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+--- Thread: Pre Chamber failure - OM606 (/showthread.php?tid=7599)
Pre Chamber failure - OM606 - hummermaniac88 - 01-28-2017
Well guys, bad news. The prechamber broke clean off and lodged around in cylinder number 4. I have the head rebuilt prior putting it on the engine.
I Have a new engine coming in. I'm wondering what could cause this? High EGT? Faulty pre chamber? Bad timing?
I'm trying to prevent this to hapenning to engine number 2.
![[Image: 16325643_10158178133960437_1487408550_o_zps7nziiovs.jpg]](http://smg.photobucket.com/user/hummermaniac88/media/G%20wagon/JAN%2026TH%202017/16325643_10158178133960437_1487408550_o_zps7nziiovs.jpg.html)
![[Image: 16357754_10158178134210437_1662347986_o_zpsb03orsyg.jpg]](http://smg.photobucket.com/user/hummermaniac88/media/G%20wagon/JAN%2026TH%202017/16357754_10158178134210437_1662347986_o_zpsb03orsyg.jpg.html)
The car's setup is the following:
OM606
220cc 8MM superpump
HX40W
RE: Pre Chamber failure - OM606 - barrote - 01-28-2017
Well, something else happened there, u are showing 2 damaged cylinders (head faces)!!! and only one has the pre cup riped off.
are u sure the engine didn´t ingested anything ?
It seems weird .... all faults i have seen in those cups are the ball broken, broken loose, completely dissapear, clogged cup neck , but never cracks along the cup or in the tip which is heat treated and very hard to destroy.
Anyway be aware that when the head is faced, and one cuts too much like a 1mm the precups have to be shimmed(pre cup protrusion) measured, and the gasket with the correct repair thickness (piston protrusion measured in case the deck was faced), this to avoid piston contact. (the pre cups are not same size they may differ by some tenth´s
Despite your pistons don´t show evidence of contact, it does not mean they didn´t.
At high speeds and high temperatures many things happen, and i bet the engine kept going litle limp but going....
Good luck
RE: Pre Chamber failure - OM606 - hummermaniac88 - 01-29-2017
Thanks Barrote! Might be caused by that, it was they're first OM606 head rebuilt. I might just leave my replacement engine unopened to hopefully save some trouble.
RE: Pre Chamber failure - OM606 - baldur - 01-29-2017
(01-28-2017, 12:05 PM)barrote Well, something else happened there, u are showing 2 damaged cylinders (head faces)!!! and only one has the pre cup riped off.
are u sure the engine didn´t ingested anything ?
It seems weird .... all faults i have seen in those cups are the ball broken, broken loose, completely dissapear, clogged cup neck , but never cracks along the cup or in the tip which is heat treated and very hard to destroy.
Anyway be aware that when the head is faced, and one cuts too much like a 1mm the precups have to be shimmed(pre cup protrusion) measured, and the gasket with the correct repair thickness (piston protrusion measured in case the deck was faced), this to avoid piston contact. (the pre cups are not same size they may differ by some tenth´s
Despite your pistons don´t show evidence of contact, it does not mean they didn´t.
At high speeds and high temperatures many things happen, and i bet the engine kept going litle limp but going....
Good luck
It's quite common with engine damage for the damaged cylinder to eject shrapnel into the inlet manifold where it gets ingested by adjacent cylinders.
RE: Pre Chamber failure - OM606 - barrote - 01-29-2017
Its hard to belive that can happen in this engine type.
spit a bit of metal through valves across the manifolt and land in adjacent cylinder? well many weird things happen...
like this pre cup being cracked open in the tip.
Got some questions for u may send u a PM?
RE: Pre Chamber failure - OM606 - baldur - 01-29-2017
I've witnessed some petrol powered engines blow pistons apart and there I found bits and pieces of the vaporised piston and rings in all of the remaining cylinders. Of course the vacuum assists there but I can see the same thing happening on a diesel once some of the broken pieces get wedged in an inlet valve preventing it from sealing, the compression pressure will blow other pieces at full speed up the inlet runner.
PMs are welcome and so is e-mail.
RE: Pre Chamber failure - OM606 - Hercules - 01-29-2017
Many prechamber failures are due to fuel injector not spraying properly ( peeing ) causing over heating of tip. Possible also
a nozzle that hangs open or delayed closed. Might only happen after engine warm. Take apart injector look for signs of bluing ( over heating )
on pintel .
RE: Pre Chamber failure - OM606 - hummermaniac88 - 01-30-2017
I just got my injectors tested. They're fine apart from cylinder 1 (Piston rings went because of high egt caused by the leaking)
RE: Pre Chamber failure - OM606 - Hario' - 01-30-2017
Damn I hope mine doesn't look like that when I open it up! How are the bored and valves?
RE: Pre Chamber failure - OM606 - Hercules - 01-30-2017
Little logic,bit of science,those prechambers are tough,if the end just broke off should have done major damage, ( punched holes or cracked piston,
bent rod, beat out rod bearing,beat up head,)Did not. What did happen was the end of prechamber broke off and shattered,like a piece of glass!
Look at all the pieces. What causes metal to do that? The metal has become crystallized. How does that happen,heat the metal hot and cool to
quickly. Leakey injector (drips into prechamber after shut down ) causes tip to be cooled to fast. Did not happen over night,many repeated cycles
but it will get there given enough time,damage started many miles ago. Mbz says it will happen if drippy injector not repaired.
Metal in other cylinders can come back through the exhaust valves. Proven fact.
RE: Pre Chamber failure - OM606 - Gelubelea - 01-30-2017
Happened to me once when I have lost the coolant ( small plastic drain knob not tight in place ) and overheated the 606.962 motor , 25 minutes with 120km/h on highway (three prechambers damaged ). Filled with coolant , easy starting but many misfires Weird , but still good the head gasket after that experiment ....
RE: Pre Chamber failure - OM606 - hummermaniac88 - 01-30-2017
False, the injector on cylinder #4 didn't leak and had a good spray pattern. Most likely from the extreme -35 cold we've had and the high EGTs.
RE: Pre Chamber failure - OM606 - Hercules - 01-31-2017
Question: If the cold temps.and high exh.temps are the answer why is #4cyl.prechamber the only one damaged.
Question: Have you owned this engine from new,and know all repairs ever done? Is it possible some one else installed
injectors because of and earlier problem? Just asking questions,I do not know all the answers!
i
RE: Pre Chamber failure - OM606 - addi.bigg - 01-31-2017
(01-30-2017, 11:17 PM)hummermaniac88 False, the injector on cylinder #4 didn't leak and had a good spray pattern. Most likely from the extreme -35 cold we've had and the high EGTs.
I don't think that it can be because of the cold weather. The whole block has to get cold and as it is quite a huge one it can't get suddenly cold after shutting down.
RE: Pre Chamber failure - OM606 - barrote - 01-31-2017
after all who have seen pre cups damaged?
I did seen many but not like that. That tip broken off by the holes plane is the first .
Causes!!! Sure it wasn't cold weather. Neither Egt's ...
How is the ball ? How is the rest of the cup like?
RE: Pre Chamber failure - OM606 - Hercules - 01-31-2017
I worked for Mercedes Benz of North America for 25 years,mercedes says Note; Crystallization of prechamber tip is caused by dripping injector
after engine shut down. Seen the pictures my self. Start of damage to prechamber did not happen with present injector! That was
spraying ok. Damage started many miles ago,possible several injectors ago.
Note; injector can spray properly and still drip. Was the injector even tested for drip?
Best hopes in finding your answer to why.
RE: Pre Chamber failure - OM606 - hummermaniac88 - 02-01-2017
(01-31-2017, 11:08 PM)Hercules I worked for Mercedes Benz of North America for 25 years,mercedes says Note; Crystallization of prechamber tip is caused by dripping injector
after engine shut down. Seen the pictures my self. Start of damage to prechamber did not happen with present injector! That was
spraying ok. Damage started many miles ago,possible several injectors ago.
Note; injector can spray properly and still drip. Was the injector even tested for drip?
Best hopes in finding your answer to why.
That's a wealth of information. It does make sense. I presented your points to my diesel injector shop, they tested them again under heat, they are dripping.
I should change the prechambers on my replacement engine and put my rebuilt injectors in.
RE: Pre Chamber failure - OM606 - Hario' - 02-01-2017
So they just drip a bit until the hard line pressure bleeds down, only a few drips surely?
RE: Pre Chamber failure - OM606 - Hercules - 02-01-2017
(02-01-2017, 05:42 PM)hummermaniac88Great! you have the answer. Best method of repair if possible is test under normal working conditions (all things).(01-31-2017, 11:08 PM)Hercules I worked for Mercedes Benz of North America for 25 years,mercedes says Note; Crystallization of prechamber tip is caused by dripping injector
after engine shut down. Seen the pictures my self. Start of damage to prechamber did not happen with present injector! That was
spraying ok. Damage started many miles ago,possible several injectors ago.
Note; injector can spray properly and still drip. Was the injector even tested for drip?
Best hopes in finding your answer to why.
That's a wealth of information. It does make sense. I presented your points to my diesel injector shop, they tested them again under heat, they are dripping.
I should change the prechambers on my replacement engine and put my rebuilt injectors in.
RE: Pre Chamber failure - OM606 - Hercules - 02-01-2017
(02-01-2017, 07:07 PM)Hario So they just drip a bit until the hard line pressure bleeds down, only a few drips surely?
Each injector will vary,at what pressure does the injector stop dripping?? so what is the volume dripped??
Not more than is in the line to (o) pressure for sure.
RE: Pre Chamber failure - OM606 - Hercules - 02-01-2017
To help is all stay out of trouble in this area.
What were the symptoms before the disaster.
Here are the only things that come to mind.
1- small bit harder to start. possible
2- slight miss 1-2 sec. until line refills and pressure is restored.
Any others??
RE: Pre Chamber failure - OM606 - hummermaniac88 - 02-02-2017
(02-01-2017, 11:34 PM)Hercules To help is all stay out of trouble in this area.
What were the symptoms before the disaster.
Here are the only things that come to mind.
1- small bit harder to start. possible
2- slight miss 1-2 sec. until line refills and pressure is restored.
Any others??
- Hard to start in the morning (Especially after a cold -40C night)
- When cranking it sounded like rumbling of metal (Probably pre chamber already shattered at that point)
- Louder and louder injectors (Clacking noise, Clack, clack , clack!)
- Power slowing declining (Power loss)
- Rough idle
- Turbo having trouble making boost (Started at 1.5 bar then never made .7 bar again)
- If you change gears from R to D (vice versa) the car would stall
RE: Pre Chamber failure - OM606 - barrote - 02-02-2017
these engines , last and last and last , i bet u put it a new chamber and it continued untill yellow smoke coming out the exaust...
how´s the turbine, sure it was hit by some debris and may be damaged , a way damaged... i had that just by ingestion of sand...
RE: Pre Chamber failure - OM606 - hummermaniac88 - 02-02-2017
The valves are not holding seal anymore. They got damaged. It wouldn't be worth rebuilding on a destroyed head.
RE: Pre Chamber failure - OM606 - barrote - 02-02-2017
for the record, the diesel shop where i have some friends , and do some works , is open since 1974, no one seen a MB precup like that...
even the old fellas, joining to that the shop in servisse since 1953 , but no one is alive from those days.
keep the head, rebuilding is easy , this are though engines , small hammer and chisel repairs last for ages. sometimes
RE: Pre Chamber failure - OM606 - hummermaniac88 - 02-04-2017
I got a new engine and might keep this one around as a spare. Anyone know where to get new chambers?
RE: Pre Chamber failure - OM606 - Hario' - 02-06-2017
(02-04-2017, 02:16 PM)hummermaniac88 I got a new engine and might keep this one around as a spare. Anyone know where to get new chambers?
Forum member ak47is1337 said he had some on my wanted thread recently. (I got mine in Europe)
http://www.superturbodiesel.com/std/showthread.php?tid=7493
RE: Pre Chamber failure - OM606 - hummermaniac88 - 02-06-2017
(02-06-2017, 05:33 PM)Hario(02-04-2017, 02:16 PM)hummermaniac88 I got a new engine and might keep this one around as a spare. Anyone know where to get new chambers?
Forum member ak47is1337 said he had some on my wanted thread recently. (I got mine in Europe)
http://www.superturbodiesel.com/std/showthread.php?tid=7493
How much did it cost you with Hents99?
RE: Pre Chamber failure - OM606 - Hario' - 02-28-2017
(02-06-2017, 06:20 PM)hummermaniac88(02-06-2017, 05:33 PM)Hario(02-04-2017, 02:16 PM)hummermaniac88 I got a new engine and might keep this one around as a spare. Anyone know where to get new chambers?
Forum member ak47is1337 said he had some on my wanted thread recently. (I got mine in Europe)
http://www.superturbodiesel.com/std/showthread.php?tid=7493
How much did it cost you with Hents99?
It was a deal for a favour. But they are $50 each new, so probs $15-30 each good used? Don't know tbh
RE: Pre Chamber failure - OM606 - Ryanhayward1660 - 07-18-2018
I know this is an old thread but I had the same thing happen to my race car and not a whole lot of support with these motors in the states. Did fixing the leaky injectors address the issue on the new motor? My injectors were rebuilt and pop pressures set by a local diesel injector shop when I put the dieselmeken pump in. It happend to two motors which is my fault because I thought I just lost compression in the first motor due to big boost and a lot of miles so I didn’t take it apart until I hurt the other motor. Any help would be awesome thanks....
RE: Pre Chamber failure - OM606 - g wizz - 10-19-2018
(07-18-2018, 08:27 PM)Ryanhayward1660 I know this is an old thread but I had the same thing happen to my race car and not a whole lot of support with these motors in the states. Did fixing the leaky injectors address the issue on the new motor? My injectors were rebuilt and pop pressures set by a local diesel injector shop when I put the dieselmeken pump in. It happend to two motors which is my fault because I thought I just lost compression in the first motor due to big boost and a lot of miles so I didn’t take it apart until I hurt the other motor. Any help would be awesome thanks....
i cant for the life of me see how some drips of fuel could damage the pre cup when under working conditions its being bombarded by a flame thrower. especially if there is no visible smoke and the engine runs fine before hand. that just sounds like some bs but im not a 25 year Mercedes mechanic and i just want to blow these things up.
this sort of stuff cracking in my mind would be related to the head, cooling, and localized hot spots. in your case racing i can only assume your throwing too much fuel. i cant imagine timing being the issue? i dunno this seems like a strange failure. but in your case its most certainly related to localized heat in the pre cup. its really hard to say with the OP, cause the head was at a machine shop so god knows what happened to it, so protrusion cracked/damaged on install ect. i for sure will be dye testing my precups for cracks when they come out.
you should ask jeemu on instagram or some of the other finns. they probably have done this.
RE: Pre Chamber failure - OM606 - engineengineer - 08-05-2019
(10-19-2018, 12:01 PM)g wizz(07-18-2018, 08:27 PM)Ryanhayward1660 I know this is an old thread but I had the same thing happen to my race car and not a whole lot of support with these motors in the states. Did fixing the leaky injectors address the issue on the new motor? My injectors were rebuilt and pop pressures set by a local diesel injector shop when I put the dieselmeken pump in. It happend to two motors which is my fault because I thought I just lost compression in the first motor due to big boost and a lot of miles so I didn’t take it apart until I hurt the other motor. Any help would be awesome thanks....
i cant for the life of me see how some drips of fuel could damage the pre cup when under working conditions its being bombarded by a flame thrower. especially if there is no visible smoke and the engine runs fine before hand. that just sounds like some bs but im not a 25 year Mercedes mechanic and i just want to blow these things up.
this sort of stuff cracking in my mind would be related to the head, cooling, and localized hot spots. in your case racing i can only assume your throwing too much fuel. i cant imagine timing being the issue? i dunno this seems like a strange failure. but in your case its most certainly related to localized heat in the pre cup. its really hard to say with the OP, cause the head was at a machine shop so god knows what happened to it, so protrusion cracked/damaged on install ect. i for sure will be dye testing my precups for cracks when they come out.
you should ask jeemu on instagram or some of the other finns. they probably have done this.
come on, use brain
RE: Pre Chamber failure - OM606 - g wizz - 08-07-2021
(08-05-2019, 04:00 PM)engineengineernah(10-19-2018, 12:01 PM)g wizz(07-18-2018, 08:27 PM)Ryanhayward1660 I know this is an old thread but I had the same thing happen to my race car and not a whole lot of support with these motors in the states. Did fixing the leaky injectors address the issue on the new motor? My injectors were rebuilt and pop pressures set by a local diesel injector shop when I put the dieselmeken pump in. It happend to two motors which is my fault because I thought I just lost compression in the first motor due to big boost and a lot of miles so I didn’t take it apart until I hurt the other motor. Any help would be awesome thanks....
i cant for the life of me see how some drips of fuel could damage the pre cup when under working conditions its being bombarded by a flame thrower. especially if there is no visible smoke and the engine runs fine before hand. that just sounds like some bs but im not a 25 year Mercedes mechanic and i just want to blow these things up.
this sort of stuff cracking in my mind would be related to the head, cooling, and localized hot spots. in your case racing i can only assume your throwing too much fuel. i cant imagine timing being the issue? i dunno this seems like a strange failure. but in your case its most certainly related to localized heat in the pre cup. its really hard to say with the OP, cause the head was at a machine shop so god knows what happened to it, so protrusion cracked/damaged on install ect. i for sure will be dye testing my precups for cracks when they come out.
you should ask jeemu on instagram or some of the other finns. they probably have done this.
come on, use brain
RE: Pre Chamber failure - OM606 - baldur - 08-09-2021
Leaking injectors can definitely cause damage.
One, you can have pre ignition when fuel that is already present in the chamber prior to the timed injection event.
Two, poorly atomised fuel will ignite with a bang when it gets hot enough to evaporate rather than burning smoothly.
Three, and probably the most prevalent problem for the prechamber is that in normal operation you have fuel delivery for maybe 30 degrees of crank rotation followed by 690 degrees to transfer heat away from the chamber into the cooling system. If you have fuel constantly dripping into the prechamber you aren't able to keep it cool.
RE: Pre Chamber failure - OM606 - dieseltorque - 08-31-2021
Never seen broken tips from 8 hole chambers, only 10 hole tips. Can it be reason as well? More holes, less material, less strenght,,,