i am having 2 problems i have a 1999 sls when it is cold out it runs fine if there is any heat outside it runs really rough like there is a miss in the engine it idels fine then hesitates and every so often it will back fire when starting.my other problem is the back shocks it does not seem to loose any air while the car is sitting but if i put any more than 2 people in the car it starts loosing air and the pump starts to run alot

 

you may have a leak in the rubber boot on the struts that is exposed when addd weight is added. check the condition of the rear struts to see if there are cracks in the rubber boots that might have pin size wholes that are causing the air to escape when extra wheight is added. I just replaced mine and they are easy to do your self but cost some money.

 

thanks i will check that out

 

also when was the last time a tune up was done? may need plugs and wires to start. i had a car that did a simular thing and at night it looked like a light show cuz of all the bad plug wires, this may not be the case with you but giving a car a tune up if it hasnt had one in awile sometimes eliminates some or all of the problems. let us know what you come up with.

 

if it is't a tune up it's a sensor, forgot which one. I replaced my rear shocks on my 99 sls
with used ones, saved a bankroll,they are as good as new