How hot does your 116 run?

[koan]

Have a search of the forum on over heating problems, high coolant to water ratios seem to increase temperatures.  I changed from 50/50 to 30/70 for that reason.

koan

[brettj]

Thanks Koan.

The temp gauge held steady at 185F this morning after a drive of 21 miles. On the ride home with the ambient temp at 89F the car held steady at about 185F even in traffic. Although a strange thing did happen. After I parked the car and went into the bank for like 5 minutes, I restarted and the temp gauge shot up to 200F. Once I started to drive away the gauge went back down to 185F. It repeated this behavior until I parked the car to about 90 minutes and then it returned to normal. I've never experienced this before. My mechanic filled the radiator for me with Mercedes coolant which I told him to mix 50/50. I know he believes that the motor is better off running cool and likes to mix the coolant 60/40 which I asked him not to do. Maybe he didn't follow my instructions and the coolant mix is causing this problem.

[13B]

Thats normal.  Its a V8, google "heat soak".  Both my V8s do exactly the same thing.  In very hot Melbourne days I can turn the engine off at 110 cels and restart it 5 min later and see the needle nearly touching the red zone.  But by the time you move off and have covered a few hundred metres the temp is on its way back to where it was before.

I. 

[goldacre]

I was not aware of a bleed bolt when i replaced the coolant in the 450 although i was aware that my old Toyota manual said to disconnect the heater hose (highest part of the water circuit for the old Holden Nova) and then fill it till the water came out of it.

I translated this for my 450 by disconnecting the heater hose from the fire wall and filling it from there and the radiator end, then drive around for a while with the radiator cap off. The car rarely ever gets above 82c and in winter often sits just below 80c and that's with a new thermostat in it (75c type)

I am in the process of installing a new radiator, clutch and pump with another new thermostat so it will be interesting to see any difference, not that i want it to run any cooler!

J

[TJ 450]

Disconnecting the heater hose would be more effective than opening the bleed plug.

I recently changed the coolant on my 500SEC, opened the bleed plug and filled until coolant came out. Even though I did this, there was still a huge air pocket and the car overheated in a big way.

So, if the system was drained by removing the plug in the lower radiator tank and 5L fills the expansion tank, watch out. 

I think this is particularly relevant to those with the US climate control, which is not too dissimilar to the W126 version.

Tim

[another sad 280s]

the temp gauge would also go up sometimes when the engine was turned of for a few minutes. m110.

[TJ 450]

I think the temp gauge going up after turning the ignition off (hot soak) is pretty standard, my 450 usually goes up to 100 C in that situation. It's still not hot enough for the aux fan to come on.

Tim

[Big_Richard]

If i have driven the 6.9 in a "spirited" manner, prior to coming home it also does this, but if i have had a nice sensible drive (is that even possible in a 6.9?) the temperature doesent elevate after shutdown.

[WGB]

All Mercedes-Benzes I have ever owned (before they stopped fitting temperature gauges anyway) go up very high after being parked on a hot day with a hot engine.

When filled with the correct coolant at the correct concentration (and I disagree with Koan as all my Benzes have always had 50:50 and not run hot) with no leaks and a healthy correct pressure cap there should be no fluid loss or boiling with the temp at the red line.

The trick is they also go down again almost immediately on startup.

I think the problem with the 116 gauge is that it is too honest and tells you what is really happening when other manufacturers measure more of an average.

Bill

[pez]

It seems like you are running about 85-90C, which is perfectly normal and fine, esp. under load and in warm weather. You'll need to pull the air cleaner off to see the bleed bolt - this should only be an issue if you have just recently flushed/changed coolant.  Even if not bled out, running the car will allow the air to eventually ride to the top and the coolant to settle.  If you have not done it, do a good flush and fill up with correct coolant and water; also, use Red Line Water Wetter and you will no problems unless there is an issue with something in the cooling system.

[zedster]

It is starting to get warm here in Las Vegas. This is the hottest I have seen my temp recently. About a month ago I had the coolant changed, thermostat replaced, and temperature sensor(sending) thing-a-ma-jig replaced. Does this seem normal?



TIA,
Bill

[13B]

its a tad high... did you switch it off a few minutes before turning it back on to get a reading like that?

As long as it works its way down again after you start moving I guess thats alright.

Ian.

[zedster]

I took her for a run and then had her idling for a bit. Yes it goes down once I drive.

[brettj]

Ran the car on a 60F day and the temp gauge pretty much stayed in the middle of 175F and 200F. Did not have any of the symptoms described on the very hot days. I did notice the needle move a bit higher in traffic but again never hit the 200F mark. I beginning to feel that everything is ok with my system. Going to drive as is and keep an eye on the situation.

Zedster, I agree that in your pic the car is running a bit too hot. Even on a hot day my temp gauge never exceeded the 200F mark.

[zedster]

I thought the mark between 175 and 250 was 190? Nevermind lol