First time valve adjustment - Can't get nuts to turn - Page 3 - PeachParts Mercedes-Benz Forum

Junkman · #31 04-18-2016, 08:45 PM

Quote:

Originally Posted by Rogviler

Those stupid valve covers... One thing that helps is to really drop the valve cover with gasket onto the head a few times to seat the gasket. But, mine still leaks even after torquing properly and all that, so I'm going to be trying the mod where you file just a little off the valve cover where the stud holes are so it clamps more. Reportedly it'll never leak again.

Are you going to grind the valve cover only where it contacts the shoulders on the mounting stud? If so, what tool do you plan on using. Some have said to flatten the edge of the cover by grinding on sand paper mounted to a piece of flat glass. This would result in less clamping, not more.

I installed the seal dry but used a straight edge to make sure that the bottom of the gasket was flat before installing. The car has been down for front end refurb so it has very little mileage on the gasket but it wasn't leaking after idling for a 1/2 hr and going on a short test drive.

People have surmised that the gasket has changed but that seems strange since they'd have to make new tooling. If going to the trouble of changing tooling, a better strategy would have been to make the gasket thicker so that it works.

leathermang · #32 04-18-2016, 10:27 PM

Quote:

Originally Posted by Ceristimo

@Leathermang

Allow me to open up a big can of worms here, but where exactly does the factory manual say you can't use the power steering nut? On one hand are the folks that say you can use the power steering nut just fine, on the other hand are the folks that say it's strictly forbidden... I understand the reason for not wanting to use the power steering nut, that makes total sense. However, looking at the FSM I see a warning about the camshaft sprocket, but the power steering nut isn't mentioned?

This is not to start some kind of a flame war so don't take it as such; I am genuinely interested.

Following the valve-adjustment how-to on DieselGiant, I did use the power steering nut, and I found I can rotate the engine easily and without using all that much force using the power steering pump.

NOT using the power steering nut is in one of the ' warning boxes' in the FSM....
Diesel Giant knows a lot more about these engines than the Mercedes Factory... so it is just fine to follow his directions instead of what the FSM says to use to turn the engine... the nut on the front of the Crankshaft.
You won't know if you have messed up unless and until you need to remove the pulley from the power steering pump shaft.

Rogviler · #33 04-18-2016, 11:09 PM

Quote:

Originally Posted by Junkman

Are you going to grind the valve cover only where it contacts the shoulders on the mounting stud? If so, what tool do you plan on using.

Yes, that's exactly right. The tool would be a file, I'm assuming. As I understand it, you only need to take off like 1/32". Basically that will let the valve cover come ever so slightly closer to the head before hitting the studs, thus clamping the gasket tighter. Shouldn't take much.

I have no theory as to why it would need to be done, other than the cover itself just getting worn out or warped over the many intervening removals and replacements, so I have no basis to carry on a three-page debate about it. I will definitely know whether or not it works, however. Mine's a gusher at the moment.

-Rog

Clemson88 · #34 04-18-2016, 11:47 PM

I imagine the aluminum is twisting from decades of heat. Evidently the bolts prevent the movement in their general location.

Ceristimo · #35 04-19-2016, 12:39 AM

@Leathermang
Well, I can just feel your sarcasm oozing out of my laptop screen, but thanks for the comment and for clearing up where in the FSM it says that.

In other news;
The valve cover leak was indeed due to a vacuum hose pinched in between at the rear of the engine. Can't believe I didn't notice that yesterday. Anyway, that has been fixed, and I put the 4 nuts on hand tight + a quarter turn, and nothing seems to leak currently.

The fuel leak got fixed too, but I had to crank down on the 24mm nut pretty hard to get it to stop leaking when revving the engine high. I don't think that's correct, I thought the filter should be hand tight. For now it's fixed, but I think I'm going to get a copper crush ring at the auto-part store and put that in between the bolt head and fuel filter housing, to see if that will make it better.

leathermang · #36 04-19-2016, 12:52 PM

Quote:

Originally Posted by Ceristimo

@Leathermang
Well, I can just feel your sarcasm oozing out of my laptop screen, but thanks for the comment and for clearing up where in the FSM it says that..

If you will access a FSM and read it you will realize that MB did not do a ' good job' of putting things where they 'might' be most helpful for cherry pickers..... They figured that if they posted the WARNING somewhere that ought to be sufficient...the same for me posting a Warning from the FSM... I do not memorize where they are.... I read the FSM and post a warning where I remember them..... . they were not set up for people who were going to ' cherry pick' information just for a particular repair job.

That warning may be in the section dealing with the power steering pump...it may be in general information ..... there are a huge number of warnings in the MB FSM... that you have to just read the thing to find and know.... or you can do a good job of using the search feature here on the forum and you will surely find me saying do not use that nut because the FSM says not to use it... Do you have your forum setting set to where you are not seeing people's signatures ? If so, then my signature is of no use to you.... and other people's attempt to share stuff goes unseen also...
If , for each of your projects, you simply start a thread and ask a question... then you will get all sorts of input .. some of which has been shown to be outside the norm.... but which has over the years been thoroughly discredited ...and those conversations are in the archives... but that is a lot of reading compared to just asking a question and seeing who accidentally shows up ( immediately ) and adds their view. If you do not think any advice could be bad enough to cause you lots of extra work and or money... then go with the flow.... but I am conservative and want everyone's time and money to be utilized as best as can be... which causes me to follow the FSM as close as I can and to share the warnings in it with others...

Here is the other side to this conversation.... if you just think about what exactly you are turning with that nut...and the fact that the FSM SAYS to use the crank end nut...... the entire engine... which has four inch pistons pushing against 20 plus compression ratio.... one of which should be in the compression stroke at any point in the job. So lets say you have almost no experience with machines....
That is what the FSM is for....and what a forum is for... which has to include searching the archives because some people only stop by once in a while..... but a good thread will be a really good thread.... lots of back and forth... with WARNINGS or RED FLAGS..... which you then need to use other sources and ask more questions to separate the wheat from the chaff.

funola · #37 04-19-2016, 01:38 PM

To check if the valve cover is warped or not, install w/o gasket. Measure gaps all around with feeler gauges and vernier caliper. Also measure gasket thickness. Measurements gathered will tell you if there is any warp-age and how much the gasket will be compressed. You can then decide if any machining is necessary to flatten valve cover or lessen the gap between valve cover and head to increase gasket clamping force.

funola · #38 04-19-2016, 01:49 PM

Regarding the cam shaft base circle, it's been verified by me as well as other members that it is a machined ground surface. cam lobe pointing at 10 o'clock, 12 o'clock, or 1 o'clock does not matter. The feeler gauge reading will be the same.

leathermang · #39 04-19-2016, 02:02 PM

Quote:

Originally Posted by funola

Regarding the cam machined ground surface. cam lobe pointing at 10 o'clock, 12 o'clock, or 1 o'clock does not matter. The feeler gauge reading will be the same.

Logically that leaves it up to YOU to explain why they specified in the Factory Shop Manual ( with a picture even ) the ONE O'clock position.
' It was verified by you' .... LOL.... there are different cams installed in our engines... you have not ' verified' it for each ' serial ' number of cams which might be in one of our cars....
Still .... do you think the Mercedes people were just ' messing ' with us... trying to make it harder to set the valves... by saying One O'clock instead of12 O'clock ?
You do not need to answer.... normal people understand what I am saying.

There is another way of looking at their instructions.... that they were not comfortable saying 11,12,or 1 o'clock because of liability concerns.....that they were not confident they were going to hold all those cams they sent out to your ' round base' assumption...and did not want anyone burning a valve by using accidentally faulty instructions.... thus ' the specified the One O'clock position'....

Clemson88 · #40 04-19-2016, 02:05 PM

Quote:

Originally Posted by funola

Regarding the cam shaft base circle, it's been verified by me as well as other members that it is a machined ground surface. cam lobe pointing at 10 o'clock, 12 o'clock, or 1 o'clock does not matter. The feeler gauge reading will be the same.

Aim small, miss small.

rocky raccoon · #41 04-19-2016, 02:23 PM

I am going to conduct the following experiment. On my next valve adjustment, probably toward end of summer, I am going to set cylinder one intake cam at "1 o'clock, adjust it, then adjust all other valves whose base circle appears on the valve. I will then rotate until the next cam is at "1 o'clock" and adjust the remaining valves.

Before buttoning up, I will rotate again and check clearances one cylinder at a time as per FSM. If there is a difference I will be amazed but in any case I will satisfy myself if not the rest of you.

If any of you want to do this before I get around to it feel free but please report to the rest of us.

BTW I intend, as always, to remove my glow plugs and rotate using the power steering pulley. Hang the danger.

leathermang · #42 04-19-2016, 02:28 PM

Rocky Raccoon, That will test the cam in your engine...
but that is not something one should use to suggest others take a chance on THEIR cam not being the same...
It still comes down to WHY the FSM would specify the one o'clock position.
Which none of you ever even try to answer....

Rogviler · #43 04-19-2016, 03:20 PM

So anyone could just test their own engine. Try each valve at 10-2:00 and then again at the "must be precise to .0001 of a degree" in the FSM. If it matches then they'll know they can use the easier way from then on. I don't get the big freakout. Nobody will die if your valve is ever so slightly off and needs to be done again.

Seems like if your cam is wildly un-circular or bent then you have other problems.

I've tested mine, and recall a post where several others did as well. Nobody reported a difference in measurement.

-Rog

leathermang · #44 04-19-2016, 03:36 PM

Quote:

Originally Posted by Rogviler

So anyone could just test their own engine. Try each valve at 10-2:00 and then again at the "must be precise to .0001 of a degree" in the FSM. If it matches then they'll know they can use the easier way from then on. I don't get the big freakout. Nobody will die if your valve is ever so slightly off and needs to be done again.

-Rog

WHOA !!!!! A wrongly set valve.... ie, too tight , can burn a valve within a few miles of running the engine...

HALF the cooling a valve gets comes from the time it is in GOOD CONTACT with the engine head.... that is why setting the valves correctly AND setting them according to a schedule based on miles as suggested in the FSM is SO IMPORTANT....

and again... someone being smart about the precision called for... who makes NO ATTEMPT to explain why the FSM puts a picture and calls for the one O'clock position to be used to set the valves....

Do you people understand that the Factory Shop Manual was written by the people WHO MADE YOUR CAR ? Why would you assume they did not know what they were talking about ?

Rogviler · #45 04-19-2016, 04:09 PM

Okie dokie. All I'm saying is each individual can (and should) test their own car if they want to know for sure. Otherwise they can stick to the FSM.

I maintain that if you have such problems with your camshaft that something will break if you set your valve clearance with the lobe at slightly off of the 1:00 position then you surely have worse problems to deal with.

Clearly there's a lot of emotion (and ellipses) here, and I can't compete with that. Everyone should take the available info and decide how they want to do things on their own car. Do it all at your own risk (including anything in the FSM). Or take it to the dealer.

-Rog