| Author |
Message |
Marc (Mps9000) (64.158.63.116)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 16, 2003 - 9:23 pm: | |
Hi all,
I tried searching the archives and couldn't find a thing on this.
I was driving my bus today and suddenly the engine warning light (and buzzer) came on. I'm guessing this is similar to the check engine light in a car. Temp & oil guages were fine. Air was fine. The engine kept running fine, with plenty of power. The light would go out during acceleration, then come back on when the RPM's leveled off. Same thing after I parked it...light stayed on while idling, then if I pressed the accelerator the light would go out as I increased the RPM's, then when the RPM's leveled off, the light came back on. There are several electronic sensors on the top of the engine, but I have no idea which one is making the light go on. Any ideas?
My engine is a Cummins 5.9, and the bus (if that matters) is a 1991 Blue Bird TC2000. Thanks. |
Jayjay (198.81.26.104)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 17, 2003 - 12:17 am: | |
Lights that go on/off in response to RPM changes are usually associate with pressure or voltage changes. Since your oil pressure is constant I would look for a bad alternator, weak battery, or poor/corroded connections between them. You might also check for a rapid leak down of air pressure after shutting the engine off. If there is a problem there, the compressor will keep up with a rather healthy leak. G'luck...JJ |
Darryl (68.184.122.103)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 17, 2003 - 11:01 pm: | |
Marc, these are just WAG's, but look for a loose wire that might be dangling. As you accelerate, it rubs against a ground. I had a simular problem with my Alarmstat system on my Thomas. It ended up being a bad sensor, but mine was temp related.
Be sure and check the wires around the alarmstat, which is probably located in the electrical panel all the way to the front of the bus. If a loose wire is touching one of the terminals, it could cause your symptoms. |
Paul (205.210.53.253)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 22, 2003 - 9:37 am: | |
Check your coolant level. There should be a sensor in the overflow tank or the upper radiator tank. Our Cummins will turn on the light when the coolant is low. |
H3Jim (68.107.60.182)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 01, 2003 - 11:27 pm: | |
The check engine light in a car is only concerned with pollution control devices. Oxygen sensor, snug fitting gas cap etc. Are there any pollution control devices on a bus? |
Tom Caffrey (Pvcces) (65.74.64.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 06, 2003 - 12:03 am: | |
Marc, if you have an internally leaky oil pressure sensor and idle oil pressure is substantially below working pressure, you might get the symptom that you are describing.
When you have been idling for a bit, the pressure would have no effect and the light would stay on. When you step on the throttle and the pressure rises, it could shut off the light until sufficient oil bleeds past the diaphragm and the light comes back on.
I have seen this condition in brake light switches.
Good luck running down the problem!
Tom Caffrey PD4106-2576
Suncatcher |
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