+- STD (https://www.superturbodiesel.com/std)
+-- Forum: Maintenance (https://www.superturbodiesel.com/std/forumdisplay.php?fid=22)
+--- Forum: General (https://www.superturbodiesel.com/std/forumdisplay.php?fid=4)
+--- Thread: overheating and idle ? (/showthread.php?tid=462)
overheating and idle ? - heavyD - 06-28-2009
so my 123 617952 overheats 110C-115C according to dash temp guage only on the hwy 70F ambient temp. ive replaced the tstat and expansion tank cap. i don't really think it's the water pump cause its fine around town. my theory is that at sustained higher engine speeds 4000rpm+ the coolant is not flowing through the radiator enough. i.e. the radiator is clogged. does this sound right or a common problem? ive read on forums about citric acid flushing and other methods to unclog but am skeptical. any opinions? no oil in coolant or vice versa. the other day after hwy driving it puked all the water out of the expansion tank.
also- after the car is warmed the idle shakes the car. before it would shake badly and smoke on cold start. i adjusted the valves and that problem went away. still idles rough when warm. if i raise the rpm enough to see the tach needle move "very little" the shaking stops. the idle speed is set per the benz service manual. are these problems overheating and this related?
RE: overheating and idle ? - winmutt - 06-29-2009
Ive never done a flush but people say it does wonders. When you run the heat do you smell coolant?
RE: overheating and idle ? - heavyD - 06-29-2009
no. and i pressure tested the system. thanks for the response
RE: overheating and idle ? - winmutt - 06-29-2009
Sounds to me like you have a leak somewhere. You might want to try bypassing the HVAC stuff with a long hose. You sure the replacement Tstat was good? Have you tested the sensor?
RE: overheating and idle ? - ForcedInduction - 06-29-2009
Go to a carwash and pressure wash the radiator from both sides. Also change your temp sender, its at least 24 years old now and its only $3.
RE: overheating and idle ? - willbhere4u - 07-04-2009
I agree I have seen so many radiators plugged externally with road gunk cotton wood debris its not funny! At my old shop we use to remove the radiators out of the Cummins trucks just to wash them they would get clogged between the rad and inter cooler made a huge diffrence
RE: overheating and idle ? - ForcedInduction - 07-04-2009
Same here. At the insulation company I worked for it was weekly maintenance on each truck to take the hood, A/C condenser and intercooler off to blow the insulation out of all the fins. We tried a catch screen but that only made them clog and overheat quicker.