will replace valve seal , need help

[erickmarciano]

Hi will replace my valve seals soon but have a few questions before I start

1-when I replace the valve seals with head in place : I was told by an experienced mercedes mechanic that if I see a louse valve guide , I can epoxy it in place, so I don't have to remove the head?is this true?

thanks
Erick

1971 280sl
1962 VW
1954 Allstate vespa
1958 gs150 vespa
1962 gs160 vespa

[ja17]

Hello Erick,
This may be an emergency fix but it is in no way a lasting repair. Originally the valves are precisely ground and seated after the valve guides are secure and in place. You may be able to secure the guide with epoxy but you have no way of getting the valve to seat properly.
Keep us up to date!


Joe Alexander
Blacklick, Ohio

[JimVillers]

Erick .... You can replace the valve seal with the head in place but not the guide.  It is tricky.  Put the piston at top dead center so nothing will drop too far.  Pressureize the cylinder with compressed air to hold the valve against the seat.  Cover the top of the valve spring with a socket, tap it with a hammer to break the keeper loose then compress the spring, remove the keeper and spring.  Install a new seal and reassemble.  The compressed air is the key.

Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor

[erickmarciano]

thanks guys ,
I am asking in case I have a bad valve guide , if the engine runs great no bad noise , and I only get a puff of smoke sometimes at startup . also when in heavy hot trafic when I start moving but clears up after 2 hit of the gas pedal . can I asume my guides are ok?and my compresion is 160 160 160 160 140 160

1971 280sl
1962 VW
1954 Allstate vespa
1958 gs150 vespa
1962 gs160 vespa

[JimVillers]

Erick .... Sounds like it is the valve seal.  This is the oil seal for the valve shaft.  When idling for a few minutes, you will get a puff of smoke.  You will also get a little smoke when decelerating.  It doesn't heart anything; it is just annoying to have a good engine smoke.

Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor

[Benz Dr.]

Your mechanic is an idiot. Tell him I said so.

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org

[erickmarciano]

would I feel by driving it that the valve guides are bad?Noise ...etc

1971 280sl
1962 VW
1954 Allstate vespa
1958 gs150 vespa
1962 gs160 vespa

[ja17]

Hello Erick,
First, try to determine the history of your engine. If it is over 100,000 miles and smoking you may wish to do the head reconditioning as a preventative measure. Most likely you will maintain the car  better than the previous owner you should get many, many years of good use afterward.

If you are not sure about the history or the head has been reconditioned once already you may want to just try valve seals. There is a slim chance it may solve the problem or make it better.

You may not have any obvious signs of valve guide wear except for the smoke. Low compression or excessive oil consumption may be a symptom.

Replacing the valve seals is a bit of work for the amatuer with obvious dangers and pitfalls. Occassionally it will solve the problem or help it temporarily. If a valve seal has come loose you can view it resting higher than it's neighbors. Take a "torch" (flashlight) and view the seals inside the valve springs (make sure the cam lobe is upward.

Joe Alexander
Blacklick, Ohio