LNF Chain guide snapped...

[cubaniche]

Hey guys.
Have you ever heard of someone snapping the black plastic chain guide repeatedly? The issue seems to correlate with my istall of the 78lb supertech spring kit last year. A few months after the install I started to notice a ticking sound. I thought it was the springs because it was minimal. After another month or so it got worse. I had taken the VC off before to look for issues with the springs but it never occured to me to check the timing components. Anyways, last month I got in there and happened to look down into the timing components and I saw the guide was snapped and was like WTF? So I tore it down with a friend and replaced it.

FF to this week, I start hearing the same noise again only this time its louder. When I listen for it the sound, it's more prominent right there where the chain guide is so Im 99% sure that it snapped AGAIN. Im going to try and tear it apart this weekend. Until then Im just driving her easy. As long as she doesnt skip a link on the chain I should be good, even if she did, the ECM will disable VVT anyways so tapping avalve is less of a worry.

Just wondering what your thoughts are on this as it's totally baffeling to me. Thanks for any input you guys may have to offer.

EDIT
Here are some pics of the failed o-ring in the tensioner that was allowing the oil to seep out, ths causing the pressure to lessen allowing slack to build in the chain.
Carnage:


Tensioner apart:


O-ring eaten away and snapped:


What it looks like when almost assembled. You can see how the o-ring is supposed to keep the oil in the tensioner and with it broken, it looses pressure:

[USMCFieldMP]

I would stop driving it and take of the valve cover immediately. Anything else is lunacy. If that guide is getting torn up by the chain... those little bits of plastic can very easily clog up your oil pump pick up... and now you've starved your engine of oil.

As far as why it keeps breaking... I dunno. You didn't give us too much detail about where it broke, etc. I'd be very tempted to say installer error though, as I don't recall ever hearing about someone else having this problem.

[cubaniche]

I would stop driving it and take of the valve cover immediately. Anything else is lunacy. If that guide is getting torn up by the chain... those little bits of plastic can very easily clog up your oil pump pick up... and now you've starved your engine of oil.

As far as why it keeps breaking... I dunno. You didn't give us too much detail about where it broke, etc. I'd be very tempted to say installer error though, as I don't recall ever hearing about someone else having this problem.

LOL True. I plan on dropping the pan and cleaning all that out. Once I have the cover off Im going to take the oil pump gear cover off and clean it inside as well. Its snapping in the middle. The top bolt and bottom bolt are still attached. Like I said, I need to check it out tomorrow and see if it really did break again. I dont see installer error as a factor as you can't really mess that up or even over tighten the bolts as all they do is loosely hold the guide in place so it can pivot/rotate as the chain passes over it.

Your right about not driving it any longer though. And it is very perplexing. Thanks for your comment. Could it be that the chain is slapping the guide introducing stress cracks until it finally snaps? Ill try replacing the tensioner this time instead of tacking it apart and resetting it like Ive been doing.

[qwikredline]

yes Rob is 100% and you should put the updated tensioner in it that should have been your first mission. I assume you dont have a liteweight mrz bs crank pulley

[cubaniche]

yes Rob is 100% and you should put the updated tensioner in it that should have been your first mission. I assume you dont have a liteweight mrz bs crank pulley

No no. No lightweight pulleys for me! I dont jump on bangwagons like that. As for the tensioner, Ive already replaced it once and I should have mentioned this is an LNF not an LSJ. It already comes with the new tensioner, but when I did the piston build I replaced it with a new one. One thing I did not do when I fixed the guide last time, was take it apart and drop the pan to clean things out. I guess I FAIL there for sure. All I was concerned with was taking the broken one out and replacing it with a new one. I did however replace the oil right away and filter.

Oh well, all I can do is replace it again but take my time this go around to clean the pan and the oil pump gears. Maybe run some cheap synth for 30 mins drain and replace with the good stuff right after too just for good measure. Just something else to add to the list of weird things that happened to my engine.

[qwikredline]

lnf dont come with new style tensioner from what I have seen including 2010's

[qwikredline]

dont overtorque the bolt on the tensioner guides. do you know what the correct torque is? wondering

[cubaniche]

dont overtorque the bolt on the tensioner guides. do you know what the correct torque is? wondering

Yeah its def a new one and I believe the bolts for the chain guide are like 15/lb. I know its not overtightned though because the guide still moves freely a bit after Ive tightened it.

[montecarloman]

Just did a 2.2 head, chains, and guides yesterday. Bigger shouldered bolts that hold the black guide and the balance shaft guides should be torqued to 89 in. lbs. I can't remember off hand what the other bolts should be tq'ed to. I also put GM blue thread locker on them for the "just in case" factor.

[USMCFieldMP]

Just did a 2.2 head, chains, and guides yesterday. Bigger shouldered bolts that hold the black guide and the balance shaft guides should be torqued to 89 in. lbs. I can't remember off hand what the other bolts should be tq'ed to. I also put GM blue thread locker on them for the "just in case" factor.

Anytime I see it, I feel like I should stress the point: this is INCH lbs... not ft. lbs.

An idiot friend of mine made that mistake on one of his cars.

[cubaniche]

lol See I was wrong with the while 15in/lbs. But Basically im just tightening it down enough, not torquing the crap out of them. Ive never overtorqued a bolt in my life maybe ill use my small tq wrench this time.

I honestly think I have some sort of oil pressure issue. Ive always had a loud rattle at cold start almost as if it took a sec or two for the oil to make it through the system. I think that the tensioner is not holding the pressure allowing slack to build in the chain, then on a cold start it slaps the chain guide as it tightens up causing stress cracks until it finally snap in the middle. Ive replace the tensioner twice now and the timing cover is new with new oil pump, well, now its a 10mo old but I dont see why the pressure loss is occuring while the car sits.

[USMCFieldMP]

What oil are you using? My car has sat unstarted for months without any sort of issue like that.

[cubaniche]

Its done it with both Mobile1 5w30 and Pennsoil Ultra 5w30 and even the new RP HPS, same 5w30. That issue started only about 10mo into ownership. But it was very sporadic, once in a blue moon kind of thing so I never worried about it much. Over time it has become an issue at pretty much any time I start the car after its sat for more than a few hours. Do we have an oil sender? or something that regulates pressure that could be bad? I keep ruling out some sort of blockage due to the fact that its fine once its running. I appreciate your suggestions man. Ill find out for sure whats up tomorrow when I pull the VC off.

[qwikredline]

I keep coming back to the tensioner ; replace it. ecos are sooo good for start up no rattle etc....Gosh I love my two ecos, one with a 250k km and one with 60 k m. (and many motors lol) they really are kick ass motors. its so unusual for the issues you are having and you sound like a smart guy, so ....basic steps review.

[cubaniche]

I keep coming back to the tensioner ; replace it. ecos are sooo good for start up no rattle etc....Gosh I love my two ecos, one with a 250k km and one with 60 k m. (and many motors lol) they really are kick ass motors. its so unusual for the issues you are having and you sound like a smart guy, so ....basic steps review.

LOL I know, I love my LNF! Thats why Ive kept with it for so long even though shes had so many weird issues. The good thing is that when an issue has come up, Ive fixed it and been good. This is the only one that has repeated itself and the weird loss of pressure from the tensioner. Ill try yet another tensioner as you suggest. Maybe third time's the charm

[qwikredline]

did you replace the chain? wondering...

[cubaniche]

did you replace the chain? wondering...

No sir. The engine only has 40k on it. I contemplated replacing the chain and even bought one. But when I compared the two there was no dicsernible difference in length. I even measured them by applying weight to them to see if they stretched LOL
But no, its still the stock chain that looks good to me still.

[montecarloman]

We've been having issues with cold start up rattles in the new Equinoxes with the DI 2.4. Far as I know gm doesnt really know the cause but we've been replacing both chains, tensioners, and all the guides with new parts.

[qwikredline]

MC man, is it chain or is it fuel rail/ hp pump chatter\?\ wondering Maven may know....

[montecarloman]

Definitely chain, sounds like a diesel for 3 to 5 seconds then quiets down to the normal tick. Replacing everything has been fixing the problem vehicals. Haven't checked the bulletin lately, might be a revision, have to check later today.