Rescuing a M1025

[mdainsd]

A new project for me! (Need that like another hole in my head). Found a not so nice M1025, less top and other parts for a price I couldn't refuse. Partially disassembled but about everything included to put it back together.

Installed is a brand new 6.5L, never run. And there in lies the current problem. The engine may have been installed months or even years ago. Its all there, but does not have good compression, not enough to get it to fire off.

Has anyone experienced this? I will be investigating by pulling the valve covers and seeing what we have lurking under there, like corrosion or anything out of the normal. Pan has clean clear oil in it. While the glow plugs were out for a compression test a little MMO was added to each cylinder. I'll let that sit a few days and check compression again.

Any other suggestions?

 

[mdainsd]

Question: What is up with the windshield glass? My other Hummer and H1 have laminated glass as one would expect. This one has laminated glass but seems it has a plastic coating on the glass which is dull and clouding in places. It is on the surface of the glass not in the laminated center.

Thoughts?

 

[desmodromic]

The windshield glass is ballistic glass. The plastic helps keep chunks of glass spraying all over the occupants.

 

[mdainsd]

Thank you! Can that plastic be stripped off or just go get new glass made?

 

[desmodromic]

The ballisitc glass is pricey. You can replace it with the standard glass fairly easily. I have heard of people peeling off the plastic and having a tint shop apply a clear film, but I can not speak as to it’s efficacy.

 

[mdainsd]

Spent the day with the old girl today. Got enough cobbled together to try for a compression test. New fangled digital military test gear turned into a time sink, hours and never got a real reading. While testing cylinder 1, all other glow plus out, she'd pop on that cylinder (like trying to start) so I thought that a good sign. Since we couldn't do a meaningful compression test, put in all the GPs (all brand new). Used a voltmeter to check GP voltage was coming on. Tried starting, not even a pop. Uneven cranking and then an explosion in the pan that sent the dip stick flying. enough. So moved onto installing helmet top, got that on no problem. Some some success.
Now Im going to find a mechanical compression tester for diesels and start over. But in my heart I think this engine is toast.

 

[dhaumann69166]

If it blew your dipstick out your engine is most likely shot and your compression from at least one cylinder is going into the crankcase, pressurizing the the crank case and the dipsticks is the easiest break away point to release the pressure. Any signs of metal in the oil after the bang in the pan? Uneven cranking could be bad or dirty connections on the battery or starter possibly. Easy place to start would be cleaning all electrical connections on the batteries, starter and alternator.

When you try to start it have you cracked the fuel lines at the injectors to confirm fuel without air bubbles to each cylinder? 6.2 and 6.5 diesels don’t like even the tiniest air bubbles in the line and will NOT start if any air is present. You can loosen the fitting on the injectors and have someone crank the motor for you, when you start getting diesel spray tighten the fitting.

 

[dhaumann69166]

Thank you! Can that plastic be stripped off or just go get new glass made?

I got new glass for my humvee windshield for $90 per side including shipping. It think it was $55 for the glass (not ballistic). You might be able to get the haze off your existing glass with polishing compound or headlight restore stuff and some elbow grease. Avoid any glass cleaner with ammonia. Most cleaners now are ammonia free thanks to so many people having tinted windows.

 

[gimpyrobb]

Better to pull the glows and crank the motor. Wait for fuel haze out of the GP holes, then re-install and start up.

 

[dhaumann69166]

If you pull the glow plugs and crank it you are not accomplishing the same thing. It takes way longer to push all the air through the injector than it does to crack a fuel line. If you pull the plugs and crank it you can’t actually see the fuel to see that you have a steady stream of fuel and not pushing spurts of diesel and air through the line. Also you will have to dump a lot of fuel into the motor to get a fuel haze out of a cold motor and it puts a lot more cranking time on your starter. Start at the fuel filter and make sure you have good flow to there, then move your way down the line till you get to the injectors.

 

[mdainsd]

Thank you for the help. Will crack the lines next time I get to work on it. I didn't mention but even with the GPs out it cranked slowly and uneven, at least slower than i would expect with no plugs in. And would only crank a few revolutions before dragging the batteries way down.I pulled the starter yesterday and I shop I know will test it this week. Then when it goes back in I will address the cleanliness of each connection.

 

[dhaumann69166]

If the starter tests good it could be bad ground somewhere. That would cause the drag and slow/uneven cranking. 99% of the Scouts I get running won’t crank at all or crank REALLY slow and hard. I clean the negative battery cable on both ends and they crank like I put a new starter in. Sometimes they look clean but a file proves otherwise.