Does it take a long time to warm up?

You might need to replace the thermostat and do a coolant flush.

I had to do this on my 300SD. It took forever and a day to get anywhere near 80C. New thermostat and a flush later. It heats up just like it should

My 190E 3.0 heats up in no time and stays a little north of 80C all day long, without ac. Ac doesnt work so cant say what it does when that is on.

__________________
Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

(4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!)


82 300SD 145k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k

It takes around 10mins in the city to reach 80C, I always use lower gear until it reaches 60C, i.e. I use 2nd gear when 3th gear would be used in operating temperature.

If 80C and 90C don't make a lot of difference in economy and engine wear so I would stick to the 80, as the risk of wire harness damage is lower.