So the whole overheating thing seems to be a hot topic with the Pioneer 1000 models.
I put together a quick guide based on what I have seen. (ignoring what may be flakey).
Is something broken?
Let’s face it when a P1k overheats everyone jumps to conclusions about the items below. If there is something out of order your SxS will overheat. The fan is controlled by a black box under the driver's seat. The computer controls this box based on several unknown things.
- Is the box plugged in correctly? Several have reported it was not at assembly.
- If you extended the vent line on the radiator fan it could cause the motor to overheat and stop working.
- If you used a bellows to vent the fan all sorts of bad things could have happened as other users have mentioned the cause pressure to build up and push out seals.
- Coincidentally, if you didn’t vent the radiator fan you could have mud in fan motor or a blocked breather tube (did you read the manual? Don’t drive in water over 10" deep).
Symptoms: it’s likely the fan will come on but the temperature will continue to rise.
- Something blocking the radiator, Usually mud.
- When cleaning shine a light from the back side, looking from the front you can see if the passages are clean. The fins can look clean but mud could still be blocking between them.
- Do you have a large bumper? (compensating for something?) This might restrict airflow!
- Aftermarket lights, winches, and other objects could also block the airflow.
Symptoms: temperature will continue to rise only under high load conditions. Insufficient cooling capacity
- Some people are saying the cooling system is undersized.
- As the temperature rises to 3 bars or more, slow down or stop, leaving the engine running, this will allow the cooling system to catch up.
- High altitude, like above 6,000 feet or more.
- Long continuous pull – EX. uphill on a forest service road in Utah.
Link referencing insufficient capacity: Overheating issues.
Symptoms: the temperature will continue to rise and the fan doesn’t come on, nothing will make the fan come on until the computer is reset.
- Computer glitch
- Some dealers are saying there is a computer glitch that controls the fan.
- Turn the key all the way off, then turn it back on.
- Basically, you are resetting the computer.
Link for computer glitch: P1000 - Engine cooling fan problem
Other symptoms:
- The fan may cycle on and off or if the temperature sensor is in the air pocket the gauge will not register hot and the fan will not cycle but the overflow bottle will be boiling furiously.
- The temperature will continue to rise even with the fan on.
- Sometimes it will seem just fine, only acting up under high load conditions.
Air trapped in the system
- For some reason, there seems to be a lot of units with air trapped in the system from the factory, and it seems to be getting worse, not better.
- If you have an air pocket the cooling system will have reduced efficacy as the boiling point is lower.
- The air pocket will allow the coolant to expand and act like the pressure system is not working.
- Sometimes it boils over a few moments after you come to a stop.
Burping
- There are several threads discussing how to ‘burp’ the system.
- Most methods involve raising the front end up, be careful you don’t drop the vehicle on yourself.
- Some methods have you running the engine while the front end is lifted, don’t lift the nose and uncover the oil pickup – watch the oil light for any signs of trouble.
- For the ‘burp' method to work the thermostat must open to allow coolant to circulate and the air bubble to be expelled.
- It’s probably better to start with a hot system, it takes less time for the thermostat to open.
- You can feel the lower hose to see when the thermostat opens, the hose will get hot when the thermostat is opened.
Link for burping procedure: Overheating issues.
