[Twenty seven]

w220 S-500. car was in the shop for AC servicing they said radiator was bad so it was replaced, now AC is cold but when car is started it will heat up to 80c and stay there but As AC cools cabin temp, engine temp goes up will stabilize at about 95C.As AC temp goes up, because cabin has reached selected temp I guess, engine temp will rise to red line stop driving car let it idle and temp goes back down to 95C, did not touch AC controls. Next took car, after it cooled down, on highway at 70mph it got hot put it in neutral with engine idling and car slowing temp went down,great car in traffic stays at 95c,AC not cold. On initial start up AC is great ice cold goes to hell when system tries to maintain temp by warming cabin. could something be restricting the flow of engine coolant at rpm above idle when cabin temp system is working DUNO valves maybe ?? diagram looks like it dose. Note below 50 outside air temp car seems good (or maybe i should drive it further)this all happens in 50miles or less.

Thank you for letting me rant

 

[tusabes]

It's a bit hard to understand your post but does your coolant temp go down at highway speeds , but get hot when slow /at stoplight /stuck in traffic ?

If so that's the symptom of a fan that's not working properly.

 

[plinker17722]

The thermostat needs changing . And buy one that open a few degrees sooner than the one you have now . You need to get that 95 deg down ..to about 84 deg If the stat is not opening up till the 95 is reached no way will you change it .

 

[Twenty seven]

thank you. Thermostat is new with radiator i hope it is right, i will check, engine temp stays at 95C. after 30 min,the time it took AC to get cabin up to selected temp, 68. then as AC warms (AC temp goes up) to maintain cabin temp, car engine temp goes up over 120C and more if I let it. The strange thing is i pull off the road and let car idle temp goes down (did not touch anything.) to 95C and stays there. Let it idle for 20min stayed at 95C, AC on but not hot or cold . Out side air temp was 80F. AC temp control dose not seem to make a difference.
Start driving again engine temp goes up. AC not maintaining 68, heating / cooling system on or off makes no difference,ran the diagnostic check on system and values were close except for Sun Sensor readings were hi with engine off and cold. cooling fan seems to be working correct.
Drove car on highway at70 mph with engine temp at 120C put car in neutral (rpm went to 550 )car engine temp cooled to 95C.As speed slowed. AC never kept car cabin at 68. Car only has91 thousand miles on it. I think 95C is too warm for that engine.
Thanks

 

[wallyp]

The car is designed to run at 95c.

Thirty minutes seems like a long time to cool the car interior.

Was the radiator replaced with a new one? Or a used one?

The symptoms are somewhat unusual in this case. Sounds as if coolant flow (or, less likely, airflow) is being partially blocked at higher engine speeds/loads, but is sufficient at low speeds/loads. Blocked radiator or faulty thermostat are most common causes, but both reportedly have been changed in your case. I'm not pointing fingers, but are you certain that both the thermostat and the radiator were changed?

There are a few uncommon causes for this kind of problem. These can include, but are not limited to:
- Lower radiator hose collapsing at high RPM (sucking shut). Some vehicles with long hoses susceptible to this problem have coil springs inside the hose.
- Water pump impeller slipping on the shaft at high load/high speed operation. This can lead to sufficient coolant flow at low engine loads, but slipping and insufficient flow at higher engine loads.
- Water pump impeller fins eroded away enough to cause the same conditions as above. I have not seen any reports of either of these conditions on the W220, but I certainly don't have any knowledge one way or the other.
- There are things that can block airflow at high speeds, but they are really unusual. A license plate or similar item in front of the grille is one. On the Porsche 928, there have been reports of the plastic sheet between the grille and the radiator getting loose on the front, and then curling up at high speed and blocking the airflow. Not likely on our cars.

 

[pinkster]

Did they backflush the motor when they did the radiator change?

 

[Twenty seven]

Radiator was new will ask about back flush grill area is clear, interesting about water pump and hoses although they appear good
Thank you

 

[Twenty seven]

Thank you everyone for the advise. New radiator, thermostat, water pump and a flush job on engine cooling system and proper anti freeze seems to have cured the overheat issues. Water pump was bad the impeller was bent causing some cavitation (maybe)
Thanks again

 

[Twenty seven]

2001 S500 been two days since something broke. Had the left front ball joint replaced due to clunking noise, car drove perfect, straight just great. Now after ball joint
change car still drives fine but ABS,ESP and BAS lights on. turn car off start back up lights are off drive 200feet or so back on. Shop turns light off with computer and turns
wheels all the way right then left makes no difference lights come back on. I noticed car seems to ride higher in the front now and suspension air pump runs more often, car looks and drives great steering wheel appears to be straight. What do all the lights have in common and what could they have broke to cause this.
Thanks

 

[tusabes]

Most often an electrical connector that was unplugged during the suspension work was not fully plugged back in upon reinstall

 

[Dave2302]

Shop turns light off with computer and turns
wheels all the way right then left makes no difference lights come back on. I noticed car seems to ride higher in the front now and suspension air pump runs more often

Hi,

And the workshop didn't ask you to leave the car so they can rectify the fault that was not there before they did this repair, or at very least check over their work ??

Did they advise you what codes were showing in BAS ESP and ABS, because if it's the same side they worked on you can bet Tusabes is right, they've not plugged something in correctly, or worse, damaged wiring or plug(s) ...........

I think I'd be getting a second opinion, or insisting they fix it properly :wink

HTH,

Cheers Dave

 

[wallyp]

One of the more common causes is the speed sensor at that wheel, or its connection. Agree - they should fix it at no cost.