folks,

i have recently treated my 1990 masterace diesel turbo auto 4wd to the superb temperature gauge alarm from dave mason, and after a bit of testing at various combinations of revs, speed and load, my new gauge sits at the 13th/14th dot in normal running, increases slightly under heavy loads up hill and is fairly steady there on high speed runs. my part of the world is flat so i'll have to wait to check it out on a long motorway hill. the one thing i did notice is that after a period of high revs or heavy load when the revs drop back down the temp goes up very quickly, presumably as the cooling fan speed drops off. i investegated this a bit further by provoking this effect. after a bit of hard acceleration (if there is such a thing in our beloved busses) i coasted in neutral with idle revs. my temp went up to the 18th/19th dot before dropping back fairly quickly. it seems that the heating effect of running at high revs under load is more than offset by the cooling effect of the huge fan. when the fan rpm drops off after getting to the top of the hill the engine gets a bit of a hot soak as the cooling airflow dies away. ram effect of forward speed seems to be negligible (in fact doing my 'high revs then idle' test but stopping instead of coasting brought the temp back to normal faster - curious). im running a toyota rad cap, but i suspect the thermostat is an aftermarket job. so far - no cooling probs since ive had the bus, but the gauge has given me a whole new insight into whats going with the engine - it'll be getting a new thermostat in the spring.......

- (#11568) John Tuck, 8 Nov 03 2:29

john
since fitting my temp alarm, i, like most others who have fitted an alarm, now tend to drive much more at ease knowing the alarm is installed although i did at first have several shocks especially when climbing a half decent hill, but as you say at least you can monitor the stat operation. you must admit these vehicles are pretty consistant, as we all seem to experience the same things
regards
brian

- (#11569) brian squire, 10 Nov 03 0:12