No power, banging exhaust, lots of smoke... HELP!

[Jorrit]

Hello there all,

Last week my head gasket was blown at the back of the engine. Lots of oil coming out there.

Replaced the gasket with a new one (old style gasket i think, with separate fire rings and no permaseal, but vented). The truck did perfect again after the change, but only for 200 kilometers.

Suddenly, after "slowing down on the engine" quite a lot (for a very short time, did the wrong lower gear), the engine runs horrible.

The symptoms are: rough and hard running (like some cylinders don't do anything, like 'bop bop bop' instead of normal 'bbbbbbb', it sounds like an very old 1-cylinder diesel engine when running idle), loud bangs out of the exhaust when accelerating, exhaust is getting VERY hot (much much much hotter than normal), lots of white/grey smoke when idling (turning into black when exhaust is banging), and no power when trying to drive. Only that banging and smoking.

The following things we did or checked:
- Checked the injectors one at a time by loosing injector supply lines. Motor stops on all injectors when loosing. There is fuel coming from IP. So injectors are OK? No dribbling injectors i think?
- Did a cold retorque of the head nuts to 157 lb/ft. Have seen some oil leaking from the vents (more than at the other head).
- No air coming into cooling system, no water in oil.
- Fresh fuel filters.
- Inline tank pump not working (but did run good without it before).
- Removed air filter.
- Checked valve lash, all OK.

But without succes so far...

What could it be? Head gasket blown again? Injectors?

It's driving me insane... Hope anyone can help!

Greets from Holland!

 

[desertfox]

Do not run the engine anymore. You could toast the turbo. When slowing down the engine did you happen to notice the RPM? You may have over revved?
Any way pull the head. Check for cracks in the head and leaks at the valve seats. With the engine popping out the exhaust I suspect cracked head, seat and or head gasket? Especially with grey/white smoke out the exhaust.
Others should chim in here since my experience is somewhat limited with the multifuel head problems.

 

[mistaken1]

Black smoke can indicate lack of air for combustion.

Does the turbo spin by hand (through the intake)?

 

[FreightTrain]

Sounds like you could have floated some valves and smacked them with the pistons.Loud popping out the stack and dead misses means you got some dead Cylinders.You still have fuel going into them but no compression since you are getting grey then black smoke.I would yank both heads and pray.

 

[Alex400]

Sounds like you could have floated some valves and smacked them with the pistons.Loud popping out the stack and dead misses means you got some dead Cylinders.You still have fuel going into them but no compression since you are getting grey then black smoke.I would yank both heads and pray.

that's what i was thinking. probably a bent valve. Good luck.

 

[Jorrit]

Thanks for your replies so far!

The turbo spins when running (i hear it whistling)...

I think it has been over revved when changing gears. But for very short time and i don't know how much RPM's.

 

[FreightTrain]

when you get it straightened back out please don't down shift to slow down.The manual states not to cause the gears are so far apart and the engine offers very little if any braking power like a bigger diesel.

 

[dburt]

When you get the heads off again, be sure and take pictures of what you find and post them so the rest of us can see what happened and what you find wrong. Thanks!

 

[WillWagner]

Tons of input on this one, but, ! Probably bent some push tubes too.

 

[OPCOM]

Sorry to hear about this mishap. Hope the carnage is minor.

 

[Jorrit]

I will make some pictures when i have the heads off. Hopefully next week.

FYI: the white smoke is definitely unburnt fuel, no water / steam. That unburnt fuel ignites in the exhaust (running on mixed diesel / petrol / used motor oil) by the heat of the other running cylinders i think.

Hopefully the turbo isn't damaged by the heat. I hear it turning, so...

When there are some bent push rods, the valve lash wouldn't be OK on all valves, i think?

I can't buy the new style head gaskets here in Holland. Are the old style gaskets that worse?

And is it true that all injectors are working when engine stops at loosening the supply lines one at a time? I mean, it's not possible that some injectors are dribbling instead of spraying?

I am afraid it's a blown head gasket again, maybe the other head this time...

 

[Rolling_Eudaimonia]

Here read this manual once you're deuce is fixed...

 

[Jorrit]

I have read that manual!

But I didn't know that the multifuels are so sensitive to over revving...

 

[joec]

sometimes when you break a injector nozzle. It will pump out white smoke..!

 

[Jorrit]

Took the rear head off this morning.

When i pulled the injectors i could clearly see that injectors 5 and 6 were very WET and black, instead of DRY and black. So that were the faulty cylinders!

I was 'happy' to see that it was a blown head gasket again! Nothing wrong with valves, push rods, cracked head or worse.

The gasket was blown exactly between the last two cylinders. Even the fire rings were blown!

Im going to do the new head gasket trick again end of this week...

Turbo seems to be OK. No damage and it turns free!

 

[bottleworks]

I was 'happy' to see that it was a blown head gasket again!

Be sure to machine the heads flat before throwing another gasket at it. You can get the correct/new style head gasket through the right channels. Don't put the old style back on.