Coolant replacement interval
Q: Got a question for you regarding my 2003 SLK320. That car was one of the first generation to have a 15-year/150,000-mile coolant interval. Since the car only now has 37,000 miles, I decided to let it go to the 15-year interval. So far so good, but I’m coming to the time when I need to change it. There is a silica gel packet in the overflow reservoir that degrades over time, thus allowing such a long interval. It seems that after 15 years, there is still some inhibitor left in the gel pack and that changing out just the fluid will give me another 15 years. Do you have any advice from Mercedes on whether a routine coolant change will give me another 15 years or is there a way to test the contents of the gel pack and/or replace it?
A: The interval is as you stated. Only the coolant is changed, not the gel pack. My dealer technician is not aware of gel packs for sale from Mercedes-Benz Parts. Leave the gel pack with the residual inhibitor in the coolant reservoir and have the coolant flush done. This may not give you a full 15 years, but by using the Mercedes-Benz brand coolant, you should be good for at least three years of corrosion protection before another coolant flush and replacement is needed.
Wheel paint colors
Q: Thanks for the technical columns that appear in The Star each issue. I joined the club in 1993 and do most of the work on my cars, so I appreciate the articles. I have a 2002 E320 4Matic Special Edition. The wheels are looking pretty bad; I’d like to refinish them. The part number for the wheel is 2104015002. I would like to get the code for the wheel paint so I can order paint. My local dealer was unable to help with this information. By the way, my other car is a 178,000-mile-young 1976 450SL. Any information you can provide would be appreciated. Thanks for your help!
A: Finding this took a bit of research, but here is what I discovered. First, the MBUSA website STAR Tekinfo – www.startekinfo.com – listed two bulletins that go to dealers and authorized wheel refinishers. I’m passing them on to you: “MBUSA Approved Refinishing Products,” which includes the names of paint distributors who can probably give you the exact paint you need based on your VIN and wheel part number, and “Cosmetic Processing of Light Alloy Wheels,” intended for dealers and authorized wheel refinishers.
Secondly, a web search for alloy wheel paint codes led to Brilliant Silver Metallic, DB 744, which is the color my dealer said was common on earlier wheels, and Titanium Silver, DB 9765, the standard-silver wheel color for more than 25 years – Wurth German Alloy Silver Wheel Paint spray is the correct aftermarket product – and Griot’s Garage based in Washington now sells it under its own label. It’s a very good product. I suggest you contact one or more of the paint distributors or Griot’s Garage and ask for the correct paint color for your specific model. You can decide what to do from there.
Restoration advice
Q: I’ve inherited my mom’s 1976 240D – my parents bought it brand new off the showroom floor and have kept it well maintained since. It has 150,000 original miles and runs well – slowwww, but smooth – with no mechanical issues. It does have some rust issues, mainly in the rear-quarter panels, and the interior is in really great shape, too, with the exception of needing new padding for all seat bottoms. Can you recommend any good sources for restoration parts?
AFirst, you should decide how you want to use the car. Do you want to clean it up and use it as a driver or restore it to as-new condition and enter it in concours d’elegance car shows, where it will be judged on originality, condition and cleanliness? Once you decide what is important to you and the amount of money you want to invest in it, you can begin searching for parts and technical experts to help you achieve your goals. If your goal is to make a nice driver, you will probably want to limit your investment to the current market value of the car after you clean it up. If you want to restore the car to as-new condition, and the amount you invest will not be a consideration, you can create your masterpiece.
That said, I encourage you to start with your local MBCA section and find members who have or are knowledgeable about W114 and W115 vehicles; ask who they’ve utilized for parts and services. Next, there are numerous advertisers in The Star magazine that provide parts and services, including the Mercedes-Benz Classic Center in Irvine, California. Ultimately, what you do and where you get parts and services will depend on your goals, budget and timeframe – how much work you’ll do yourself – and whether you’re at peace with investing more in the 240D than its market value by the time you’ve finished the project.
Radio repairs
Q: I am trying to find a rebuilt amplifier for my 2005 SL500 (R230). The amplifier is draining the rear battery and I cannot find the cause. Dealers don’t seem to carry repair parts or even replacement radios for cars that are not currently in production.
A: Get in touch with Becker AutoSound in Saddle Brook, New Jersey, at 201.773.0976. The firm repairs a variety of Mercedes-Benz radios and audio components and will refer you to another source if it doesn’t work on your particular model of radio. Further, if technicians rebuild a unit, they may be able to upgrade it to use Bluetooth or provide a port for your MP3 player, iPad, iPhone and/or Google devices.
Gremlins in the lights
Q: The seat belt light in my 1991 560SEC won’t stop flashing when the belt is plugged in. At the same time, my dome light stays on long after the doors are closed – it never turns off unless I manually flip the switch. I also had a dead battery after a weekend of not driving the car (even though I manually turned the dome light off). Troubleshooting – multi-meter and pulling the fuses one at a time – indicates that the power drain is related to fuse 15, which includes the dome light and seat-belt functions. When I reconnect fuse 15, I hear something move/click under the dash and the current coursing through the multi-meter increases greatly. I don’t think the issue is the seat-belt sensor because both retractors are working perfectly and have no control over the dome light. Do you have any ideas?
A:The first thing to check when there are electrical gremlins is to make sure each circuit has a good ground. If the retractor circuits are working, check the seat belt and dome light circuits. It may be more than wiggling the connectors and tightening the bolts. A spray can of contact cleaner and mild rubbing with an emery cloth or fine grit sandpaper may be required. If solid grounding does not fix the problem, a visit to a dealer or independent repair shop with the Mercedes-Benz Star Diagnostics System may identify another problem in the circuit or faulty components. As for the battery drain and load in the system when it should be off, I strongly advise that a technician who is an expert in Mercedes-Benz models of this era be consulted. Ask if there is a Technical Service Bulletin on this issue.