Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Chevy S10 - GMC S15 and Sonoma Engine and Underhood Problems



  • hopkins7hopkins7 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.
  • Sounds like your fan clutch has gone bad.
  • 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
  • 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
  • Thanks 2002sonoma, fan clutch is working fine, so that has been ruled out. It's a different sound.
  • 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.
  • 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.
  • 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 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 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 how much its worth if everything is ok with compression and vacuum?
  • 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 Posts: 879
    Remove valve cover and check for broken camshaft.
  • 1989 Gmc s15 pickup 2wd , odometer - 112000 4 cylinder 2.5 liter automatic

    I checked vacuum is approx. 15 and goes little lower...

    and when I start its high idle like 1050 rpm and than after a while it calms down

    I tried to check timing which should 8 btdc...but I can't see timing mark

    can you guys suggest me how can I find timing mark? I can see 12,8,4,0 marks but noting on pulley..

    also what could be main reason for low vacuum like 15? and how to trouble shoot?
  • etravlretravlr Posts: 1
    1996 4.3 TBI, auto. I have having the same problem as the first half of your problem, did you ever find a solution? I was getting a code for a bad TPS sensor but it looked new and tested fine. I did remove the molex plugs at the ECU a few times and reseated them. This seemed seemed to correct the issue for a while but now the problem has returned. It does seem worse with damp weather. When my truck surges/bucks, the brake and antilock light come on and go off. No codes. I am going to check the distributor cap to see how it looks next.
  • i got a 98 s10 keep dying on me me while going down the road it pulls crank sensor code put new one in still does the same thing can anyone help me out
  • i have a 93 gmc sonoma 4.3 non vortec it is have a misfire problem i changed the plugs a few days ago and now its doing it again last year i changed out the brain and the distrubitor plus igniton system
  • eronieroni Posts: 9
    Is that "intermittent" or "constant" ?
    When you say "ignition system" does that includes the spark plug's cables ?
    Have you checked compression in all cylinders ?
    Good luck and keep in touch.
    PS.: Depending on symptoms (details), I would clean/check injectors and relevant wiring and connectors.
  • yes changed out the wires the distrubitor and the cap the rotor button fuel filter the ignition coils. a few days ago i changed the plugs and the problem was fixed but i drove it to the store to put gas in it and on the way back it started skipping and back firing again
    i just cant figure it out
  • spcshumanspcshuman Posts: 1
    edited January 2012
    I have a small oil leak that me and mechanics believe is the rear main starting to go out but keep everything checked and that`s okay for now. My biggest issue now is the truck just started shaking and sounds as if it`s gurgling when I put and or have it engaged in any gear and press the gas. I have checked and replaced my motor mounts and the transmission mount. Have already done a tune up on it and only had the small oil leak until now. Any advice on why all of a sudden there`s no power and SO much shaking when I accelerate but fine when I downshift or at an idle? Just not understanding why not only is it acting as if its restricted but how much it shakes as well at the same time?
  • gonogogonogo Posts: 879
    Check catalytic converter for blockage, usually the problem.
  • removed broken mount-drivers side.engine is jacked up far enough,cant get the bottom bolt in;engine side.any suggestions? Thanks for any ideas.
  • I've replaced 2 sensors and I still have the code, it will not clear and doesn't erace with the scanner
  • mikewoz84mikewoz84 Posts: 2
    edited March 2013
    I have a 1998 GMC Sonoma V-6 that is making a terrible noise from under the hood.

    The noise is so loud that it makes it difficult to isolate. It sounds as though the noise if coming from either the a/c compressor pulley/bearing, the power steering pulley/bearing, or the water pump/fan clutch (in that order).

    I removed the belt and spun all of the pulleys.

    The a/c compressor pulley has a slight wobble to it and creates a noise similar to a bearing going bad in a skateboard wheel however there is no grinding or sticking in the motion of the pulley itself (although I suspect it is the culprit). I have not had a working a/c unit for almost 5 years so I would not mind buying a by-pass pulley to replace the compressor altogether.

    When grasping the power steering pulley it has play back and forth but not up and down. When I spin the pulley it seems as though it is smooth and makes no noise that I can detect.

    The water pump and fan clutch (when spun) is smooth and hardly makes any noise at all but I did notice a little weeping (fluid) on the water pump itself (smaller than dime-size). My truck stays at a nice temp so overheating is not an issue (yet?).

    I have bought multiple "quiet" belts in the past 2 years but it does not seem to help that much. I have replaced the idler pulley, tensioner pulley, alternator, and serpentine belt all in the past 2 years.

    I took it to a local shop 3 months ago and they could not isolate the problem either. They said they put brake lubricant on the smooth part of the belt and the noise went away completely - for one month. They said it was the labeling on the belt and I took their word for it.

    They recommended putting more brake lubricant on it every month (a big "dab" they said) to alleviate the noise. So I followed their suggestion but it no longer has the same effect.

    Yesterday I cleaned the belt with mild soap and water and cleaned all the pulleys with a degreaser and made sure everything was dry. I placed the belt back on and the same noises were coming from the engine bay.

    Without buying EVERYTHING and walking into a dealership with a blank check, I was curious if someone had a similar issue or suggestions to help me isolate it further.

    If I left out any information, please let me know and I will do my best to help.
  • 8
    ECMB fuse blowing on my 93 Chevy S-10 Tahoe 4wd.

    I have been fighting this for 3 weeks now and just tonight I think I have found a way to solve the problem without any costly or major repairs. It's only cost me bout 20 bucks and was an easy and fast fix once I figured out how to do it. That is 3 weeks later but it works fine for me and I didn't have to change the entire wiring harness.

    First I disconnected the battery to prevent damage to the ecm. I went to the auto parts store and bought 40 feet of good quality 14 gauge automotive wiring, an inline blade single fuse block some wire connectors electrical tape and some tools to get trim down to access the ecm. If you can get to the wires without removing the brain even better. I was able to luckily.

    I started at the fuel pump relay. I cut the orange wire a few inches of the relay. I did the same with the grey wire. I taped the ends and they won't be used anymore. I spliced my own wire into the orange wire and I ran mine directly to the battery and put my fuse block in where I spliced another wire into it to run to the ecm. So a single wire comes from battery into the fuse block and on the other end of the fuse there are now 2 wires one to relay and one is going to go to the orange wire coming out of the plug on the ecm a 3-way splice.

    Locate orange wire on ecm plug cut it down far enough to splice into splice your hot wire that is coming from your 3-way splice from battery. You now have bypassed the orange completely and you have a new always hot wire going to oaring on relay and one to orange coming off ecm plug.

    The next thing you do is take the gray wire that's been cut and coming off the relay plug and splice a new wire into it run it back to the fuel pump plug. At the tank cut the gray wire on the truck side of the harness, not the pump side of the harness plug, splice in your new wire coming off the gray at relay. Only cut the gray wire, the other is the fuel gauge wire and doesn't need to be cut.

    Plug your fuel pump plug back in connect your battery make sure your relay is bolted back in place on firewall and you're good to go. My truck still blew the ecmb fuse on the fuse panel inside the truck, but it didn't affect the pump because I bypassed it all so I just left the fuse out of the ecmb slot on fuse panel in truck and everything works great again.
  • leot3leot3 Posts: 1
    I have a 2003 sonoma p/u. I have changed the thermstate and I still have no heat. I also see that the temp. of the engin is running cooler then normal, which is why I changed it. This did not work and I am not sure where to go next.
  • The engine overheated. I saw the temp gauge go up and down. I replaced the tstat, wpump, and radiator. Now I have a leak at the rear of the engine, and a hissing sound. Hope its not a cracked head!! Anyone heard of this? #chain reaction
  • what did u find out?? because I have same do I see the answers ppl gave u?
  • I own a 2000 GMC Sonoma, with 105,000 miles on it, it has been very reliable up until yesterday. We are driving down the freeway at approx 60mph, when it gave a popping sound (back fire I gather) then lost acceration, it back fired twice, while I coasted to the shoulder of the road. When I attempted to turn the key on, the dash lights up, the engine turns over but is not able to start. Hubby checked oil, added some this morning, still will not start. Alternator appears to be working. Suggestions? Ideas? or is it because we were discussing trading it in for a van :) Any help would be great,, thanks

  • KCRamKCRam Mt. Arlington NJPosts: 3,516
    edited February 2014

    @sonomanogo said:
    I own a 2000 GMC Sonoma, with 105,000 miles on it, it has been very reliable up until yesterday. We are driving down the freeway at approx 60mph, when it gave a popping sound (back fire I gather) then lost acceration, it back fired twice, while I coasted to the shoulder of the road. When I attempted to turn the key on, the dash lights up, the engine turns over but is not able to start. Hubby checked oil, added some this morning, still will not start. Alternator appears to be working. Suggestions? Ideas? or is it because we were discussing trading it in for a van :) Any help would be great,, thanks

    Most common causes of backfiring are:

    • too much fuel/not enough air getting to the engine
    • bad spark plugs/distributor causing a misfire in a cylinder
    • head gasket leak

    If you or your husband noticed the temperature gauge creeping upwards lately, that may have been a sign - an engine not keeping its cool is also a sign of the above. No matter what, this is likely a job for a pro to check thoroughly.

Sign In or Register to comment.