2nd Oct 2006, 16:10
On the misfire: Check the ignition points and especially the condensor. Mine was bad on my 74 SLC and caused arcing in the points. Replacing it cured the problem.
20th Oct 2006, 00:44
I own a 450SL (1974) this car is in excellent condition, run great, but drivers seat is worn out. This car has blue interior, I am looking to purchase used seats preferably in good to excellent condition. Any suggestion where to purchase. please send comments at: R3goldhill@yahoo.com.
24th Feb 2007, 23:12
On other note on the misfiring: My 450 SLC has the old style distributor cap, and the previous owner apparently had it just slightly misaligned (the hold-down screws do not have a nice positive engangement the way the newer clip-on caps do.) Re-seating it got rid of the remaining misfiring on my car! Replacing the ignition condenser was also crucial. (You may have to search a bit online to find the part.)
A few other tips:
--My car had a high idle when I bought it (about 1300 rpm). Replacing a dried out hose to the manifold pressure sensor helped a lot. I then simply adjusted the idle speed screw.
--Stumbles during warm-up for a few minutes, but then runs fine: I replaced the engine temperature sensor and it fixed the problem.
Questions for others:
--LIkely cause of erratic gauges?
--If you've had a fuel pump fail, what were the early warning signs?
10th May 2007, 01:05
Update on my 1974 450slc from previous posting:
1) Began to be tough to start when cold, but started fine when warmed up and otherwise ran fine.
--Solution: Corroded contacts on thermo-time switch for cold start valve. (Be careful removing the connector, as it has a plastic tang that must be nudged before the thing pops off.)
2) Had been suffering from random, but continual popping and spitting (almost like a misfire). Only occurred when warmed up.
--Solution: Finally cured it by carefully adjusting ignition point gap and setting idle speed to specifications. (It's always the simple things!)
24th Jan 2008, 13:55
I got a 1974 450SLC from my grandpa. It runs pretty well, but is idling very fast, and the gas peddle is sticking. I can't find out how to turn on the windshield wiper fluid. I have checked all the knobs, but maybe it isn't working. Can anyone let me know which knob it is.
23rd Jun 2008, 13:11
I have a 1975 450sl. The window washer switch is located in the footwell for the left foot.
19th Jun 2010, 22:02
Original poster here.
I have now had the car for almost 5 years. Since the initial servicing I did after purchase, including the 120K mile service, the car has had only 2 new problems.
1st problem was the battery failed during winter storage - it was old. And, yes, I had the battery on a trickle charger all winter. New battery and it quickly started.
2nd problem was not the fault of the car. I was taking my daughter for a short cruise thru the hills here in Jo Daviess County, and about a mile out of town, as I powered thru a curve, Bambi came 'out of nowhere' and jumped in front of the car. Fortunately he flew forward and slid off the road. Because of the cars age, repair time is longer, about 6 weeks.
23rd Aug 2010, 04:53
I have a 74 Mecerdes 450SL. I got it for $800. All it needs is some interior work and I will paint it. The motor runs perfectly since the former owner put a little over 3k into it and it shows. I can't wait until I finish installing everything which cost me about 1k. A very powerful car for the age.
25th Aug 2010, 13:48
Haven't had my 74 very long. It has 90,000 miles.
I have just had a tune up done, but it 'lunges' every once in awhile. The mechanic looked for a vacuum leak, but hasn't found one. We know the air conditioner compressor is bad, but didn't think it would cause issue if it was off.
6th Oct 2010, 18:43
Update on "Bambi Strike".
Car took 1 week less than 3 months to repair. Car required new hood, left fender, left headlight assy, radiator, condenser, fan shroud. Factory hood of these cars is aluminum. Insurance called for used hood, Shop ordered 2 (they were steel) and could not get them to fit. Insurance allowed a new hood (aluminum) - no more problems.
Shop converted AC to R134 (conversion used to require replacing everything and cost $1000's. Now conversion only requires new fittings, about $100). AC now works.
Car looks fantastic (actually better than before the accident).
Total cost of repair was $8500. My cost was $0. Thank goodness for classic car insurance.
16th May 2015, 15:49
Thank you very much for your honest assessment and experience with this vehicle. It was very helpful.
17th May 2015, 14:55
I had a 450SL roadster 2 top in the 80s. It was on my bucket list to own one for quite a while. The classic design was already present, even then. A very sharp car back then. I did have some emission issues and only used the hardtop once. Even with 2 people, it was the hardest top to remove ever. There is a ceiling pulley kit for this top. And trust me, it will stay above your car in the garage. The convertible top is pretty sharp 3 plastic windows. My top was chocolate. Keeping the soft top down ready to go out of the garage was the norm. I added 560SL exact paint match ground effects, 560 rims, tires, and the rear deck light. Painted the housing body color. Even changed the emblems. Wouldn't do that today, but I did. Upgraded the stock stereo system using stock speaker openings.
These cars do quite well at sustained high cruising speeds; not a light to light car. Very heavy feel for their size. It's not very fast up to speed. It's a car maybe less noticed as much today maybe due to the radical design changes of the new SL. The 60s SLs today are very eye catching though. And many are hot investments, even as a 380. But that really large front chrome emblem on a small roadster was really sharp. I added a chrome MB duplicate emblem license plate below. Parts as I recall were high. 50 dollar oil changes seemed steep then, and I think it was 10 quart as part of the reason Even the front shocks, which I seem to recall were unusual dual posts. The convertible hard top is a complete waste. Try unlatching the rear latches. The removable hardtop really looks good and may be fine for winter driving. But it was a royal pain.
I have had a number of different brand convertibles over the years. Some powered, some not. I prefer manual if you can order it that way. Some mechanisms are a higher maintenance concern. My first convertible was a 60 MGA, and I now have a new Corvette Convertible, which is cake to raise and lower. Many key fobs today auto drop the windows, and change the mirrors and seat settings. Pretty cool, but I still like less if I am keeping it long term. Some of Mercedes' options, like the rear deck first aid kit, and city horn and country horn, are kind of amusing to see. But it's a neat car. Have fun! You only live once and it's great to love a cool car vs a bland beater! Makes driving fun.