AUGH! Please help me with valve adjustment tips! = broken valve guide
 

Hi guys,

I'm having a HORRIBLE time adjusting the valves (well, ONE valve) on my buddy's 240D.

Here's the deal - using Diesel Giant's guide, I laid out all my tools (by the way, I've done this on many a gasser, I'm pretty familiar with the procedure).

Everything went very smoothly until the Exhaust Valve on Cylinder #2.

The clearance is REALLY tight- I can't even get the .3 mm feeler gauge in there (all the rest were tight too). I've tried backing off the lower adjusting nut by like 5-6 turns, and then I try and turn the top nut clockwise to open up the clearance. I hold the bottom nut while turning the top one clockwise. To my understanding, this should open the gap. I keep turning the top nut while holding the bottom one still, but no matter how much I turn it, I can't get .3 mm worth of gap on it.

No matter how many times I do this - Hold top nut still, turn bottom nut 5-6 turns, then hold bottom nut still, while turning top nut 5-6 turns clockwise, the gap just seems to be the same!

Augh! What am I doing wrong? The other valves seem to adjust just fine!

Sincerely,

PE

P.S. OK, Now that I came inside and calmed down and had a cold drink and I'm thinking about it, I think that I have a stubborn valve that spins while I am trying to turn the nuts. I don't have one of those fancy wrenches that hold the hex cap of the valve spring still. How can I get around this?

I determined that the stubborn valve that spins while I try to turn the nuts is indeed the case. I don't have a hex-cap valve spring wrench, so I hit the valve, spring and cap with some penetrating oil, and then used a needle nose vice grip to hold the hex cap still while I turned the adjustment nuts.

Not perfect, but it did the trick, enough to finish the job.

Both valves on cylinder #4 were similarly spinning. Hmm. Maybe I should have sprung for a hex-cap valve spring wrench.

Still, anybody have any tips for this that would keep from buying a hex-cap valve spring wrench?

Thanks,

PE

Indeed - there are three wrenches in the valve adjusting set => two for the lock nuts and one for the hex head cap that sits on top of the valve spring.

Someone mentioned to jam a screwdriver through the spring to keep it from turning. I had one do that one time, and it worked.

Here is the 3rd wrench on e-bay.


HAZET-NEW --MERCEDES -VALVE ADJUSTING WRENCH--30MM--# 2769-3 | eBay

charlie

Yes, if you are able to wedge a screw driver against a cam tower, go that route.

I always jam something against the spring retainer... I've never had an issue with it not working...

OK, thanks for the hints. If I understand this properly, you insert a screwdriver through the valve spring so that the spring holds the screwdriver and the screwdriver is braced against a valve tower so that it doesn't turn?

Anyone have a photo?

Sincerely,

PE

I gonna have to say this - I can't stop myself - I think it is fair to warn you and others that wedging foreign objects in the valve gear is potentially dangerous. I can't prove it - but I see no other way in which the so called Mercedes expert managed to break a valve guide on my engine but I guess it was done by not using the correct tools.

http://www.peachparts.com/shopforum/...alve-guide.jpg

So my warning is be careful if you decide to wedge stuff in there - I think the cost of 3 wrenches is cheaper and a lot less hassle than head off and off down to the machine shop if the worse case scenario "happens"...

WOW! That's horrible!

I think that a Hazet valve spring cap wrench is in my future...

Thanks,

PE

Thanks for the Pic Army, never thought it would/could/possibly do that.

That wrench I posted is $59, I have see them cheaper. this guy wants $59 for each one of the 3. :eek: that is pricy. there was a guy a few months back that had them for $20 each for the bent one`s.

I picked mine up a few years ago, along with 3 other MB tools for $58. was in the right place at the right time with that deal.

Charlie

Please note - the picture shows an end result of...


...well I don't know exactly what - I can only assume some monkey used the wrong tools and was too rough. How rough? I don't know. My suspicions do fit in quite well with other stuff I found on the car - including the rocker arm sets being installed incorrectly on the head - put the group of two over cylinders 4 and 5 and both of the shafts bow making the rocker arms run on their corners (not on the flat) on the cam surfaces...

Army, Isn`t it about your bedtime over there? :rolleyes: 8:25am here and the sun just got over the tree tops.

I remember that thread where you had all the fits about the rockers being wrong.

Charlie

Valve adjusting wrench
 

I found some cheap wrenches, $20.00

Hazet Valve Adjusting Wrench | eBay

$15.00

Hazet Valve Adjusting Wrench | eBay

$35.05

HAZET 2769 - 1 Valve Adjusting Wrench | eBay



Charlie

Hi Charlie,

Thank you, you're always very helpful.

I actually have the correct adjusting nut wrenches, that's not the problem.

The problem was that I had a stubborn valve where the valve kept turning when I was trying adjust the clearance. That's what the "Valve Spring Hex Cap Holding wrench" is for.

I haven't found anything else that is designed to address the problem I just described. Looks like they are around $50.

Sincerely,

PE

wow...
I must say, I do not WEDGE or PRY on anything I have jammed against the retainer... I merely set something in the path of the rotation that prevents the nut from loosening...
care is a must!