Lifter, Cam Swap Help

[drastevenson]

I have a 2007.5 GMC Yukon SLT.

Quick Story: did a cam swap and now it won’t crank up. It makes an almost clattering noise and won’t catch. I don’t want to keep trying to crank it on.

Long story:

About a year ago, I started having the lifter tick issue but was able to temporarily fix it by spraying some seafoam down the rocker arms (breaking it up topside) and a motor flush (to hit the bottom end).

That fixed the issue until a couple months ago, driving home, the check engine light came on. Cylinder 8 misfire.



Took it to a local shop, they quoted me ~$2.8k to replace the AFM/DOD lifters. Another shop I talked to told me it would just happen again and I needed to look into AFM/DOD delete. He quoted me a little less than $8k to do it (along with some other necessary upgrades - which I agreed with him on those).



When it comes down to it, I’m cheap, don’t trust anyone and would rather do it myself.



Bought Black Bear Performance Tune for the computer side of the delete. Grabbed an AMS Racing AFM/DOD delete kit with a stage 2 cam and new beehive valve springs. (Hopefully pictures I added show up).

Using the Hanes service manual and YouTube University… I managed to tear the engine down, swap everything out and get it all back together. (Minus a few small mental breakdowns and rage moments). This was over two off days and three days off after work working on it.



Unfortunately when I went to start it, it slowly started to crank and cut off. Started it again and it made this wild clattering sound from what sounds like the cam or crankshaft? (I’ll post a video of it).

Clattering Noise on Start Up

I’m thinking I didn’t properly set the cam position actuator and timing chain in at TDC but I wanted to see if anyone else has ever had this issue.



Since I have to remove quite a bit to get to it, I’d like to check all the troubleshooting boxes while I’m in there.

 

[Foggy]

I can't get to the video, but I don't have instaG...
That cam is going to need some tuning work to even get it to start and stay running.
Did you replace the oil pump, timing chain, anything else besides the cam and lifters??
Did you check your valve lash? It's only "adjustable" by changing length of push rods. And
you are probably going to want hardened pushrods since your spring pressures have changes..
Also did you really check out your rocker arms? They won't last with that cam and springs...
you could be getting noises from the rockers too

 

[drastevenson]

I can't get to the video, but I don't have instaG...
That cam is going to need some tuning work to even get it to start and stay running.
Did you replace the oil pump, timing chain, anything else besides the cam and lifters??
Did you check your valve lash? It's only "adjustable" by changing length of push rods. And
you are probably going to want hardened pushrods since your spring pressures have changes..
Also did you really check out your rocker arms? They won't last with that cam and springs...
you could be getting noises from the rockers too

Based on my research, this cam was as far as I could go without upgrading anything else. Maybe a new oil pump but I wanted to address is after the fact.

I inspected everything and cleaned up the push rods before I put them back in there. Nothing looked concerning or over worn.

My main issue is that it’s not starting and the noise it makes. I figure it should at least be able to crank up .

 

[wjburken]

That sounds horrible.

How sure are you that you’re not 180° out of time? What process did you follow to set your timing chain?

 

[iamdub]

Me when it tried to start:

Sounds like the cam is out of time, meaning your valves are smacking pistons. Don't attempt to crank the engine until you've opened it back up. the damage has probably already been done, but there is a chance it survived if the lifters weren't pumped up for that first start.

 

[wjburken]

Me when it tried to start:

Sounds like the cam is out of time, meaning your valves are smacking pistons. Don't attempt to crank the engine until you've opened it back up. the damage has probably already been done, but there is a chance it survived if the lifters weren't pumped up for that first start.

Right!?!?

good time to get a borescope and put it in a spark plug port to see if there is any damage to the piston head.

 

[iamdub]

Right!?!?

good time to get a borescope and put it in a spark plug port to see if there is any damage to the piston head.

From my recent experience, I'd say the damage would be a bent valve before substantial piston face damage occurred. *cringes*

@drastevenson, I'd remove the rockers and closely inspect the valvetrain from there. If all looks okay, hold the throttle pedal to the floor and crank the engine to see if it acts and sounds normal. It won't start, but you're cranking it to see if it has compression and sounds like it always has when cranking to start. If so, then you've pretty much confirmed a mis-timed cam.

 

[wjburken]

From my recent experience, I'd say the damage would be a bent valve before substantial piston face damage occurred. *cringes*

Agree. I was just thinking it would be a quick thing to check to see if there are any marks on the piston.

 

[iamdub]

Agree. I was just thinking it would be a quick thing to check to see if there are any marks on the piston.

True. One shouldn't use valves to remove carbon from pistons.

I'm still pulling for him that he threaded the needle and it can be fixed with an (albeit time-consumuing) adjustment and the mighty LS will come away unscathed.

 

[Dustin Jackson]

Man that’s sucks. Need to take it back apart and reinspect for damage and start over.

What cam and cam sprocket did you use?

 

[j91z28d1]

man that it tried to start is what gets me. if it was 180* out. I might have to popped a bit thru the intake? that sounded like it tried to start for a second and then friction killed it.

that's rough, but with that much noise, I'm pretty sure you're going to find it pretty quickly once taken apart.

you could try turning the motor over by hand with a wrench on the crank pulley and no plugs in it. see what you feel.

 

[Geotrash]

Oofta. I concur with the others here. Sounds like the cam timing is way off.

 

[Trina]

I have a 2007.5 GMC Yukon SLT.

Quick Story: did a cam swap and now it won’t crank up. It makes an almost clattering noise and won’t catch. I don’t want to keep trying to crank it on.

Long story:

About a year ago, I started having the lifter tick issue but was able to temporarily fix it by spraying some seafoam down the rocker arms (breaking it up topside) and a motor flush (to hit the bottom end).

That fixed the issue until a couple months ago, driving home, the check engine light came on. Cylinder 8 misfire.



Took it to a local shop, they quoted me ~$2.8k to replace the AFM/DOD lifters. Another shop I talked to told me it would just happen again and I needed to look into AFM/DOD delete. He quoted me a little less than $8k to do it (along with some other necessary upgrades - which I agreed with him on those).



When it comes down to it, I’m cheap, don’t trust anyone and would rather do it myself.



Bought Black Bear Performance Tune for the computer side of the delete. Grabbed an AMS Racing AFM/DOD delete kit with a stage 2 cam and new beehive valve springs. (Hopefully pictures I added show up).

View attachment 403023

Using the Hanes service manual and YouTube University… I managed to tear the engine down, swap everything out and get it all back together. (Minus a few small mental breakdowns and rage moments). This was over two off days and three days off after work working on it.



Unfortunately when I went to start it, it slowly started to crank and cut off. Started it again and it made this wild clattering sound from what sounds like the cam or crankshaft? (I’ll post a video of it).

Clattering Noise on Start Up

I’m thinking I didn’t properly set the cam position actuator and timing chain in at TDC but I wanted to see if anyone else has ever had this issue.



Since I have to remove quite a bit to get to it, I’d like to check all the troubleshooting boxes while I’m in there.

While you are at it make sure to put a genuine gm head gasket. The one from AMS racing was cheap Chinese crap and failed in 2 places 6 months after doing delete on 13 suburban.

 

[drastevenson]

Well I can confirm that the timing was off. Got in there, stripped everything out, and inspected it. Only damage was a couple bent push rods, I got very lucky on that.

Took my time putting it back together. And went to start it..

First try, it cranked and then died.
Second try, ol gal started right up.

It’s idling pretty rough though. I let it run for about 30 minutes and throttled it some to double check the oil pressure.

The pedal was very soft and then it died once the engine throttled back down. I watched the RPMs drop from 3 down to 0 and then it puttered out.

 

[Dustin Jackson]

@drastevenson Did you inspect the valves and pistons?

 

[drastevenson]

@drastevenson Did you inspect the valves and pistons?

I did. They looked the same as when I pulled them. Not great but nothing that indicated they immediately needed to be replaced.

I solved the sputtering out issue however I am waiting on the BlackBear tune files to get in to turn off the AFM/DOD in the computer.

Currently, these are the codes it’s throwing (I fixed the temp issue)

 

[j91z28d1]

oh yeah, I forgot you deleted afm. it will run like crap till it's turned off in the tune now. at least from what I read.

until then. I wouldn't worry to much. maybe do a compression check just to double check none of the valves bent a bit and aren't sealing. since you bent the push rods, they did hit the piston pretty hard and it's possible they are leaking a bit.

 

[Dustin Jackson]

^

 

[Geotrash]

I did. They looked the same as when I pulled them. Not great but nothing that indicated they immediately needed to be replaced.

I solved the sputtering out issue however I am waiting on the BlackBear tune files to get in to turn off the AFM/DOD in the computer.

Currently, these are the codes it’s throwing (I fixed the temp issue)
View attachment 403680

Yup, those are vlom codes. That tune will fix you up. Good job finding your root cause.

 

[wjburken]

Yup, those are vlom codes. That tune will fix you up. Good job finding your root cause.

I have heard of folks plugging in the old VLOM to get past that for a moment.