The car is a 92 buick riviera with the 3.8. About a month ago i had a problem with the car stalling that turned out to be the MAF sensor. Well i had pulled the ECT sensor in order to test that too at that time. Since then, as the car reaches operating temp, the guage fluctuates instantly from operating temp to about 250 Degrees and back and forth for about 20 minutes before either reading a constant 250 or operating temp. Of course the car runs like shit the whole time. Ive replaced the sensor 3 times now, and tried bleeding the sytem probally about a 100 times.
One thing i noticed is that it doesnt draw the water back into the radiator from the expansion tank.
Ive also replaced the water pump, the thermostat and the radiator cap
I’m at a dead end as to what it might be, I’m ready to take it to a shop but afraid they’ll have the same luck as me and charge me for it
Which coolant temp sensor did you replace? There is one for the ECU and one for the Gauge. Those motors usually will need at least intake manifold gaskets, there is also a redesigned intake manifold as the early one was prone to cracking. Then you get coolant into the intake tract and it will run like crap until the coolant is burned off. Are you getting any kind of CEL? I’m betting it’s the intake.
there is only one dual purpose coolant temp sensor on the 3.8. Im pretty sure that its runnin like shit because the computer is pulling fuel and timing because of the high temp that the sensor is reading.
i’m gonna go ahead and assume that you unhooked the battery for at least 5mins each time you replaced the sensor to let the computer reset itself and clear the codes. if not it will ignore the new sensor and keep registering the problem. other than that im sure you already replaced the MAF as you stated you found that it was the problem the first time around…did you buy new or used? refurbished? if its anything but new i would try to find a refurbished one from auto-zone or something, or maybe even new depending on how costly the sensor is. did you have the codes read to see what they say is the problem? if you know what the codes are telling you is wrong then you can call the dealer and speak to a mechanic who will run over the possibilities with you if they arent assholes…if not PM me and ill give you the number for a guy who will.