Now how did I do this? Cracked Pistons.

[AndrewH]

My '09 has been trying to die for awhile it seems. I noticed it smoking and missing around thanksgiving. I pulled the RH head and found the valves werent perfect. I had done a compression test but I'll not include that here because I found my tester was doo-doo. New head and new gaskets ect and back together. Still some smoke and some missing. I left it alone because that is my plow truck and I was lazy. Well in case no one has notices we never really got winter. So I pulled the truck in and tore it down again. I had a ton of blowby by now coming from the rocker covers and the oil fill. This time I had a good compression tester. 410 accrpss the entire LH bank. 410 on 2 and 6 RH bank. Less than 100 on 6 and 8. I found 6 and 8 both had cracked the pistons. 6 parallell with the wristpin right through the middle of the head of the piston and 8 was almost 90 degrees different. The crack running up and down. In both cases the piston had pinched the rings and not allowed them to move. I'll get you some pictures. So my question is this : If it was water in the fuel why didnt I kill all of them? Or was it something else?

 

[AndrewH]

The pictures I promised

Pics of the cracks and how the lands pincher the rings.

 

[Ken_86gt]

I'm not much help with this - does water in the fuel really do this? It does not seem to me that it would, but I don't have any experience with this condition. Did you use starting fluid at any point?

 

[jrobinson5093]

Maybe leaking head gasket between 6 and 8. Just a guess but was it 7 and 8 or 6 and 8 that where low?

 

[gringeltaube]

One way I have seen this happen was max power, high rpm acceleration with engine still cold.


G.

 

[DriverSideImpact1008]

Yeah, what Gringel said. Or could be if it gets too hot.

 

[doghead]

Could it be from bad injectors?

 

[zout]

I would make sure your injectors are not overfueling and are tested for popoff and drizzling fuel when they should be shut. From looking at the pic's several times it does not appear as coolant.

 

[ryan77]

If your rebuilding the motor i would put new injectors and ip pump in anyways!

 

[mudman]

Just me..But, have you been using Either on it ?... Either in a glow plug engine is a Bozo No No!! Just asking!!

 

[Wile E. Coyote]

Just me..But, have you been using Either on it ?... Either in a glow plug engine is a Bozo No No!! Just asking!!

I've had to do it sometimes with CUCVs and HMMWVs I've just *had* to get running for emergency reasons, but always, always, always disable the glow plug systems first, and when you hit the spray button on the can it's *barely* a half second. On a CUCV you can pull the card under the dashboard.

I was wondering if the damage was ether start too. Put too much ether in and it detonates halfway up the compression stroke and breaks stuff (con rods, pistons...ow ow ow.)

 

[AndrewH]

Either: I dispise the stuff. This has always been the best starting 6.2 ever. This engine just barely need glowplugs. when warm it starts with just a thought of cranking. when cold the most I need is 15 seconds of glowplugs.

I try to let the truck warm up before driving. Yes, I have driven with it still cold. I really try to avoid it though.

6 and 8 were low. 2 and 4 have 410 psi. Same as the LH bank.

I have never used either on this engine. Thats not to say the govt never did. I have put 12000 miles on the truck and I bought it from Uncle Sam. When I picked it up from Ft Campell I had to put a stater battery and driveshafts on it. It looked like everything was new or rebuilt from the radiator to the rear axle.

I have read that advanced timing may make it start easy so I may have a timing issue. (I searched here, don't tell anyone.)

I have an appointment to do some govt work at a local diesel shop and will be pop testing all of the injectors.

 

[wayne pick]

Andrew, Sorry to hear about your engine. Like you said, who knows what the GOV did to it. I did a search on some GM diesel web sites and found their answers to your piston cracking question pretty much match what our members here said. Bad injector hydrolocking came up most. Head gasket failure. Cracked head. Porous piston castings arround wrist pin bores was also mentioned. Running a cold engine hard. When it's cold, i get up a little earlier and warm my truck untill I feel warm air from the defroster vent, then a 5min ride to the highway and pour the fuel to it. U gonna rebuild or swing another one in? Ted's trucks n stuff has lo mi GOV takeouts for about a grand, says he test's them and scraps or parts out the bad ones. Heard good reviews on them and what i gather, they are decent people that will work with you. If work picks up im getting one as a spare. Good luck, WCP.

 

[AndrewH]

I learned stuff.

Yes. I spelt that rong on purpose. Ok, I have cleaned things up a bit and have learned that the injection pump is advanced. The scribe marks are misaligned by 1/8 inch. I havnt figured what that is for flywheel degrees but it IS advanced. Pump towrds D side. Good and tight bolts. It didnt move. It was set there. Parts ordered...............

 

[AndrewH]

Ok, I have looked at this, that, and the other thing. I think what we have here is detonation damage caused by advanced timing made more severe by cold weather. I bought the truck out of Ft Campbell, if it was warmer and the truck didnt run with the cold advance for any period of time it may have survived. (?) A local old timer, the guy who pop tested the injectors, put together a few things for me. Cold advance and the advanced timing setting added to winter starts. The other pistons and bores do not show any cracks. Now I need to try to locate two oversize pistons and rings. .5mm over. I have standard and .75 mm over. DAM the bad luck. Anybody know where I can order two pistons? I could buy a couple gov take outs for the price of a new set! While we are at it, I'd also like to locate two 1mm oversized pistons for another engine. ....... Any Ideas?

 

[Wile E. Coyote]

Honestly, with all the low-miler takeouts out there in MV land...I just wouldn't bother with the broken piston problem at all and just use it for parts. Yes, just those two pistons were done in - but who knows if the remaining pistons have been weakened as well? Replacing two pistons might well be...pardon the expression...putting lipstick on a pig.

If it were me I would've made it a paperweight the minute I discovered cracked pistons. Life's just too short.

 

[AndrewH]

I do recognize there are a lot of take out engines out there. I have a few. I suppose I am a glutton for pumishment. Also, I want to fix it to say I did. I kinda like to know why it failed and know it will run again.

 

[wayne pick]

Check out DieselPage.com forum, cracked piston 6.2 L diesel. Good insight and possable solutions to 6.2 piston cracking. great photos. Used Federal Mogul H587CP sealed power found on CL posted in Jan. he may still have em.

 

[rickf]

1/8" is WAY, WAY advanced!!!! That might be your problem. I will bet it was pretty noisy.

Rick

 

[AndrewH]

There are five m1009s locally. Mine sounds the same as any others here. Mine always started the best. That was the only clear difference. They all have a different sound when the cold advance is active, they all quiet down when they warm up. They make about the same power. (closed course, professional driver)

I have located some pistons, we'll see when they get here how things go.

Wayne, which craigslist? local to washington? I'll take a look.