I have a 1990 300 SEL and was wondering if the thermostat would be the same as domestic vehicles? In other words can I get one from Napa? My car does not have any heat. It sits allot but the engine is not running hot at all. The CCU seems to be working fine so I thought maybe the Thermo might be sticking. Anyone have any other ideas on what it may be?

Most parts stores will carry a domestic t-stat for Mercedes but the quality is usually lacking compared to the OE suppliers.

I bought a thermostat for my 300SEL at the local parts store several years ago. It is still in there and working fine.

I am going through this problem with my 300SE right now. Just replaced the thermostat, and it made no difference. If the car isn't running hot, then your problem is most likely the dreaded monovalve and not a sticking t-stat.

The problem I've seen with some non oem thermostats is the gasket sucks compared to the proper O-ring that's supposed to be in there. I just got the t-stat with the O-ring at the stealership for $27.


J.

monovalve? where would a guy find that?

In-between the the The Two Firewalls on the right-middle.


The first article is the "Repair Kit" which is probably all you need.Four screws
hold the top plate.Unscrew them and R+R the insert.(the rubber diaphragm
goes bad)

When you find the Mono-Valve (By following the Heater hoses to it...'Looks
like a train station for heater hoses) You'll be looking down on the top aluminum
square plate with the Electrical plug in the center and a screw at each corner.

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'84 300SD sold
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