m998 glowplugs blow and hard to start

help Please!!!

I have a M998 that keeps blowing the glow plugs. We changed the sensors, controller and protective control box. The only thing that I can think of left is the front wireing harness or maybe something could be wrong with the batteries? or the engine could be losing compression. When we try to start the vehicle a blueish tint smoke comes from the exhaust... fried piston rings maybe?

help please!!!!
thank you...

Blue smoke would be oil, but since is sounds like you haven't actually started the Humvee yet, It can't be that as you need to have it running before blue smoke will show up. Even an engine with good rings and cylinder walls may have a large amount of blow by "blue smoke" if it has been sitting for a long time. Only driving and loading up the engine will get the piston rings moving to clean out their grooves and allow them to seal properly. If you see smoke while cranking it is probably unburnt fuel and is probably white. What do you mean when you say "blowing glow plugs"?

A little back ground on the truck? Have you had it running before or is this a truck you just got and are trying to start it? How many miles? What are you doing when you try and start it? Did you put in new nonswelling plugs?

dilvoy, the 'blue smoke' he is referring to, is probably just un-burned diesel from the lack of glow plug operation.

dooleydragon... first of all, put your location in, as specified in the FAQ on the left. Its a forum requirement.

Second.... what are you using for glow plugs?? Brand... Model #, etc. You cant just wander into your favorite auto parts store for these ones

I'll bet he's using 12V glow plugs from an autoparts store, when he should be using 24V. Same thing happens when SSA sends us the wrong glowplugs, easy to figure out, because the right glowplugs come in the same box all 8 together that for CUCV comes 1 per that same box.