Been looking into a cooling issue on my 03 auto. Looking into changing the waterpump next weekend but wanted to verify the radiator was ok. Drained the radiator to check the flow and only got @ half a gallon from it. Any ideas on how much water it holds? Wanted to make sure that some of the channels/tubes weren't blocked affecting capacity. I did run water from the garden hose into the top of the radiator and it only took a few seconds before water came out the bottom hose. But a half a gallon just seems like a small amount. Anyone know??

 

When you pull the drain plug thats about right. Picturing the drain pans I usually get about half full maybe. You will fill it up to the top anyways and add a little more as it drops when you bring it up to temperature and drive around the first time after the refill so capacity doesnt really matter because you wont add near that much in. Waterpumps usually dont go bad. Sure its not a bad thermostat causing your overheating?

 

I changed my coolant last summer and drained a little less than a gallon when I undid the radiator drain plug, and took the same amount to fill it back up too. According to the FSM, radiator capacity is 4 quarts, and total capacity is a little over 8 quarts.

 

Sounds good then. I flushed the radiator twice. Thermostat was replaced about a month ago. Not sure of the problem. It's not overheating, but stays around 215 degrees. The fans run constantly once up to temp. My mom's Altima v6 heats up to 203 then fans come on and temp drops to 185 then fans cycle off till temp reaches 203 again. My max heats to 210 and fans come on and stay on. the temp never drops. With only water in the radiator last night I started the car with radiator cap off. When the thermostat opened, I saw antifreeze enter the top from the engine so I assume the waterpump is working, just not sure how well.

 

What kind of antifreeze do you run in the car? The American antifreezes like dexcool and prestone have silicates in them that can wear down the water pump over time. Try to run the silicate free Japanese antifreezes (nissan green, toyota red, honda blue).

Also, who replaced the thermostat and what brand of thermostat was it? Non-OEM thermostats have been known to go bad very quickly. Did the problems start before or after you changed the thermostat?

 

Problem started before the thermostat which is why I tried it first. Ordered a waterpump from Rockauto and gonna change this weekend I guess. Don't know what else to try. Saw on a manufacturers website that a bad headgasket can cause heating problems but would guess the engine would run rough if that was the case, maybe skip or something.

 

Hmm so thermostat and fans are ruled out (both fans are running, correct?). Definitely sounds like either water pump or head gasket. Water pump problems seem to be more common than blown head gaskets on our engines, so change the water pump and report back with results.

However, keep in mind that head gaskets don't necessarily have to cause the engine to run rough or have noticeable symptoms. A friend of mine towed a trailer across the state (about 300 miles) in his F-250 with blown head gaskets without even knowing it. Also, a quick check for head gasket problems can be done by checking the bottom of your oil filler cap or you radiator cap. If you see light colored, foamy, gooey looking stuff on the bottom of your oil cap, or if you see oil in your radiator filler neck or on the cap, then you've got head gasket problems