93 525 Paul
12-05-2006, 10:13 PM
Took the wife's 525 on a biz trip to Santa Barbara. First time out of town in a loooong while. Temp in town was always straight up, but it seemed to warm up slowly. Temp ran way cool on the freeway, but when I got there and was doing the in-town shuffle, temp went back to the normal straight up.
Thought to myself, either the gauge/sending unit is going goofy or the thermostat is hung open. Leaning toward the tstat guess. Ran fine cool that way, on one stretch of highway with no cars in sight rolled her up to an easy 115mph. Smooth as silk. Weird thing was that with the guage dropped all the way into the blue, the heater wouldn't blow warm. It was 50*F out and it was blowing cold air. I didn't think it was possible for the water to get that cool in a running engine, so I thought I might also have a problem with the heater core or controls. What are the odds of that happening at the same time? No way, it's got to really be running that cool. Hard to believe.
Got home and promptly read the Royce manual. Right there it says that a thermostat that is stuck open will lead to low highway temps. Taa-daa! Love that manual.
Was in a hurry, so I didn't order from BMA or Autohaus AZ, but in retrospect I should have. Paid the stealer $15 too much for the tstat and after I get it all apart, I paid a local parts house $6 too much for the TMC aluminum tstat housing (my original plastic one was cracked.) Small change, but it's the principle of the thing.
Pulled the old one out and it was not just hung open, it was broken and was stuck WAY open.
http://i123.photobucket.com/albums/o284/pmcdougal/BrokentT-Stat2.jpg
http://i123.photobucket.com/albums/o284/pmcdougal/BrokenT-Stat.jpg
Replaced the thermostat, housing, o-ring and profiled gasket. The surface of the head where the thermostat housing bolts was slightly corroded. Since it was right where the profiled gasket sits, I cleaned it up thoroughly and put a very very thin coat of RTV on it. Let that set up for 20 minutes and put it all together.
Wish me luck! So far (knock on wood) seems to warm up quickly and operate at "straight up" on the gauge on the freeway and in town.
Searched the archives and nothing similar with follow up. One fellow was going to let us know how he ended up and that was back in October.
Thought to myself, either the gauge/sending unit is going goofy or the thermostat is hung open. Leaning toward the tstat guess. Ran fine cool that way, on one stretch of highway with no cars in sight rolled her up to an easy 115mph. Smooth as silk. Weird thing was that with the guage dropped all the way into the blue, the heater wouldn't blow warm. It was 50*F out and it was blowing cold air. I didn't think it was possible for the water to get that cool in a running engine, so I thought I might also have a problem with the heater core or controls. What are the odds of that happening at the same time? No way, it's got to really be running that cool. Hard to believe.
Got home and promptly read the Royce manual. Right there it says that a thermostat that is stuck open will lead to low highway temps. Taa-daa! Love that manual.
Was in a hurry, so I didn't order from BMA or Autohaus AZ, but in retrospect I should have. Paid the stealer $15 too much for the tstat and after I get it all apart, I paid a local parts house $6 too much for the TMC aluminum tstat housing (my original plastic one was cracked.) Small change, but it's the principle of the thing.
Pulled the old one out and it was not just hung open, it was broken and was stuck WAY open.
http://i123.photobucket.com/albums/o284/pmcdougal/BrokentT-Stat2.jpg
http://i123.photobucket.com/albums/o284/pmcdougal/BrokenT-Stat.jpg
Replaced the thermostat, housing, o-ring and profiled gasket. The surface of the head where the thermostat housing bolts was slightly corroded. Since it was right where the profiled gasket sits, I cleaned it up thoroughly and put a very very thin coat of RTV on it. Let that set up for 20 minutes and put it all together.
Wish me luck! So far (knock on wood) seems to warm up quickly and operate at "straight up" on the gauge on the freeway and in town.
Searched the archives and nothing similar with follow up. One fellow was going to let us know how he ended up and that was back in October.