Couple of weeks ago I overheated on the side of the highway, got it home and found out my fan clutch was not operating properly.
Replaced fan clutch, and have been driving it around town for a few weeks, and back roads (55-60mph) to work a few times with no issue.
Also, last week I knew I was going to be changing the oil soon, so I did a seafoam treatment in the oil and gas. Wanted to drive it a few miles and then change the oil.
Last night, I check the oil, Its milky, and a little low (leaky valve cover) So I think to myself, "I might have blown a head gasket when that fan clutch went bad and I overheated, or is it the seafoam?" So I go ahead top off with a quart of oil.
Today, I drove around a little bit, and then I get out on the highway (70mph) and it overheats on me again, and I'm thinking, yeah my headgasket is blown.
Get it home, and my neighbor, who is/was a mechanic comes over and we pull out the dipstick and my oil looks fine now?!? He grabs ahold of my fan and it spins pretty easy, and he says your truck is hot, it shouldn't spin this easy, I think your fan clutch was bad out of the box.
So I guess my questions are, does seafoam turn your oil milky like water or coolant would? Could my fan clutch be bad out of the box? He told me on his truck he just removed the clutch and it spins with the water pump. I know older trucks didn't have fan clutches, is there and adapter I can buy to do this? Would my fan explode at 4000rpms or would I need to get an older fan to go along with it?
I guess it kind of makes sense that my fan clutch is still bad, it works in town, and up to 55, but if I go faster it doesn't seem to be keeping up. I could probably take the hose out there and give the radiator a good washing too to make sure there isn't too much dirt and stuff packed in there.
When you got the engine hot you also got the oil really hot and boiled the water out of the oil. Seafoam will not turn your oil milky'
I overheated, left it for a few hours, came back, refilled the coolant that had spilled out when i overheated, and then drove 5 miles home under normal temps, i drove 40-50 mph and it never rose above the "o" in normal.
In those 5 miles you don't think i would have seen some water in my oil?
Maybe the head gasket fracture is very small, and until I get the rpms up on the highway is doesn't leak?
"You don't even need a fan if you never get below 25 or 30 miles an hour.. There is MUCH more air coming through the grill at 55 MPH than a fan could EVER pull through it. Think about it!!!!"
White 97 xlt,
yesterday here it was about 80° with 70% humidity, just fyi, not too hot, but it was pretty muggy.
I recently drove a 91 camaro that my buddy had just bought, it was a wiring nightmare the previous owner had done. Electric fans were installed on it, but were just wired to a switch on the dash. We realized this going down the highway at 55 mph, "oh crap it overheating, I forgot to turn on the fans" Now whether there is another underlying issue for it to be that hot in the first place while going 60mph, that may be true, but I have witnessed the fan help at highway speeds.
Under normal conditions if your motor didn't have a thermostat it would run cold at highway speeds fan or no fan so you have a problem that needs fixin. The fan clutch is supposed to slip too.. it's designed that way because of the above.
Too clarify for you, your fan is definitely not your issue if you are overheating on the highway. I removed my engine fan and installed electric fans that I have wired to a switch on the dash.
In 90 degree weather with a stock temp thermostat, in stop and go traffic I can drive for 10-15 miles before my truck heats up enough to get to the "o" in normal. Now if I drive from my house straight to the highway, I never have to turn my fans on at all since the airflow on the highway is MORE than sufficient to completely cool the engine. At highway speeds the gauge stays at "n" of normal.
So after all that, moral of the story, don't chase ghost issues in your fan, get a pressure tester for your cooling system and start doing some hands on diagnosis.