valve stem fell inside hole - PeachParts Mercedes-Benz Forum

lsmalley · #1 08-27-2011, 09:35 PM

anyway to get this out without removing the entire head?

benzme · #2 08-27-2011, 11:36 PM

Can you see the end of the stem down the hole? I seem to remember a post that said to stick compressed air in the spark plug hole and it might pop out. Or a small magnet on a rod. Unless it's dropped into the chamber...

lsmalley · #3 08-28-2011, 12:06 AM

I have the valve stem right at the base of the valve guide, need to know if once I am able to center it will the piston push it back up

Merkey · #4 08-28-2011, 12:56 AM

I did it once with a piece of coathanger wire with a small bend in the end inserted thru the plug hole... fish and lift!

duxthe1 · #5 08-28-2011, 01:05 AM

Probably not. It will be coming at enough of an angle to the piston that I'd expect it to bind, but give it a shot just be careful. If it is far enough in the guide you may be able to inch it up slowly using the piston as a moving stop keeping it from dropping back down. I like the magnet idea if you can procure one small enough to go through the guide

koplinhagen · #6 08-28-2011, 01:05 AM

Don't use the piston to push it up. If its not aligned, microns, you'll snap it and scar the head, bore, and piston head. Use a magnetic reach that can get in the hole or, use a probe through the spark plug hole. When changing valve seals, use a compressed air adapter, in the spark plug hole, fitted with a gauge and valve. These are pretty cheap at most auto parts stores. Do not exceed more than 3/4 compression rating of the engine cylinder, or you risk blowing the head gasket (at which point you might as well wait until you pull the heads, to do the valve seals) with the compressed air, this will hold the valve in place and allow you to change the seals with no problem. Make sure you lube the new seals with clean engine oil before installing. I just did this on my 500 SEL, and it works like a charm.
I hope this helps.

lsmalley · #7 08-28-2011, 02:02 AM

ok, guys I'm gonna have to take the head off....never before even dreamt of doing this so I will not sleep tonight because more than likely it will take hours and hours....please offer any help and advice. I will definitely take pictures and mark things. I know the timing will be key.

benzme · #8 08-28-2011, 04:26 AM

Don't despair. I haven't done it (yet) but there are countless threads here and Benzworld.com that will help big time. Take it easy and post along the way for the benefit of knuckle heads like me.

Good luck!

koplinhagen · #9 08-28-2011, 08:23 AM

When you pull the heads, just do as you say, mark and take pictures. Do not scrape the carbon buildup from the heads until you check your engine type, some engines were glass lined, and you'll kill the lining, then it's new heads. May as well lap the valves and plane the heads while in there, and check the cam bearings also. It sounds like a lot, but doing this now will save you a lot of headache, not to mention your new headgaskets, later.

mpolli · #10 08-28-2011, 03:36 PM

Can't you fish it up with a small wire through the spark plug hole? You can look in there with a bore scope. I have the Pro Vision 100 which is .4" diameter and I have looked into cyloinders with it. It is about 140 on Ebay. This one is only 1/4" and going pretty cheap

http://cgi.ebay.com/ebaymotors/Pro-Vision-618-Small-Diameter-18-Fiberoptic-Borescope-/260841509074?pt=Motors_Automotive_Tools&hash=item3cbb5d90d2

I also bought a video one at Harbor Freight for 80 but I think it is a little bigger diameter like .45" or .50" so it won't fit (even though they claim it will...) But I got that one for looking into walls not engines...

Don't take it apart, you can do it!!

Chas H · #11 08-28-2011, 04:41 PM

It can't be fished out wit a piece of wire because both the wire and the valve stem will not fit in the valve guide at the same time. There is a chance the tip of the valve stem is still in the valve guide. If it is a pencil magnet will/should/might pull the valve up through the guide. I have been in this situation and managed to retrieve the valve with a pencil magnet.

mpolli · #12 08-28-2011, 05:34 PM

I said wire through the spark plug hole. Magnet would help also provided the valve guide is non-magnetic (I don't know what they are made of).

lsmalley · #13 08-29-2011, 02:22 AM

Ok everyone...thank you all. I managed to finally get the valve stem out after about 20+ hours!! Number 1.....the damn stem is NOT magnetic!!

What I did was remove the exhaust headrs and bingo! I could see the stem right there through a large enough opening to fit a pair niced sized needle nose pliers and push it right up through the guide. Once I got it through the guide I had a friend rotate the crank to push the piston up so that it would not fall again. I was able to change out all 12 valve seals. I did not complete the reassembly yet however, but hopefully the rest is simple depending on what input you all have for me. 1.) Since we rotated the crank manually via 27mm socket, will that throw off the "timing" or anything??? 2.) There were 2 types of seals a larger one (Red) and a smaller one (Green) see pics below. My question is that when I took the oringinal ones off, I'll say brown (on the left) and black (on the right) see pic below, they looked identical except for the flat top (brown) and dome top (black). The dome top (black) was on the spark plug side, and the flat top (brown) was on the intake side so the way I put them on was I replaced all the dome top (black) ones with all the green ones and I replaced the flat top (brown ones) with all the red ones, does that sound about right? sorry for the confusion.