560sl stereo removal & high idle - PeachParts Mercedes-Benz Forum

LittleE · #1 04-14-2006, 12:10 AM

Howdy folks,

I have been reading these forums for weeks and finally registered today. You have a heck of a lot of info here but I dont seem to be able to find the cure to either one of my car problems.
I have an 88 560sl with 50k, been great for 8 years except needed a solenoid on starter once and a couple batteries but it is finally needing some attention.

1st problem is as usual when it starts it idles high but here lately it takes a long time for it to idle down, then when I turn it off just for one minute it goes throught the same phase , about 15 minutes to idle down, and this is after a good warmup over 20 miles. I am in south Texas so it is usually around 80 degrees minimum. I am totally in the dark on this one.

2nd problem is the radio (becker) quit powering up one day then a couple weeks later it came on and started smoking really heavy. I was able to take the batt. wire off in time thankfully. I removed the fuse to the radio but it still clicks when I try to turn it on so I am hesitant to reconnect the batt. wire. (also disconnected the plug on the antenna in trunk) I would like to install a cd so I am in need of some info on stereo removal in this model. I have read everything I can find in the forums about console and stereo removal and this one seems different than all the other models.

Is the mercedes cd for this model any good or not, I would like to know all I can about this very well engineered machine so I was wondering if it was worth the investment. I have read lots of manuals in my time and about 70% dont tell you much more than if you use common sense. Can anyone point me in the right direction? Thanks much and I hope I have posted in correct forum.

Roncallo · #2 04-14-2006, 02:13 AM

The CD stinks compared to my Ford Taurs CD and manual. But it is about the only economic source of information. If I need more I go to the library.

John Roncallo

LittleE · #3 04-17-2006, 12:01 PM

Thanks for info on the cd, does alldata or mitchell supply more info or are they also as weak?

halman2228 · #4 04-17-2006, 10:22 PM

...we have an "idle control valve" and an "idle control unit" in our SLs.

The valve is the first suspect if idle calms down after a while...

If it begins to remain high all the time it is most likely the ICU.

Appropriate search will lead you to the cure (cleaning the valve or putting in a new one). We even have threads descibing how to resurrect the ICU with a little soldering. Further reading will lead you to some less obvious causes like temp sensors, etc. that may be the culprit... do some diagnostics first before tossing in parts & hoping.

Can't help with the electrical issue .

Regards,
Kevin

tecqboy · #5 04-17-2006, 10:57 PM

If you want to stay "original", you can have your radio repaired by www.beckerelectronics.com That site includes instructions on how to best remove your unit. Most of us have "upgraded" our systems to after market units which include all the latest innovations like Mp3 and or satellite radio. Crutchfield is probably the best source of info on after market systems.

LittleE · #6 04-18-2006, 05:13 PM

Thanks for the replies, was just what I needed. Now I have something to go on and some reading to do.

iwrock · #7 04-18-2006, 05:30 PM

This may be unfortunate for some of you to hear, but the same goes with my 1988 300TE. The stereo that is in there is almost obsolete. For you stereo problem, I would reccomend replacing it with a new stereo, one to your liking. Blaupunkt is apparently the stereo that is regarded as high quality, and very low key with good features, and not alot of "bling".

It will probibally be cheaper to replace the radio with a newer one, as it can get costly fixing these old headunits.

Personally, the sound in my wagon was very dull with the stock stereo. With about $350, I was able o create a sound system that puts the stock one to shame. Maybe that should be the direction that you should head. Update it with a Blaupunkt that way you can retain the factory look, and get the features of a modern headunit.

ctaylor738 · #8 04-18-2006, 06:48 PM

We also have "vacuum leaks" which allow "false air" to get into the system, causing a high idle. This is in addition to the "over-protection relay" which provids power to the idle control system. It has a fuse that can blow and then the system defaults to 1200 RPM.