Help! Oil Pressure has dropped!
03-08-2007, 09:20 PM
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Help! Oil Pressure has dropped! I just freshly rebuilt my 6.0 with mods in signature. I took the car to the gm dealership to get the pcm flashed and the mechanic held my car on and off the rev limiter for a few seconds at a time and said thats how they flash the knock sensor with their prgrammer. Well the car has about 70 psi cold and 50-60 cruising. Right after flash it runs 40 cruising and 50 cold. Could the flash have anything to do with it? It only has 40 mile on the rebuild. Im just hoping its not a bearing or 5.
03-09-2007, 07:16 AM
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Flash has nothing to do with it, oil PSI is mechanical. The program should not have screwed with the PSI gause either. I would bet he jacked it up by revving your car like that, which was 100% not needed. I have never heard of having to rev limit an egine to program a knock sensor, thats the dumbest thing I have ever heard. I would have kicked him in the nuts if he bounced my motor off the limiter.
Its hard to say why you are losing pressure, it could be many different things.
Its hard to say why you are losing pressure, it could be many different things.
03-09-2007, 07:35 AM
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the psi dropped immediately after he was done. Im fixing to go change my oil and investigate. BTW I couldnt here if it was knocking or not big cam and open headers=loud. I hope it didnt spin any.
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03-09-2007, 07:50 AM
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I hope not, especially since its a new rebuilt engine. if you spun one id go kick that guy in the nuts. I would also try to make them pay for it too, I know they will resist but I would be asking in what technical data from GM is it stated that in order to "program a knock sensor" you must bounce a car off the rev limiter. If they cant show you the data then ask them why he did it if it isnt approved procedure for "programing a knock sensor".
03-09-2007, 10:25 PM
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After an OE flash a "Crankshaft Position System Variation Learn Procedure" must be done or it flags a code. Thats what he was doing. Every time I've done one though it only required a WOT snap, but I believe service procedure calls for a slow RPM increase to 4000, (not a good idea IMHO) but snap throttles have always worked for me. I haven't heard of that affecting oil pressure before, hope you get it figured out.
Last edited by rnl35thss; 03-09-2007 at 10:31 PM.
03-09-2007, 11:57 PM
#11
Dead on must do when a reflash is done via gm techline reflash or it sets a dtc. I have never tried it just by blipping it I usually slowly ramp it up until the pcm hits the rev limiter and it learns and sets. I'll try a quick blip of the throttle next time and see how it works.
