Last summer, I did a lot of cooling system work on my '91 350SD. New parts/services included:

- New Aux Fan (only one bad)
- 2 Complete System Flush
- New Thermostat
- New Fan Clutch

The system was neglected and needed to be cleaned. An overheating 350SD was cured. She did run a little hotter than I would like on a summer day, but it was much, much better.

This spring, I just changed my radiator. Put in a new Behr and pulled out the original. FIgured it was good insurance.

While, she hasn't overheated, she seems to get hot quicker with loads now. Her cooling behavior is not the same. I am thinking of putting the old radiator back in. I'm fed up. Should have been an easy change.

Is it possible that I could have air pockets somewhere in the system. I have run her at high RPMs with the defroster on Hi (and sun roof open).

When not under load, she does cool down. Sometimes she seems to get a little warmer than she did before around town. The fan clutch still stops on a dime when the car's temp is at 90 or 100.

Can you offer any help? Please.....