| Author | Message | ||
| quantum merlin (Quantum500)
Registered Member Username: Quantum500 Post Number: 36 Registered: 8-2007 Posted From: 70.57.21.17 Rating: N/A |
I'm having trouble keeping the old girl cool. I believe that the alarmstat is a 190 wich I thought was a bit too cool, but if its not a pressurized system it would be just right. So please enlighten me. | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 418 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
QM, You're saying "alarmstat?" Do you mean thermostat, or hot engine alarm? Anyhow, if your bus has 180 thermostats, they will just about be fully open at 190, and if thats where your alarm comes on, its a false alarm. Your bus and mine will hit 190 uphill on a warm day with no problem. In my opinion, the hot engine alarm should be set for about 205. The cooling system is equipped with a pressurized cap, so the bus won't boil at 205 at high elevations. A common cause of heating problems in the squirrel cage cooling systems, is worn "grommets" on the ends of the blower shafts allowing air in around them instead of pulling it all in through the radiators. This is also assuming you still have an 8V71 with stock injectors, and the radiators are clean inside and out, and the belt is tight? Look back in the archives, please, as this got well kicked around a couple of months ago. HTH, George | ||
| quantum merlin (Quantum500)
Registered Member Username: Quantum500 Post Number: 37 Registered: 8-2007 Posted From: 71.33.238.169 Rating: N/A |
MCI uses the alarmstat made by Kysor. I'm unsure of what thermostats I have but 180 would be a fair guess. At 190 the alarm comes on and shuts the engine off. Thats why I was asking. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 163 Registered: 3-2006 Posted From: 209.50.74.6 Rating: N/A |
QM You might want to use an infra red temp gun and see what temp you are actually running at. Your temp gauge might be away off and you are running hotter then you think. 190 is too low to shut off the engine. Alarmastat could be defective. Bill | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 419 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
QM, Bill is right, and we both agree 190 is too low for a shutdown. It also sounds like your temp gauge is correct, and you are getting a shutdown way too early. I would do something to check the accuracy of the dash gauge, as something is definitely wrong. High resistance wiring, (poor grounds, loose terminals, etc.) will cause the dash gauge to read lower than the actual water temp. So, get a new mechanical gauge if you don't already have one, and install it in the rear piping. Run the bus a ways, stop and compare the readings. If they're the same, adjust the alarm setting. I have an infrared gun also, but it gives different readings on metal surfaces, depending on their texture and color. The manufacturer advises painting a spot flat black for a true reading. FWIW, George | ||
| quantum merlin (Quantum500)
Registered Member Username: Quantum500 Post Number: 38 Registered: 8-2007 Posted From: 67.41.221.134 Rating: N/A |
Yep I have a gun also it reads about 5 degrees warmer than the dash gauge. I have not checked it when it shut off, I try to avoid that if at all possible, but from what I can tell it turns off at about 185 on the dash gauge. So 190 actually. I do plan on putting a mechanical in the engine bay and changing out the alarmstat to at least a 210. | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1279 Registered: 12-2000 Posted From: 76.66.19.23  Rating: N/A |
Hello. One big problem... the temp will drop rapidly when you pull over to take temps when trying to zone in the dash gauge, making the exercise useless for temps above the thermostats. However... an assistant who is able to shoot the infra red gun down through the engine access hole at an appropriate piece of piping, is able to get a real time reading and shout it forward to the driver. Daughter #2 reports you need to be ready for a lot of wind and noise when you pop that floor hatch open at highway speed! happy coaching! buswarrior | ||
| Don Evans (Doninwa)
Registered Member Username: Doninwa Post Number: 119 Registered: 1-2007 Posted From: 208.81.157.90  Rating: N/A |
"Daughter #2 reports you need to be ready for a lot of wind and noise when you pop that floor hatch open at highway speed!" No joke. My son pulled the hatch on the trip home. With nothing but a shell lined with plywood it makes a real echo chamber. Don 4107 | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 431 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
QM, I finally got time to find my MC6 schematics, and have to apologize for not posting this sooner. On mine, wire #48 can be removed from stud #51 in the front junction box, and taped. This will prevent the bus from shutting down with either a hot engine alarm, or low oil pressure. It does NOT disable either the light or the buzzer. It does beat holding down the start button while going uphill, and trying to shift, put on the turn signal, steer, and look for a place to get off at the same time. I'm not sure if it would be the same terminal number on your bus, but look for the relay labeled: BATT MOTOR GUARD RELAY, (at least on mine) and disconnect the wire coming off the GEN terminal on it. If you and yours are the only people driving the bus, I don't see a reason not to. HTH, George |