Frustration with W123 Valve Adjustment! - Page 2 - PeachParts Mercedes-Benz Forum

Graham · #16 05-10-2015, 11:15 AM

Quote:

Originally Posted by leathermang

You have been here since 2004 but trust DG ? Do you not remember him, as a seller of Duracool, promoting that with all sorts of misleading posts ?

Sorry to go off-subject, so will keep it short!

Duracool? That or equivalents are being used more and more here in Canada, because they are not subject to the crazy rules regarding flurocarbon refrigerants.

On my 300D, the A/C gave up for about the 3rd time several years ago. I asked our best local auto A/C shop what they would suggest. They said best bet for the old car was to use a HC refrigerant so that leaks, if they occurred, would not be subject to the "rules" and system would run at lower pressure than the R134a which is the only alternative here.

I understand the downside, so no need to go there

leathermang · #17 05-10-2015, 11:46 AM

Quote:

Originally Posted by Graham

Sorry to go off-subject, so will keep it short!

Duracool? That or equivalents are being used more and more here in Canada, because they are not subject to the crazy rules regarding flurocarbon refrigerants.

On my 300D, the A/C gave up for about the 3rd time several years ago. I asked our best local auto A/C shop what they would suggest. They said best bet for the old car was to use a HC refrigerant so that leaks, if they occurred, would not be subject to the "rules" and system would run at lower pressure than the R134a which is the only alternative here.

I understand the downside, so no need to go there

Thanks for being honest about why they are being used... NOT because they are the best refrigerant for your system... but to avoid the ' crazy rules' imposed by Canada....

For OTHERS......stop reading Graham.... since the differences are subtle... Duracool is a blend.. so any leak.... and your system HAS a DESIGNED IN leak to keep the AC compressor front seal LUBED.... leaks not as a unit... but the lighter smaller molecules leak first... so the MIX of several refrigerants immediately starts being something different... SO you can not just ' top off' as the refrigerant level goes down... a complete evacuation and refill is necessary...

Many times a shop will base ' best bet ' for suggestions on things like whether they have the machines to deal with something....

So R134a IS available for you to use while following the law... interesting..
In addition to the question of flammability which causes HC to be illegal in 19 states in the US....

The fact that your AC kept giving up... something not really investigated as to cause.... leaves a lot of questions open... which may not be being addressed by the refrigerant you are using...

for anyone with an R4 compressor.... OIL MISSIBILITY ... the ability of the particular oil IN THE SYSTEM ... to be carried around IN THE REFRIGERANT..... is very important because the R4 had NO OIL SUMP.. all the lube must be supplied by the refrigerant traveling around the system...

Stretch · #18 05-10-2015, 12:34 PM

Quote:

Originally Posted by Graham

.. It would be interesting to know what torque is needed on the PS nut to rotate the engine.

Quote:

Originally Posted by Graham

... Any idea what torque it takes to rotate engine against compression?

...

It depends on how worn the engine is and how quickly you are trying to fight the compression.

If you go slow and allow the air to escape I reckon - wild guess - the torque on an OM617 would be in excess of 40Nm. Try and do it faster then it feels (to me) like more.

The problem with fighting the compression for some jobs is that you overshoot your mark - which is why I reckon (for this type of thing) you are better off with no compression => more control

Graham · #19 05-10-2015, 01:00 PM

Quote:

Originally Posted by Stretch

It depends on how worn the engine is and how quickly you are trying to fight the compression.

If you go slow and allow the air to escape I reckon - wild guess - the torque on an OM617 would be in excess of 40Nm. Try and do it faster then it feels (to me) like more.

The problem with fighting the compression for some jobs is that you overshoot your mark - which is why I reckon (for this type of thing) you are better off with no compression => more control

If I had a fishing scale, I would go check the torque

But you are right, it hardly takes any force to fine tune the cam position using a ring spanner on the PS nut if you go slow, which of course is what you have to do. (after first jogging with starting motor)

leathermang · #20 05-10-2015, 01:20 PM

Here is the problem with some of you people....
while I can with the proper extensions and size ratchets turn the engine from ABOVE....
no one says that all cars can be done that way.... .
You may have to turn it FROM UNDER the car...... there IS room to do that on all our cars......
The MB FSM says turn the engine by the Crank Bolt.... if you later have problems because you did not follow instructions that will be your fault.

ROLLGUY · #21 05-10-2015, 07:21 PM

Quote:

Originally Posted by leathermang

The fact that your AC kept giving up... something not really investigated as to cause.... leaves a lot of questions open... which may not be being addressed by the refrigerant you are using...

for anyone with an R4 compressor.... OIL MISSIBILITY ... the ability of the particular oil IN THE SYSTEM ... to be carried around IN THE REFRIGERANT..... is very important because the R4 had NO OIL SUMP.. all the lube must be supplied by the refrigerant traveling around the system...

Not wanting to turn this into an A/C thread (maybe we have already gone down that "rabbit trail"?), this is another reason to go with a Sanden. Of course with any compressor change, the system should be flushed well! The R4 has a tendency to distribute it's innards throughout the system before failing.
As for turning the engine during a valve adjust, I tried the PS pulley once and went to the crank bolt instead. Been using the crank bolt since (many times). The only downside is having to get up off the ground several times.....Rich

funola · #22 05-10-2015, 07:43 PM

Why not do it the easy way with a remote starter. I've been using one before learning that it's one of the methods in the FSM. Turning the crankshaft is a miserable way of doing it. If you forget to take the ratchet off it can become infinitely more miserable.

leathermang · #23 05-10-2015, 07:51 PM

As this forum's Inventor in Residence ..... I was secretly anointed a while ago...
I would like to suggest this :
If you put the correct socket on the crank nut....
and use the correct length extension ... I have no test vehicle so you will have to determine this....
and put a ratchet on that assembly... nothing inventive yet....
then attach a broom stick extension on the end of the ratchet handle... so we are now at 90 degrees to the longitudinal center line of the car....
make this long enough to be under whatever hole is available from the top of the engine compartment..... it does not have to be 90 degrees to the ground....
then attach a joint from another broom stick to the end of the first one.... with a loose joint on it...
You now have a way to rotate the Crank Nut while standing up leaning over the fender and working on setting the valves or whatever..... Just by up and down movement of the wooden rod.
Want to get fancy.... put a bicycle handle on the top....
Note.... be sure you have set your ratchet to move the crank in the direction you want it to move... to avoid an unnecessary crawl back under the car.... something well worth avoiding....

and I totally agree with... if one is able.... upgrading to a modern compressor like the Sanden.....

leathermang · #24 05-10-2015, 07:54 PM

Quote:

Originally Posted by funola

Why not do it the easy way with a remote starter. I've been using one before learning that it's one of the methods in the FSM. Turning the crankshaft is a miserable way of doing it. If you forget to take the ratchet off it can become infinitely more miserable.

When you put the ratchet on the crank nut....
PUT A STICKY ON YOUR FOREHEAD.....
AND ON THE STEERING WHEEL OF THE CAR...

The remote starter does not give the ACCURACY that using the crank nut does....

Again you sound like the Mercedes people are just out to make your life ' miserable' with their instructions....

ROLLGUY · #25 05-10-2015, 08:06 PM

Quote:

Originally Posted by funola

Why not do it the easy way with a remote starter. I've been using one before learning that it's one of the methods in the FSM. Turning the crankshaft is a miserable way of doing it. If you forget to take the ratchet off it can become infinitely more miserable.

Although I have not done it this way, I can see how easy it would be to pass by the desired spot. I have done so many with the ratchet on the crank bolt, I know just about the amount it takes to get to the next cylinder without getting back on the ground. Also, not all of these cars have an easy way to hook up a remote starter switch. Only the later cars have the junction block on the wheelhouse, the earlier cars do not. Wait, don't you like the sound the ratchet makes when you forget to take it out and start the car?

vstech · #26 05-10-2015, 09:19 PM

I've never needed to be accurate setting the cam position... The base circle is large, I just adjust the valves that are not under the lobe... Hit the starter a sec, and adjust the rest.
Simple, and fast.
I used to recheck after finishing by checking the lobe up valves, but I've never found one not right...

mytmousemalibu · #27 05-10-2015, 10:53 PM

Same here, not only on every Mercedes that required valve adjustments but many, many other cars too. Literally hundreds of valve adjustment jobs over the years and bumping the starter over is by long and far, the fastest, easiest and simple way of going about it and not once had a problem doing so. Way easier than barring the engine over by hand. If you overshoot your mark, hit it again. You do not need to be perfectly accurate as long as the cylinder you want to adjust has the cam lobes on base circle and you have plenty of room either side of dead center. Like on my old SD for example, the little black plastic terminal enclosure next to the turbo has easy to access starter jump points right from under the hood while you watch the cam. No jacking around with wrenches, ratchets, pipes, jacks, and jackstands. Start to finish I could usually do an OM617 in about 15min on average.

Stretch · #28 05-11-2015, 04:57 AM

Oh you're all going to hell in a hand cart now! He's just gonna get more and more agitated...

leathermang · #29 05-11-2015, 07:24 AM

Quote:

Originally Posted by mytmousemalibu

........ bumping the starter over is by long and far, the fastest, easiest and simple way of going about it and not once had a problem doing so........ No jacking around with wrenches, ratchets, pipes, jacks, and jackstands. Start to finish I could usually do an OM617 in about 15min on average.

Clearly you have your priorities in place. Fast and Easy.

For regular folks , not superheroes like MightyMouse , engines often have a tendency , due to uneven resistance due to the compression stroke , to come to a stop at certain stages in the four stroke cycle... as others have mentioned... so getting the engine turned to a specific point is not as easy as having an accurate timing finger on the alternate starter button. I have used them on cars for decades..... tried it on my wagon valve settings and decided the slow and safe method felt better.

I have seen long time mechanics put the wrong feeler gauge to a valve... it is easy to do...and it is a good idea to mark the valves before starting ....as many in the archives have suggested with methods included....

HERE IS WHY CAREFUL ACCURATE SETTING IS IMPORTANT.

Half the cooling a valve needs comes from contact with the head. Conduction from metal being in good contact with other metal.

This cooling is what keeps the valve from BURNING.....
If you do not do an ACCURATE job of setting the valve lash... which is the extra space allowed on a cold engine setting so that the working HOT valve... when expanded in LENGTH.... is STILL in GOOD contact with the HEAD.....

The ONLY way to fix a Burned Valve... .is to TAKE THE HEAD OFF THE ENGINE..... and do a valve job...... Expensive is the word which comes to mind.... and certainly not Fast or Easy.....

So while you see posts of ' fifteen minutes total '.... which you have no way of judging the quality of the work performed in that time....

IS IT WORTH THE CHANCE OF A BURNED VALVE TO SAVE THAT TIME ????
It is YOUR CAR... YOUR TIME..... YOUR RISK.... totally up to YOU....

I do not care one way or another what you do with your car... I only care that potentially misleading posts are balanced by some of the logical bigger picture views so often left out of the discussion.

As to the ' big base ' on the camshaft method.... again.. the FSM shows the position of the top of the lob at about one oclock.... why so many chaff at being given Explicit Directions for important procedures by the Makers of the Automobile they own..... and brag on.... and seek short cuts.... I do not know. If you carefully follow the instructions in the FSM a regular mechanic can do a legit valve setting on these engines.

Graham · #30 05-11-2015, 09:18 AM

Quote:

Originally Posted by Stretch

Oh you're all going to hell in a hand cart now! He's just gonna get more and more agitated...

Once again you were right on the money