2007 5.3 year compatibility

[strutaeng]

Yikes! Not good when timing chain breaks! I tore down an LQ9 that had a timing chain broke and it also had bent pushrods and bent valves, along with a spun main bearing. Engine was basically thrashed.

Have you pulled the heads yet?

I actually thought Gen IV had a timing chain dampener (?) , not a tensioner (?) but I admit I'm not an expert on Gen IV engines.

 

[tjoyce81]

Yikes! Not good when timing chain breaks! I tore down an LQ9 that had a timing chain broke and it also had bent pushrods and bent valves, along with a spun main bearing. Engine was basically thrashed.

Have you pulled the heads yet?

I actually thought Gen IV had a timing chain dampener (?) , not a tensioner (?) but I admit I'm not an expert on Gen IV engines.

Have not pulled heads yet. But if you look close, the cam stopped turning just after tdc on #1 - so, it will be interesting to see what maybe (or may not be) bent.
I replaced the OE tensioner and chain just because I was in there - cus I replaced the oil pump chasing an oil pressure issue (which had nothing to do with the pump). Point being, this gen 4 engine had a tensioner from factory. After seeing this, I will not install a tensioner - I will install the dampener.

 

[strutaeng]

Have not pulled heads yet. But if you look close, the cam stopped turning just after tdc on #1 - so, it will be interesting to see what maybe (or may not be) bent.
I replaced the OE tensioner and chain just because I was in there - cus I replaced the oil pump chasing an oil pressure issue (which had nothing to do with the pump). Point being, this gen 4 engine had a tensioner from factory. After seeing this, I will not install a tensioner - I will install the dampener.

Thanks for keeping us updated and background.

So out of curiosity, what was the cause of your low oil pressure then?

And I just reread your initial post about the reluctor wheel not turning...did your crank...break??? I'm really curious about that part.

 

[j91z28d1]

Have not pulled heads yet. But if you look close, the cam stopped turning just after tdc on #1 - so, it will be interesting to see what maybe (or may not be) bent.
I replaced the OE tensioner and chain just because I was in there - cus I replaced the oil pump chasing an oil pressure issue (which had nothing to do with the pump). Point being, this gen 4 engine had a tensioner from factory. After seeing this, I will not install a tensioner - I will install the dampener.

I always worry about replacing parts cause I'm there. it's hard not to, but I've seen things fixed until they are broken so many times.

either bad parts, or just bad luck. it's always annoying.

I broke a crank once right behind the timing gear. it was at hi rpm, but it bent every single valve over and jammed it into the head. hopefully yours is way less drastic than that one was.

 

[Dustin Jackson]

@strutaeng Does a broken timing chain cause a spun main bearing?

 

[Dustin Jackson]

@tjoyce81 I’ve heard of that being a concern but until now it was more of a legend, this is my first time seeing it. Glad I used the LS3 dampener

I look forward to seeing the rest of it

 

[strutaeng]

@strutaeng Does a broken timing chain cause a spun main bearing?

I've thought about the sequence of events in my case and I think no, but I really don't know for sure. Probably, if engine ran low on oil, all these things can happen almost simultaneously in a very short time.

Certainly, a broken timing chain is never a good thing :-(

You always hear guys "thinking": did my engine jump timing? when they can't get it to start. I always think in my mind, if that was the case, you'd have bigger problems. I'm talking LS and similar engines. You are right: not a common failure, but over decades of use and literally millions and millions of miles combined, any failure is obviously possible.

 

[Dustin Jackson]

@strutaeng I hear you, discovering a broken timing chain and a spun bearing does widen the scope of repair

 

[petethepug]

I see a preloved 3/4 or wun ton 6.0L L96 Silverado 380 hp (not the Express van lower hp version) floating into the engine bay of your future. All the signs are there.

 

[strutaeng]

I see a preloved 1/2 or 3/4 ton 6.0L L96 Silverado 380 hp (not the Express van lower hp version) floating into the engine bay of your future. All the signs are there.

Those different HP ratings are due to different tunes; the engines are mechanically the same.

Typically, manufacturers "derate" HP in the heavier gvwr chassis to help with longevity. Often they'll simply hold back the maximum RPM to achieve this.

The L96 was never installed in a 1/2 ton BTW.