My '90 300sel is using around a quart per 500 miles, so I gather it is about time for the head to be rebuilt... I did stem seals to hold it over and have 20/50 in the sump. Does this seem high for oil use? (just want to verify)



Also, am I able to use all 103 heads on this motor? I have access to MANY early heads (pre-smog crap added) for around $20. Or will I need a '90+ head?



Thanks

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Yes. My M103 has not lost a single drop at all since I had my stem seals done.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

Well crap, guess it's to be expected at 255k.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Hey Hitman. Yeah, I'm familiar with that type oil usage. When just a baby, mine used oil on the highway when the revs were up. It used MUCH less around town. Seems there is so much oil pumped up to the head at high rpm's that it can't drain back quickly enough, and floods the area around the valve stem seals. At 255k, if it's on original valve guides, then just new seals may not help much; those valves are probably flopping around like bobble-dolls. Pop that baby off and see the local machine shop for a valve job.

I bet you could use an earlier head, but I certainly don't know for sure.
My car is not here today, so going from memory:
All the 103 engines in my engine manual had 9.2 compression.
I think all the sensor fittings are on the intake manifold, not the head flange? But I think the AIR pump actually pumps into passages in the head? So, that might be an issue.

DG

AH! That's right, the AIR system is the other difference. I yanked my setup off as the bearing on the pump was about shot.

I checked and the gasket, valves, etc were all the same between early and late. Next time I'm out in the yards I'll have a look at an early head close.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Don't know where the break between "early" and "late" is, but they are different. You will know when you go to bolt the cam gear on and find that the threads in the cam flange are smaller than the bolts that came off of the old cam and you then need to drill and tap while its on the engine, etc., etc.

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Hanno
'79 6.9 Sold (after 27 years of ownership)
'83 280SL, 5 spd.
'94 E320 Sdn. 5 spd conversion
'95 E320 sedan
'02 E320 Sdn.(on loan to mom!)
'87 300E (5 spd. conversion) Sold
'05 E500 Wagon

'89/90 MY... when EGR and AIR were added is what I would say.

Bolt the cam gear? I would still use the '90's cam...

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]