Bleeding the system is also important, I have never been able to completely bleed the system, with just the bleeder. You also have to loosen the small hose at the top right side of the radiator this hose is supposed to be a self bleeder for the radiator but it does not work as intended. Everytime I have to drain the system down there will always be air trapped in the radiator that doesn't seem to leave. Loosen the small upper hose and pull it back just enough so you can hear the air rush out. As soon as the you have liquid present quickly push the hose back on and retighten the clamp. be very careful when loosening this hose if you have an OEM plastic tank radiator. It is very easy to break the fitting. If that happens you will be replacing the radiator for sure. Reqardless of whatever parts you replace, anytime the system is drained you will need to do this step. I would also lean towards Dave Swingles advice, to clean and flush the system. A partially plugged or resrticted radiator will cause exactly what you are discribing. I personally experienced a bad OEM thermostat that went bad by not opening when it should have. I went for a drive one day and noticed my needle was climbing past 220 the fans were on but the temp would not come down below 220. After some investigating I discovered the LH coolant pipe was hot going into the radiator and the RH coolant pipe was cold (ambient) coming out which ment I was not getting any appreciable flow. This is when I decided to replace the thermostat. (I had previously replaced the radiator 2 yrs earlier so I new plugging was not the issue) After I had the new thermostat I did a comparison test be putting them in a pan of water on the stove. I turned the burner on and waited to see when the units would open. The new unit hit the temp range and opened very quickly. The old unit took a little longer but did finally open, but it was very slow and did not open as far as the new unit. I put new unit in and everything was back to normal. Dennis --- In dmcnews@xxxxxxxxxxxxxxx, "sweitzel_2000" <sweitzel@...> wrote: > > This weekend, I took 3231 on a reasonably long trip out of the Bay > Area to Gold Country to visit my in-laws in the hills north of Nevada > City, CA. Aside from having an absolute blast driving the winding > mountain roads, something cropped up that I thought I might ask the > group. Now, the Sacramento valley is notoriously hot this time of year > and this weekend was no different. Now my cooling system has been > flawless for the time I've owned my car. Two years ago, it got new > hoses, new otterstat, new thermostat, John H's auto air bleeder tube, > and a stainless header bottle. I've never experienced an overheat > thusfar. When I drive the car in normal weather, the needle usually > fluxuates between just above the first white line and right below the > 220 line when the fans come on. With the AC on (most often outside > temperatures above 78 degrees), the needle typically stays just below > the 220 mark. > > This weekend was a little concerning. Once I hit highway 80 and the > outside temperature was 100 degrees, I found that with my AC on and > cruising at roughly 70 miles per hour, my temperature began to creep > higher than normal. First it was right on the 220 line, then as I > began to climb the hills outside of Roseville, the needle crept a > third of the way to the red line. Fearing potential problems, I kicked > off my AC and the needle stayed slightly over 220, but didn't get any > higher even with heavy hill climbing. I stopped in Auburn and checked > to verify that both of my fans were running and they were. Once I > passed through Auburn and the outside temperature began to fall, my > coolant temp came down to it's normal spot slightly below 220. > > Coming back today was much easier. It was still just as hot out, but a > third of the trip is all downhill. I found today that cruising on the > flatlands at 70ish and AC on the needle would hover just a sliver > above the 220 mark. If I slowed to 55mph after about 5 minutes the > needle would drop directly on the 220 mark. > > So here's my question? Was I up against major engine problems with my > cruising temp slightly above the 220 mark? Do you think my cooling > system is functioning correctly? I do still have an original OEM > radiator with 10600 original miles on it. > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/