I am trying to keep my ~200k miles Mitsubishi Diamanté, 2002, going. Up until recently. It has been 100% reliable. It has recently had new brakes, timing belt, water pump, valve cover gaskets and cam seals replaced, a new thermostat, a new fuel injector, distributor coil, and rear oxygen sensor, and coolant added. Often when I depress the accelerator hard, on freeway on ramp, lights will come on like brake, or antilock, w sharply rising temperature gauge. I always pull over or slow down to recover; it has never heated to the red zone. Cylinder heads were removed and looked fine. What could the problem be?
Update: car failed head gasket test: a very small leak, and took a long time to show, but the color change was eventually there.
There is also a converter issue; thank you so much for your help Scotty. I have a ticking time bomb.
Thanks for reporting back.
Get rid of it while you still can. I wouldn’t recommend you put anymore money into it, as 200,000 miles is already twilight for that Mitsubishi.
That's a classic sign of a clogged catalytic converter Id have it pressure tested
Thank you Scotty! Thank you for giving me hope / direction. The P04021 “check engine” has been on for 4-5 years, but only in the past few months have the symptoms gotten acute. Always before I could fix overheating at a stoplight, etc, with topping off coolant or pressure washing the cottonwood and bug juice cement off the radiator. Lately the problem has gotten more scary.