My son has a 1996 4x4 blazer 4.3L automatic. Long story. He had it parked at my place for a few days over Christmas and it rained here for 3 days straight. He went to start it and said it wouldn't start. Gas was really low so I figured he was out of gas. Put in a quarter tank and tried to start it. The starter only turns the engine over for about 1-2 seconds then it seems like it freewheels and isn't engaging into the flywheel (flexplate?). It wasn't doing this before now. This happens every time I try it now. Today it is warmer and dry. In the past when the truck was started up cold it would need to turn over for about 3-4 seconds before it would fire and start. I can hear the fuel pump run when I turn on the key. Another thing I noticed was there was no coolant in the overflow jug and when I opened the rad cap I can't see any either. I am going to get some coolant now.

I tried to get the starter out but couldn't as it sits now. I may have to tow it to someones garage where I can work on it. I was able to unbolt it from the engine but couldn't get it out from under the vehicle. I slid the starter gear out all the way on the shaft and it doesn't seem to be chewed up, a little wear but not much. Is this a common failure on the starter or should I be looking at other issues.

Sorry about the long post.

 

Sounds like the starter bendix solenoid is weak and not holding the starter engaged.

 

From the description it sounds line the starter drive (bendix) is bad. It is an over running clutch that is designed to turn the engine over nut not let the engine drive the starter and overspeed it when the engine starts. It is a set of roller bearings that run up a set of ramps until they contact the inside of a drum and that drives the starter gear. When they wear out they may fail all at once or they may start to turn the engine over and then slip. The freewheeling you describe it the starter motor running but the starter drive is slipping.

 

Thanks for the replies. I have topped up the antifreeze, it only took about 1 litre so it don't think its an issue. I will be trying to remove the starter again this weekend provided the weather is decent. I will post back when I resolve the issue.

 

I have the starter removed. I was able to test it on the bench and it seems fine. The bendix gear springs out and stays out even with me trying to pry it back it while its spinning. I took it apart and couldn't find anything obvious.
I want to inspect the flywheel/flexplate but I don't know how to turn the engine over. While I am under the truck looking at the opening from the starter can I just remove the serpentine belt and have someone reach down and slowly turn over the engine at the main pulley? Any other ideas?

 

I would pull all of the plugs and turn the motor over with a breaker bar on the bolt in the front of the crank.

 

Do I need to pull the plugs? Anyone know what size socket I need on the crank? Does it matter which direction I turn the engine over ie. clockwise/counterclockwise?

Can I jack the rear tires and spin them with an automatic transmission in drive to turn the flywheel?

 

Pulling the plugs will allow you to turn the engine over much easier.

As far as the socket size goes... I do not recall the size off hand, but I'd take a guess at 21mm.

It shouldn't matter which direction you turn it.

You cannot spin the engine over with an automatic transmission.