2010 Yukon 6.2L DIY DOD Delete / Engine Rebuild - Starter issue - RESOLVED

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jjmasterson

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RESOLVED

There was some strange anomaly. When I pulled the plugs to test the starter without compression, it turned over just fine. When i put the plugs back in, it also started right up. When rebuilding, I put the plugs in before putting the motor back in the vehicle, then put heads on, and buttoned everything up. Being a first rebuild, once I had the plugs in, I felt the resistance of the compression, which was pretty significant compared to no compression. I figured it was normal. Regardless, it's up and running now. Really appreciate the feedback from folks!

J



Hey there,

6.2L had a burnt valve and chipped piston. Did a rebuild with new:

- Pistons and rings
- Valves
- Lifters (LS7 DOD delete)
- Chevrolet GM OEM Camshaft L96
- Cam bearings
- Oil pump
- Valley cover
- Spark plugs
- Plug wire
- Battery

I went to start it up, and crank was a bit slow but eventually started up. Sounds great. No issues when running. Each time it was started is seemed like the cranking was slowing or labored more and more, until nothing but a click. No start. Jumping the relay will get the starter to crank VERY slowly. Labored.

Testing:

- Battery is charged 12.53v (Tried a 2nd battery. Battery is not the issue)
- 12.53v at the starter main
- Engine is grounded
- Voltage metering on starter drops to 10.30v during jumping the relay
- Starter relay is good
- Starter fuse is good
- Replaced starter - same result
- Not terribly difficult to crank it by hand but can feel the compression
- Remove plugs and engine cranks normally

Is there some sort of compression issue I'm missing when doing a DOD delete?

Video Start with Key

Video Start by jumping relay (with plugs in)

20250422_171205.jpg


MUCH APPRECIATED!
 
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Joseph Garcia

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As @donjetman recommended above, take out the battery, take it to a local auto parts store and have it bench load tested.

Also, did you closely inspect the battery main wires? They often rot from the inside out, so you should check the resistance of those main wires with an Ohm tester.

Confirming the above two, you should be able to establish whether or not the full charge/amperage required to start the motor correctly is available.
 
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jjmasterson

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Thanks all! I also tried another battery from my F150 which runs well, and ran jumper cables from it directly to the starter and jumped the solenoid. Same slow crank from the starter. I'll load test my car battery also.
 

mikeyss

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Did you have the main caps off at all? The reason I ask is because years ago I had this same issue with a 383 stroker I had built. I was young and I experienced at the time, and found I installed the main caps in the wrong locations, and the starter did the same thing as what yours is doing.
 
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jjmasterson

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Did you have the main caps off at all? The reason I ask is because years ago I had this same issue with a 383 stroker I had built. I was young and I experienced at the time, and found I installed the main caps in the wrong locations, and the starter did the same thing as what yours is doing.
Thanks for the feedback! It's my first rebuild so very much could have missed that. I was careful to make sure they went back to were they came from and used existing bearings, as they looked ok. I didn't do a plastiguage tho. Maybe I should have? The crank seemed to spin ok after I re-assembled it.
 

donjetman

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Thanks for the feedback! It's my first rebuild so very much could have missed that. I was careful to make sure they went back to were they came from and used existing bearings, as they looked ok. I didn't do a plastiguage tho. Maybe I should have? The crank seemed to spin ok after I re-assembled it.
If there's a mechanical problem causing the binding?
drain and look at the oil
remove and cut open the oil filter
there will be a lot of metal.
 

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