Throw code 25 and whirling noise in 3rd and 5th
01-20-2015, 05:35 PM
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Throw code 25 and whirling noise in 3rd and 5th
I recently bought a 1988 pickup 4x4 22RE manual 5 speed. The vehicle sat for about ten years before the previous owner bought it and only had it less than a year. He replaced the muffler from behind the header with a new O2 sensor and cat, alse he replaced the spark plugs, wires, distributor, plus cap, thermostat, and the head gasket (that was why it sat for so long he said). This last weekend I cleaned the EGR valve and reset the code by disconnecting the battery for about 30 minutes. The code and check engine light went away for a few days and has come back. The check engine light only comes on when I am driving in 4th or 5th gear on the hwy. I don't want to just throw money at this thing like the last guy did, so any help narrowing the problem would be great appreciated. Lastly, there is a loud whirling noise coming from the transmission area and gets much louder in 5th than 3rd. I have not check the fluid yet and was waiting till I picked up some Redline MT-90. Thank you for any help.
01-20-2015, 05:47 PM
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Code 25 says you're leaning out. http://personal.utulsa.edu/~nathan-b...26diagnosi.pdf The list of possible causes holds more true for "newer" vehicles (as in: back in 1990). For an older vehicle, I would closely for vacuum leaks (I'm told an unlit propane torch works well.)
The code should never appear at idle, so the fact that you get it in higher gears is not too surprising. But you could have a weak fuel pump/old fuel filter/clog that is reducing fuel pressure at load. You could try putting the fuel return line (from the pressure regulator) into a bucket, and race the engine. You should always have a good flow on the return line; if engine load reduces that to a trickle you could have a fuel delivery problem.
The code should never appear at idle, so the fact that you get it in higher gears is not too surprising. But you could have a weak fuel pump/old fuel filter/clog that is reducing fuel pressure at load. You could try putting the fuel return line (from the pressure regulator) into a bucket, and race the engine. You should always have a good flow on the return line; if engine load reduces that to a trickle you could have a fuel delivery problem.
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