adjusting valves
 

i plan to adjust the valves on my 300sd but i dont have the money to buy the special wrenches.:mad: so, i was wondering if i can just use regular and stubby wrenches from harbor freight. also can anyone tell me what i need to adjust the intake and exaust too. is this job hard to do? i think mine really needs to be adjusted because it has a rough idle for at least 5min of running when cold. my gp are good and i have good compression. would the valves couse this? any info would be appreciated.

yes
 

valves can cause rough idle. Use the search feature to get the info you are needing. Type in "adjusting valves" or something like that and you should get PLENTY of info.

Kevin

Dear kmaysob:

1) Make sure your engine is cold, by leaving it overnight.

2) For your 300SD, intake lash = 0.10 mm and exhaust lash = 0.35 mm.

3) You can just use 2 regular 14 mm open end wrenches to adjust your valve lashes. It may take a little longer than using the proper bent wrenches. If this is the first time you try to do any valve adjustments on these MB diesels, it should take you less than 1 hour to adjust all 10 valve lashes (5 intake + 5 exhaust) using regular wrenches.

4) You can use a 22 mm wrench or socket to rotate the power steering bolt CLOCKWISE to move the valves into positions for adjustment. You can also use a 27 mm socket to rotate the crankshaft bolt CLOCKWISE.

5) Be sure to replace the valve cover gasket after adjustment, otherwise it will leak oil soon.


Eric

There has been lots of debate as to whether or not you may rotate your valves by bumping the starter. I finally tried it after 4 or 5 previous valve jobs. Wow is that easier and seems less stressful than wailing on the PS bolt or even the crank bolt.

In cold days up here there is simply no way our engines will fire without being glo-ed anyway.

I just bent and ground (the heads thinner) on two cheap 14mm wrenches. I actually prefer them to the bulkier 'correct' wrenches that a buddy has.

.10 and .35 is correct

I do believe you'll see a difference after a few hundred miles.

Don

On my 83 300d there is a relay on the passenger fender for bumping starter. Makes the job easier. Then fine tune with p/s bolt to bring the lob to the top. Keep track of valves adjusted by marking head with chalk or felt tip pin. It also helps to have diagram of valve layout, intakes and exhausts so you don't get confused. Also I believe you hold the top nut firm when get the proper lash then tighten bottom nut then recheck lash. They are kind of touchy. You will see what I mean. But a little loose is better than a little tight, as they will tighten on there own with mileage.

adjusting my valves
 

do i need a special feeler guage or can i use one from autozone>

It does not need to be exact, so Autozone feelers are fine. I use .10, then make sure a .15 won't fit, and .35 and .40. Make sure to check it a second time after tightening up, because until you get the hang of it you may find that you've thrown off the gap that you just set. Finally, make sure you tighten them up snugly.

I just adjusted my valves. I used two 9/16" open wrenches, one being a stubby. I didn't need to grind down anything. The job gets easier after the first valve. Since I removed the injectors, I used the CAMSHAFT to rotate the valves. No problems in that, except that I have bent some of linkage in replacing the valve cover. I just found a picture of the correct linkages at this site, which is helpful. I found that ALL of the valves where tighter than specs. As soon as I complete re-connecting the linkages I will test drive.

I removed all of the fuel injectors, several of which were loose enough to loosen when I removed the fuel line fittings. No need to do that in your case. I was just curious. I DID also remove the fuel return hoses in order to remove the injectors.

Good luck on yours.

Jeff72_220d

You are asking for trouble using the cam bolt. :eek: Use the steering pump, much safer

I've always reused my V/C gasket with some sealer and it's never leaked.
A few words of advice as noted in the CD manual:

If you have ever had trouble getting the tapered pulley off the steering pump you will feel strongly that the Crank Bolt is the correct place to rotate the engine.

I was aware that the instructions specified using the crankshaft bolt, but it looks difficult to get to, given that it's on the botton, so that access would need to be from below. Once I removed the injectors it was easy to rotate the engine from the camshaft bolt. I wouldn't have tried to rotate it with the injectors installed. Is there an easy way to get a socket onto the crank nut?

Just pop underneath and turn the crank bolt w/ your ratchet - takes a 27mm deep set. Or, you can remove the fan, put a cheater bar on your ratchet as an extension, and do from the top. I would think either one would be safer for your vehicle than using the cam bolt, and less work than removing the injector lines.