Hi Guys,

1984 230TE: after leaving the car overnight when it's cold outside (10-40F) the transmission shifts incredibly hard . . . almost feels like someone's hitting the car from behind. After it warms up, it shifts fine. Other than the typical fluid and filter change anything I can check for? Also, what's the consensus on synthetic gearbox fluid for these older cars?

Second, per my dad's (apparently lame) advice I tried using some Prestone stop leak in the cooling system. I was getting a faint smell of coolant (prolly a small leak in the heater core) when the heat was on so I figured I'd give this Prestone crap a shot. Well, as you can imagine it didn't work and now the car runs much hotter than before. Somewhere about 105-110C cruising on the highway. Again, I'm going to flush the system, but could I have messed up anything else?

Thanks a stack,

Paul

On the stop leak, you probably killed the radiator. Mercedes radiators have small passages that do clog easily...

On the tranny, have the vacuum source checked at the modulator and have the modulator valve checked.

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Benzmac:
1981 280GE SWB
1987 16V
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Thanks, Benzmac. I had an eerie feeling that I might have toasted the radiator. Unfortunately that Prestone crap isn't idiot-proof as I have proven . . . I'm still going to try to flush it out though and keep my fingers crossed. The temp gauge isn't going into the red . . . any problems from driving the car at a slightly warmer running temp?

On the transmission, what do you think about running synthetic fluid?

Thanks again,

Paul

Paul,

Red Line MTL is supposed to be pretty good stuff. I am considering it in my 300SD when the next fluid/filter change is due. I have heard many many good things about it from MB and BMW owners alike. Hope this helps!


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Rgds,
Aaron Greenberg
MB technician
Precision Motorcars, Cincinnati, Ohio
'67 250SE Cabriolet
'77 450SL
'79 6.9
'80 300SD
'85 380SE
'89 420SEL
'93 300E 2.8

DON'T USE MTL!!!!!!"MTL" stands for Manual Transmission Lubricant and is meant precisely for that application. I run "Synthetic ATF" (their specific product name) in both of my cars, and have been very pleased.

If you actually have an MBZ with a manual tranny, then MTL's great stuff!

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Best regards, Michael
'92 500E
'88 300TE

'86 230TE Radiator Question
 

I decided to change the water in the radiator with a 50/50 mix. While the car is running cooler, it leaks (few srops) when cold. I could trace the leaks from the core and tanks seams. It was running fine with water and I am thinking that 50/50 requires working at higher pressure & temp and a marginal leak has just enlarged. Any additive to stop the leak suggested? Where can I get an original Behr cheap?
Thanks