Edmunds dealer partner, Bayway Leasing, is now offering transparent lease deals via these forums. Click here to see the latest vehicles!

Chevy S10 - GMC S15 and Sonoma Engine and Underhood Problems



  • gonogogonogo Member Posts: 879
    If you google around I think you will find a unit a lot cheaper then the factory one, it will let you run just gasoline.
  • wmwinkwmwink Member Posts: 1
    Can a bad MAF sensor give me the P0300 Code? The Service engine light comes on and stays on for a few days then goes off for a few days. The truck memory shows the misfire code. When light is on I get a MAF code as well. Where is this part located at on the truck? Thanks for any input as I am wanting to sell this truck but want it fixed first
  • s10forlifes10forlife Member Posts: 2
  • s10forlifes10forlife Member Posts: 2
    I have a 95 4.3 vortec vin code Z and when I accelerate my motor bogs down to the point it almost shuts off. My fuel gauge and battery gauge go haywire unless i barely touch the gas then it goes fine. I cannot find a posting that specifies this particular motor....any ideas? I have replaced the fuel pressure regulator because an old guy at the parts store recommended that may be the problem.
  • pepppepp Member Posts: 1
    It is most likely the heater core ,i would almost bet. :D
  • squatchdogsquatchdog Member Posts: 3
    I'm looking for a diagram that will show me that I have all the fuel injection lines in there right ports, there are 2 that possably could be crossed. I have a slight vibration to the car....hard to tell if its drive train or what but my therory is crossed line could cause a minor missfire.
  • spyderlockspyderlock Member Posts: 1
    Passenger side... middle tube goes to the far back port, tube farthest back on your injector goes to the middle port, and tube the closest to the front of the vehicle on the injector goes to the port at the front. Drivers side... back tube to back port, middle tube to middle port, and front tube to front port.
  • squatchdogsquatchdog Member Posts: 3
  • squatchdogsquatchdog Member Posts: 3
    Thx...hopefully I got it wrong and this will make it better.
  • dontom13dontom13 Member Posts: 3
    does anybody know where i can find a heater vacuum line diagram for my 95 gmc sonoma,
  • ashleysandersashleysanders Member Posts: 1
    We recently did a motor swap on a 97 GMC Sonoma 2.2L 4cyl. In the process we got the firing order confused. We are trying to find the firing order for the vehicle... does anyone have any suggestions? We were also told that it is possible that number one is closer to the firewall can anyone shine some light? :sick:
  • mickeymouse2mickeymouse2 Member Posts: 161
    Firing order is 1,3,4,2 number 1 is in the front of the engine. Your coil pack is numbered 4,1,3,2 or 2,3,1,4 depending how you look at it. Number 2 on your coil pack is the post closest to the engine block.

    Engine 4 3 2 1 front
    Coil pack . 2
  • kunesjskunesjs Member Posts: 1
    Hey did you get this resolved? I have the same issue!!! Do you have any advice?
  • dontom13dontom13 Member Posts: 3
    i had problems with my heater and 4 wheel drive, i did't have any problem with loss of power, but if you have problem with your heater or 4 wheel drive i can probably help let me know
  • drizztdrizzt Member Posts: 1
    I just swapped a 4.3l from a 2000 S10 to a 1996 S10, it runs but has a miss and low power. Do I need to swap anything like control modules and what not over with the engine?
  • gonogogonogo Member Posts: 879
    Well I think the PCM software would be different.
  • joesz2010joesz2010 Member Posts: 1
    I bought my 2000 chevy s10 4.3 4x4 a year ago with 49000 miles. It ran like a dream until about a month ago. I now have 58000 miles and recently have been experiencing a drop in power when accelerating. In March I had a magnaflow muffler installed and it increased the juice, but now im losing that juice. It will speed up gradually until about 3rd gear, then it loses power at about 2500 or 3000 rpms at 50mph and needs to kick into passing gear to make it to 60mph. Could this be an engine problem or tranny?
  • gonogogonogo Member Posts: 879
    Have your catalytic converter checked for plugging.
  • zengetsizengetsi Member Posts: 2
    edited June 2010
    Hello Forum. i have a problem thats concerning me. when i drive my truck to work in the morning (its usually a 30 minute drive to and from) after 15 mins of driving i stop at a red light and when it turns green i give it some gas its seem like the gas doesnt go to the injector and starts to make a "boom boom boom" sound.. so i put the car in neutral and turn off then on the car and its works. same thing happens coming home from work. does anyone have a solution? thank you in advance.

    Friends tell me to check the gas filter. could that be the problem?
  • zengetsizengetsi Member Posts: 2
  • troyce2troyce2 Member Posts: 2
    I have a 98 with a 2.2L bottom end rebuild and new head installed. I bought the truck not running guy thought it had bad set of rings. I find when i took it apart that had a hole in the head next to valve guide seat. New coils,plugs,wires. It still has misfire on #3 I have moved the injector on #3 to #1 no change. replaced all o-rings on injectors. Fuel pressure is where it should be did compression check had 175 LBS on all four cylinders. Did leak down compression check and they where 12% to 14% on all cylinders. Moved coils around and had no change. I have checked continuity on all injector wire back to pcm. checked voltage to module to coils have 12 volts. I have pressure checked intake manifold to 30 psi. Still can not find the problem. PLEASE HELP!!!! I'm running out of ideas.
  • gonogogonogo Member Posts: 879
    Put a noid light on #3 and see if the PCM is commanding the injector on.
  • troyce2troyce2 Member Posts: 2
    edited July 2010
    I did that and it was flashing. On a scanner that a friend has he can tell the injector is firing a 4.3 milliseconds the same as the rest.
  • 00mickx00mickx Member Posts: 3
    My guess is the TPS (throttle position sensor) - good luck!!!
  • mode1mode1 Member Posts: 1
    I have a 2002 S-10 4cyl. and had the same problem especially when it rained and was damp out.... it was very frustrating. It went on for several months. Finally, I found a mechanic who knew what it was. Coils! Replaced both of them had NO problems since!
    Six cylinders have 3 coils
  • ricky16ricky16 Member Posts: 10
    i have a 96 s10 2.2 5 speed stop at a stop sign and went to take off and would not rev up over 2 grand it idles good and starts good but just will not rev up i have checked every thing i know of all sensors converter. put on scanner all it showed was bad map sensor put 1 on no change could use some help from someone please. checked compression 110 on every cylinder checked fire it is good if you might be some help i would like to hear from you help please !!!!!!!!!!!
  • gonogogonogo Member Posts: 879
    Did you change fuel filter?
  • ricky16ricky16 Member Posts: 10
    yes changed filter checked fuel pressure 65 pounds ran compression check it was good but thanks for the help if you might know any thing let me know i am at wits end
  • faublijdfaublijd Member Posts: 1
  • waynicuswaynicus Member Posts: 8
    I just bought an 82 S10, 2.8 V6, no idea how many miles on it since the odometer doesn't work. There were some rattling noises when I bought it, the owner said it was the exhaust manifold, needed a new gasket. Well, the noise has gotten worse, and I'm not sure it's the exhaust. The noise is a steady, LOUD, metal clacking noise, doesn't seem to change in intensity or speed regardless of whether I'm idling or accelerating. It seems to be coming from driver's side lower engine. I have almost no mechanical experience or knowledge, and I realize I probably bought a major headache, but does anyone have any ideas?
  • 2002sonoma2002sonoma Member Posts: 6
    Have you gotten under the truck and looked or felt around for something loose?
  • waynicuswaynicus Member Posts: 8
    I had somebody tell me it sounded like loose torque converter bolts, and that it was easy to tighten them. I crawled around under there looking for what he described, but no luck. There is some sort of brace, looks like it goes from the transmission housing to the bottom of the engine or suspension, that has the bolt missing on the transmission end, but the noise isn't coming from there. I have a Chilton's manual on the way, hopefully I'll figure it out. From what I've read here and elsewhere, could be lifter noise, but I'm wondering just how loud lifter noise is, cuz this is LOUD. If it is, I've read that it could be a bad oil pump.
  • 2002sonoma2002sonoma Member Posts: 6
    The problem i see with loose bolts or lifters is that you said the noise didn't speed up with engine rpm. If it was either one of those the clanging would get faster or slower with engine rpm's. If it remains constant i would think it's something outside of the motor? Crawl underneath with the engine running and see if you can pinpoint the source of the noise. (Set the emergency brake, block the wheels, ....etc... to be safe)
  • eronieroni Member Posts: 9
    I would like to know, (from a kind person who has the service manual) the correct torque for the following bolts in a 2.2 liter VIN 4 GM engine of 1994, used in the GMC Sonoma (and other models):
    a) Flex plate (flywheel) to crank shaft bolts.
    b) Flex plate to torque converter bolts
    c) Push rods bearing bolts.
    d) Crank shaft bearing bolts.
    e) Drive shaft rear U joint bolts/nuts.
    f) Bell housing bolts.
    g) Oil pump bolts.
    h) Oil pan bolts.
    Thanks a lot, in advance, for the help.
  • s10fan_kys10fan_ky Member Posts: 1
    edited August 2010
    Does anyone have a vacuum diagram for a 2001 Chevy S-10 Crew Cab 4x4 4.3 V6 that they could send me? It is not in the manual that Autozone has, nor can I find it online. Any help would be greatly appreciated.
  • cyn777cyn777 Member Posts: 1
    I have replaced batt,distrib,alt,plugs,wires heads gaskets cad convert and muffler and now have a problem that stumps everyone..on hot day with air on going uphill it loses power and rpms go up and down. Once over hill she runs ok and if I turn air off before hill it doesn't do it at all
  • dfleming63dfleming63 Member Posts: 2
    My 2002 Sonoma has the same problem. Giakamo, did you get yours fixed? What was wrong? Anyone with any other ideas, please respond!!!
  • dfleming63dfleming63 Member Posts: 2
    Did you find the answer to your problem mikeythekat? I have the same problem.
  • gmc4x4s15gmc4x4s15 Member Posts: 2
    edited November 2010
    okay just bought a 1987 s-15 with a 2.8 liter v6 when i try and start it after its been sitting and cooled down it takes forever to get it to fire and then when it does fire i have to keep pumping the gas for it to idle and even then it runs really rough and tends to die. after it warms up it runs good usually but sometimes will die on me.......replaced the gas tank, sending unit, all new fuel lines return and sending, new filter,new tps, new map sensor, and a new air filter. im pretty knowledgeable when it comes to motors but im stumped help is much needed
  • gmc4x4s15gmc4x4s15 Member Posts: 2
    okay today was different. i read on a similar post to turn the key on and hold the gas petal to the floor. so i did this and it fired immediately still had to do it a couple times but it didn't take as long to get it running this time. any other ideas will help
  • hopkins7hopkins7 Member Posts: 9
    edited December 2010
    2000 S10, Extended Cab, 4.3 6 cy auto, 159k miles, well kept, serviced, and maintained for the past 10 years I've owned it. Recently began having roaring noise, seemingly from under the hood. Noise is most prominent, continuous and loudest at 68 mph, but is also noticable, and intermintent, at other speeds - 35, 50, 55+ mph. All wheel bearings, axle bearings, gear oil, and seals have been changed out. All tires checked and in excellent condition (it's not a tire/wheel noise). Noise is still there. My trusted auto shop for 25 years is stumped. Exhaust system/muffler checks out to be ok. Haven't been to dealer, yet. Any suggestions? Funeralman.
  • 2002sonoma2002sonoma Member Posts: 6
    Sounds like your fan clutch has gone bad.
  • lilbearlilbear Member Posts: 4
    if the oil level gets higher on the dip stick the yes it could be coolant look in the radator to see if y have oil on top of coolant
  • lilbearlilbear Member Posts: 4
    your maf is located between yor air filter and tb if it is un plug see if truck runs better if it does try cleaning it with maf cleaner if does not help replace it
  • hopkins7hopkins7 Member Posts: 9
    Thanks 2002sonoma, fan clutch is working fine, so that has been ruled out. It's a different sound.
  • cranemec1cranemec1 Member Posts: 1
    I have run into this problem with several of my fleet trucks. The easiest way to find out what the problem is is to have a full diagnostic run on the vehicle, depending on the area you live in this may be available only from the dealership(the computer is very expensive and some shops just wont put out several thousand dollars for one). But I do have some advice on what the problems were with mine and I will offer a starting point. The crank position sensor was my most common, especially during wet weather, the cost is relatively low, about sixty dollars. the second problem I had was coil packs, I also had good fire, but it weakened when wet. The final problem I had was plugged catylic converters, this was rare though. I suggest starting with the crank positioning sensor, if it is not reading correctly you will get plenty of fire, just not at the correct time. Hope this helps.
  • hopkins7hopkins7 Member Posts: 9
    Problem solved. Noise was unlike any I had experienced. The roaring noise was coming from my double cardan ujoints. Due to high cost of repairing the cardan ujoints, I had a new drive shaft with regular ujoints installed - expensive, but $200 cheaper.
  • vikasintlvikasintl Member Posts: 26
    We are considering buying a used 1989 gmc s15 which is 4 cylinder and 2.5 L and wondering how can we check vacuum ..I mean I want to 'tee' in vacuum gauge to intake manifold to check possible valve problems and more..but have not seen any s15 under the hood till now..so if some one can show pictures or video that would be great...

    also I know how to check compression ....but don't know compression values in healthy engine so I don't know how to compare...so if some one can share ..what are those compression values in each of 4 cylinders?

    also this care does not have power steering or cruise control etc...its 2.5 L and 4 cylinder with TBI fuel system..so how much its worth if everything is ok with compression and vacuum?
  • sawsmithsawsmith Member Posts: 1
    the radiator started to leak so I put in stop leak (followed directions) Tried to get home about 30 min later in the interstate the oil presure began to drop so We drifted in to a weigh station engine cut off comming in. The pressure droped to zero before cutting off temp was 240 did not red line.
    We let the engine cool down then put more collant in radiator heard a pop noise ( blue seam on radiator) Tried to restart engine turned over quickly but would not start.Had it towed repair shop said timing jumped or chain broke. Towed it home tore it down to timming chain not broke or jumped looks real good. Still wont start. Any Ideas?
  • gonogogonogo Member Posts: 879
    Remove valve cover and check for broken camshaft.
Sign In or Register to comment.