WHATS WRONG WITH MY MERCEDES?

New in 2010! After years of receiving email and forum requests for tech help, the problems most customers have and the questions they ask start to follow a very predictable pattern. So to better help you find out what is wrong with your Mercedes and what parts you need to fix it we are launching a new WHATS WRONG section on our website. Each category will list the common problems, what steps need to be taken to fix them and links to the parts and instructions needed to tackle the repairs. Where applicable you will be directed to one of Kents kits or manuals for help in diagnosing your problem. We know that isolating the problem can be more frustrating than fixing it!!!

Categories are listed below. Please note some are currently under construction. The ones highlighted in blue are finished and you can click on the title to go directly to it. We will be expanding this list in the future. Please email us if you have suggestions or comments that can add to or improve this help section.

GENERAL MERCEDES HELP

• I want to buy an older diesel. What is the best model?  Which models should I avoid?
• I just acquired this old diesel. Love the car and want to repair it myself. Where should I start?

DIESEL ENGINE HELP

• My diesel is not running very well. Where should I start?
• I want top performance and mpg. What do you recommend?
• Not sure if my turbocharger is working as well as it should. What do you recommend?
• I have a later model 60x diesel. Where do I start?
• My diesel wont crank over - Whats wrong?
• How do I quickly find parts to fix a number of engine problems?
• I cant figure out whats wrong with my glow plug system. How do I test?
• What are Kents top recommendations for fixing common problems?
• I am swapping my engine out. What should I replace before I put the replacement engine in?
• What do you think is causing the knocking noise in my engine?
• My exhaust system rattles a lot. What do I do to fix it?
• I need to replace my starter motor. How hard is this to do?
• I am running vegetable oil in my diesel. What long term maintenance do I need to be concerned with?
• I am having problems with my vacuum door locks and shutoff in my 123 - Do you have a kit to help me repair this on my own?

GAS ENGINE HELP

• My gas engine won't crank over. Where do I start?
• My 102 103 104 gas engine doesn't start easily. Whats wrong?
• What can I do to make my gas engine run smoother?
• My exhaust system rattles a lot. What do I do to fix it?

 TRANSMISSION HELP

• How can I tell if my transmission needs replacing?
• I am having a hard time diagnosing my transmission trouble. Can you help?
  
• What are those funny little white vacuum valves for on my valve cover? Are they important?
• Sometimes my shifter pops out of park. What is it is loose and rattling?
• I need to remove and replace my transmission. How hard is it?
• My 4-speed manual shifter is binding up. What do you think is wrong? (Member access only)
• Diagnosing, Adjusting and Fine Tuning Mercedes Automatic Transmissions - where do I start?

 BODY AND TRIM HELP

• My sunroof does not work properly - Whats wrong?
• How do I dress up my 123s front end?
• I am dealing with body rust. How can I affordable and permanently repair it?
• Can you help me to figure out what my cars chassis number is?

INTERIOR HELP

• Whats wrong with my front seats? Is there a cheap fix?
• I cant figure out how to get my door panel off. Can you help?
• My car leaks water - under construction

ELECTRICAL HELP

• My key wont turn in the ignition. Whats wrong? Should I worry about it? How easy is it to fix?
• How do I fix my late model 123 center dash console lights?
• My battery won't hold a charge. What should I check? 
• Can you help me fix my instrument dash lights?

CLIMATE CONTROL HELP

• Is there an alternative to a $600 fix of my early automatic climate control (1977 to 1980 models)?
• How can I get my later climate control to hold steady heat?
• Whats wrong with my heater motor? Sometimes goes on and off.

SUSPENSION HELP

• My rear end clunks when I drive over rough ground. How can I fix it?
• Whats Wrong with My Wagons Self Leveling Suspension (SLS )? Is it Worth Fixing?
• Troubleshooting 123 Chassis Front Suspension and Parts Breakdown
• Troubleshooting 126 Chassis Front Suspension and Parts Breakdown
• Restortion Article: 1982 123 Chassis 300D Suspension and Final Drive Repair
• What is making my exhaust system rattle?
  

FINAL DRIVE HELP

• I have multiple rear end problems. How can you help?
• I hear clunking noises in the rear end - Whats wrong?
• My mechanic wants a fortune for 123 rear axles. Are there any alternatives?
• My axle boots are leaking. Do I have to replace the whole axle?

BRAKE SYSTEM HELP

• How do I isolate and repair brake problems myself?
• What is the best way to bleed air out of my brake lines?

RESTORATION ARTICLES: How does Kent approach major repair and restoration challenges

• 1983 300D Sedan
• 1978 450SEL 6.9
• 1966 230
• 1987 300SDL