OM606 Coolant flush/t-stat question
 

Hey all, hope everyone had a fun Christmas.

I am getting ready to do some more routine work on my new OM606.910 (N/A W124 car) and I was just planning on running a stock temperature thermostat, but after some reading I found out that the turbo cars have a 5*c cooler t-stat than my N/A car. I am planning on taking the car down to the desert SW this spring and summer (hopefully permanently) and was wondering if any of you aluminum head vets thought there was any merritt to installing a cooler thermostat to help my motor run that much cooler, if it matters at all? It gets well north of 110 on the routine where my family resides down there, and there are plenty of hills to boot. I don't worry about such things in my 617, just MB gold flushed regularly and a new stock t-stat and away I go, but this 606 is a little new to me still.

I know it's very important to keep these aluminum cars from over heating, so any advantage I can get while running through extreme heat seems like a good plan, especially with a little older car that has some road warrior status :). Thanks a ton.

I don't have an opinion on the t-stat, but I strongly suggest that you replace the t-stat housing when you do this job. They aren't expensive - like $30. The old ones are prone to leaking. Just saying that its a simple thing to replace when you're in there.

If you have the original thermostat in there, you must replace the housing. The originals had the thermostat built into the housing. Replacements must go in a new housing - easy job and cheap though. If the thermostat has been replaced in the past though, all you would need is the thermostat.

Thanks guys. The dealer did the thermostat in 2005 along with a coolant flush, according to records. The coolant has been flushed regularly, but it's been about two years now based on records, and the stat has been in there since '05 so I want to make sure everything is in perfect running order.

I know once open the 80* and 85* can both exceed their speced temps and I'm at the mercy of various factors like the radiator and climate I am driving in, but I am just thinking that any advantage on my side I will take.

Its gets hot down here in Australia and my car was always running in the 90C to 100C but changing to the 80C thermostat from the spec'd 85C, there really is little difference.

In the early mornings before it ramps up in temp outside, the thermostat opens up a bit earlier and will maintain the temp close to 80C on the guage but once the outside temp goes past 110F it makes no difference as the thermostat is fully open by this point and you are rellying on the condition of your radiator, viscous fan and thermo fans.

In winter the cars temp guage sits spot on 80C most of the time with the exception of a hill or bumper to bumper traffic but you will be down on power slightly on the N/A. With no turbo they run better when warmer - at least that is the case with mine.

Thanks that is great to hear. I think I will do it, I currently live in a mild climate anyway up near Seattle, so it shoouldn't be a problem in the interim. I also live in a very hilly area with a ton of traffic and stop lights, so I guess it could be good anyway.

I appreciate all the responses guys.