Valve adjustment
Valve adjustment
Here is a handy graphic to print and use while adjusting.
Tips:
Valve lash should be adjusted every year or 12-14,000 miles.
The feeler gauge should have a just hair of resistance at the correct clearance.
With a bit of practice, the third wrench is not needed at all.
Do not rush. Rushing leads to things like forgetting to tighten a valve nut or using the wrong lash clearance. The first time will probably take 2-3 hours and USE the printout to mark off when you finish a valve.
Its much better to set the lash a little loose rather than tight if you just can't get it exactly right.
The gasket can be reused several times. I replaced mine after 7 years and at least 6 reuses.
If you buy your gasket at the local MB stealership, negotiate the price! I saved $6 on mine by quoting online prices.
NEVER use any kind of sealant on the cover gasket. Clean surfaces are all you should need.
Never close the hood after working on the engine without starting it at least once. Mine fired up to 5,000rpm today from a binding idle adjust cable!
An off-topic tip: Use synthetic oil, your engine will love it. The brand does not matter much.
This is what my engine looks like inside with 2,811 miles on 9qts of Mobil Delvac1 (~20,000miles total on full synthetic). I didn't clean or wipe off anything before taking these pictures (except the smudge on the 8th lobe).
ForcedInduction
02-03-2009, 01:35 PM
#1
For those needing it, here is the official guide to adjusting your valves: ValveLash05-210.pdf.zip
Here is a handy graphic to print and use while adjusting.
Tips:
Valve lash should be adjusted every year or 12-14,000 miles.
The feeler gauge should have a just hair of resistance at the correct clearance.
With a bit of practice, the third wrench is not needed at all.
Do not rush. Rushing leads to things like forgetting to tighten a valve nut or using the wrong lash clearance. The first time will probably take 2-3 hours and USE the printout to mark off when you finish a valve.
Its much better to set the lash a little loose rather than tight if you just can't get it exactly right.
The gasket can be reused several times. I replaced mine after 7 years and at least 6 reuses.
If you buy your gasket at the local MB stealership, negotiate the price! I saved $6 on mine by quoting online prices.
NEVER use any kind of sealant on the cover gasket. Clean surfaces are all you should need.
Never close the hood after working on the engine without starting it at least once. Mine fired up to 5,000rpm today from a binding idle adjust cable!
An off-topic tip: Use synthetic oil, your engine will love it. The brand does not matter much.
This is what my engine looks like inside with 2,811 miles on 9qts of Mobil Delvac1 (~20,000miles total on full synthetic). I didn't clean or wipe off anything before taking these pictures (except the smudge on the 8th lobe).
If the valve retainer spring turns you can use a wrench inserted between the cam tower and spring nut to keep it from turning.
I always double check lash and valve nuts after I am done. First time I did this I left a nut loose. Takes 5-10 minutes extra to double check it all.
Use a bump starter, failing that use two screw drivers to short the #1 and 3 terminals of the connector on the wheel well infront of the battery. For older and 240D you may need to bump start on the starter it self. This will save mucho time. Don't use the power steering bolt and doing it via crank bolt is PITA.
1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42
Pressure wash the engine first to help clear debris around the valve cover.
If the valve retainer spring turns you can use a wrench inserted between the cam tower and spring nut to keep it from turning.
I always double check lash and valve nuts after I am done. First time I did this I left a nut loose. Takes 5-10 minutes extra to double check it all.
Use a bump starter, failing that use two screw drivers to short the #1 and 3 terminals of the connector on the wheel well infront of the battery. For older and 240D you may need to bump start on the starter it self. This will save mucho time. Don't use the power steering bolt and doing it via crank bolt is PITA.
1987 300D Sturmmachine
1991 300D Nearly Perfect
1985 300D Weekend/Camping/Dog car
1974 L508D Motoroam Monarch "NightMare"
OBK #42
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