it overheats while throwing hot air, then heat stops and it temp goes down to half

had bad throttle posistion sensor changed it. Shortly after the fan coolant temp sensor went bad replaced it. Then car overheated due to bad sealant on lower intake end. boughgt gasket kit changed head, exhaust intake upper and lower. changed injector and fuel pressure regulator orings. clean and checked plugs.now car cranks over slow but does not run. have checked for spark,fuel, THEY ARE GOOD TRIED STARTING FLUID NOTHING. IM LOST AND NEED HELP

Check engine light on due to vent control valve

Im leaking oil from a small circular spot which looks like it could be an o-ring sealant. It doesn't leak until i turn off my engine. Then it leaks for a little while. How do i know if its the o-ring seal or if its the intake manifold gasket if heard of?

It runs rich if unplugged but it does run. Runs well in morning but won't if I have to shut it off. I have replaced ignition , and fuel pump. Had checked for vacuum leaks and it doesn't seem to be that. Any ideas? Thank you

When I firt start out from a stop I can feel the traction control kick in and the light comes on. It does it for a couple of seconds and returns to normal. I had the brake pads all around replaced about 2-3 weeks ago. The traction thing started not to long after that.

my 2001 monte carlo starts and runs fine until I get up to 55 and then the engine shuts off and wont restart, I have to disconnect the battery to reset the security system and then its fine until I hit that speed again. I have replaced my ignition and even had it bypassed and that didn't help as it still stalls, never at low speeds just when I get up to 55.there are no codes thrown please help.

Just got major engine work done ..a new intake manifold . now fan runs "on "after the engine turned " off" I see the fan is near the front end near the lever which opens the hood. is it related to a/c .?.i was told the a/c compressor needs replacing and a new thermostat. helpful info please .... the mechanic was not helpful in this regard. i never heard or saw this fan running before now.
thank you

Was driving yesterday and after car was fully warmed up I put the gas pedal to the floor while driving down the highway. I held it there until it redlined and shifted into the next gear I then let off. About 5 minutes later low oil pressure started flashing on the dash I pulled over and all the oil had leaked out from somewhere I haven't yet located. I had my oil changed the day before by a shop and it didn't leak anything before this happened. Please help!

My car's speedometer seems to have issues with the colder weather. I know next to nothing about cars, so I'll try to describe the issue the best I can. It seems that in the colder weather my speedometer is freezing. I have no issues with the other gauges in the car, and have not noticed the issue in warmer weather. So, I'll be driving around, and according to my speedometer, I'm driving at 0 mph. Sometimes it'll be 5 or 10 mph lower than the actual speed I'm going. Is there any way to stop this from happening? Is the gauge faulty? I honestly have no idea why it's doing this, or what could be wrong with it.