Ignition Problems

[JMilby]

I own 2002 Express 3500 w/5.7. I've just had motor replaced for second time due to cracked block where the starter bolts up. When starting, there is a slight hesitation or knock. Motor really shakes. Almost sounds like diesel. It causes the starter to torque and cracks the block after time. The truck has 138,000 miles, but the last two motors were installed within 18,000 of each other. 3 total. Dealer is doing the work but can't seem to find the problem. Any ideas. New motor, new tranny. Don't know what else to replace.

[rhandwor]

They make shims for the starter it appears the gear is sticking or the bendix is bad. You can buy shims at a parts store. Loosen the starter one side will slide in the other you have to pull a bolt.
Otherwise I would find a dealer who can fix the problem as he is creating work with your excess cash.

[jonsonton]

I don't know for sure, but it sounds like the starter is kicking back on you. Sometimes if you have a leak(coolant, fuel) in a cylinder, completely filling it up, and it has nowhere to go it will go in reverse of normal rotation kicking the flywheel in reverse. I'm not sure, but this might cause some damage to the starter area as well as the engine.

[furious408]

We had the same problem with a friends van.. Afew things to look at...
1 Make shure the starter bolts are correct...The bolts have a knarled section that looks like crosshatch marks right after the threads,, If they are not there , or worn out.. Replace the bolts.. The knarls keep the starter from shifting or bouncing
2 Make shure if you use an after market starter that the nose cone was not ground off to replace the bearing.. If you see the nose cone at the front has a hole in it you can look into and see the bearing and the tip of the shaft. The starter will not be long enough to sit in the trans housing and hold it from bouncing
3 make shure your distrib cap is clean and in good shape (if you have a distrib cap ) ours was bad and we noticed that on the G vans that when the dist cap goes bad ( witch is almost all the time, you will change it more than any other tune up item ) That it can make the spark jump and mis-fire the wrong cyl causing the engine on start up to try to turn back on itself against the starter.... Good luck