Engine will not start (2006 Chevy Express 3500 chassis)
We have a 2007 Winnebago 331C Motor Home with a 2006 Chevy Express 3500 chassis (6.0 L V8 gas engine). We cannot get the engine to start. Here is a summary of what we have done, along with some hypotheses:
Problem
The starter cranks the engine with no problem, but it will not start. The engine will sputter briefly, but will not fire. We just got back home from a 1,400 mile round trip to Washington DC. The oil pressure light went on and off briefly a few times (it was on for a few minutes each time). Checked the oil a few times during the trip, it was full each time. The oil pressure gauge never went too high or too low.
Aside from the oil pressure light, we did not notice any problems during this trip. The first time we tried to start the engine after we got back home (the next day,) it would not start.
Things we’ve done
- Scanned for OBD codes several times with two scanners. No codes found.
- Inspected/cleaned the mass air flow sensor (did not replace it.)
- Replaced all spark plugs, wires, and ignition coils.
- Replaced the crankshaft position sensor.
- Checked fuel pressure at engine, 55psi (minimum limit, per the Haynes manual).
- Checked grounding wires/straps from the chassis to the engine.
- Looked for various fluid leaks. None found.
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Possible Causes?
- Bad fuel?
- Clogged injectors?
- PCU problem?
- There is an “AUX START” switch on the driver’s side kick panel, below and to the left of the steering wheel. I damaged this switch when I removed the panel. This is a momentary switch which connects the motor home’s marine batteries to the vehicle’s electrical system, so the marine batteries can be used to start the engine, if the vehicle’s battery is dead. Is it possible that this switch needs to be assembled and in place to start the engine?
We welcome and and all advice! Thanks in advance!
Problem
The starter cranks the engine with no problem, but it will not start. The engine will sputter briefly, but will not fire. We just got back home from a 1,400 mile round trip to Washington DC. The oil pressure light went on and off briefly a few times (it was on for a few minutes each time). Checked the oil a few times during the trip, it was full each time. The oil pressure gauge never went too high or too low.
Aside from the oil pressure light, we did not notice any problems during this trip. The first time we tried to start the engine after we got back home (the next day,) it would not start.
Things we’ve done
- Scanned for OBD codes several times with two scanners. No codes found.
- Inspected/cleaned the mass air flow sensor (did not replace it.)
- Replaced all spark plugs, wires, and ignition coils.
- Replaced the crankshaft position sensor.
- Checked fuel pressure at engine, 55psi (minimum limit, per the Haynes manual).
- Checked grounding wires/straps from the chassis to the engine.
- Looked for various fluid leaks. None found.
-------------------------------------------------
Possible Causes?
- Bad fuel?
- Clogged injectors?
- PCU problem?
- There is an “AUX START” switch on the driver’s side kick panel, below and to the left of the steering wheel. I damaged this switch when I removed the panel. This is a momentary switch which connects the motor home’s marine batteries to the vehicle’s electrical system, so the marine batteries can be used to start the engine, if the vehicle’s battery is dead. Is it possible that this switch needs to be assembled and in place to start the engine?
We welcome and and all advice! Thanks in advance!
