Did I toast my 6.2 engine somehow, and how do you jump a 24v HMMWV?

[FlameRed]

Partial update as I spent several hours looking at things. So I did not expect and resolution and I was not disappointed

I removed the torque converter inspection plates, or whatever you call them, and I did NOT note any missing teeth on the flexplate. I did note some minor evidence of grinding or a few teeth. Nothing major.

As @Retiredwarhorses predicted, two shims were too many and it had excessive clearance or play or whatever you call it. Not being an Olympic weightlifter, I disconnected the batteries again and loosened the bolts and was able to pull both spacers without removing the whole starter. As usual, that was a mistake. Without any spacers, the clearance was way too tight. So then I got to spend an pleasant time cursing struggling to get one spacer back in. After tightening that bolts back up again, the clearance was good.

But no joy - grind city still.

So next I thought I would tackle removing the glow plugs at least on the driver's side where they should be easy. One previously disintegrated and is not removable. But I was able to remove the three others. One I had previously replaced, and two other I did not as I did not want anymore of them to disintegrate on me.

Breaker bar trying to rotate the engine was still pretty hard in spots so I did not expect any improvement, and I was not disappointed.

Next I will look more carefully at the battery and connections. Maybe try jumping it. On the pass side I have one glow plug that is rusted in. Even removing the three other is a day's work for me.

If it is hydrolocked, I bet it is the two cylinders that I cannot remove the glow plugs without removing the heads.

To be continued...

 

[Mogman]

Partial update as I spent several hours looking at things. So I did not expect and resolution and I was not disappointed

I removed the torque converter inspection plates, or whatever you call them, and I did NOT note any missing teeth on the flexplate. I did note some minor evidence of grinding or a few teeth. Nothing major.

As @Retiredwarhorses predicted, two shims were too many and it had excessive clearance or play or whatever you call it. Not being an Olympic weightlifter, I disconnected the batteries again and loosened the bolts and was able to pull both spacers without removing the whole starter. As usual, that was a mistake. Without any spacers, the clearance was way too tight. So then I got to spend an pleasant time cursing struggling to get one spacer back in. After tightening that bolts back up again, the clearance was good.

But no joy - grind city still.

So next I thought I would tackle removing the glow plugs at least on the driver's side where they should be easy. One previously disintegrated and is not removable. But I was able to remove the three others. One I had previously replaced, and two other I did not as I did not want anymore of them to disintegrate on me.

Breaker bar trying to rotate the engine was still pretty hard in spots so I did not expect any improvement, and I was not disappointed.

Next I will look more carefully at the battery and connections. Maybe try jumping it. On the pass side I have one glow plug that is rusted in. Even removing the three other is a day's work for me.

If it is hydrolocked, I bet it is the two cylinders that I cannot remove the glow plugs without removing the heads.

To be continued...

Can you remove the injectors?

 

[FlameRed]

Can you remove the injectors?

Yep, for the cylinders with unremarkable glow plugs, that was my plan.

But I don't understand one thing about a hydrolocked diesel I can turn the engine with a breaker bar on the crank multiple revolutions. It is not locked solid to the point I cannot turn it. So my question is if the valves are opening, won't the water go out the exhaust values into the exhaust manifold?

 

[WillWagner]

If you can turn it and it does not stop, it isn't hydro locked. The "stiff" spots are most likely just the pistons coming up to tdc and going over the hump. Put some juice in the batteries, give them a load test to see how they hold a load and give it a shot if they test good. Nothing changed from the time you parked it and when you tried to re-start except for the AC stuff and time. If it started fine before, you let it sit to do the AC and now it won't start, we know the AC didn't cause the issue, just time.

 

[FlameRed]

Today's update.

I should have stated that both batteries are always on a NOCO dual bank trickle charger whenever parked.

Not much progress as I did not have much time. I measured each battery and they were both over 13 volts. Did a jump on each battery, at the same time on both, and tried to start it but it did the grind thing again.

All the connections seem clean and tight, but I have to dive deeper. Will have to continue another day...

At least I will get new glow plugs, for those I could remove, out of the deal.

 

[biscuitwhistler37]

It's kind of difficult to do but a video would really help here, the word "grind" has a very broad definition..... Does the engine rotate at all under starter power?

 

[FlameRed]

It's kind of difficult to do but a video would really help here, the word "grind" has a very broad definition..... Does the engine rotate at all under starter power?

When I crank the engine the fan moves a small amount and stops cold. Maybe a quarter turn at the most. Others time maybe one blade width. And then it grinds. I can turn the engine complete revolutions by hand with a breaker bar. Just frustrating as the socket keeps falling off the crank bolt as the pulley is deep and the fan and suspension components are in the way.

I think I tried turning it over three or four times and it sounds like a grinder.

I am really thinking the first starter ground down the flexplate just enough that the freshly rebuilt starter's gear is going to be ruined in short order.

I am starting to think that I need professional intervention. Problem is, few, if any shops here in central Florida, will look let alone work on HMMWV;s.

 

[Retiredwarhorses]

When I crank the engine the fan moves a small amount and stops cold. Maybe a quarter turn at the most. Others time maybe one blade width. And then it grinds. I can turn the engine complete revolutions by hand with a breaker bar. Just frustrating as the socket keeps falling off the crank bolt as the pulley is deep and the fan and suspension components are in the way.

I think I tried turning it over three or four times and it sounds like a grinder.

I am really thinking the first starter ground down the flexplate just enough that the freshly rebuilt starter's gear is going to be ruined in short order.

I am starting to think that I need professional intervention. Problem is, few, if any shops here in central Florida, will look let alone work on HMMWV;s.

A starter will only grind for a few reasons…
no flexplate teeth
weak solenoid
bad bendix gear
missing teeth on the bendix

have someone attempt to start the truck while you observe the bendix gear working, obviously you need to pull the inspection cover to do this.
A seized motor wont grind the starter, you will just hear a click or clunk and the bendix wont turn the flexplate….

 

[98G]

I think you have effectively ruled out battery problems at this point. Jumping it as you did should have started it even with bad batteries.

 

[WillWagner]

@Retiredwarhorses, low amps too. Just because there is 13VDC at the batteries doesn't mean the power supply has the amps to push the voltage to do what needs to be done. Load test the batteries to rule that out. DVOM on the batteries or starter solenoid and see what the voltage drops to. Better yet, amp clamp it. If amps drop to nothing, there is your issue.

 

[Retiredwarhorses]

@Retiredwarhorses, low amps too. Just because there is 13VDC at the batteries doesn't mean the power supply has the amps to push the voltage to do what needs to be done. Load test the batteries to rule that out. DVOM on the batteries or starter solenoid and see what the voltage drops to. Better yet, amp clamp it. If amps drop to nothing, there is your issue.

he was already advised to load test the battery’s…

 

[WillWagner]

he was already advised to load test the battery’s…

Yeah, I knew that, but I have not read where he did, only checking VDC.

 

[87cr250r]

Measuring the battery voltage without a load is absolutely meaningless. Usually you use the starter as the load. Since yours is kicking out you don't have much time. Does your meter have a hole function? You can use the hold to capture the lowest voltage. If it dips much below 19 volts your batteries are toast.

You can also use the glow plugs as a load but it appears you're missing some.

 

[WillWagner]

Measuring the battery voltage without a load is absolutely meaningless. Usually you use the starter as the load. Since yours is kicking out you don't have much time. Does your meter have a hole function? You can use the hold to capture the lowest voltage. If it dips much below 19 volts your batteries are toast.

You can also use the glow plugs as a load but it appears you're missing some.

I was thinking that, but, would the meter only hold the high voltage? I know my Flukes have that function, but it has been a hot minute since I needed to not look at the display and see low volts, the meter is usually within eyecrometer site.

 

[Coug]

I've seen batteries that failed within a few months of purchase. They will show a full charge, but have little capacity left.

The fact that the OP keeps his on a charger when not in use doesn't rule out the possibility of a failed battery, but it would mean they pretty much always show higher voltage.
I believe I did mention that he should check battery voltage while trying to crank and they shouldn't be dropping below about 22 volts if everything is operating properly. Below 22 volts doesn't necessarily mean the batteries are bad, but below about 19 or 20 while cranking would, especially for ones left on the charger.

The few times I've cranked mine on low batteries the starter still engaged, and stayed engaged, it just wouldn't crank. I just think battery voltage should be checked, especially while cranking, to help eliminate them as a possible cause to help narrow down the issue.

 

[87cr250r]

You should have a Min Hi function with the hold feature. Set it for min and it will record the minimum voltage while hold is active.