Adjusting valves on 617 ?
 

Hi.

I joined this forum last night after reading numerous posts here and one on particular caught my eye.
Somebody is about to do a valve adjustment today and as I began doing mine yesterday I came back to the forum to see if there were any updates.
Never mind the updates . . . I couldn't even find the original post.

I'm in need wisdom here too.

I've adjusted valves on a 4 cyl Honda overhead in an Accord and it was actually not hard at all but this engine's a bear. My Haynes guide says to turn the engine from the crankshaft with a ratchet but I can not get to the bolt inside the pulley and don't know what size it is. I also don't know how long an extension to use.
My thought was that I could perhaps turn the engine with the bolt at the end of the camshaft but I don't want to damage anything.
After I surmount this obstacle my next problem is which valves to adjust when the motor is in any given position. I read that the cam must face away from the valve spring but I am thinking that there should be more than one cylinder to adjust for each turn of the motor.
Hmmm.. I think I'm rambling too much here.
Sorry.
The upshot of all this I guess is that I'm hoping someone can direct me to a better explanation than offered by the Haynes.

PS> I am on my way to buy a 14mm that I will bend with my torch but I'm really wondering how I'm supposed to manipulate three wrenches at once. :)
I love the html features on this site.

I just bought the 1980 last week and I'm really excited about it so far but there's a lot of smoke for 195,000k.

Ramble, ramble, ramble . . .

thanks . .
jim.

Not sure which car you are talking about but you will need a 27 mm, 1/2" drive socket. This same socket is used to remove fuel injectors on these engines. Some cars you can get on the crank with the fan shroud in place and others you can't. If you remove the glow plugs you should be able to just turn it with the power steering bolt. Make sure you ONLY turn it in the direction that it normally goes (look at the fan - it should move in the direction to pull air through the radiator toward the motor). As far as the direction of the cam lobes just make sure that they are not in a position to be "opening" the valves. That is where you set the clearance.

Congrats. on the acquisition. If you will pick up a haynes manual, all will be clear. The diagram in the book help me a lot. It is a remarkably simple job. Just give yourself plenty of time so that you are not rushed at any point. As for turning the egine, I turn the power steering pulley with an adjustable wrench (plugs pulled). The 14mm wrench: I heated and bent one to 45 degrees (dropped in cold water to temper) and then ground off about half the thickness an the bent end. Works great.

Reply & Thanks
 

Thank you very much . . . to both posters.
On my way out to bend my newly purchased wrench.
Thanks for the tip on removing glow plugs. I didn't clue in to that but in retrospect, it's obvious. And yes, I think I'll try the PS pump pulley. It seems like it would be easier for me.



1982 300D 335,000km;
1980 300D 195,000km

Anon-E-Mouse,

I have done this a number of times, and have used a variety of means to rotate the engine. My driveway has a slight slope, so I park with the car facing downhill and put it in 4th gear. Then, when I need to move the engine, I pull it toward me while standing in front. I have also used the power steering pulley, but I have never gone through the trouble to remove the glow plugs unless I was changing them. Not a hard job, just cuts your hands up a little and takes time. If I can avoid taking something that works apart, well, the old "if it ain't broke, don't fix it" saying comes to mind. I have heard there is a chance the power steering pulley bearing can be damaged if you apply any forces that generate side loads or bending moments.

At any rate, you do not have to be worried about the exact position of the cams, the lobes just have to be pointing mostly away from the rocker arms. You have to pay attention to which valve is an exhaust and which is an intake, as the position changes from cylinder to cylinder. Look at the intake and exhaust manifolds to keep things straight. I do one cylinder at a time following the firing order on the valve cover. I know you can do more, but then you have to keep track of them.....

I have rarely used the wrench to hold the spring retaining part, and when I do, I find a postion where it is on and wedged in place so the direction I am turning the valve lash adjustment acorn nut and lock nut will not rotate the valve or spring.

I also usually rotate the engine a few more times and check things to make sure I was not too rushed, and that the gap stays stable.

Good luck, Jim

And again thanks.
Didn't get Jim Smith's post until I had already removed the glow plugs.
Now there's a vexing job. Did you know about the powerful electro magnet between the ignition pump and the block ? On four separate occasions it sucked the ratchet or wrench out of my hand and as for relinquishing the tools . . . only a coat hanger was able to extract them.
Next time I'll probably skip removing those plugs.
On the other hand, as I turned the engine with the power steering pulley nut ( 7/8" by the way) I had no fear of damaging the bearing as it turned smoothly and with little effort. Perhaps with the plugs in, the extra force needed might have caused problems.
All the exhaust gaps were good but the intakes were another story. All but one were significantly too tight. My number one cylinder was at .02mm and except for the number five the rest were at about .04mm.
I don't know wether the reduction in intake gaps could be what's causing all the smoking but it makes sense to me. I'm assuming it's having trouble breathing.
Here's a question.
Is the tendency over time for the gaps to reduce or increase in size.
If the tendency is for the gap to increase then I can assume the last person who gapped them screwed up. I do remember reading the answer somewhere but it escapes me now.
Anyways I'm back out to the driveway to put it all back together again and test drive it.
All going well the next task is going to be dealing with the flaring transmission and I notice there are several on the list who are knowledgable about this one.
Thanks all.
Jim.

1982 300D 335,000km;
1980 300D 195,000km

Jim,

The valves tend to get tight as the engine runs. They kind of pound their way out of the head over time, and that is why you need to adjust them. I would imagine a tight intake valve would shut early and open late, making it hard to get good compression values. I am not too sure this would cause oil burning but it would cause the fuel to be unburned under most operating conditions which would mean black sooty smoke. Sorry I was too late with the last post to do you much good. I have never had a problem with the power steering pump bearing, but I am careful not to put any adverse loads on the shaft and bearing when I use that method. Jim

Ya BA Da Ba Doo !
Done . . .!
Took it for a spin and an Italian tune up.
Got that engine Real hot !

It had a bit of trouble starting ( had to use the Quick Start which I don't like doing) and it smoked some on start up though it was dark by the time I finished and hard to make comparisons.

When I got back to my driveway I stuck my nose halfway up the exhaust and damned if I smelt anything at all. Not a trace of diesel or oil.
I'm starting to get optimistic about this car. I bought it last week from a dealer who advertised a 6 cyl Mercedes for $1,995. That's cheap where I live. It looked pretty good in the picture and when I phoned him he told me it only had 195k. He had absolutely no service records for it so I knew I was taking quite a chance but now that the engine seems to be OK I'm half way there.

Thanks Jim for explaining about the valve clearances. It makes sense to me now.

jim

Jim,

It must have been late last night when I answered your question about valves. The net effect, a poor pressure level in the cylinder when the Diesel is injected, will result, but not because the valves open late and close early. It is just the opposite, which means it opens early and closes late. Closing late is the reason you get poor compression as some of the compression stroke is completed with the valve open and you get no compression effect for that part of the stroke. Sorry, and Greg, if you read this you are going to have to excuse me again. I hope this is not habbit forming. Jim

Good to hear about the (now) lack of smoking. When JimSmith speaks, EF Hutton listens.

Maybe I do it all wrong, but I use a remote starter switch (homemade, but a good one can be bought for $20) to turn my cold engine. That way I don't have to pull glow plugs, ream the holes with my greasy reamer, and put the system back together wrong. My glow plugs have been in place 80,000 mi. I also did a I O I I O ... pattern on a 3 x 5 recipe card, with I = clearance O = clearance at the top. Punch a hole in the corner of the card, laminate the card, and place over the valve cover stud so I can see it. Wipe off and in the glove box when done.

I O I O I O ?

Sorry, you lost me there.
Clearance at the top ?

Starter switch sounds good and I guess there's no danger of it starting and spreading oil all over the place if you hold down the stop switch while you're cranking.

Thanks for the input.

When E F Hutton talks . . investors run for the hills.

jim

Jim,

I=intake, O=outlet or exhaust, valve. The pattern is the front to rear, or cylinder 1 through cylinder 5. If you look at the intake and exhaust manifolds, you will see they try to make them with two intakes together followed by two exhausts, except for the first and last cylinders as they cannot have two of the same kinds and function. For example, the last valve of cylinder 1 and the first valve of cylinder 2 will be the same, then the last valve of cylinder 2 and the first valve of cylinder 3 will be the same, and so on.

You measure the clearance between the rocker arm and the camshaft. I can scan some photos and sketches from the manual if you like. Jim

From Jim Smith . . .

"I=intake, O=outlet or exhaust, valve. The pattern is the front to rear, or cylinder 1 through cylinder 5."

Oh . . . ;->
I get it now.

And also . .

"You measure the clearance between the rocker arm and the camshaft. I can scan some photos and sketches from the manual if you like"

I actually found it easy to distinguish between intake and exhaust on my engine. Mine is not turboed and I had the air cleaner off for cleaning. I had an unobstructed view of the manifolds and of course they line up nicely with the rockers.
The Haynes also has a fairly good little diagram on the appropriate page.

I took it for another little spin today after starting it from cold.
Happily no problems starting this time and didn't need the Quick Start.
I didn't have time for a long drive but got the temperature high enough to tighten up the clearances.
Stuck my nose up the exhaust again and while not quite as sweet smelling as I had (imagined?) it last night; there was a tremendous improvement. As I said previously
"I'm starting to get optimistic about this car. "

jim

Cool it all worked out for you... A good and careful valve adjustment can be like a bolt on camshaft upgrade--you maximize valve lift and duration, optimizing gas flow in and out of the engine.

-Joe

I'm starting to feel insecure.

- Audi "FastTrack" graduate, Technician level
- Chrysler MasterTech training, Driveability Specialist
- Kia Certified Technician, 1998

Yikes ! The qualifications on this board are frightening.

Maybe on second thought that should be "secure" !

Thanks to all who helped with this one.

I'm about to tackle the "flaring tranny" and I've studied the other concurrent thread on that one pretty assiduously.

When I get into trouble I'll post a new one.

Jim