My car's fan is running all of the time and the check engine light is on. I had it checked and it was an oxygen sensor. The light went off for a while and so did the fan. Now it's back. Would that have anything to do with the oxygen sensor? I didn't replace it. The guy just told me to use the high test fuel on the next fill up.
Your cars fan is running because it is hot. Have you checked your radiator fluid lately? A fan is supposed to run a lot by the way. The oxygen sensor and the fan are unrelated, unless there is some electrical problem.
Haven't checked the fluid. The fan is on all of the time. It kicks on when the car is started and cold, so I'm thinking maybe some switch is going bad? It's also unrelated to the a/c running because it's on when the a/c is off. Just seems weird that the light came on and the fan started acting up, the light goes off and so does the fan noise and then they both start up again.
Try blowing out the air filter with an air compressor. If the light still comes on, replace the air filter. If that doesn't fix the problem, try these steps: replace the fuel filter, then the PCV valve, and if that doesn't fix it, live with it long enough to get rid of the car, because it might be the ERV at fault ($160 for a new one on my Chevy)
Check the oil stick. If the oil looks 'milky' you might be in some stink. If the radiator is low, causing it to run hotter than usual, the fan will stay on trying to cool the motor. If the radiator is low, and there is no sign of leakage, it might be the head. If the head gasket is leaking, the oil will look milky on the dip stick, if you hold an index card up to the tailpipe and you have an excessive amount of moisture that might be another tell-tell sign.
The air filter is good and the oil looks fine. The traction control doesn't come on when the check engine light it on. I leave it off normally, but I was bored at the bank drive thru a couple of weeks ago and clicked it and it wouldn't come on. I know it works when the check engine light is off because the light went off on my birthday and the traction control started working again, so somehow that is connected because since the check engine light came on again, the traction control isn't working and the fan kicks on as soon as the car starts. I have also noticed that it looks like something is leaking from car. It's not oil and it doesn't appear to be anti-freeze. I put a paper plate under it to catch it but then it wouldn't leak and my plate blew away. So we got a check engine light that Auto Zone said was an oxygen sensor, a fan running all of the time, a small leak and the traction control isn't working, The only other thing I have noticed is that the car (and it's only done it twice) acted weird after I started it and took off. It revved funny. Kinda like it wanted to stall, but kinda like it was possessed. It would kinda lurch a little... Rev, stop, rev, stop, rev, stop and then it was fine. I'm getting the fuel filter changed this week, running premium fuel in it and adding a can of seafoam to the tank. This is the first kind of trouble I have had with the car in 9 years. It was never stalled or left me sitting or had to be in the shop, so it's allowed to need maintenance. I just like avoiding the garage if I can.
Is it out of the question just to take it to a reputable mechanic and get it fixed? A couple of hundred dollar repair bill is cheaper than a new car. If no, then the Sea Foam is a good idea. It could also be a throtle position sensor. On Nissans these give a lot of problems. The possessed thing sounds like a throttle position sensor. It is not a do it yourself fix it job, it is a trade the problem to someone else job. What kind of car is it?
It could be the ECU as well. If it seems to be a bunch of gremlins a good central source of problems could be the computer. I had one get fried in an S-10 (85 model) left me stranded about 6 miles from my house. Just wouldnt do anything other than turn over. But it was fried, not just 'getting fried'.... The autozone scanner will tell you what codes its popping, but if the ECU is shit then it wouldnt really tell you that. Im with Baz, (of course I just painted the 'new' fender on my Acura in my front yard, so I cant say I would do it, but you're kinda cute so maybe you can get a good deal....
If I take it to a mechanic, they are going to tell me something is wrong with it. Seriously, I always get jipped. They'll tell you that there are a million things wrong. I went to the dealership after I bought the car for a thumping noise in the trunk. I had the strut mounts, strut plates, strut towers and a few other things replaced and it STILL made the noise. I changed the struts and the noise stops. All it needed was the struts replaced. So naturally, I start taking it to the place that simply replaced the struts to get the oil changed and inspections. I pass every inspection wth no problem and then the last time I take it there when the inspection really counted because I was getting my Recon title, I ended up spending 400 bucks on two tires and a turn signal switch. The switch had been bad for a couple of years and they always passed it. I just felt like they knew they could stick it to me and they did. I don't trust mechanics or doctors. I like to find out what it is first and go in with that knowledge to see what they come back with.
take it to autozone again, tell them to pull the codes off of your ecu. if it has a check engine light on, then it has trouble codes stored. as far as i can tell from what you've described, here goes. you might have a faulty coolant temperature sensor causing the fan to be running constantly, and because the coolant temp sensor isn't getting the right reading, the car's computer isn't sending enough fuel to the engine based on the temperature that it's receiving from the sensor. also the fact that the oxygen sensor is sending different info to the computer is probably why your car ran funny. it might just be a bad connection or that the connection is dirty or corroded. take the car to autozone for the free scan, then take the scan to a few different mechanics, see who tells you the same diagnosis, and go with the cheapest. ask for a final price out the door type of deal in writing and make sure to tell them to alert you if anythign is added to that final price before any additional work is done. oh, and good luck.. what kind of car is it???
Thanks. It's a Sunfire. I took it to a mechanic the other day and it was the oxygen sensor like Auto Zone said. They cleared the code before they checked the fan noise. Since they cleared the code, the fan didn't kick on. I told them it was somehow related to the check engine light but they didn't listen. So now, the light has stayed off and the fan has stopped kicking on when it's not supposed to. The ABS light comes on sometimes and then goes off. Is there anyway you can clean area around the sensors? I feel like they are dirty.
that may very well be the case, that the sensors are dirty corroded, or just a bad connection down there, but on that same note, since it is an older car, the sensor will be brittle and likely to break off when removing them to clean them off. another thing, how are your brakes? if your brakes are too worn down, the brake fluid level might trigger the sensor so that you get the light on in the dash. check your fluid level before asking anyone to do anything, and if it is indeed the sensors being dirty, be prepared to buy new. make sure to check gorunds and connections. and as always, good luck!
I haven't checked the fluid, but the brakes passed inspection a couple of months ago. I'll check the sensors out... if I can find them.
