GM Automotive Technicians Technical Discussion and Fixes for Jan 27, 2005

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Open Help Requests for GM

	Help Request	Answers
	1990 Cadillac DeVille 4.5L Hesitation, Cuts out VIN: 1G6CD5331L Hey there cadillac techs, This one is eating me alive. You can see by previous repair that we have done all the basics. The car wass ready for a tune because it had never had one & fuel pressure was low so we replaced pump but car still had intermittant miss &...	View
	1976 Chevrolet Corvette Stingray 5.7L engine performance VIN: 1Z3716S440 This engine was built to replace the very weak stock engine (195hp). There is a brand new Holley 670 Street Avenger setting on top. Engine builder say's 350+ hp. This engine has a Crane 292H cam. Builder say's this cam works fine in the many engines he has bui...	View
	1988 Chevrolet C1500 Cheyenne 5.7L loss of power Under load the engines starts cutting out like it is starving for fuel. As soon as intake is sprayed with carb cleaner it will burn rubber. It is indicating lean condition with the 44 code. Have looked for vacuum leak and found none. Engine was rebuilt about 3... Trouble codes: 44 (lean condition)	View
	1994 Chevrolet Camaro 3.4L tcc VIN: 2G1FP2259R help this one is driving me nuts.. we have a 1994 chevy camaro that the tcc will not fully engage . we have put this vehicle on a shaffer sfifter which takes all the electronic controls from the car out of the picture and it shifts fine and we can control the ...	View
	1996 Chevrolet Cavalier Z24 2.4L cv joint - clutch ? VIN: 1G1JF12T9T Used to do a lot of work for this lady. She traded for a new Blazer so I don't see her very often anymore. Her son got a Cavalier. she called and asked me if I would put a clutch in it. She brought it in this morning, I can't find anything wrong with the clutc...	View
	1999 Chevrolet Express 2500 5.7L Misfire VIN: 1GCGG29R9X This van has a skip under light load after warm, scanned- no codes, but showed miss fire on cylinders 3&6 when driving, disconnected egr valve and vehicle runs perfect, but still no codes even when valve is disconnected. Tried a known good EGR valve from anoth...	View
	1999 Chevrolet Camaro 3.8L MIL Lamp on, engine power loss li VIN: 2G1FP22K2X This camaro has been towed in twice now, each time showing a code 1515, customer states that it ran horrible, no power, felt like it was running on half the engine only. Problem has happened both after driving for 70 miles and after driving only 10. Each time,... Trouble codes: 1515 (TAC control problem)	View
	1999 Chevrolet Silverado 1500 4.3L Poor Idle Quality VIN: 2GCEC19W9X With engine hot in gear at idle truck pings/clatters very heavly. Driving or in park it does not ping/clatter even under heavy accceleration, only in drive at idle. Checked fuel for diesel (cause it sounds like one) but none found. History is unknown. Map,puls...	View
	2001 Chevrolet Silverado 2500 6.0L transfer case/differential VIN: 1GCHK24U91 This truck came in the other day and the customer complained of a loud clunking in the area of the transfer case when shifting into 4x4 and a whine while in 4wd. We drove the truck with the customer and experienced the clunk while shifting into 4wd and what so...	View
	2001 Chevrolet Silverado 3500 6.6L Starting VIN: 1GBJK34151 I jumped in the truck monday morning(5 Degrees outside), waited for the "wait to start" light to go out and it fired right up. It ran for about 20 seconds and died. It will not restart. I figured gelled fuel so we towed it inside. After sitting for 6 hours and...	View
	2002 Chevrolet Trailblazer LS 4.2L No Start VIN: 1GNDT13SX2 we have several issues no interior lights,no radio,no remote entry, no hvac, no starter, please if anybody has seen this kind of problem help. RON Trouble codes: U1000 (no stat of health from module), U1041 (loss of ebcm communication), 1026 (loss of class 2 from ebcm), 1152 (loss of hvac communication)	View
	2002 Chevrolet Tracker 2.0L heather core VIN: 2CNBJ13C12 we have replace heather core last time but now they say we have to ground the heather core and replace prestonne by dexcool . have anybody have similar problem . thank you in advance robert	View
	2002 Chevrolet S10 4.3L frt diff i have this 2002 chevy s10 pickup with a grinding noise from the frt end when you drive on the highway for a while starts off low and then the noise gets very loud when you come to a stop you hear a snap kinda sound and the noise is gone until you drive for a ...	View
	1998 GMC Jimmy Envoy 4.3L ignition lock VIN: 1GKDT13W6W Hi GM PRO'S, the ignition key is stuck half-way back and will NOT come out, unless I push-in the core of the solenoid located right on the back of lock cylinder, than it will come all the way back to OFF position and the key will come-out NO problem... There ...	View
	2003 GMC Savana 3500 6.0L Alignment VIN: 1GTHG35U13 We are interested if anyone else has hit frontend problems on these newer GM trucks this is a fleet vehicle that we service and the company has 2 more of these with lower mileage that are also showing signs of wear on the idler,pitman and upper ball joints.All...	View
	1988 Oldsmobile Cutlass Ciera S 2.5L Excessive Emissions, Poor Idle Quality, Stall, Poor Fuel Economy VIN: 2G3AJ11R3J I got this car for 2 weeks and just give me a headache. The car came in for running always rich and it surge and stall whether on idle or cruising. I check all sensors and everything is good. The head was replaced before so I conclude that the head is the prob... Trouble codes: 45 (rich exhaust)	View
	1990 Pontiac Grand Am SE 2.3L Cuts out VIN: 1G2NW54D4L I can not find any specs for the ignition coil primary resistance for this vehicle. I have been told that .5 to .7 is normal but .3 seems a bit low. This vehicle has a driver in the ignition module for the 2-3 coil that intermittently goes OUT TO LUNCH. I feel...	View
	1990 Pontiac Bonneville SE 3.8L Brake Lines VIN: 1G2HZ54C5L Sorry for such a basic question, however, we are repairing rusty steel brake lines on the rear of the car. The two lines from the brake sensing pressure valve to each rear wheel are 4.5mm diameter with ISO bubble flares and are available from any jobber. Howev...	View
	1996 Pontiac Grand Prix 3.1L Door locks & window motors VIN: 1G2WJ12M7F This car has locked the owner inside and they had to hand keys through the sun roof for others to unlock the doors from the outside, because the windows would not roll down. The trunk lid pops open at hwy speed, the interior lights stay on for more than 8 minu...	View
	2000 Saturn LS2 3.0L Poor Idle Quality, Hesitation, Surge, Cuts out, Stall, Poor Fuel Economy, MIL Lamp on VIN: 1G8JW52R2Y when reset vehicle codes car starts up fine ,but when hot vehicle surges and stalls. O2 sensors are stuck at 1.000mv in both banks.TP sensor reading 7% at idle,is this normal. vehicle TP percentage does not change when accelerating after clearing codes. When t... Trouble codes: P0050, P0030, P1516	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	1981 Cadillac DeVille 6.0L check engine light VIN: 1G6AD4790B Considering the fact that the car runs great and that the customer is not too worried about the s.e.s. light flickering ocassionally we did not dig too deep. The T.P.S. voltage at idle and koeo was 1.69 volts. Power and ground was normal. What limited informat...	6
	1992 Cadillac Seville 4.9L ride control VIN: 1G6KS53B6N tHANKS FOR THE TIP THE CAR JUST CAME BACK FOR THE RELEY UPGRADE I WOULD HAVE NEVER THOUGHT OF IT THANKS VERY MUCH	4
	1992 Cadillac DeVille 4.9L Hesitation VIN: 1G6CD53B8N thanks for all the info you gave me, one of the replys asked me to check the injector fuses, which took some time to find, they were hidden behind RS instument panels. there i found an ERLS burnt out fuse, still trying to trace the circuit as to why it was blo... Trouble codes: 61 (Pump motor test problem ABS).	5
	1990 Chevrolet R1500 Suburban Silverado 5.7L speedo VIN: 1GNER16K9L i appreciate your time and expertise on this. the drac in this vehicle was found under the radio just left of the ashtray suspended by the wire harness. i would like to express my thanks for the helpfull responses . jimmy	8
	1991 Chevrolet K2500 Cheyenne 5.7L Poor Idle Quality, Stall, Poor Fuel Economy VIN: 2GTFK29KIM Replaced the Super chip with stock chip and all is well. Thanks for the help.	9
	1994 Chevrolet K2500 Suburban 6.5L cooling system VIN: 1GNGK26F0R Howdy Boys n Girls, I got several testamonials on the merits of different block sealers, some that require engine disassembly and some flush and pour in types. I elected albeit the lazy route to use the GM seal tabs. My machinist highly recommended them and in...	16
	1996 Chevrolet K2500 Cheyenne 6.5L Surge, Cuts out VIN: 1GCGK24F3T Thank you to everyone who replied, especially Brent from British Columbia and Paul from Texas. We replaced the injection pump and that fixed the problem.	4
	1996 Chevrolet Blazer 4.3L engine VIN: 1GNCS13W1T thanks for everyones help. this is what we did to fix vehicle: based on several replies about a possible short to power we removed fuse box and found several wires melted together. at this point we traced all wires and found short to orginate at cig. lighter. ...	17
	1998 Chevrolet Prizm 1.8L No Start VIN: 1Y1SK528XW Well finally got the beast running, I compared all my data to a corolla that came into the shop, everything was the same, so back to the drawing board I went, I found with my noid light attached that at WOT I still had pulse, this car does not have a clear flo...	4
	1999 Chevrolet S10 2.2L Misfire VIN: 1GCCS1443X As I stated earlier the truck does not have EGR, it also does not have PCV (internal in the intake manifold). We did a clinder leakdown and found number one leaking more--26%, others 11-12%. The reading would fluctuate while wiggling the valve and we could fee... Trouble codes: P0300 (Random cylinder misfire).	10
	1999 Chevrolet C2500 Suburban 5.7L unknown VIN: XGMXTO5.71 Wow, we got 18 replies to this posting. The majority said this noise is a form of piston slap, due to carbon buildup just above the top ring. GM has coated pistons that might eliminate the buildup, but no one who answered had tried them. Basically everyone sai...	21
	2002 Chevrolet Avalanche 1500 5.3L transfer case VIN: 3GNEK13T52 thank you to all that responded the encoder motor was bad replaced it & the encoder harness connector & all was good part of my test problem turned out to be a test lead wire failing for my dmm thanks again	3
	2003 Chevrolet Silverado 2500 HD 8.1L auto 4wd VIN: 1GCHK29G43 unable to get truck to dealer as of yet. suspect the 4wd switch or a reprogramming issue of transfer case. many posts suggest that reprogramming is correcting many problems. spoke with local chevy dealer and they have confirmed several updated programming issu...	4
	1996 GMC Jimmy 4.3L turn signals VIN: 1GKDT13W5T thanks everyone for all the input, the problem turned out to be corroded wiring under the drivers floor carpet. i am sorry it took so [...] to post this fix, but there has been a blizzard here on cape cod and things are almost back to normal. thanks again	30
	1994 Pontiac Grand Am GT 3.1L coolant temp VIN: 1G2NW55M8R Rick of ohio is the winner on this one . His first sugestion about coolant bottle cap was the problem . What was happening is the system coudnt maintain pressure.As the thermastate would close and the radiator was cooling properly going down the road it would ...	17
	1997 Pontiac Grand Am SE 3.1L Poor Idle Quality, Hesitation, Surge, Misfire VIN: 1G2NE52M0V thanks to all that replied, i did a pressure drop on the injectors, ohm checked all the injectors, and also did the voltage test per alldata. all the tests said the injectors were good, the #4 injector was the only one that was slightly different than the rest...	7
	1998 Saturn SL2 1.9L trans line blows out VIN: 1G8ZK5274W Replaced the trans lines and fittings at transmission. The plastic retainer in the fitting seems like it needs to be put on the line first and then inserted into the fitting. After installing this way the line could not be pulled out. Thanks for the help.	4
	1998 Saturn SL2 1.9L reverse VIN: 1G8ZK5272W well this thing is fixed thanks alot for everybody that responded. it was defective brand new valve body from saturn, after taking the side cover off i could not find the nuts for the shafts loose they were tight ,so i decided to take the valve body that i had...	4
	1998 Saturn SW2 1.9L Stall VIN: 1G8ZK8278W thanks for all of the replies...three of you agreed on the fuel pump...we had the customer get one installed in their home town and that has done the trick...seems that the diagnosis id to dive the vehicle over 70 mph with fuel pressure gauge attached...by doi... Trouble codes: 1599 (loss of ckp signal to computer).	12

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