Chevy and GMC Duramax Diesel Forum banner
1 - 7 of 7 Posts

· Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Good evening and happy holidays everyone, today I went and checked out an 03 Silverado 2500 LB7 (272xxx miles) and the engine cranks but will not run. The current owner said he was having hard start problems and replaced all the injectors but that did not fix the problem and said he thinks the camshaft position sensor is the culprit. I brought my scan tool to check live graphs and DTCs but none were stored. After letting the batteries charge in the truck I attempted to start the truck, it shut off my scan tool so I was unable to see the fuel pressure that the fuel rails were seeing. Also when cranking the starter engaged for about a second, then stopped for another second, and continued cranking until I let off the key, I had seen somewhere else where someone said that is a symptom of a bad crank sensor. This truck is located over an hour away from me so I'm unable to look at it except for once a weekend. Again, this is the first diesel I’ve ever worked on so please be easy on me!
 

· Registered
Joined
·
7,748 Posts
Check battery cables for voltage drop - all of them. Make sure the batteries are fully charged. Bad crank sensor bad cam sensor bad ecm. Lots of possibilities.
I attempted to start the truck, it shut off my scan tool so I was unable to see the fuel pressure
Not sure what this is about but your scan tool should be able to connect through all testing scenarios and not shut off. Sounds like it is losing power or ground.
 

· Registered
Joined
·
4 Posts
Discussion Starter · #4 ·
Have since got the truck home today, was able to borrow a friends Snap On scan tool, and Rail pressure read around 250 psi, i then proceeded to change the oil and found it was more Dexcool than oil, as a gasoline guy I immediately think head gasket, but i have seen other people say possibly the water pump or injector cups, any other recommendations?
 

· Registered
Joined
·
4 Posts
Discussion Starter · #5 ·
Tested the compression on cylinders 6 and 8 today as i already had the fender cover off to replace the fuel filter. Cylinder 6 only had around 150psi of compression while cylinder 8 had no compression at all, would I be better off finding a known good running engine and fixing common failure points before installation or should I pull the current engine and hope for the best that its salvageable?
 

· Registered
Joined
·
105 Posts
Tested the compression on cylinders 6 and 8 today as i already had the fender cover off to replace the fuel filter. Cylinder 6 only had around 150psi of compression while cylinder 8 had no compression at all, would I be better off finding a known good running engine and fixing common failure points before installation or should I pull the current engine and hope for the best that its salvageable?
I would at least autopsy the engine just in case its something worth repairing.
 
1 - 7 of 7 Posts
Top