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"Gretchen" my 1986 300E 286000 km+ (RIP) August 2015
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Discussion Starter #1
Ive been doing some serious thinking on the refurbishing of my cylinder head
and with the cost quite high, I figured that since the camshaft & rocker arms, etc have been updated since my 86 was produced what years have the updated camshaft, arms been installed.
Would the updated version fit my 86 without any serious modifications, that being the complete head assembly. And if modes are required what would that entail? Id like it to be a plug & play:)
What Ive been thinking is to find an auto at the junk yard with the updated version and have that head reworked, this way I have a rebuild head with the updated parts. An additional plus is that I can have the head rebuild & installed at less then $600 only additional cost is my time bringing to the machine shop and back if all this methodology works out.

By the way the compression & leak down tests came back satisfactory. Thanks in advance.
 

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1968 gto (sold) , 91 volvo 740, 89 $300TE, 89 560SEC
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Supposedly everything past March 1989 had the chilled cam/rockers. The 1989 to 1991 (I think) is a direct swap. I've seen a few in the pull-a-parts with "fresh" heads on them....

The m103 head may be a direct swap up to end of production. I know the 89-90 will swap. As far as later years, I'm sure someone will chime in shortly with a definitive answer.
 

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"Gretchen" my 1986 300E 286000 km+ (RIP) August 2015
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Discussion Starter #3
Thanks for the start of information, looking forward to fellow responders.
 

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W124
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Isn't combustion chamber shape different for some M103 vs others? I don't know for sure so hopefully someone with more knowledge can comment.
 

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W124 Moderator
86 190E 2.3L 16V, 2 95 320TE's, 02 S500
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"By the way the compression & leak down tests came back satisfactory. Thanks in advance."

If this is the case, why not go the route of just having the valve stem seals replaced? I know you've been chasing a solution to oil comsumption for some time. Since the compression/leak down test seem fine, go with the stem seals. Accomplished in a few hours vs the many hours and dollars involved with head removal, referb and replacement.

Jim
 

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2008 E350 4M, 2016 Audi Allroad, 2019 Audi Q5
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Remember the 2.6L head will not work as it uses slightly different flow to the 3L. It will "work", but who knows if you'll suffer power/fuel economy/emissions due to it -- so stick with 3L.

I'm with Jayare on this one...if your only issue is consumption, do the stem seals. It'll either cure it entirely and you won't burn a drop, or if the valve guides are very worn, you'll burn some, but much less. That was the case with my 260E. I was burning 1qt/500mi, and after VSS, .5qt/3k mi.
 

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"Gretchen" my 1986 300E 286000 km+ (RIP) August 2015
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1,092 Posts
Discussion Starter #7
"By the way the compression & leak down tests came back satisfactory. Thanks in advance."

If this is the case, why not go the route of just having the valve stem seals replaced? I know you've been chasing a solution to oil consumption for some time. Since the compression/leak down test seem fine, go with the stem seals. Accomplished in a few hours vs the many hours and dollars involved with head removal, referb and replacement.

Jim
You know you are correct, but I just seem to want to get this done and I can forget about it for a couple of decades or so. I think sometimes its frugality in the most grandiose way. Im sold :surrender:, its that stubbornness us G Men have. Thanks guys, but for my own edification and (others) I still am curious on the info requested to put into my MB Library, now all I need is cooler weather to do the job at task.

George
 

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1990 Mercedes Benz 300E
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1,336 Posts
When you pull the valve cover why not check for wear on the cam lobes first. If there is excessive wear then refresh the cam with the updated ones... if not, just drive it till it shows.

On an earlier head I would check to make sure the rocker cap bolts are not stripped. They are fine threaded into aluminum and I read somewhere that the earlier ones are sometimes known to strip @ higher mileages. If so, I would put proper Time-cert threads in for a more durable fastener. Apart from that, unless there was excessive wear on the camlobes I would leave well enough alone.
 
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