2005 Tahoe 4.8 Shaky crankshaft

[Jwill945]

05 Tahoe with the 4.8. Has 140k miles. This the second one I’ve owned and I absolutely love it. I’ve replaced/repaired the list below. But after the purge/evap repair it is idling rough and dying at stop signs/red lights with no codes at all. Took it to my guy’s shop (long time friend who also provides services for my company’s fleet vehicles) who I trust 100%. He replaced harmonic balancer but same issues on my drive home. After talking with him and my own observations, we found out the crankshaft is bent/warped causing the harmonic balancer to wobble and the ac belt tensioner to go crazy. His advice was to sell it as is or drive it until it blows up and replace the engine. I’m torn on what to do, like I said I love this old ‘hoe. Any advice is appreciated!!
-new plus and wires
-new water pump
-new battery and alternator
-replaced rear main seal and oil pan gasket
-replace charcoal canister, purge solenoid, clean out fuel lines
-new harmonic balancer

 

[Tonyrodz]

05 Tahoe with the 4.8. Has 140k miles. This the second one I’ve owned and I absolutely love it. I’ve replaced/repaired the list below. But after the purge/evap repair it is idling rough and dying at stop signs/red lights with no codes at all. Took it to my guy’s shop (long time friend who also provides services for my company’s fleet vehicles) who I trust 100%. He replaced harmonic balancer but same issues on my drive home. After talking with him and my own observations, we found out the crankshaft is bent/warped causing the harmonic balancer to wobble and the ac belt tensioner to go crazy. His advice was to sell it as is or drive it until it blows up and replace the engine. I’m torn on what to do, like I said I love this old ‘hoe. Any advice is appreciated!!
-new plus and wires
-new water pump
-new battery and alternator
-replaced rear main seal and oil pan gasket
-replace charcoal canister, purge solenoid, clean out fuel lines
-new harmonic balancer

From what I've read--and seen myself--it's somewhat common. My 05 Chevy Express wobbles. Bought it with 110k, it now has 151k. Also has the 4.8.

 

[Jwill945]

From what I've read--and seen myself--it's somewhat common. My 05 Chevy Express wobbles. Bought it with 110k, it now has 151k. Also has the 4.8.

Had any issues pop up with it? Just worried about developing enough wobble to cause piston damage.

 

[Tonyrodz]

Had any issues pop up with it? Just worried about developing enough wobble to cause piston damage.

Nothing mechanical due to that. You should be able to see it here.

 

[Matthew Jeschke]

I had a 1998 Buck Century w/ 3400 V6. I ABOSOLUTELY loved it. Got it with 115k on a newer motor (guy swapped it from junkyard). I drove it to 185k and sold it to my buddy who drove it to 200k when it blew up.

I found same issue after I owned the car. Somebody must have hoisted the motor on balancer or something. It visibly wobbled... I couldn't believe it, I was so daring as to touch the balancer and feel it wobbling.

And *sigh* in the end it spun a bearing. Other than visibly though was only way to notice it. I don't think it would have any effect on pistons? I think a main bearing went out if I recall what my buddy said. And yes I did disclose the issue to him when he bought it

I hate to say this, but honestly... Isn't hard to swap a engine in one of these. I've done it now haha A lift and a weekend and you can have a different motor in there. Plus the engines are CHEAP and plentiful.

 

[Jwill945]

Been avoiding the issue for a bit. My wife is getting a new ride, so I’m driving her Terrain for now. I posted the Tahoe for sale (included issues in post) but no real interest. I’m pretty sure it has a bad main bearing causing the wobble. Now what to do??? Sell it for whatever I can get or replace engine? If I do decide to swap engines, what to put in it???

 

[Jwill945]

I had a 1998 Buck Century w/ 3400 V6. I ABOSOLUTELY loved it. Got it with 115k on a newer motor (guy swapped it from junkyard). I drove it to 185k and sold it to my buddy who drove it to 200k when it blew up.

I found same issue after I owned the car. Somebody must have hoisted the motor on balancer or something. It visibly wobbled... I couldn't believe it, I was so daring as to touch the balancer and feel it wobbling.

And *sigh* in the end it spun a bearing. Other than visibly though was only way to notice it. I don't think it would have any effect on pistons? I think a main bearing went out if I recall what my buddy said. And yes I did disclose the issue to him when he bought it

I hate to say this, but honestly... Isn't hard to swap a engine in one of these. I've done it now haha A lift and a weekend and you can have a different motor in there. Plus the engines are CHEAP and plentiful.

Do I get a salvage/reman/new engine? Also do I stick with 4.8 or go 5.3, or even find the elusive 6.0?

 

[Tonyrodz]

My Tahoe originally came with the 4.8 also. I decided to swap to the 6.0. Cammed it, with long tubes, a tune and a 3k stall. Originally went with the lq4, when that motor went I eventually got an lq9.

Do I get a salvage/reman/new engine? Also do I stick with 4.8 or go 5.3, or even find the elusive 6.0?

 

[Jwill945]

My Tahoe originally came with the 4.8 also. I decided to swap to the 6.0. Cammed it, with long tubes, a tune and a 3k stall. Originally went with the lq4, when that motor went I eventually got an lq9.

Where did you source the lq9 from?

 

[Tonyrodz]

Where did you source the lq9 from?

I'm not sure where the mechanic originally got it from. It was his, and he replaced the lq4 I supplied to him after it dropped a valve and destroyed itself. I think he got it from CL.