Hello I just got a 450sl and have a few questions

[ALLGIRLUSA]

My husband and I just bought our first MB, a 1974 450sl. We bought it from a good friend who owned it about 18 months and kept it in storage and bought it from the original owner.

We have been reading and learning alot also, but are still having a tempurature issue.

Once warmed up, it runs 225F and warmer on the freeway.

We have replaced the thermostat and temp sensor. My husband insists that they are designed to run hot, but form what I'm reading, not that hot.

We have also contained all vacuum leaks, new plugs, wires, and points, and the cat was removed previously.

What should we try next?

[LUVMBDiesels]

Look up 'Citric Acid Flush' on this site and follow the instructions that are repeated in many posts. This should open up the coolant passages. Replace the coolant with Zerex G05 (Mercedes OEM)

If this does not help, go to radiators.com and get a new radiator. After 30+ years, you can't expect much from a radiator.

Good luck!

[edsl94]

first, i agree with tomguy, definitley more cowbell! for the girl, 225 is way to hot. you won't blow up if your antifreeze is good, but do find the problem. does that car have a fan clutch? air conditioning radiator full of bugs, blocking air flow? fan shroud missing? slipping transmission? did the cat convertor blow up and plug the muffler, as you mentioned it was changed. crushed exhaust pipe? stuck calipers, causing brake drag? just things to consider before the flush. the radiator can be cleaned at a shop and flow tested. good luck. let us know.

[edsl94]

me again. i just reread your post and noticed that the cat wasn't changed, just removed. you could have a lean condition if there is a change in back pressure. might have to install one to bring the fuel/air ratio back into spec or leave it off and rejet the fuel system.