Wife has been the one who drove the car. I periodically drove the car and took care of the things I notice. But you know how women are - as long as the car seems to run they think everything is just fine. Anyhow I was aware the operating temp sat at 84c (with a 80c Wahler thermostat) and in the summer it goes up to 90 - 93c after I replaced the water pump and thermostat about 2 years ago. I noticed the 120C just this Tueday when she picked me up for lunch. She said that just happened that day. I'll just leave it there.
Anyhow, what I think we need to focus on is that the lower radiator hose stayed cold after the test run during which the temp shot up to 120C again. So the coolant wasn't flowing through the radiator. If it had flowed at all I shouldn't have a cold lower hose, right? Thermostat - this was ruled out by the boil test. Plugged up radiator - very unlikely although possible. I bought this car while it had 103,000 miles. Replaced water pump around 180k miles. Between 103,000 and 180,000 miles, the temp gauge was at 80C or 82c solid even with A/C on in hot summer. Trapped air bubble - wouldn't they start to show up as soon as they were there? Tan --- "Dave M." <[EMAIL PROTECTED]> wrote: > Tan, > > Refresh my memory. Did the problem happen overnight, > meaning the car > has been running at 100C for a while and suddenly > popped to 120C? Or > has it gradually been climbing from 100C to 120C > over the past > months/years? If it was an overnight thing, I'd lean > towards the water > pump as suspect - or at least worth a closer look. > You can always > re-install it if the impeller is properly attached > and intact. > > If the problem has been slowly getting worse, with > temps higher every > few months, I would *strongly* suspect the radiator > is bad (corroded > internally). It may flow just fine, but be unable to > transfer heat > properly. This assumes the fins are all clean in the > condenser AND > radiator. > > The bubble theory mostly applies to when the cooling > system is first > filled. If you've been driving the car for months, a > bubble should NOT > just suddenly appear out of nowhere. > > :-) > > -Dave M. > > > ------------------------------ > > Date: Thu, 29 Dec 2005 07:22:51 -0800 (PST) > > From: Tan Qu <[EMAIL PROTECTED]> > > Subject: Re: [MBZ] SOS - '87 190Dt Overheat! > -update > > > > I am pretty positive on the first two but not last > > one. The thermostat on OM602 only goes in one > > position. There is a tab in the thermostat housing > > that sits in a small recess on the thermostat. Put > it > > in other ways the housing would not close > properly. I > > missed it when I put the second thermostat in and > > found that out when I started to fill the rediator > > from the upper hose. The coolant came out right > there. > > So that should tell me the radiator flows ok, > right? > > On the 190Dt it is hard to get the hose clamp for > the > > upper hose end on radiator so I detached from the > > engine end and filled radiator from there. It is > > possible there may be an air bubble trapped in the > > head. How do you normally purge the air in the > head - > > by filling the engine from the upper hose? > > > > > > Tan > > > > --- Jim Cathey <[EMAIL PROTECTED]> wrote: > > > > > > Did the boil test last night, the thermostat I > > > just > > > > took off the car opened nicely near the > boiling > > > point. > > > > Fully opened when the water was boiling. Also > > > checked > > > > the upper hose again, no pressurized syndrome. > So > > > I > > > > guess new pump is the next course of action. I > > > still > > > > have a Laso pump on hand. Would you all think > > > dealer > > > > parts is superior than the OEM parts on this > one? > > > > > > I think the pump you have ready to put in is the > > > superior one, but only because I'm still not > > > convinced > > > that it will make any difference and using it > will > > > allow > > > you to conduct the test immediately. You're > _sure_ > > > the > > > radiator flows well, the thermostat is in the > right > > > way around, and that there's no huge air bubble > > > trapped > > > in the head? > > > > > > -- Jim > > _______________________________________ > http://www.striplin.net > For new parts see official list sponsor: > http://www.buymbparts.com/ > For used parts email [EMAIL PROTECTED] > > To Unsubscribe or change delivery options go to: > http://striplin.net/mailman/listinfo/mercedes_striplin.net >
