When the car is running hotter then normal is the radiator cooling fan on?Did it overheat before you replaced the coolant?Do you have a temp gun and multimeter?

Answered by saturntech9 (expert)
23,156 answers provided

Great questions. Prior to the fluid change, the fan would run. To be honest, not sure now post fluid change. Easy to find out. it does not take much to get the engine running hot. Let me go and find out. Yes on multimeters (I have several) but No on temp gun. Locally AutoZone has them for under $30 (checking harbor frieght now)

Response from Crash
2 questions asked

Lets start with if the fan comes on and also get a temp gun so we can see how hot it gets and what temp the fan is coming on.

Answered by saturntech9 (expert)
23,156 answers provided

Also you never answered if the engine overheated before the fluid change?

Answered by saturntech9 (expert)
23,156 answers provided

Ok good news and bad news. First, good news is fan is coming on properly at mid-range temp. Bad news, car is still overheating.

Yes car did overheat previously. That's what prompted the fluid change. On out of state trip for funeral from Baltimore, MD to Akron, OH, all was well until 3/4's the way on return trip. Car overheated. It was very hot day, so pulled over, ate at a restaurant to let engine cool down, went rest of trip (100 miles) using heater to keep engine cool. It worked. That's what prompted fluid change. Fluid looked dark brown and nasty. So changed fluid with flush and replaced thermostat.

So not that fan is working, headed to Harbor Freight for leak down tool and hopefully infrared temp gun.

Response from Crash
2 questions asked

Dont worry about the leak down tool that is used to find a loss of compression in the engine mostly.You can rent a chemical tester from auto zone for free all you have to do is buy the fluid for it for about 8 dollars that will tell you if you have a blown head gasket.Which doesnt sound like you do i think the fan isnt coming on at the correct temp or lack of correct flow or there is sand debris blocking air thru your radiator.

Answered by saturntech9 (expert)
23,156 answers provided

Ok, do you have a part number or name for this chemical tester? Can not find anything like this on autozone website search.

Any suggestions for clearning or cleaning the radiator? While I am suspect that this is the issue due to the sudden onset of this condition after a long trip.

Response from Crash
2 questions asked

http://www.autozone.com/autozone/accessories/Tools-Garage-and-Equipment/Block-Tester/_/N-25dh
Do you have a air compressor ?If so get a blow nozzle like one of those plastic blow nozzles with the metal tips and blow the fins of the radiator and a/c condensor out.Use your temp gun to see what temp the fan comes on at.Measure the temp right where the upper hose goes onto the engine.

Answered by saturntech9 (expert)
23,156 answers provided

Just got home. Block tester from AutoZone immediately indicated yellow. Ran it 4 times. Air was so hot going in there it warped the plastic chamber :(

Response from Crash
2 questions asked

Question: Will a "block sealer" additive to the radiator fluid help? Does it really work? is there one brand better than another?

Response from Crash
2 questions asked