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OM617 Engine issues
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Posted 4/29/2006 3:51 PM
petermerle
Expert




Date registered: Apr 2006
Location: Cape Town ( deep south )
Vehicle(s): W460 *1, W123 *2, W124
Posts: 1315
1000
OM617 Engine issues

My G ( OM617 non turbo ) has a lumpy idle and a ticking noise ( worse when cold ) noticable at the end of the exhaust pipe. The lumpyness exists upto about 1200 rpm from then on up ist smooth. Loosened fuel lines and it appears that #2 or #3 or both are slightly down on power. Have yet to do compression test.

Questions : What could be the cause of the noise from the end of exhast - sticky exhaust valve ? ( valve clearances checked OK ) .
Low power from #2 / #3 could indicate a cracked head -I guess whcih begs the question can the heads be repaired or is it a through away?
Peter
#5558
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Posted 4/29/2006 4:12 PM
jdc1244

Date registered: Dec 1899
Location:
Vehicle(s):
RE: OM617 Engine issues

Sorry, Peter, need to attack you with questions:

How many miles? Is it hard to start? Is there excessive smoke? What PM or repairs were done recently?

petermerle - 4/29/2006 3:51 PM

Loosened fuel lines and it appears that #2 or #3 or both are slightly down on power.


I’m not quite clear on that one, are you saying you pulled the hard fuel lines from the injectors and the output is weak on two and three?

At this point I think the exhaust noise is just a symptom and it may be an IP timing issue.



#5564 - in reply to #5558
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Posted 5/10/2006 4:27 PM
petermerle
Expert




Date registered: Apr 2006
Location: Cape Town ( deep south )
Vehicle(s): W460 *1, W123 *2, W124
Posts: 1315
1000
RE: OM617 Engine issues

Compression test done and # 1 is very low 8bar - others 16-18bar. What does not add up is that when disconnecting #1 injector engine engine becomes quite rough indicating that #1 cyl is firing strongly when connected . Disconnecting #2 there is only a marginal change in engine note/stability. Injectors 3-5 behave as per #1 . Injectors all open 115 -120 bar with good spray. IP timing correct. Slight smoke, oil consumption 1l/1000km

Something does not add up ! Suspect sticky valve and will have to do a leakdown test somehow
PEter
#9598 - in reply to #5564
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Posted 5/14/2006 1:03 PM
BenzDieselTuner

Date registered: Dec 1899
Location:
Vehicle(s):
Re: OM617 Engine issues

is every single valve ok?

did u check?
#12101 - in reply to #5558
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Posted 7/27/2006 5:32 PM
BenzDieselTuner

Date registered: Dec 1899
Location:
Vehicle(s):
Re: OM617 Engine issues

any luck Peter????

did u already fix ur problems or what?
#33348 - in reply to #5558
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Posted 8/12/2006 2:16 PM
petermerle
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Date registered: Apr 2006
Location: Cape Town ( deep south )
Vehicle(s): W460 *1, W123 *2, W124
Posts: 1315
1000
Re: OM617 Engine issues

Left it - the vehicle still goes well - I don't think it will leave me stranded!.
PEter
#37876 - in reply to #33348
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Posted 8/12/2006 11:53 PM
BenzDieselTuner

Date registered: Dec 1899
Location:
Vehicle(s):
Re: OM617 Engine issues

good luck!
#37946 - in reply to #5558
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Posted 1/1/2007 1:08 PM
petermerle
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Date registered: Apr 2006
Location: Cape Town ( deep south )
Vehicle(s): W460 *1, W123 *2, W124
Posts: 1315
1000
Re: OM617 Engine issues

Have now eventually taken engine apart and have found a crack between inlet and exhaust valves on #1 with lots of pitting on piston 1 and 2 . I suspect there is a crack on #2 exhaust valve seat but its not that clear. Can thes ecracks be repaired sucessfully?
Peter
#58114 - in reply to #5558
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Posted 1/1/2007 11:45 PM
hipine



Date registered: Jul 2006
Location: US, CO, Bailey
Vehicle(s): 460 1980 280GE w. 617A
5000
Re: OM617 Engine issues

Do you have factory repair mauals, Peter?  Any help there on what kinds of cracks might be normal or permissible?  My friend was freaking out over the same kinds of cracks in his VW Tdi head until he took it to a factory repair station and they showed him the factory specs of how many cracks and how wide a gap in the cracks was considered normal.

I'll try and remember to check my 617A manual tomorrow and see if it says anything about permissible cracks.  Maybe ask AMZ.  I know he's had his apart for head work before.

JMO, but I'd suspect leaks between valve and seat for causing low compression more so than small cracks in the head.  But further investigation is warranted.

I wonder if an inquiry to Metric Motors would yield any results.  You could indicate to them that you're thinking of sending your head in for refurbishment and were wondering if the cracks you see would make it unfit for same.  Just a thought.  Maybe ask them what rules they use to disqualify a head based on cracks.

And if the cracks are really the culprit, I wouldn't try to repair it.  Good refurbished ones are still easy enough to get that it's not worth trying to weld it and risking another, maybe worse, failure later if the weld comes out.  Also JMO.  I think the full rebuilt head with new valves, springs, guides, seats, etc is like $850 US from Metric.  Expensive, but not prohibitively so. (I know you'd then have to get it to ZA, but the price is just for comparo)

All the best,

-Dave G.

#58143 - in reply to #58114
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Posted 1/2/2007 1:49 AM
petermerle
Expert




Date registered: Apr 2006
Location: Cape Town ( deep south )
Vehicle(s): W460 *1, W123 *2, W124
Posts: 1315
1000
Re: OM617 Engine issues

I have the manuals and there is no description of allowable cracks. It is a serious problem as 2 cylinders are seriously pitted indicating water is getting into combustion chambers . Used heads are difficult to come buy here and they also are likely to have damage to them. A new head costs arround $1400.
Thanks
PEter
#58145 - in reply to #5558
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Posted 1/2/2007 10:19 PM
hipine



Date registered: Jul 2006
Location: US, CO, Bailey
Vehicle(s): 460 1980 280GE w. 617A
5000
Re: OM617 Engine issues

I have a head on the motor from the parts truck (300GD) I bought.  I haven't had the head off, but I don't havea  use for it.  What do you know about shipping here to there?  Do you think it would be worth it?  Since new fully re-furbished heads for these are $850 here, and "cores" about $250, I'd probably go $500 for this one if you want it and it turns out to be good.  Look into shipping if you like and see if you want me to pull it and send some pix.  If you'd rather have the whole long block (incl pump), that's available too, say $1000 US.

Of course AMZ is trying to get me to travel to ZA this year....maybe I can pack a 617 in the luggage, eh? 

-Dave G.

#58274 - in reply to #58145
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Posted 1/8/2007 3:32 PM
c250d

Date registered: Dec 1899
Location:
Vehicle(s):
Re: OM617 Engine issues

would this help? http://cgi.ebay.co.uk/mercedes-80s-G-wagon-diesel-engine-4-speed-ge...
says he can put it on a pallet, hopei have the right type of engine as it didnt give much detail.
#58802 - in reply to #5558
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Posted 2/17/2007 1:42 AM
Boy G
Expert


Date registered: Feb 2007
Location: Bushveld, South Africa
Vehicle(s): Diesel G's: 617A and 602
Posts: 1683
1000
Re: OM617 Engine issues

Peter,

If you are still looking for a head try Majestic Motors in Pretoria. If they havent got one they have another company next door called Partfinders and I'm sure they'll track one down. If you need help shipping to CT give me a shout.

I have an old head cracked between 4 and 5. Perhaps you can saw yours off and glue my good part............

OK don't.


Thanxanrgds
#64122 - in reply to #5558
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Posted 2/18/2007 2:34 PM
petermerle
Expert




Date registered: Apr 2006
Location: Cape Town ( deep south )
Vehicle(s): W460 *1, W123 *2, W124
Posts: 1315
1000
Re: OM617 Engine issues

Boy G
Thanks I might give them a call - I did manage to get a replacement head but am considering a complete spare engine for my 2 G's and W123.
Cheers
PEter
#64261 - in reply to #64122
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