300CE won't accelerate on 100 deg. day.
This is my first summer with the 300CE. A few times while driving in really hot weather (about 100 degrees) it has refused to accelerate from a stop. The problem is intermittent and it's only happened about five times so far.
I can't quite tell if the car just has no power, is in the wrong gear (failed to downshift when I stopped), or what. It doesn't shake like the engine is about to stall. It doesn't cough or sputter when I hit the gas, it just doesn't go anywhere.
If I stand on the accelerator and force a downshift to 1st gear, the car will accelerate, although it is sluggish at tip-in. Once it gets to about 1000 RPMs it's back to normal.
Again, it only seems to happen on really hot days in mild stop-and go driving. (City streets, but not gridlock - I'm in Oklahoma) I'm running the A/C full-blast, but coolant temp is normal.
Is it simply time for a tune-up? I can't verify whether the PO did one.