1996 6.5 NA won't turn

[cdnewt]

Howdy, I'm new here and to diesels in general. Got a 96 g30 short bus with a 6.5 n/a. Has a db2 mechanical pump and mechanical fuel pump. She won't turn over. Had a bad knock on passenger side then oil pressure drop, smoke and nothing. Wont even crank now. Gone through electronics--most comfortable area. All good more or less--one funky ground thats been holding for 4, 000 miles on block/ tranny. Obd1 key just reads the code 12 flash set.
I'm a greenhorn farmer with no access to a shop and time for engine/rebuild work only after 12 hours In the field and sundays. Could build something to work in, I.e. greenhouse converted to a shop. Looking for any pointers or advice. Local mechanics are full up with work. Also, it's been harder and harder to start for the last 3 months and oil pressure has cosistantly been off hilter. thought It was the cold. Read the gm manual, army manual and diesel page troubleshooting manual. Want to know what I'm in for. Thanks. Eat local!

[a5150nut]

Well welcome to TDP. Your in the right spot for 6.5 info.

Can you pull the glow plugs and try turning it over?

[cdnewt]

Thanks! Sure it'll take me a minute what with the van doghouse dealy. What does removing the glow plugs help resolve? Pressure? And low coolant light is on now.

[cdnewt]

Pulled the plugs. Just a big click from the starter and now a wee little squeel from the starter as well.

[DmaxMaverick]

Starter problem? Or a locked-up rotating assembly problem? Get a wrench on the balancer bolt and see if it'll turn by hand. Your description of how it quit isn't encouraging, though. I have a couple guesses, but I'll wait until you try to turn it by hand.

[cdnewt]

Turned with no happy adou. But it moved at least.

[cdnewt]

Adieu* Could the starter be messed up from the one and only possible corroded ish ground?Thanks UP school district salt trucks btw. But it seems to be clicking into the wheel pretty hard. Only dealt with starters on tractors so may be different in this case.

[Yukon6.2]

By your description my guess is the motor is toast.
How is the oil level?You mentioned the low coolant light,is the coolant low?
Was it hard to turn over by hand?
If the coolant is low,loosen the oil plug with a pail under it.Keep turning the plug out while holding pressure against the pan,until you can just pull it out and let a little drain out.If coolant comes out first you have an issue.Replace plug.
You can also cut open the oil filter and look for signs of metal in the pleats.
Good Luck,hope i'm wrong.
Thomas

[cdnewt]

It wasn't as hard to turn over by hand as I expected. Big storm coming in so no more tinkering tonight. Bus is outside. No workspace here. Yet
What makes it toast? The more scenarios thrown at me right now the better.

[cdnewt]

Coolant light only on when obd key is in. ??? Idk. Definitely checking for the coolant in the oil thing. I'll be hacking my filter as well. Always wanted to see the inside. Almost bought one of those stainless reusables which would make it much less invasive to constantly check for metal particulates.

[cdnewt]

Okay. No coolant in the pan, just oil. Cut apart the filter--nothing real out of the ordinary. Some pinhead sized particulates. She was a bit low on oil but not empty. Any suggestions for the next step would be greatly appreciated.

[DmaxMaverick]

The events that lead to the first shutdown (noise, oil pressure, smoke), screams of catastrophic failure (crank and/or cam). Turning the crank by hand eliminates hydro-lock (major head gasket failure, etc.), but doesn't eliminate the catastrophic possibility. Many 6.2/6.5 engines run a long time with a broken crank, and lesser with a broken cam. Cams usually just break clean. This means, at least the oil pump drive (rear end of the cam) doesn't drive, and oil pressure drops. Depending on where, it can also mean piston-valve collisions (some of the noisy part). A broken crank can see lower oil pressure do to the new "leak" in the oil path. One can cause the other, as well. The starter motor could be failed, but I think you're going to find more than that. It doesn't explain the preceding symptoms. There are still other possibilities, none of them good.

[cdnewt]

Alrighty, so at this point there is no other option but to pull engine? Is a broken crank and or cam the end of this engine? Or can I rebuild? Does this whole issue depend on collateral damage to the block and heads/pistons? Am I better off buying an army surplus engine or rebuilding this one? Thank you for the insight thus far. I appreciate it. Been in the dark here till this forum.

[DmaxMaverick]

It may not be that bad. I only voiced a "guess" according to the symptoms you reported. It could be a wrong guess. It could be something more simple, such as a rocker-rack or rocker arm. If it ran well before, I'd be inclined to look into it further before pulling the engine.

[cdnewt]

Righto. So pull heads to take a gander is next step?

[DmaxMaverick]

Not just yet. I'd start with the oil pan and valve covers, not necessarily in any specific order.

[Dvldog8793]

Howdy
Allot of info can be found by having a GOOD oil analysis done and having someone interpret the results if needed.

pressure test the coolant system with 16lbs and let it sit for a couple hours. See if it holds pressure. See if you have any coolant in the oil pan.

Did it have green or orange antifreeze in it? Some of the extended run anti freeze will mix with oil and form a sludge rather than separate out.

Try to turn the engine over from both the front and watch the ring gear to make sure it turns as it should. My last 6.5 had a catastrophic crank failure and the engine still turned over but the block and crank were both grenaded! My front half was only turning about 1/2 what it should.
If it turns easy from the front it might just be in two pieces. :(

Remover the starter and see if it functions out of the system.

These are some trouble shooting things to try, and they will only verify that you need to pull the engine.

Given your symptoms before hand it does not sound too good. Many times when the crank goes it take the block with it. two of mine came apart like puzzles...:mad:

Many of the Gov surplus engine have issues. make sure your can test it before you buy. Might be better to try to get a good runner from a donor vehicle. Rebuilding a 6.5 can get expensive. How much is the vehicle worth for you from that stand point?

Good luck!

[sctrailrider]

Like said before, remove the glow plugs, then use a bolt on the front pulley and you can "rock" the crank back & forth and see what you feel & hear, if there is any slop you will see & feel it... and go from there...

[cdnewt]

Pulled valve covers. Can't see aything out of the ordinary. Cannot remove oil pan without pulling the motor. When I dropped the oil pan as far as she'd go, I heard a clunky sound=something rattling on the bottom? Next step is to pull motor as far as I can tell. Does anyone have any experiece with a sportvan frame. Everything is real tight with the doghouse/in-chassis access. I can turn the crank by hand but it ain't easy and nothing is heard but movement. What should I hear? Can you define slop?

[cdnewt]

I should mention I am not getting rid of this chassis no matter what. No way I'm letting go of the turtle bus. Too much irreplacible time and energy put into modifications: wvo fuel tank mounts, deck board stage on top, music festival memories...etc. So, I'm in this all the way. Fix, rebuild or replace. All advice accepted.

[DmaxMaverick]

If you can rotate it by hand without too much difficulty, the problem is much more likely the starting system. Verify good power supply (batteries, cables, terminals, etc.), then focus on the starter and ring gear. A bad ground can, and does, cause significant issues, and isn't uncommon.

[phantom309]

It's been my experience over the years that nasty noises leading to a motor not turning over on the starter anymore is pretty much positive indication the motor is pooched,.the "squealing" noise from the starter, is the sound it makes when it has plenty of power but is unable to turn the crank,.
People telling you to check grounds and other bull****,. is a waste of time,. anytime a motor is knocking, loses oil pressure and shuts off,. having a poor ground is the least of your problem,. pulling valve covers and oil pan just promotes a longer period of denial,..


My opinion is based on your last comments,. the vehicle is sentimental to you,.

I would pull the engine,. pull the rad cradle and go out the front,.
put it on a stand and see what you need,. you may very well just need a short block.
There are always deals out there on complete 6.2/6.5's,...

[DmaxMaverick]

..... Or simply a broken flexplate or torque converter.

But I do agree, mostly. The events leading to the stoppage didn't sound encouraging, as said early on.

[phantom309]

..... Or simply a broken flexplate or torque converter.

But I do agree, mostly. The events leading to the stoppage didn't sound encouraging, as said early on.

broken flex plate,. won't stall the motor,. and the starter will "buzz" but not engage,. a broken torque converter will not stall the motor,. but will definitely impede forward motion,.

[cdnewt]

Number four jumped out of bounds. Any advice? Block seems alright. Rebuild?

[cdnewt]

Dampner pulley had a lot of cracks.

[phantom309]

do what you want,. you're gonna anyway,..

another short block was already suggested,.

[RAYMONDK]

The engine is most likely contaminated with the micro-particles generated during the destruction. The oil filter will not protect against metalic particulates as they can cut through the filter element but mainly because of the near 100% bypass that occurs during startup with cold oil. Whether you rebuild or replace depends on two things. The first is your mechanical prowess. If you are a competent mechanic with an eye for detail and follow the FSM word for word, you stand a chance at a successful rebuild. The second is the degree of thoroughness with which you approach a task. The most time consuming and also the most important part of this rebuild will be the decontamination. Every part you reuse must be completely dissassembled and cleaned to steril. Every passage in the oil system must be flushed over and over until there are no more shiny specks. I made flushing tubes and spent hours with my 6.2 and the shinny specks just kept on coming. After I was satisfied it was clean I installed the cam and lifters, oil pump, filter, cooler bypass line, etc. Then set it upright with the pan on it with 3 quarts of 30 wt. cut 1:1 with kerosene. Then spun the cam with a drill for a few minutes. Pulled the pan and found shiney specks, also in the filter. Repeated three or four times and finally last count was 5 specks in the filter, none in the pan. Cleaning the oil cooler took another several hours. That was 95,000 miles ago. You should be able to find the parts cheap enough if you search. I found a reground crankshaft with bearings for less than $100.