Mitsubishi Repair: 2001 Eclipse oil light when stopped, blown head gasket, rebecca rebecca

Question
Hello,
I have a 2001 Eclipse RS.  Recently, when stopped at a red light, the oil light will flicker.  When stopped for longer than 30 seconds or so, the light will stay solid.  Once I step on the gas, the light goes away.  My oil level is fine.  

Tonight, I warmed up the car before heading home (about a 20 minute drive.  When I got in the car, I noticed I had very little heat.  Once I began driving, the heat came on.  After about 10 minutes, the heat turned off and cold air began blowing.  At this point I noticed the temperature gauge going up.  Thinking I might overheat (even though it's about 30 degrees outside), I quickly turned on the A/C on full blast.  This brought the gauge down to normal.  Unfortunately, I had to drive the remaining distance with the A/C blasting, but at least I got home okay.

I'm thinking oil pump or, God forbid, head gasket (cylinder head).  What do you think?  What would be the approximate cost of each repair?

Thanks very much,
Rebecca  

Answer
Rebecca: It is called a Thermostat, it controls the water as it runs through the engine. Your's is closed, so you need to go to a shop and get that replaced. As with it closed, no water or not much is being pushed through your engine, which is what cools the engine. I had not thought of turning on the AC but please get that fixed. Or you will blow the head gasket. Don't think it is a blown head gasket at this time and place. But do check the oil, if there is a water in it and your car is blowing a white smoke out the back; then it is. But mean while, what kind of oil are you putting into your car? When is the last time you had your oil changed? Could they have put 5/30 weight of oil when they did this? A lot of shops that change oil these days will put in a light weight oil. Telling you it will be easier for you to start your car in the Winter. But some engine do not run well on that light weight oil. I always go with 10/30 weight. So that lighter weight oil might be your problem for the oil light. Could be a bad sensor that controls the light. I really don't see it as a oil pump when the light will go off when you give it gas. If the oil pump was going, I believe the light would stay on no matter what you did with the car. Have your belts checked too, could be something to do with that. Just an idea on my part. But you will have to get that thermostat replaced, so get the shop to check your belts and also maybe have your oil changed to that 10/30 weight to see if that helps. I once had a pick-up with a mitsubishi engine in it. It was doing just what you talk about, but it turned out that when I had the oil changed; they put in that 5/30 weight oil. Once I fixed that, the light stopped coming on. So it is a easy fix and will then explain if that was the problem or not. Hope this helps and good luck!