After doing a little bit of reading in my Chilton manual, I have decided to adjust the valves in my engine myself. I can definitely hear a knock in the No. 8 cylinder.
I am reaching you experts for advise and wonder what special tools I will need to perform this task.

You need:

- Feeler guages, preferably a metric set.
- A special crows foot that fits a 1/2 drive breaker bar.
- A 1/2" drive torque wrench (recommended).
- A 28mm (1 1/8") 1/2" drive socket.
- A 3" long 1/2" extension.
- A 1/2" drive breaker bar.
- A pair of needle nose pliers.
- A 10mm socket, w/suitable wrench.
- A 22mm flare wrench.
- The real manual (toss that haynes POS).
All but the crows foot & manual are available from sears. A good foreign autoparts store might have the crows foot. You can omit the torque wrench if you like, but if you have it, use it.

1. Pull the valve covers from the motor. Use the flare wrench to undo the vacuum line to the brake booster. Take care when undoing spark plug wires so as not to damage them or confuse which one is which.

2. Hand crank the motor through two revolutions, while doing so, keep an eye peeled for each valve as its cam comes up. When the cam lobe points away from the rocker, you can measure your clearance. The gauge should be able to pass under the lobe, but with some bite.

If the guage moves to freely, "loosen" the rocker stud a partial turn. If the guage can't move under the cam, "tighten" the stud. You are using a torque wrench for this, because if the torque required is LESS THAN 2mkp, the stud needs to be replaced (and/or the socket that it sits in).

If the stud bottoms out in the socket or is turned out far enough to expose the unthreaded section in its middle, then you will have to replace the thrust washer that the rocker rests on directly above the springs. MB supplies a host of sizes. They're cheap (and thankfully usually don't need replacing).

The needle nose pliers are on hand, should you need to remove the springs that retain the rockers. Sometimes they are in the way of the spanner. When you are done with a rocker, be sure to check the spring. You don't want it dislodged from the rocker's base.

When you're done, take the engine through another full revolution, just to make sure that you didn't screw something up and reassemble.

Be sure to remove the breaker bar and the socket from the motor before you use the starter. I took out a perfectly good radiator one day, because I got distracted and left the spanner in place.


Should you decide that the fan is in the way of hand cranking the motor and want to remove it, get yourself:

- A pair of 10mm 6-point combination wrenches.
Sears sells them for about 3$ each.

Use one as a hold-down, the other to undo the bolts. To undo the last bolt, you're going to retighten one as a hold down. It will loosen with hand strength. Be sure to put the bolts back immediately so you don't loose the pulley. And yes, you can run the engine this way, just don't idle it for an hour and overheat it.

-CTH

__________________
- cth350@gmail.com
http://www.111lakeside.com/

Charles ... Excellent description of the procedure. I would only add the "crows foot" is in fact a special tool that is mandatory. I tried the "Sears crow foot" and it just opened up the wrench and rounded the nut. The special "crows foot" will cost $60-75 but you need it.

__________________
Jim Villers
190SL, 230SL 5-speed, 95 E320 Wagon, 01 E320 Wagon, MGB, Boxster 'S', 190SL "Barn Find"

On this post.

I just got my new valve cover seals and planned to check the adjustment while in there. My local Tech, Franz is one great guy. I stopped by to talk to him about using a Craftsman 17mm crows foot, and he was kind enough to loan his "special" spanner, actually two, since he wasn't sure which adjustment set up I may have. One looks like a heavy duty crows foot, and the other looks a little heavier, but the bottom side is relieved. Both are HAZET tools, #329-3 and #329-4 respectively (both 17mm) one is for the old style and the other for a newer style. Guess I'll see which it takes this weekend.

Franz did tell me to hit the adjustment with a quick rap after setting it, then recheck the distance, just to be sure it didn't move.

This is why Franz gets the jobs I am unable to do, be it for lack of time or knowledge.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

Mustafe 36,
You will need the heavy duty wrenches to turn the rocker arm post. Don't waste money on regular crows foot. You'll break everyone you try.
You can get the same one your MB dealer will sell you from Baum Tools, Sarasota,FL.34277-5867; Ph. 1-800-848-6657
Part no for 17mm crows foot 915 589 00 01
Part no for 24mm crows foot 911 589 01 01
I don't remember which size your car uses, but I'm sure you know.
I don't believe they would ask any where near $60-$75 for any of these tools. Call them and check them out.
Bill Lewallen;Lexington,Ky. Home of Valvoline Oil..

Also available from: http://www.technictool.com/mercedes.htm
(about half way down this long page)

__________________
Jim Villers
190SL, 230SL 5-speed, 95 E320 Wagon, 01 E320 Wagon, MGB, Boxster 'S', 190SL "Barn Find"

Only took about an hour to adjust the valves (not counting disassembly/reassembly of valve covers and wiring). Most of that time was spent turning the crank. I would also suggest having a set of valve cover seals on hand before starting. Mine were very brittle and leaking.

I found 15 of 16 valves to be too tight. Several of the exhaust valves were tight enough to require three bites with the crows foot. I'm guessing the valves have not been adjusted for a very long time as a couple of lobes had been polished all the way around, but there was no scoring or discoloration.

I did find that I had to disconnect the fuel feed as well as the brake booster vacuum line to remove the left cover.

As for turning the crank, if your hands are too big to fit between the radiator and crank try this: 6 point socket, shorty extension and a breaker. Using your finger tips set the socket & extension on the crank bolt, then fit the breaker. You get about 1/4 revolution before reaching the tranny line. Now using a long screwdriver, separate the breaker from the extension and carefully pull the socket off the bolt, turn the socket 1 flat counter clockwise and reseat it. The breaker should now reset in the extension at about the 4 o'clock position. Takes for ever, but you shouldn't get any cuts or cruises to you hands from trying to squeeze them in there.

Now I'm gonna check the torque values for the valve covers and go finish. Just had to crow.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

Mike,
Here's how to turn your engine over when adjusting valves or doing any other work that requires turning the engine over. Find the bundle of wires coming from the starter. Slit open the plastic sheath for about an inch or two. Reach in and fish out the purple wire. This wire goes to the starter solinoid. Some of the newer cars have these wires in a junction box on the right inner fender. Skin back some of the insulation and splice in a short piece of wire. Touch the wire to the battery + pole. The engine will turn over. Make sure the transmission is in 'N' or'P' because you are by-passing all other switches. Mercedes has used this purple wire for the starter solinoid since at least 1960. I have three MBs and all have this wire soldered in. Comes in handy when adjusting valves, or if your neutral/safety fails, or shift linkage bushings wear out.
Bill Lewallen; Lexington,KY. Home of RDC Bearings..

besides the valve adjustment???

OK, got everything back together, car fired right off. Sounded good and idled smoother than ever. Decided to road test it and grab a cup. Soon as I pulled away it felt like the engine was running rough as it no longer glided glass smooth. Once up to speed and at a steady RPM the engine is smooth.

Took it through a couple full throttle accelerations while rolling and it didn't seem to have the pick-up it did before. It did accelerate nice, just didn't seem as fast though. On the plus side, under full throttle there wasn't the slightest hint of black smoke. Always before under full hard throttle there would be a bit of belching for a second or two.

Why the roughness?

I set the intakes to .004" and exhaust to .008" as per the plate on the radiator support. Checked the plugs while I was in there and they looked very good, slightly tan no carbon or oil residue. Nothing else tinkered with.

After returning home I checked that I didn't dislodge any of the injector leads, everything OK there. Listening with a screwdriver on each injector I can hear the intake valve closing on all cylinders except #6(unless I'm hearing something mechanical in the injector - bad injector?). Tomorrow's game plan - pull the covers and recheck all the valves.

Anything else I should do? I really don't want to tighten all the valves back the way they were just to get smooth running.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

Mike,
Do you think one of the rocker springs came off? I have seen the rocker arm come off its post. Does'nt seem to hurt anything, but sure will make them run rough.
Try the purple wire trick. You'll be glad you did. Saves time and busted knuckles.
Bill Lewallen;Lexington,Ky. Home of Jif Peanut Butter..

Now that you mention it...

I think it was on #6 that one of the springs moved outward (but can't remember whether intake or exhaust). I though I got it back in place, perhaps not. When I do a double check tomorrow, I will be sure to check those springs too.

I'll take a look for the purple wire too, sounds a whole lot better than wrenching the engine over.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

THE BIG car has been running really miserably latetly. Hesitates, runs very rough, just awful. Couple of Mercedes mechanics did few things to it and finally gave up. Well I am not. Today, while getting familiarized with my engine compartment, I noticed that the #8 spark plug wire was hanging out (loose) so I connected it back. Now the car run even worse.
One mechanic changed the distributar cap, trigger points (ouch!! I am really not sure they were needed), points, condenser, spark plugs, and fuel filter. I noticed that the way the spark plug wires going into the dstributor then into the plugs are in the right order (1 5 4 8 6 3 7 2).
Here is the big question and please excuse my ignorance. Is it possible that the mechanic sarted plugging the wires at the wrong location on the distributor? If he actually did this would it explain why the car is running so badly? Would it actually start at all?
How can I tell where the First wire going to spark plug no.1 would be on the distibutor? How would the car run if the firing sequence was changed?

Thank you and I apologize for my ignorance. I am really trying to learn about my car as much as I can.

THE BIG car has been running really miserably latetly. Hesitates, runs very rough, just awful. Couple of Mercedes mechanics did few things to it and finally gave up. Well I am not. Today, while getting familiarized with my engine compartment, I noticed that the #8 spark plug wire was hanging out (loose) so I connected it back. Now the car run even worse.
One mechanic changed the distributar cap, trigger points (ouch!! I am really not sure they were needed), points, condenser, spark plugs, and fuel filter. I noticed that the way the spark plug wires going into the dstributor then into the plugs are in the right order (1 5 4 8 6 3 7 2).
Here is the big question and please excuse my ignorance. Is it possible that the mechanic sarted plugging the wires at the wrong location on the distributor? If he actually did this would it explain why the car is running so badly? Would it actually start at all?
How can I tell where the First wire going to spark plug no.1 would be on the distibutor? How would the car run if the firing sequence was changed?

Thank you and I apologize for my ignorance. I am really trying to learn about my car as much as I can.

Mustafa,

To find #1, pull the cap off and look for a mark cut on the surface of the distributor. That's the #1 mark. If you hand crank the motor to the 0 TDC mark AND also check the mark on the cam tower(s) for alignment with the cam thrust washer, the rotor should also line up on the distributor. Remember guy, this forum exists for you to have questions and for us to answer them. So, don't sweat it.

Mike, as for the poor running condition, changing the valve clearance affects the valve timing. Recheck your igition timing, and also the idle settings. Over tight is not good. However, recheck, just in case that you over adjusted. The clearance, COLD of the intakes is 0.10mm. The exhaust is 0.20mm COLD. If you have to get it "close", go for 0.08 rather than 0.12. A little too tight is better than a little too loose. Also, ensure that the piss-tubes are oiling ALL the rockers, especially the rear ones. You don't want to have me sell you a spare pair of cams. When in doubt, clean the holes in the tubes. Do NOT remove the tubes from the cam towers w/o replacing the plastic clips that hold them in place. They don't suffer handling well after long exposure to heat.

-CTH

__________________
- cth350@gmail.com
http://www.111lakeside.com/

CTH,

I am still going to check the valves in the morning (adjustment and the rocker spring), well just because. After reading your post I must admit I did check the timing, what a b**** getting the light and my head in a good enough spot to see (could they hide the pointer any better?).

It looked like the timing might be 1-1.5 degrees retarded from spec. In retrospect I guess THAT could be the root of my roughness. I really did not expect the timing to change and didn't mention checking it earlier.

As far as the oil goes, all cam lobes were bathed in oil, so I am fairly certain the tubes are flowing freely.

I will also say now that the idle seemed to be slower than before. Not in a bad way, very smooth and low. In looking at one of my books, it says the idle screw is front center of the intake. At that location I see a large screw (near the cold start valve), I assume that is the screw they are talking about.

My feelers are in both inches and mm's, .004"=.102mm and .008"=.203mm. Should I leave it there or shoot for .003" and .007"?

To recap- tomorrow recheck adjustment, set ignition timing, check & set idle, I will of course, check here first thing in the AM.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.