yeah, man. i'd rather exhaust all possibilities before pulling the head.

you know, the previous owner had the head gasket replaced, apparently just within a few thousand miles ago---Says the car had NEVER smoked prior to that, but that the guy who did the head gasket (who wasn't known as really being a "mercedes" mechanic) work BOILED the head and she's smoked since.

i'm wondering if i'm to suppose that the guy either botched the gasket job, or whether he just didn't change the stem seals, or reused bad ones, or installed the ones in #5 poorly, or what.

i think i'll go ahead and reinstall prechambers/seals...any advice as to whether i should replace PC #5 with a new one? and how best to clean out the seal recess?

__________________
-lee
'83 300CDT (286k)

former proud owner of:
'85 mercedes euro 300TD
'80 mercedes 300TD
'77 mercedes 280e
'80 mercedes euro 250
'82 mercedes euro 250

Does your friend want to rent his PC lock ring tool?

__________________
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

A leak down test is more revealing.

well, compression results are in.

1. 340
2. 340
3. 260
4. 340
5. 410

so, obviously, concern is on #3 and #5.

#5: my guess is that there is so much oil entering this cylinder (whether it's from valves stems or rings) that it's sealing her up and effectively making all readings of #5 a WET test.

#3: the dry test was 260. a WET test of #3 gave a result of 290.

what would you do now if you were me? i know i should be doing a "leakdown" test, but, i can't find anyone who's described a way to do it that i feel i can go off, personally accomplish, and have a meaningful result. so, i put a new PC in the #5 cylinder, buttoned her up, and am driving around with the same behaviour.

does that result on the #3 cylinder mean big trouble that changes the plan, or should i just do the stem seals and continue ploddin' along?

__________________
-lee
'83 300CDT (286k)

former proud owner of:
'85 mercedes euro 300TD
'80 mercedes 300TD
'77 mercedes 280e
'80 mercedes euro 250
'82 mercedes euro 250

I'd put down #3 as 'problem not worth worrying about at the moment but may need to address in the future'. I'd still be thinking, what the hell is happening on #5. Is there a leak in the headgasket between an oil gallery and the cylinder? I don't know the pattern of the galleries to know if that's possible on that cylinder.

__________________
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

that brings up an interesting point:

could my problems on #5 be the result of a botched head-gasket job?

is that possible, considering that she smokes mostly on start-up and pulling away from stop-lights when cold? and considering she doesn't use coolant or have any oil mixed up in it?

OR

should i look elsewhere:
1. valve stem seals
2. oil control rings

__________________
-lee
'83 300CDT (286k)

former proud owner of:
'85 mercedes euro 300TD
'80 mercedes 300TD
'77 mercedes 280e
'80 mercedes euro 250
'82 mercedes euro 250

You know I'm finishing my 300sd right now ,and i had similar problem lots of smoke, compression 320 vs420 rest 4cyl. so i took head off ,and you know what was a problem--broken valve guide...when i took head off i had 2cm of oil in cyl.,i rebuild head ,put new guides ,new valve ... on that exhaust valve i lost clearance -that was my first discovery after that situation was worsening -more oil consumption ,loss of power,lots of blow by -my air filter was SOAKED in oil i could not believe it was because of the rings cause car has only 130,000 miles and compression on 4cyl. 420 , so it had to be something else , now its been 2 month and i hope im almost done , im re timing IP now.,
So check for the valve guides and stem seals , look closely at that cylinder exhaust and intake valve wit h very bright light if its broken you should see it ..
Good luck.