spark plugs replaced
Engine valve guides checked/replaced
intake/exhaust valves replaced



With such a low mileage donor engine I wouldn't expect to need to replace the entire chain setup yet.
Well that report tells me that most likely the chain or tensioner failed. The ecotec's will bend the valves when that happens. Other than that the only thing that I can think of for a reason for them to replace valves would of been a severe over heat condition and a warped head. I am not sure what year the new style tensioner was released.
 

baustin

Well-Known Member
Well that report tells me that most likely the chain or tensioner failed. The ecotec's will bend the valves when that happens. Other than that the only thing that I can think of for a reason for them to replace valves would of been a severe over heat condition and a warped head. I am not sure what year the new style tensioner was released.
I agree. If it was chain related, I expect the parts are new since it runs good as far as I can tell. That's one of the reasons I expect I have nothing to replace for the entire thing yet.
If it was lack of oil or over heating that cause it, I'm hoping what I open up looks ok after that repair.

Or that Carfax report entry is not actually correct, which could happen.
 

Karter2026

Goblin Guru
That looks like it has been in there a while.
It needs replaced!

From my end of this view I would buy the valve cover, timing cover and a crank seal ( may come with the timing cover) I would want to inspect what they claim has been done.
 

baustin

Well-Known Member
Valve cover is off, let me know if anything looks like it needs special attention. This is the first time I've opened this engine up on the top side.

15858559251954564640172602543066.jpg

Haven't wiped up the cover itself yet.
15858559739897243494851678981519.jpg
 

baustin

Well-Known Member
06 LSJ with just under 77k I think. I was hoping for what you can see but set my expectations for far worse.
 

Dsteinhorst

Well-Known Member
For some reason, I thought this was just early engines that needed the upgraded bolt. Just checked my 09 and it is the old style original. Thanks for the reminder!
 

ctuinstra

Goblin Guru
For some reason, I thought this was just early engines that needed the upgraded bolt. Just checked my 09 and it is the old style original. Thanks for the reminder!
There are at least four versions from GM of updated tensioners. I think they struggled to get it right.
 

baustin

Well-Known Member
Now that everything is reinstalled, it all is running nicely. My names for parts probably aren't right, I didn't check what GM calls each of the parts, hopefully the descriptions help enough. A couple things to note:
  • There has been some oil seeping/dripping from the driver side rear corner of the valve cover seal. I think this is because I wiped out the cover on my workbench but there was still oil between the cast aluminum and metal plate inside the cover (the piece that redirects oil flow and why you can't see the valves when you take of the oil fill cap). I think the oil I've wiped up twice is the dripping from when I put the valve cover back in place. Unless I'll need to take the stuff back apart and re-seat the seal.
    • The kit I got included all the gaskets (main one, 4x spark plug holes, all the mounting bolts)
  • The tensioner itself didn't give a nice positive confirmation of being activated. Once threaded into place, I couldn't do anything to cause the chain to noticable change tension. I know you're supposed to push on the chain from the inside, a couple mm and then release and the spring/rotation action would be free to work from there. I took the tensioner back out after first installation and it was fully functional/released whereas it was compressed correctly when I started installing it.
    • I compressed the tensioner again and then reinstalled. Same result, no clear difference other than assuming that as it gets threaded into place that it releases and becomes active.
  • I did use zip ties to hold the timing chain to the intake/exhaust sprockets, this worked perfectly.
  • On the exhaust sprocket side (towards the tensioner itself), the chain has no slack. Very difficult to move the chain around with my fingers
  • On the intake sprocket side (towards the front of the car), the chain is fairly easy to push around. Not side to side, just pinching it and moving front/rear. I don't know how much slack is normal here but most chain driven equipment needs some slack on one side, so I assume what I have is normal. No odd sounds to me when running the engine now.
 

Karter2026

Goblin Guru
I had the same thing happen with my tensioner. I installed it could not get it to release with the screwdriver. So I removed it reset it and reinstalled it it did the same thing again. On the second install I actually heard it click when it released.
 

KSLunsfo

Well-Known Member
It took me a few minutes to find a suitable tool for this. I ended up using the handle of a ~2.5 foot 1/2" breaker bar with a several pieces of tape on the end just to try to minimize metal to metal contact with the chain. With the breaker bar and leaning my body on the outside of the engine I was able to get enough force on it to displace it far enough to get the "click" that activated it. I could then immediately tell a difference in the tension on the chain.
 

Ross

Goblin Guru
Agreed, that tensioner doesn't give much confirmation when activated. I broke my first one, by getting too aggressive.

Rotate the crank and see if the slack gets taken up on the tensioner side. Then the chain should be tensioned on both sides.
 

baustin

Well-Known Member
Hmm, I probably should pull the cover back off to check it out, probably should because of the seal anyways. Might have to do that soon, the last thing I want is to have it jump timing... I have a large flat tip screwdriver that has the reach but was concerned about damaging the chain, covering the end with tape sounds like a good plan. The longest part of the initial installation was resetting the tensioner after trying to install it the first time.

I did rotate the crank with the valve cover off, I put it in 1st gear and rolled the car by hand in the garage but only while I had the zip ties still in place, so only an inch of sprocket rotation. That didn't change the amount of slack that was on the front side off the intake sprocket. I call it slack but I couldn't cause it to skip teeth on the sprocket, I did test that much.
 

baustin

Well-Known Member
When I pull the cover this time, I'll first see if the chain is fully tensioned, since I didn't rotate it very far by hand previously.
 
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