New to me 2007 Tahoe and lifter replacement

[lightflyer1]

Bought a 2007 Tahoe LT in very nice condition a few weeks back with a ticking sound from the engine. From reading here I thought I could handle the repair. Bought it for $3500. Wanted to put it back stock as I didn't want to remove the cam if I didn't have to. Was hoping the cam would still be good. Upon opening it up found a bent pushrod on #4 cylinder. Cylinder 5 seemed to be burning lean from the rest or vice versa. Pulled the lifters and they all looked great on the roller to the cam and the cam surfaces. Replaced all the parts with OEM components. Started it up and it ran with a misfire. Tuned ethanol back to 3% from 70% and no improvement. Pulled injectors and they looked like they need replacing. Started and drove today and runs like a charm! Very smooth and no codes at all. The misfire and fuel rich codes and cleared up the Stabiltrak warnings too. I don't usually open up engines to work on but this one was pretty easy for what it was. Plenty of room to work. Learned a lot from reading here on the subject, so thanks everyone who has contributed over the years. Mostly going to be used a a third vehicle and boat and other towing duties. Probably last the rest of my life in that role. I spent a little more than the bare minimum trying to be proactive in replacing in sets where possible, rather than piece by piece only what was broken/worn out. YouTube was a big help too with disassembly/assembly instructions.

Bought the following items:

Performance GM LS 5/16" Hardened 7.400" Pushrods LS1 LS3 4.8L 5.3L 5.7L 6.0L 6.2 $90
ACDelco (8pcs) Engine Valve Lifter Gen V 7.0L 6.2L 6.0L 5.3L 4.8L 4.3L 12648846 $136
8 Genuine GM AFM Lifter 12698946 New In Box $380
MAHLE B32790 Engine Oil Pump Pickup Tube Gasket $4
MAHLE Original GS33449 Head Gasket Bolts $84
MAHLE HS54442 Engine Cylinder Head Gasket Set $230
Genuine GM 12571609 Valve Lifter (VLOM) $282
General Motors Genuine Parts 12585328 Engine Valve Lifter Oil Filter $9
4 PACK GM Lifter Guide Tray 2 - 12571596(12669184) + 2 - 12571608(12669185) $36
GM Genuine Parts 19177403 Intermediate Steering Shaft Boot $5
GM Genuine Parts 12570427 Driver Side Rocker Arm Cover $135
Melling MOD100 Engine Oil Relief Valve Deflector - Rubber - Black - GM Truck/SUV $15
GM Genuine Parts 12608835 Engine Oil Pressure Relief Valve $12
oil and filter $55
Trans fluid and filter $110
Anti freeze $45
8 ACD-OEM Spark Plugs 41-962 Double Platinum + Herlux (8mm Made in USA) Spark Plug Wires + 8 Heat Shields For LS2 LS3 LS4 LS7 Engines $111
ACDelco Sequential Multi-Port Fuel Injector Assembly Part No. 217-2436 x 8 $552

$2291 total

 

[tom3]

Any idea what actually caused the bent push rod?

 

[Dustin Jackson]

@tom3 I've seen a few people post situations like this and the best theory I can think of is that the lifter collapsed enough to allow the push rod to unseat from the center and ride of the outer lip of the lifter allowing the pushrod to get squished next time the cam and lifter cycled. But what do I know lol

 

[TollKeeper]

I also had the bent pushrod on my 2006 LH6. Lifter gets collapsed from the dumb AFM/DOD, pushrod comes out of cup on the rocker, cam follower pushes lifter up, pushrod goes up against the trunion, and if your lucky, bends the pushrod. If you are unlucky, rips the trunion out of the head.

 

[TollKeeper]

Heres my bent pushrod from my LH6


You may think having a bent pushrod is bad... In the grand scheme of things, its actually a good thing, as it means the lifter is not wiping the cam lobe.

 

[Geotrash]

Nice work! Looks like she’s worth preserving so good on ya!

 

[lightflyer1]

My pushrod looked similar. No idea what caused it as it is new to me with the defect in place already. Using a DOD delete OBDII device now.