Last year my 94 LT1 automatic decided not to start. Pushed into the garage, jack up and checked the solenoid wire. Had no voltage when key turned. Replaced the starter relay and got a new neutral safety switch. (car has 181,000 miles) . Put back together and car started fine. Short time later car wouldn't start again. Jacked up took off starter and bench tested. Starter worked fine. Figured maybe a bad spot on the stator so I ordered a Reman AC Delco. Put it on and third trip out this year the car won't start. Take it off, bench test it works. Reordered another under warranty. This one does the same thing, It is locking against the flexplate. I took off the cover and flexplate was a little chewed up. I replaced the flexplate this past weekend. Got everything buttoned up and IT IS STILL LOCKING UP! I did check clearance while I had the trans out and even ran the starter against the new flexplate. It engaged fine every time. Now that the car is back together, It is doing the same thing. My only thought is another bad reman starter. Anyone else ever experience this?

 

Is the gear chewed up because it was improperly shimmed?

 

I always rebuild if possible any original item on my cars. We just had the 77 starter rebuilt for $90. He did not just replace the one part but completely rebuilt it,brushes etc. My first quote was $250.00 and that did include removing it but i removed it my self because i did not want the car flat bedded. It failed to engage in my drive way.

 

my 2-cents -- two bad starters in a row - unlikely. they bench test OK but you replace them anyway - ??? your original issue was electrical, so you replaced the safety switch and relay and then you had or have starter issues, and chewing up the flexplate to boot (I know, I know, technically, it's AT flywheel, and 99.99% incorrectly refer to it as a flexplate - at least that's what the "parts man" says - ). anyway, do you have a FSM? if not, get one! i'd take a second look into the electrical issues, and on the subject of the flexplate, w/ aklim on the shimming. the FSM is real specific on this subject. so, IMO, it's not the starter as much as the installation and there's some other electrical, or electro-mechanical issue going on here. start by double checking your grounds, especially the main engine ground cable or strap. good luck....

 

I replaced my torque converter and had to and re-shim. Mine wouldn't mesh with the flex plate, just spun in free air. I imagine yours is shimmed too close.

 

Once the shim is checked dont over look all the engine grounds. I had one of the 2 block straps off on my LT1, went through 1 reman original and a high tq yo find I was overloading the ground.

 

I had checked the starter mesh on all of the replacements, This started last fall. I just didn't notice the pattern until this past weekend. I was chasing the obvious. The car wouldn't start, check for electrical problem first. Changed the relay and socket as it cooked. Swapped out the neutral safety switch, looking for gremlin. Got a good solenoid wire voltage and thought I found the problem. Car started fine for a while, then same thing happened again. Take the starter off, bench tested and re installed, car would start. Park it and next time trying to start, Clunk no turn over just a thud into the flex plate. I bought a AC Delco reman from Rock Auto. Swapped and parked the car for the winter. Started right up this spring. She has driven it a total of 3 times. Parked in the driveway after a car show, needed to move the car....Nothing. Pushed into garage, jacked up removed starter and bench tested, worked. Reinstalled and started. Parked and next time I went to start, Clunk...Hit the key several times and she would finally turn over. Once spinning it ran fine, starts on 1 revolution, Oil pressure at 650 idle was about 35-40 no smoke. Bought another starter from rock and returned first under warranty, Got to be bad right? Installed second figuring just my luck bad reman. Same ****...Now what? Started looking at flex plate. No issue when the starter would spin, battery hot, car cranked just fine. It seemed to be a an engagement issue. Yes clearance was checked and about .035 with zero shims. Flex plate was a bit chewed so I bit the bullet and pulled the trans, replaced the flex plate. That HAD to solve it.....Nope same crap again. Bad starter again? Didn't make sense but maybe. Bought a NAPA reman. Tried it this past weekend. Started 25-30 times in a row without any sign of locking up. The only change was I pulled the pan to change my front cover which was leaking. I drained the oil and coolant. Got the car back together and re filled the fluids, Car sat for a week waiting on parts not being started. After the successful 25-30 starts I was confident I solved the problem with the NAPA starter. Came out to the garage Sat am and oil puddle at back of motor, somehow new oil pan gasket got screwed. Oh well I had another and the pan drops pretty easy, at least I fixed the starter. Hit the key and Clunk...same crap again! Ready to push this off a cliff. If I turned the motor off the alternator bolt by hand, it would crank right over. I ruled out the starter, flexplate and wiring. Injector leaking? Drained the oil to fix the pan gasket, oil didn't smell of gas and car ran fine once started....Then I saw it, the remaining oil in the freshly dropped pan had water / coolant in it! Not much but definitely there. Head gasket had gone, not bad but when the car was started and allowed to get up to temp and pressurize the cooling system it is leaking into one or more cylinder. Hydrolock. I am in process of pulling the motor for a rebuild. 184,000 miles and motor was still as installed by GM 24 years later. Time for a refresh. We will see how well the Mobil 1 has protected the wear surfaces. The motor is surgically clean inside. At least I finally found the smoking gun.

 

Damn, was hoping that wasnt the issue after reading all that...hell of a lot of work only to find that!
had a temp sensitive leak on the 89 also went nuts trying to nail it down.
184k and all those years isn a bad run really-never a good time but is certainly a good reason to improve it. Keep us posted on your plans.

 

Might be objectionable to you, but you could try some Blue Devil head gasket sealer to seal it. I know a guy who used it instead of replacing his car (import). Drove it for 3 years before trading it in. His was overheating though.

Might be worth a try to get by for a while.

 

Too Late for that now. LOL #7 was the culprit

 

And people think I am asking too much when I insist on a full inspection of a used car before money changes hands.

 

I have the FSM, and the starters were shimmed properly, Flex plate was chewed up over 184,000 mile and not really bad. I was grasping at straws looking at the obvious when I swapped the flex plate. When that didn't work I started questioning bad starters. I solved that question by swapping in a NAPA starter and when it acted the same way, then I had to conclude not a starter but a locking up problem. After I dropped the pan I found coolant. I tore the motor down and found water or fuel in #7. I sent the injectors out to be cleaned and checked. Just heard that 4 injectors were leaking and one was just streaming out. That would explain the locking up. It locked up on fuel and then popped the head gasket.Never smelled like gas in the oil. Funny thing is the car started ( when it would turn over) idled and ran fine. The inside of the motor is surgically clean and there is zero ridge on the top of the cylinders so I'm not expecting too much machining. Goes to the machine shop tomorrow.