nostopin
Member
- Joined
- November 21, 2010
- Messages
- 10
- Reaction score
- 0
- City, State
- nor cal
- Year, Model & Trim Level
- 93 exporer
So... I'll start at the beginning. For a couple years now my 4.0 makes a knocking, or perhaps pinging noise if I am driving up a long grade. Its only while its under power, If I let off the gas it stops. Gear/RPM does not seam to matter.
Last summer it started running hot. I noticed my radiator was packed with rusty mud, so I flushed the system about 17 times, and put a new radiator in it. BUT I left out the thermostat. It was restricting the flow, so I put it together without one until I could make it back to the parts store. The thing ran great, barely got warm in 100f weather. Procrastination has landed me here in the beginning of Jan with no thermostat installed. My engine has not been up to operating temp in a couple months now. there is snow on the ground and my heater doesn't work (thats a issue with the heater core, got one on the way)
Today I installed the thermostat and noticed right away that the knocking was back. It has not knocked/pinged since I took the thermostat out.
I have no idea what relation the thermostat would have with this noise, I cant tell the diff between a knock and a ping, so I dont know if its because the oil is now getting up to temp, therefore its thinner causing it to knock, or maybe since its at operating temp it has something to do with pre detonation or timing. Should I try 20w50 oil? Honestly the thing runs great without the thermostat. it gets 20.8 mpg, has plenty of power, does not sputter, knock or ping. But I know it has to be bad for the engine to run that cold, the temp gauge does not even move up to cold. even after 2hrs on a mountain road.
Last summer it started running hot. I noticed my radiator was packed with rusty mud, so I flushed the system about 17 times, and put a new radiator in it. BUT I left out the thermostat. It was restricting the flow, so I put it together without one until I could make it back to the parts store. The thing ran great, barely got warm in 100f weather. Procrastination has landed me here in the beginning of Jan with no thermostat installed. My engine has not been up to operating temp in a couple months now. there is snow on the ground and my heater doesn't work (thats a issue with the heater core, got one on the way)
Today I installed the thermostat and noticed right away that the knocking was back. It has not knocked/pinged since I took the thermostat out.
I have no idea what relation the thermostat would have with this noise, I cant tell the diff between a knock and a ping, so I dont know if its because the oil is now getting up to temp, therefore its thinner causing it to knock, or maybe since its at operating temp it has something to do with pre detonation or timing. Should I try 20w50 oil? Honestly the thing runs great without the thermostat. it gets 20.8 mpg, has plenty of power, does not sputter, knock or ping. But I know it has to be bad for the engine to run that cold, the temp gauge does not even move up to cold. even after 2hrs on a mountain road.
