So one day out of the blue I glance down at my gauges and the temp was like 90% of the way to the line indicating the start of the hot range. This startled me and as I was watching it fell back down to normal. Over the next couple min it did it a few more times, going from normal to almost hot and back, in about 20-30 second cycles. I opened the radiator and it was way low so I topped it off and it stopped doing this. Since then I have noticed a decent puddle under the car every time I get in (more under the driver’s side), so I know it is leaking. I believe it is the water pump, and I plan to change it out in about a week. I am just curious as to what exactly was going on to make it register hot and then drop back down? Air/steam trapped at the thermostat or what?
I am confused here, I thought the overflow reservoir was supposed to drain into the radiator. But it seems like the overflow is only periodically draining. Sometimes the overflow will be low and I add water to it, other times the overflow is full but the radiator is still low. Any thoughts on this?
Thanks!
Cooling problems
could be water sloshing around. A pocket of air got behind the thermo where your temp gauge for your cluster is and registered a lower temp, then when the boiling coolant got in contact with your temp sensor, it shot back up. Could be that.
Since you're leaking coolant, a good place to look just from my experience is the weeper hole under the water pump. If you've never changed the water pump, it's a very probable culprit. Next place to look over are your coolant hoses. They get old and brittle. My own altima had a weird issue where coolant was slipping by the upper radiator hose when stopping and the coolant was slipping past through a small crack I couldn't see from the top but caused a plume of white smoke from under the hood.
keeping it simple: check your water pump and check your hoses.
Since you're leaking coolant, a good place to look just from my experience is the weeper hole under the water pump. If you've never changed the water pump, it's a very probable culprit. Next place to look over are your coolant hoses. They get old and brittle. My own altima had a weird issue where coolant was slipping by the upper radiator hose when stopping and the coolant was slipping past through a small crack I couldn't see from the top but caused a plume of white smoke from under the hood.
keeping it simple: check your water pump and check your hoses.
Re: (180fan)
I do believe it is the waterpump! Looked under today right after I stopped driving and I saw coolant dripping directly off the water pump housing forming a nice little puddle.
I have been pondering it and is it possible for the gauge problem to be caused by the leak stopping and starting while I was driving, causing the coolant go back and forth from pressurized to boiling?
Another q though, when I took the cap off the radiator (cold engine, off overnight) it made a psssss sound that I believe was air rushing into the radiator. Is the system supposed to maintain a vacuum? I though that coolant from the overflow should run back into the radiator under these conditions. Anywho, thanks for the help!
I have been pondering it and is it possible for the gauge problem to be caused by the leak stopping and starting while I was driving, causing the coolant go back and forth from pressurized to boiling?
Another q though, when I took the cap off the radiator (cold engine, off overnight) it made a psssss sound that I believe was air rushing into the radiator. Is the system supposed to maintain a vacuum? I though that coolant from the overflow should run back into the radiator under these conditions. Anywho, thanks for the help!