1999 SLK 230. Recently began having a problem where the car just wouldn't crank. All lights, radio, access. work, fan will engage and you can hear the turbo click, but the engine will not turn over. After 5-15 min, car cranks and runs fine. Mech checks and finds no error codes. Now, car stalls when stopped at red light, then will not crank for 5-15/30 min. When it finally cranks, runs fine. Again, Mech check and no error codes. All the research I've done points to the CPS being faulty, but the Mech says he's not able to test when the car is not acting up.. and it will not act up while he's tinkering with it. Any suggestions???

 

I had the exact same problem with my '99 SLK230 just 5-7 weeks ago, more than likely, it's a malfunctioning crankshaft sensor; which is basically a security device. At first, I would drive it for a bit, park and come back a few minutes later and it would not start even though all seemed fine re: power, lights, no check engine light, etc. but after a few minutes it would. Then, one day, I was driving on highway and the engine just turned off, I pulled off to the side, tried starting it for 15 minutes and nothing. I got it towed to my mechanic's shop and, of course, when I tried starting it, it started. My mechanic ran all the checks but nothing came but up but later realized/remembered that E-class cars had the same problem with the crankshaft sensor but didn't think the the SLKs were using, basically, the same sensor but they are...the part was changed for $189CDN (I'm in Toronto) and I haven't had a problem since. In fact, the car is actually starting on the first once around...

Hope this helps...

 

Thanks for the response. I ended up biting the bullet and replacing... just hated throwing the money at a fix that we're not sure IS the fix. Happy to say,, at least after 3 days, everything seems to be working ok. No stalls or crank failures. Tomorrow, the mrs's will be driving it,, if it makes it through her test run with no issues, I'll feel confident.

Thanks again for the response.