About a year ago I pulled the head off my '84 300D because there was a small seeping headgasket leak. Since I had the head off I figured why not do a valve job? There was 160K on the engine. I trusted a local shop to do the work in an effort to save money. Its a reputable shop and I have a good relationship with them as they supply machine services and parts for many of my other projects. They do lots of HD diesel work.

Previous to removing the head the engine used @1qt of oil every 2500-3000miles. Very respectable. After installing the "rebuilt" head the oil use increased to 1qt every 800 miles! I looked at every possible reason for this before concluding that the valve job had to be faulty in some way. I don't use the car much anymore and other projects came and went so it was a year before I got to revisit the head swap.

Last month I ordered a "new" head from Metric Motors in CA. www.mercedesengines.net I went for broke and got the works, complete head with new precombustion chambers. This cost THREE times the failed valve job tried previously.

Today I finished the installation of the new head. I picked away at the project over the past two weeks with family interruptions, etc. No particular issues, it all went pretty smoothly. Test drove the 300D and the engine is much quieter, good power, etc. Seems like its old self. Finally.

I inspected the old head and found considerable caked oil/soot in the exhaust ports actually leading in a ridge shape on the roof of the ports leading away from the valve guides. I disassembled the exhaust valves and found the problem, the guides were shot. I have contemplated confronting the shop owner over the issue and have decided against it. The service I get is simply too good to risk screwing it up as they also provide all my marine parts at distributor cost.... I will however probably not let them do any close tolerance machine work in the future. My best guess is the valve guides they installed were not the correct parts.

So why do I write about all of this? Hopefully someone else will learn from my mistake. It would seem that MB diesel machine work is better left to Mercedes experts. Hopefully Metric knows what they are doing..... I don't want to pull a head, again. RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

1984 300d Turbo 142,000
Have Order A New Head From Metric

why is the head of the SD more expensive than the D? I thought they were the same engine.

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'85 300D Cal 280,000 miles
'14 GLK 350 60000 miles

I pulled the head off the engine from my wrecked project car and sent it to a machine shop my indy, who worked at the dealership for 10-15 years, recommended. They seemed to know what they were doing. All the exhaust valve guides were replaced, which seems to be a common thing when doing work on these heads. It sure looks purdy. Now all I have to do is get a few odd gaskets, drop it in my donor body, completely overhaul the interior of said body , and she should be up and running!

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Seth

1984 300D 225K
1985 300D Donor body
1985 300D Turbo 165K. Totaled. Donor Engine. It runs!!!
1980 300SD 311K My New Baby.
1979 BMW 633csi 62K+++? Dead odo

I sent them an email, we will see what they say.
perhaps it's N/A / Turbo??
John

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

How much are you guys paying for this?

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

Rob, as you know, I went through the exact same scenario. I found a local shop that stated that they could easily rebuild the head. But, after I noticed that they referred to a general set of specifications and had no real experience with the 617, I decided that it was a mistake. I pulled the head from them and sent it to Metric (ate the $100. deposit). Metric got the head turned around in about six weeks and did a fantastic job. No issues with the workmanship or the installation. The engine has excellent power and no smoke whatsoever.

Oil consumption remains at 1 quart every 2.5K or so. The replacement head didn't affect this consumption level.

I'm convinced that the average machine shop is not well suited to work to the tolerances required for these engines.

A good analogy that I was told years ago is that the German's tolerances are the same as the plus or minus variations allowed on US engines.

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Doug

1987 300TD x 3
2005 E320CDI

German tolerances are good when it comes to engines, bad when it comes to social policy.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I catch a lot of flack for quoting the FSM to people... and telling some people " they are thinking about old American engines" ....
But until people look carefully at the FSM they are not prone to understanding the tighter fit of these engines compared to everything else they have dealt with...
Even a GREAT machine shop.. if not using the specs put out by Mercedes will not produce a worthy job on our old Diesels...

LOL!

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1989 300E 144K

Cylinder head-reconditioned, new valves, springs, guides, etc. = $820.00
Core deposit-core open, subject to inspection = $400.00
New pre-chambers, installed = $300.00
Head gasket set+valve cover+injector shields = $40.00
Freight-roundtrip discounted = $80.00

Total = $1640.00

I should get the $400.00 core refunded.
As they say, if you have to ask......

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

I think you are thinking SDL which has the 603 with the aluminum head. the SD and D both used the om617 no differences in the head. But the 300TDT with SLS uses a different head that has a casting for the SLS pump in it.

Just call them. I think the guy to ask for is Mike, he will be very helpful.

RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

Yep Metric seems like the best. My friend needs to yank the head on his 606 this summer to extract the glow plugs. Since it has oh probably 170kish on it now, he is just going to send it to Metric and let them go through it.

If I ever need any work done on mine Metric will get it. You 617 guys are lucky, a 603 head would have cost twice that!

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200