I have a 97 Chevy C1500 5.7L Vortec 350. The other day a friend wanted to put sea foam in my throttle body to clean out my motor. Shortly after the smoke cleared my truck died. Got it to start again and while driving it started to overhead then lost power, had a water leak somewhere in the back of the motor closest to the passenger side. I took plugs out and it spins fine, no liquid comes out, put plugs back in and it won’t crank. Filled radiator back up and not having a leak anywhere. No oil in water and no water in oil. Thoughts???

 

Won't crank, or won't start?

 

No crank no start

 

Even if the plug wires were way of, and the timing that far out, with a good battery/starter the engine should roll over. I'd look at the starter/battery then proceed from there.

 

When the plugs were out, did you turn the engine over by hand, or with the starter?

Are you getting a click?

No click (starter solenoid not engaging) indicates electrical supply (circuit between solenoid and ignition switch).

A click but no crank indicates the starter motor or mechanical binding. If you’re getting a click, have a helper turn the key to crank and hold, then tap on the starter housing with a small hammer. If this causes the starter to engage, replace the starter.

 

Ok update...
I checked my harmonic balancer and I can turn it both ways. So don’t believe it’s hydro locked. I was then told to charge my battery to make sure it’s charged good. Checked it with a multimeter, it was at 12.68V. Tried starting again and I am getting a very slow crank. I can literally see my fan slowly turn then stop then turn again. Had a buddy check the battery drop when I turned the key, he said it dropped to 4V. Ideas?

 

I'd say it's the starter solenoid, if it were me, I'd replace it.

 

Had a lifetime warranty on my starter so I put the new one in it. Finally it starts but I have to keep my foot on the accelerator or else it dies. Also it is running very rough and overheating. Had water spraying from one of my hoses..

 

Also I have not tried to drive it yet.

 

Update, let the motor cool down and tried to start and now am only getting a single crank