GM Automotive Technicians Technical Discussion and Fixes for May 6, 2008

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Open Help Requests for GM

	Help Request	Answers
	1997 Buick Century Custom 3.1L Hesitation, Surge, Poor Fuel Economy VIN: 2G4WS52M9V loss of power on mid-range accell. the car ran fine with the maf reading 0g/s. i am looking for other possibilities. on light accell and heavy accell everything seems normal. noticed car has a hard time getting over 70 mph	View
	2000 Buick Century Limited 3.1L ac VIN: 2G4WY55J4Y greetings to all,i have a buick century here that has dual climate control system,the drivers side gets nice and cold but the passenger side stays warm.i evacuated and recharged ac with correct amount of refridgegerant and it does the same thing.i went to the ...	View
	2008 Buick Enclave CXL 3.6L sir VIN: 5GAER237X8 Hello everyone, I've got a tough one here. The vehicle is a 2008 buick enclave. It came to me from a body shop after a collision repair.The sir light was on the dash. The air bags deployed,so I replaced the sdm and programed it through tis2web with a tech 2 sc...	View
	2002 Cadillac DeVille 4.6L converter VIN: 1G6KD54YX2 ATTN cadillac guys. Vibration. The perverbial ever since came up. Now the vehicle has a vibration while driving and the converter is locked. The vibration seems to be around 42-48 MPH and around 1300-1500 RPM. We can get a vabration to occure in neutral in par...	View
	1988 Chevrolet C1500 Cheyenne 4.3L Poor Idle Quality, Hesitation, Cuts out VIN: 2GCDC14Z9J vehicle was towed in customer complained of a backfire and the vehicle would not run after that.i checked for spark and there was none,replaced the ignition module and coil and the engine started.i test drove and the truck would not go over 3o mph and would no...	View
	1993 Chevrolet G30 Hi-Cube 5.7L engine VIN: 1GBHP32KOR After engine replacement the owner came back with the complaint that the truck is using approximately a quart of oil every 1000 miles or so. At first we contributed it to break-in. Came in at approximately 8000 miles and spoke with vendor. They requested we re...	View
	1995 Chevrolet Caprice Classic 5.7L poping sound VIN: 1G1BL52P9S Hi Guys.Have a problem with this impala ss.I runs good but when you give it gas hard it popes out of the intake,but when you give it gas not too fast it is fine.It has a new cap and rotor,wires,and plugs look like new.at ilde the tps is .66,the iac is 0,the ai...	View
	1998 Chevrolet Tahoe LS 5.7L Surge, lack of power VIN: 1GNEK13R2W this is the second time this vehicle has been back for this problem. customer states that after the vehicle has warmed up that it starts surging and has a lack of power (states that it can't get out of it's own way). the first time we had it, it would get warm...	View
	1998 Chevrolet Blazer 4.3L Air Mix Actuator VIN: 1GNDT13W1W Hi folks, this truck came in with the AC blowing hot air only. The control module says B0408 Temperature Control #1 (Main/Front) Circuit Malfunction and B0416 Temp control circuit high. With the actuator DISCONNECTED, I have about 4.5V on circuit 733 (the ligh...	View
	2000 Chevrolet Monte Carlo LS 3.4L 1-2 shift VIN: 2G1WW12E6Y I aquired this car from one of my customers.It needed an intake manifold gasket,cooling fan assy.& a radiator. It was more money than he was willing to spend so he sold the car to me since I have a teenager that will be needing a car in the near future. He men...	View
	2001 Chevrolet Tracker 2.0L Cylinder Head VIN: 2CNBE13C61 I just want to start by thanking all who respond in advance. The customer brought this vehicle in and complained of coolant getting into the spark plug tubes. I first checked all of the tubes and found water contamination in all of the tubes but cylinder 3 did...	View
	2002 Chevrolet Camaro Z28 SS 5.7L Misfire VIN: 2G1FP22G92 This vehicle came in with a check engine light on, and I found two codes. PO300 random misfire and PO420 catalyst efficiency bank 1. I found and repaired the vacuum leak on the pcv harness. I also found a dirty MAF sensor (K&N), I cleaned the sensing elements.... Trouble codes: P0420	View
	2002 Chevrolet Impala 3.4L radio lighting VIN: 2G1WF52EX2 Radio display cuts out when interior light dimmer is turned to bright, flickers bright and dim when turning dimmer knob. Only the display cuts out, the lights behind the number keys and buttons remain constant as do the instrument display. Vehicle recently had...	View
	2002 Chevrolet Silverado 1500 4.8L Poor Idle Quality VIN: 1GCEC19V12 pickup came in with check engine light and rough running. had a random missfire code and #6 cylinder didn't seem to want to balance. spark plugs were replaced and motorvac done. customer drove for a week and came back saying it still did not idle well and chec...	View
	2002 Chevrolet Malibu LS 3.1L ignition switch VIN: 1G1NE52J92 I had to drill out the tumbler on this Malibu, as the key all of the sudden would not turn. I got a tumbler, with 2 keys from Carquest. After installing the new tumbler, the car started once and died; now no start. The red "theft system" light blinks on the da...	View
	2003 Chevrolet S10 4.3L Poor Idle Quality, Hesitation, Misfire VIN: 1GCCT19X23 Install new gasket on intake and can not get distirbutor timing set it has a poor idle... and no power lined up timing marks correctly...the books and manuals say no timing adjustments... their is no codes no vaccum leaks me just stumped... any chevy fans than...	View
	2003 Chevrolet Express 3500 6.0L Misfire, MIL Lamp on VIN: 1GCHG35U43 Hey Gm fans got a good one here, this 2003 g-van has a miss tech2 says number 6 cyl, fuel pressure ok, we have swaped ignition coils, fuel injectors, checked fuel rail for debries, none replaced upper intake gaskets, have spark and injector pulse at cyl 6 vacu... Trouble codes: P0300	View
	2004 GMC Yukon XL 1500 Denali 6.0L Traction control VIN: 1GKFK66U44 Had codes COO35 & COO40. check out rear wheel speed sensors res good bias voltage good do not loose any signal on the scantool. but at a certain speed at a certian place the traction light blinks, and the truckgo into reduced engine power for about 4 sec then ...	View
	2004 GMC Envoy SLE 4.2L Misfire, MIL Lamp on VIN: 1GKDT13S14 Vehicle was driven in, cutting off ses light was on and flashing also reduced power light was on. Check dtc found po302 cyl 2 misfire, R&R coil and plug, spark plug was soaked with fuel, used a spark tester on coil no spark. Removed cylinder 3 coil and tested ... Trouble codes: P0302	View
	1991 Oldsmobile 98 Regency Elite 3.8L MIL Lamp on VIN: 1G3CW53L2M All circuits test good with the exception of the AB circuit at the Cam sensor. It is only reading 4.99 volts. The BC side is reading correctly at 11.55 volts. Found wiring harness rubbed thru on a stud, repaired harness. Also found that the trigger for the Cam... Trouble codes: 41 (Cam sensor circuit)	View
	1995 Oldsmobile Cutlass Ciera 3.1L Poor Idle Quality, Stall, MIL Lamp on VIN: 1G3AJ55M9S This Olds runs great, but it cuts out and dies in gear at idle. Code p0341 for cam shaft sensor. Lab scope shows erratic pattern coming out of sensor. Replaced sensor with no change. I doubt we have an ecm issue because it is probably seeing the same thing my ... Trouble codes: P0341 (Cam position sensor)	View
	1997 Pontiac Bonneville SE 3.8L Starting VIN: 1G2HX52K6V Ok this is my first session getting on here. I need HELP. This vehicle is having problem with security light coming on and vehicle not starting intermitant. This problem has been happening for a couple of years know. Firts thing i did was bypass lock cylinder ...	View
	1999 Pontiac Grand Am GT 3.4L ecm VIN: 1G2NW52E2X Hello fellow techs I have a problem with this vechicle with U codes U1000 loss of class 2 serial com and U1016 lost comm with ecm. This is very intermedate have seen problem before always has been ingition switch. After replacing switch still does the same pro...	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	1997 Buick LeSabre Custom 3.8L convertor VIN: 1G4HP52K2V the replys that i received were all going in the same direction. everyone was in the opionion that the trans needed to be gone through but the customer opted out.bruce from ontario was one of the replys that i felt was right on target. i appreciate everyones h...	19
	2001 Cadillac Seville STS 4.6L Cooling Systems VIN: 1G6KY54951 thanks everyone for responding,i have in the past put the pellets in cooling system,let vehicle sit overnight with cooling press tester hooked up and the next morning when i cranked it over no coolant came out of any cylinder.it is probable that a head bolt ma...	17
	1989 Chevrolet Corsica 2.0L Stall VIN: 1G1LT5419K IATN IS A GREAT SITE, THANK YOU ALL FOR ALL YOUR HELP. THANKS ESPECIALLY TO JOHN, KEVIN, BOB, AND RAY, I WAS LEANING TOWARDS THE INJECTOR BUT I HATE TO THROW PARTS AT A VEHICLE NO MATTER WHAT THE CIRCUMSTANCES. I DID CHECK THE GROUNDS AND THE PCM FOR CORROSION...	12
	1992 Chevrolet Corvette 5.7L ars/abs VIN: 1G1YY23P4N Thank-you all who responded to my help request. All info. that was given made me go back over and ck on all that was done. The end result was that the engine coolant tempature sensor for the E.C.M. that is in the front of thewater pump was cracked and had fall...	4
	2003 Chevrolet Silverado 1500 5.3L Hesitation, Misfire, MIL Lamp on VIN: 2GCEK19T63 well, this one is out. we smoked the intake again and found no leaks. I rescoped the 02s and all looked well. finally i put the scope on the maf. Found the maf to be bad. replaced and all is well. thanks for all the great advice. sorry it took so long to clos... Trouble codes: P0420.	11
	2003 Chevrolet Cavalier 2.2L timing chain I had an insert installed in the cyl. head for the stripped threads, ordered a new bolt from G.M., and installed the chain kit. lined up timing marks with new guides and tensioner, also cleaned all debris (guides and bolt) under the oil pickup tube in the oil ...	3
	2003 Chevrolet Silverado 1500 5.3L Rear Axle VIN: 1GCEK19T63 You folks are great! Thanks for all of the responces. The vast majority of them recommended greasing the splines on the end of the rear driveshaft that fits into the transfer case. I did this and the problem went away for one day. Several folks recommend...	17
	2004 Chevrolet Venture LS 3.4L High idle condition VIN: 1GNDX03E94 Well it's fixed and here's the details. The 5v ref circuit from the pcm to the tp egr and the map and the low ref signal on the same circuit back to the pcm were rewired from the sensors back to the pcm. We found the tp sensor glitching from 0 to 1% going bac...	11
	1995 GMC WT-500 7.1L Brake light switch VIN: J8DF5A125S Gentlemen thanks very much for the replies. We finally received the proper information on this vehicle after the third try. What I found was the brake light relay having a loose internal contact. Relay replaced brake lights work!!! Yes!. Thanks again to e...	4
	2004 GMC Envoy XL SLT 4.2L trailer wire VIN: 1GKET16S94 Thanks to all who responded. The wires were in left side taped to harness. Had to remove lower trim panel and hvac floor duct for dr side to see/ acess them.	6
	2005 Pontiac GTO 6.0L starting Well the general concensus is that I shouldn't tamper with the emission system because there are fines associated with this. Several people "enlightened" me about this. As for the original reason that I posted the question wasn't even covered. I found out that...	6

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