The Check Engine Light (CEL) comes on after 5 to 10 minutes of fwy driving. If I leave the fwy and come to a stop sign or red light, the temp gauge shoots up near the red (but does not go over). In addition, I can smell coolant, although I cannot find a leak anywhere.
One mechanic told me I have a leaky head gasket and a bad water pump. A different mechanic told me I do not have a leaky head gasket and my water pump was fine, but they were unable to explain the eerie coolant odor. I don’t know much about cars but I am reasonably sure I shouldn’t smell coolant when I drive.
Some background:
After the CEL problem first started occurring, I took it to Cars, Mufflers & Automotive, who could not figure out the issue. A few months later, I suffered a dramatic overheat, with coolant erupting out of a reservoir tank. A local Mazda specialist fixed the tank, and replaced my thermostat and radiator when I told him the car was still running hot. (In hindsight, this was an unwise waste of money, but I trusted this mechanic and had been taking my cars to him for a long time).
So, my questions are: why is my Check Engine Light coming on, why does my engine runs hot after freeway driving, and what can I do to fix it?
Go to Advance Auto or Autozone and they’ll read the CEL codes for you. This is a free service and should be your FIRST FIRST FIRST FIRST FIRST FIRST FIRST FIRST step when dealing with ANY problem on a modern care. ESPECIALLY when the CEL light is ON!
As for the problem, I’d suspect a cooling fan problem. When the car is moving there’s airflow through the grille and over the radiator, removing heat from the coolant. But when the car stops, that airflow dissipates, so the fans kick in to replace it. If the fans don’t run then the car will heat up fast. So take the car for a drive, then when you stop and the temp gauge starts to creep up, see if the fans are running. If they’re not, there’s a problem with the fuse(s), relay(s), the circuit, or the fans theirselves.
The other possibilities are a dying water pump, colapsed or restricted hoses, a clogged radiator or hose, or air in the system.
-Matt
Your light comes on because the ecm detects a overheat problem. check when the car ins in the overheat mode your tail pipe for any signs of water or antifreeeze smell. Also check your heater core for leak. Do your water stay full or do you have to add? The head gasket problem could be when the enging itself warms up and creates an expansion of the gasket. The heads are aluminum. Hope this helps
That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code not just their translation into English and post it back here. It likely will have a format like P1234.