We've had our ML55 for 3.5 years and 46k miles. The car never had any problems. The coolant temperature has always been 80 degrees all year round regardless of outside temperatures.
This year I noticed that it's about 85-90 and I saw it hitting 100 when it was 80+ outside.
Is it time for coolant to be replaced or is it a sign of some problem?
Change the Coolant, and have them flush the radiator, and drain the engine block of the old coolant.Make sure they remove all the air bubbles when they refill the cooling system. The coolant should be change every two years according to the dealer. I change mine every year. I hope that's all it is.
Assuming that you have checked for obvious things such as low coolant level and bad/leaking radiator and heater hoses, I would suggest that you need to check the thermostat. It sounds like the thermostat might be stuck partially open. That would let the coolant circulate enough to cool properly at lower temperatures, but doesn't open up more to let enough coolant circulate when it is hotter.
Alex, when was the last time you had the coolant replaced? The coolant should be flushed approximately every 3 years, and the brake fluid approximately every 2 years.
__________________
<b><u>BenzWorld.org Senior Forum Host & Lighting guru</u></b>
<font face="arial"><font size="1"><a href="http://forums.benzworld.org/publications/pub.asp?id=67">MB OEM Bi-Xenons with E-code modification</a>, <a href="http://www.stongard.com/sgcontent/what_sgl.asp">custom-cut StonGard Light protection film</a>, Hella FF100 & FF200 foglamps with wireless switch, <a href="http://www.benzworld.org/forums/messages.asp?messno=81251&id=21&view=t">Hella dual tone air horns</a>, Bosch ParkPilot reverse warning system, Tomar Hide-a-way emergency vehicle front strobes, <a href="http://www.benzworld.org/forums/messages.asp?messno=58388&id=21&view=t">integrated reverse warning strobe lights with wireless switch</a>, <a href="http://forums.benzworld.org/forums/messages.asp?messno=40641&id=21&view=t">chrome handle accent strips and chrome door handle shells</a>, <a href="http://forums.benzworld.org/forums/messages.asp?messno=40351&id=21">AMG chrome ringed gauges</a>, <a href="http://www.benzworld.org/forums/messages.asp?messno=62376&id=21">Euro M-class footwell net</a>, <a href="http://www.http://www.benzworld.org/forums/messages.asp?messno=47347&id=21&view=t">3M reverse safety fresnel lens</a>, <a href="http://forums.benzworld.org/forums/messages.asp?messno=46855&id=21">Euro blindspot interior mirrors</a>, <a href="http://www.benzworld.org/forums/messages.asp?messno=54107&id=21&view=t">MCS GPS nav system</a>, chrome headlamp rings, chrome fender signal rings, <a href="http://www.mbworld.org/upload/2002/ml_int2.jpg">Personalised <i>designo</i> interior</a>, <a href="http://forums.benzworld.org/gallery/showlink.asp?parentid=32&catid=328&subname=Andrew` s_M-class">Drinkholders.com burl walnut ML cupholder</a>, <a href="http://www.benzworld.org/forums/forums/thread-view.asp?tid=1164344&posts=29">hardwired Valentine One radar detector</a>, <a href="http://forums.benzworld.org/forums/messages.asp?messno=43386&id=21">LED-based front and rear LED footwell ambience lighting</a>, <a href="http://www.benzworld.org/forums/messages.asp?messno=64477&id=21">illuminated MB door sills for each door</a>, <a href=http://www.*************.com/mb_results.asp?model=W163&class=m-class&category=Aerodynamics%3A+Roof+Wings+and+Bug+ Deflectors">Clear acrylic hood deflector</a>, Weathertech window deflectors, EGR rear deflector, 3M Scotchtint 50% tint on front windows, <a href="http://www.benzworld.org/news/extimages/48000kms/5.jpg">3M Scotchtint 20% tint on top 4" of windshield</a>, <a href="http://www.benzworld.org/gallery/pics/32832371212200211007AM.jpg">driver side mounted fire extinguisher</a>, <a href="http://www.*************.com/mb_results.asp?model=W163&class=m-class&category=Chrome+Tailgate+Handle">chrome tailgate handle</a>, "Elegance" side badges, <a href="http://www.*************.com/mb_results.asp?model=W163&class=m-class&category=Bose+Tweeters%2FSail+Panels">'02 Bose tweeters and sail panels</a>, <a href="http://www.benzworld.org/forums/messages.asp?messno=37287&id=21&view=t">'02+ tailgate filler panel</a>, <a href="http://www.*************.com/mb_results.asp?model=W163&class=m-class&category=Bumper+Grilles">AMG silver painted/chrome accented front grill, silver painted lower bumper grill</a>, MB OEM Style 1 chrome sidesteps & chrome brushguard with skidplate, MB OEM front mudflaps & <a href="http://www.benzworld.org/gallery/showlink.asp?page=11&order=id&CatID=328&parentid=3 2&parentname=&subname=Andrew%60s_M-class">aftermarket flexible rear mudflaps</a>, <a href="http://www.benzworld.org/news/extimages/48000kms/6.jpg">chrome door rubstrips</a>, <a href="http://www.benzworld.org/forums/messages.asp?id=21&messno=79983&view=t">MB Lamella Skyview roof deflector</a>, <a href="http://www.benzworld.org/news/extimages/48000kms/10.jpg">MB accessory roof crossbars & ski rack</a>, <a href="http://www.*************.com/mb_results.asp?model=W163&class=m-class&category=Exhaust+Tip">AMG oval exhaust tip</a>, <a href="http://www.benzworld.org/forums/messages.asp?messno=62611&id=21&view=t">17" EVO II Sport package wheels & Michelin Cross Terrains</a>, DesignTech halogen backup bulbs, <a href="http://www.*************.com/mb_results.asp?model=W163&class=m-class&category=LED+Brake+Lights">Formymercedes.com 20" LED brake strip with Flash alert</a>, 6" 3rd brake lamp LED strip, <a href="http://www.*************.com/mb_results_m.asp?model=W163&class=m-class&category=LED+Replacement+Bulbs">High-intensity LED taillamps, front and rear LED amber turn signals</a>, <a href="http://forums.benzworld.org/forums/messages.asp?messno=49436&id=21&view=t">HyperWhite LED city lamps</a></font></font>
Thanks for all replies.
The dealer does all maintainance on the car, so I am not sure what they did and when. However, I already scheduled it to be checked out and they will check coolant and replace it if needed.
By the way, I talked to my dealer about getting extended Starmark warranty for our ML55 and they said that AMG's are not covered.
Is it true?
Linear Mode
