Bent rod, broken valve spring, oil pump filter debris

Big_B · February 6, 2018

Purchased new 2016 Sierra Denali 1500 with 6.2L and 4wd now has about 30k miles on it.

Started by hearing the ticking of a lifter and after several days of trying to get a local GMC Service Department to accept the vehicle for repairs due to lack of any loaner vehicles, it nearly did not make it to the dealership. So far I have been told that there was a bent push rod, broken valve spring, broken lifters and today oil pump screen was checked and debris were found. Vehicle has been in shop for almost 4 weeks so far. I also took it in for transmission hesitation, lurching, hard downshifts, slipping when first driven after setting for >24 hours and the rear differntial clicks/pops whenever turning.

Dealer has so far just wanted to replace broken parts and start it up and if it runs call it good. I am very concerned about internal debris remaining and the potential for further damage to the engine or reduced engine life due to these issues.

Does it seem prudent to just replace these types of parts and nothing else? I have just contacted GMC and been given an incident number and the promise of a call from a "Senior Service Advisor".

1SLOW1500 · February 6, 2018

Purchased new 2016 Sierra Denali 1500 with 6.2L and 4wd now has about 30k miles on it.

Started by hearing the ticking of a lifter and after several days of trying to get a local GMC Service Department to accept the vehicle for repairs due to lack of any loaner vehicles, it nearly did not make it to the dealership. So far I have been told that there was a bent push rod, broken valve spring, broken lifters and today oil pump screen was checked and debris were found. Vehicle has been in shop for almost 4 weeks so far. I also took it in for transmission hesitation, lurching, hard downshifts, slipping when first driven after setting for >24 hours and the rear differntial clicks/pops whenever turning.

Dealer has so far just wanted to replace broken parts and start it up and if it runs call it good. I am very concerned about internal debris remaining and the potential for further damage to the engine or reduced engine life due to these issues.

Does it seem prudent to just replace these types of parts and nothing else? I have just contacted GMC and been given an incident number and the promise of a call from a "Senior Service Advisor".

Please don't take this wrong but you did it wrong. I would demand a new gm engine as truck is under warranty. Call the local service rep and get him to approve a work order. Then the dealer with treat you like a king. Once you said rod that was it, not that debris in oil is much better. But the cost of the half ass one rod fix isn't worth it. They sent your engine back to gm to find the reason why and then rebuild it a sell it. But you would be driving now. Oh and have a copy of oil changes on hand if possible.

You didn't say what trans you have or mods or location.

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Big_B · February 6, 2018

The truck has the 8spd transmission, no mods and is in OK and has never acted "right" since it was new. I bought the line that it needs to "learn" how to shift and adapt to you, which it never did.

I'm not one to accept just any solution to this matter but it is hard to decide at what point it is not reasonable to just replace broken engine components. I agree with you that a new engine is the proper fix but getting GMC on board with that is now the task at hand. How can you find the local/regional GM service rep with the clout to make this happen?

Dnt · February 7, 2018

Dang man, that is super bad news. Hopefully you can get a new engine but sounds like you have many hours of work and documentation to put in before that is approved. If they patched it and it was mine it would be sold immediately.....

Tahoe02 · February 7, 2018

Ask the dealer for the name of the GM rep as every GM Dealer has one.

Paintor · February 7, 2018

You bent a pushrod that cam took a hit. probably is all jacked up from hammering away at the lifter.....how tha frig did his hydraulic lifter go full solid?

Theres more damage in there than what they are telling you.

Colossus · February 7, 2018

Very discouraging. I wonder how this happened.

Big_B · February 7, 2018

Update from dealer:

GMC is going to make repairs and replace damaged parts in the engine as I was told this was their "recommendation" and what would be approved for warranty repairs. The only concession that is being contemplated to me would be an increase in the warranty period for the engine. This means they will replace some of the lifters, the bent rod and the oil pump and start it up to see how it runs and possibly just call it good at that point and offer me a warranty increase.

At least you will know how GMC stands behind its engines when they start coming apart at the 30k mile point. I have not yet heard back from my GMC chat yesterday from the "senior service advisor" but I am not expecting them to take a different line than the repair rep did with the dealership.

Add to this the transmission issues that have not yet been addressed as the truck isn't yet running and the rear differential that clicks and pops when turning and you have a truck with an engine and tranny that I have zero confidence in. No wonder that the newest Company truck purchase was not a GM product.

Grumpy Bear · February 7, 2018

17 hours ago, Paintor said:

You bent a pushrod that cam took a hit. probably is all jacked up from hammering away at the lifter.....how tha frig did his hydraulic lifter go full solid?

Theres more damage in there than what they are telling you.

And more to the story. I bet it started with the broken valve spring.

Paintor · February 7, 2018

49 minutes ago, Grumpy Bear said:

And more to the story. I bet it started with the broken valve spring.

Oh noooo....GM valve springs dont break......especially at 30,000 miles....noooo...not on a $50k vehicle....just doesnt happen.

Welder-32 · February 13, 2018

Just bought a 15 Silverado 5.3 with 35,000 miles. Only hade it a week and a lifter stuck bent a push rod broke a rocker. At least that’s all they said. I know there is more as it would have bent a valve and cam damage. Currently fighting with gm as I want a new motor! They are trying to just replace A couple rods, two rockers and valve springs.

Big_B · February 13, 2018

The dealership still has not even started the engine, so without my truck going on 5 weeks. No help from GMC customer service as they don't even call back as promised. I hope none of your vehicles gets stuck like this one.

Grumpy Bear · February 13, 2018

17 hours ago, Welder-32 said:

Just bought a 15 Silverado 5.3 with 35,000 miles. Only hade it a week and a lifter stuck bent a push rod broke a rocker. At least that’s all they said. I know there is more as it would have bent a valve and cam damage. Currently fighting with gm as I want a new motor! They are trying to just replace A couple rods, two rockers and valve springs.

What do we mean by 'stuck lifter"? You mean stuck in it's bore or stuck fully extended? (loss of hydraulic function.)

Welder-32 · February 14, 2018

12 hours ago, Grumpy Bear said:

What do we mean by 'stuck lifter"? You mean stuck in it's bore or stuck fully extended? (loss of hydraulic function.)

Yes it stuck fully open.

Grumpy Bear · February 14, 2018

3 hours ago, Welder-32 said:

Yes it stuck fully open.

So what your thinking is the piston kissed the valve as the cam was at full lift crushing everything in between. I honestly have no idea how much clearance there is between valve and crown in the newest Ecotec3 motors at TDC but it's normally enough in any rational build to accommodate a few turns of lifter preload which is what we are talking about. The lifter plunger doesn't have infinite travel. It's limited by a snap ring. So even when the lifter is in a state of 'pump up" they wont meet. Piston and valve that is. Which makes the pushrod and rocker somewhat of a mystery. Easy enough, have them bore scope that cylinder and look. Don't guess. Valve crash will stick out like a sore thumb. IF they did not meet then the rocker, pushrod or valve spring failed creating clearance that finished them off like a jackhammer. That the case the repair they offer would be about right. A valve spring doesn't have to break to fail. I can be simply weak. Ask for your parts. You bough them and own them. Then have a careful look. Have a friend with a valve spring tester?