Well I pulled into work yesterday (after a 40 mile drive) and the car lost power. Poped the hood and hear what sounded like a really bad lifter.

Got the car home, pulled the plugs and did a compression test. Everything was 170psi except #4 which was 0psi. Pull the valve cover and found that the exhaust spring broken. Why? Stuck hydrolic lifter?

Anyone have a good procedure on how to change the spring?

I'll probably change the spring, the cup, and the hydralic lifter.

Anything else I should change.

Anyone recommend a valve spring compressor that works on the M103 engine?

Thanks.

First, I'd be concerned that there may be further damage. Since the valve spring closes the valve, the valve and piston may have come in contact.

Possibly the spring itself just failed. Hard to tell without replacing the broken spring and checking.

Does the valve move smoothly in the guide? That should indicate whether the stem is bent.

Fit a new spring and test compression again to see if the valve still seats correctly. If compression is good you should be OK.

If problems show in the checks above the head will have to be pulled.

Hope it's OK for you.

You need to remove the rocker arm bracket on that cylinder & then connect at least 90 PSI air supply to that cylinder with spark plug removed. For just 1 cylinder you can use a screw-down(over-head valve) type of compressor from a regular parts store.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

If you can use a generic compressor like the one described by Doc for one cylinder, could you not use it for all of them in order to change out valve stem seals?

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

I wonder this also because I am too cheap to pay someone to do the seals and I am too cheap to buy the 'good' tool.

Anybody?

__________________
-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/831799-post13.html
http://www.peachparts.com/shopforum/831807-post14.html

Marty:

Yes indeed. I can't see paying 200+ dollars for a tool I may use just one time. If it will work for a single cyl. repair, then why not all of them?

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"