Chevy Blazer GMC Jimmy Maintenance and Repair



  • repairdogrepairdog Member Posts: 948
    4wd lights are probably a bad sensor on the front axle that signals status or the transfer case that tells TCCM (computer in the pass side kick panel) that the low gear for 4Hi is engaged. The encoder is the motor (stupid name) on the transfer that is only for 4Lo gear engagement. Also check all vac lines up front from the intake.
    As for the gauge the sender is part of the pump and has been redesigned so more robust (GM hopes it actually works for awhile that means) and is $300 Delco online and have to drop the tank - what fun.
    As for the electrical they are always fun to locate but I would look at the battery cables and terminal and down on the starter too. Under the battey tray there is a positive junction block that can get corroded and the pos cable is an octopus looking thing so follow it - I had a 99 with a bad cable. Also check the negitive and make sure the ground to the motor block is good. Starter solenoid mounted on starter can fail intermittently so look there also - when it does not do anything (start) do all other electrical items work? Always possible its the ignition key/tumbler if looks of heavy things on the key ring. Has the battery and alternator been tested too - as one starts to fail and voltage wanders Blazers get confused and electrical items such as gauges start to swing around in value.
    You are probably correct on the light switch and usually its the dome light dimmer section that fails and thats why GM put that override button on it. If fact, if thats staying on at night randomly that cause cause some of your problems so override it at night and see if problems stop.
  • repairdogrepairdog Member Posts: 948
    Sounds like an electrical connector or relay so check that all connectors under dash and engine compartment are clipped together. Only common point is the ignition switch after that for the other circuits - does it still run when all this happens?
  • maasy13maasy13 Member Posts: 6
    i need to find out where it is and what is wrong with it for it to turn on my service engine light. :lemon:
  • repairdogrepairdog Member Posts: 948
    One of the fun items on 99-01 Blazers with the 4.3L motor and 00-03 2.2L motors is the Secondary Air Injection system. So here's what it is:
    This is located under the radiator (pump, electric solenoid, and vacuum shutoff valve) and tees off up to the exhaust manifolds thru 2 check valves on 4.3L. For 4wd remove the front skid plate to access. The secondary air injection pump is used to lower tail pipe emissions on start-up for about 1 minute. The PCM supplies a ground to the pump relay, which energizes the pump and the electric solenoid valve. Engine vacuum is applied to the shut-off valve when the solenoid is energized. The engine vacuum opens the shut-off valve that allows air to flow to the exhaust manifolds. Often the pump gets water/moisture in it and freezes up blowing the fuse and the check valves rust or freeze open internally and then burn thru the rubber hose. The fuse for the pump is behind the battery in the fender by the horn (remove battery to access and its under a plstic cover).
    You have to fix the system or the SES light will always be on - the computer tests for this system running on startup via the oxygen sensors readings. After you replace the bad parts you need to extend the intake hose from the pump (it ends on pass side of radiator now halfway up) by adding a 3' piece of heater hose and end it in that fender hole by the battery and fuse so water does not get sucked in - done 2 of mine so far and OK now. GM has a bulletin on this and dealers are used to replacing these parts - but that pump is $200 list.
  • microjoemicrojoe Member Posts: 1
    Does anybody know what size the lock nut is for the hub assembly for a 2000 GMC Jimmy? Please let me know. Thanks!!!
  • repairdogrepairdog Member Posts: 948
    36mm for the CV axle shaft large nut on 4wd - the 3 bolts holding the hub on to the steering knuckle are 18mm. That 36 is sold at most auto stores as a hardened axle nut socket. Loosen it with the wheel on the ground and then jack it up - you will probably half to use a block of wood and a hammer to free it from the hub and if reusing the CV do not wreak the threads on the shaft (thats why the wood).
  • wgochwgoch Member Posts: 4
    Have an interesting problem with my 97 Blazer LS (4.3L V6). It has about 92,000 original miles on it. Unlike apparently a lot of folks, mine has been essentially trouble-free until now. Last Saturday took it on a trip of about 200 miles each way. Everything was fine until about 40 miles from my destination. I was on the interstate doing about 65 mph when the engine suddenly appeared to lose all electrical power momentarily then recovered and everything returned to normal. Did that 4 or 5 times over about 5 miles. When it happened, dash voltmeter dropped to near 0, gas gauge went squirrely and speedometer surged. ABS and Airbag lights came on and remained on. Exited the freeway and pulled into a Chevy dealer near the exit. Service and parts were closed. Checked under the hood and everything appeared normal. Started up the engine and everything appeared normal. My thought was to try and make it to a town where I could have the alternator tested. However, everything continued to be normal so I continued on to my destination. On the return trip a few hours later, everything remained normal until I was about 40 miles from home when the same thing again occurred twice. The engine recovered and I made it home with no further problems. The following day I replaced the alternator and the engine ran normally. The vehicle sat idle for 3 days. Yesterday, I drove it on some local errands that required shutting down and starting it again several times. Again, no problems. After returning home and a few hours later, I tried to start it and it wouldn't. Starter turns the engine but there doesn't appear to be any power to the instrument panel. None of the lights or gauges turn on with the key in either on or start. I would certainly appreciate any guidance or suggestions from anyone who may have had the same or similar problems.
  • repairdogrepairdog Member Posts: 948
    Easy one - known problem part is the "97 ignition switch", under $100 at most stores. This is the wiring and connectors in the column, not the actual tumbler/key. Some bad internal connections and most power runs thru it so that's why it dies and restarts. Do a search on this and you'll find lots of info on the web.
  • wgochwgoch Member Posts: 4
    Thanks very much. I'll give it a shot.
  • david97blzrdavid97blzr Member Posts: 1
    2 questions. I have a 97 blazer and it seems to be making a squeaking noise repeatedly in warm/hot conditions. With the windows down it sounds like it is coming from the rear right hand side of the vehicle. my guess would be something to do with brakes seeing as how when i hit the brake even just slightly, the squeaking stops. Not sure how else to describe the problem, because its only audible when traveling 25-???mph.

    Also, I am selling this blazer, and would like to find a good price for it, 97 4x4 brown, cloth interior(brown) premium wheels - clean flawless in nearly every way except the following small problems -
    ^the problem listed above^
    driver side door has a very slight ding in it, hardly noticeable.
    driver side door lock doesn't lock with power locks, must be locked manually.
    tread @ approximately 50%

    some positive things about the car include
    kept well & clean by mature & loving owner :)
    Roof holder thing :P
    tinted windows
    1 month old alternator
    and etc

    from what I have seen the approximate price would be 4500 - 6,000$ am I wrong? edmunds says 4g private party, KBB says 5.5g private party, whats up with this
  • steverstever Guest Posts: 52,457
    What is the "Kelley Blue Book" Price?

    Check out the Sell Your Car link on the main page if you're in the US.

    Steve, Host
  • repairdogrepairdog Member Posts: 948
    97 has rear drums so check the pads and make sure you place a dab of grease behind the pad point where it contacts the mounting/backing plate so it will move without hanging up. Also make sure the front discs are not worn and contacting the squealer/low indictor tab.

    As for price that regional and what the local market is doing vs how fast you want to sell it - all online books are averages so good luck. Mileage is also important as well as what items you have maintained.
  • auto9999auto9999 Member Posts: 86
    My 2000 Blazer is equipped with the brake replacement alarm which is designed to make squeaking/hissing noise when the brake pad is worn out. When the brake pedal is applied, this noise disappears. Mine started to make this noise at 45,000 miles and I replaced brake pads for a few hundred dollars at a dealer. 2000 Blazers have rear disc brakes. This repair seemed to be a normal wear and tear maintenance. I hope this helps.
  • cmcnearcmcnear Member Posts: 1
    I know it is a small problem but it really bugs me...the digital temp gauge is out of wack. It shows 135 todat (i know it is a hot PA day bu this is just silly) Anyone know where the sensor is? Or if something else may be wrong?
  • bgalardebgalarde Member Posts: 1
    I have a 2000 chevy blazer with auto climate control which stopped working altogether. The ac compressor runs all the time (cycles) no fan, the controls to change the vents (floor,defrost,dash)don't work, rear defog doesn't work,
    and temp doesn't change. All the fuses are good also. Is there any help for this?
  • repairdogrepairdog Member Posts: 948
    Sensor is in front of the radiator and can be changed separately. See post #2299 on this.
  • repairdogrepairdog Member Posts: 948
    Blazers have a known crappy compressor that often blows the seals and if they sniff it they will tell you. Also could be a bad pressure sensor, bad contacts on a connector, the control head, or a simple vac line - so enjoy life and take it to a good AC shop or you will be searching for some time. In fact with climate control, the dealer has more knowledge than most small local shops - been there and they took 2 hours to even analyze it so a dealer would have been cheaper - they have seen all the wonderful problems many times.
  • repairdogrepairdog Member Posts: 948
    Rear discs started on 98 models and all disc pads have the metal tabs to warn of low pad material.
  • bkgray38bkgray38 Member Posts: 1
    I bought a 1995 chevy blazer, 4.3 liter, V6 vortec in July 2004. It had 105,000 miles on it when I bought it. Now it has close to 150,000. In October 2004 I had to replace the fuel injectors and both front shocks. In October 2005 I had an oil change, new plugs and wires installed. About 2 months ago the blazer started missing, stuttering or hestitating so I took it my mechanic. He said the only problem he could find was that the transmission needed cleaned. He said the trany was in good shape. Ran good for awhile. Last week I took it to Grease Monkey for an oil change. They came out and said they could not touch it because the oil cooler assembly was not attached to the engine block and it was ready to fall off plus someone had put on the wrong oil filter and oil was leaking everywhere so I took the car back to my mechanic he said he would fix the oil cooler assembly, do a complete oil change, but he also needed to change the distributor cap,rotator button,new plugs and wires. He called me and said when he took it for a test drive the fuel pump went on so he repaired that as well plus I needed a new muffler and tailpipe. This came to a total $441.00 The blazer runs like brand new now! My question is since I just had new plugs and wires less than a year ago, did he pull one over on me? I know nothing about cars so I have no clue what really needed to be done besides the muffler and tail pipe. It isn't missing anymore and no more smell of gas fumes.
  • repairdogrepairdog Member Posts: 948
    I got alittle lost in there on the "fuel pump went on" because thats in the tank so maybe the fuel filter was replaced under the frame rail. If oil sprayed all over the engine also then it could have coated the dist and wires etc so arching and replacement may have been the best solution. Price was good for all that work. When the remote oil cooler lines go (crimps on hoses) you are lucky that all oil did not blow out and destroy the engine.
  • whitgmc2001whitgmc2001 Member Posts: 1
    I have a 2001 GMC Jimmy. It has always made a popping sound when I turn to the left to tightly. Recently, It has gotten worse. I was told that the front coil spring is out of position and the front end needed to be repaired. The repair will include the front end, Idler Arm, and the Pitman Arm at a cost of about $800. Has anyone had this problem - do you have any other suggestions?
  • james2006james2006 Member Posts: 6
    hi wanted to know if anyone can help me on this i have 95 gmc jimmy 4dr 4x4 4.3 vortec . does not want to start sometimes. seems its not getting fuel . already put in fuel injectors and fuel pump . but its makeing a lound umm noise seems lounder then should be . could it be the pump again . can anyone help me on this

  • repairdogrepairdog Member Posts: 948
    2wd or 4wd makes a big difference but have to assume 2wd if a coil spring cause 4wd have torsion bars. Coils have rubber insulators between them and the frame. So, depending on mileage etc could be the center steering link assembly (common) or idler, tie rod ends, hubs, or ball joints - a shop should be able to tell by inspecting and doing some pull/push on the tire/wheel at 12/6 oclock and 3-/9 oclock position, as well as listening to the hubs as they rotate. Now if actually a 4wd its the lower ball joints as #1 fault area and popping.
    Grease all front end fittings and see if it goes away or lessens - any pulling or drift in steering or during braking is also a clue. Also if caliper slide colts are not free and greased they can bind and shift/pop. Have to jack it up and inspect so if you don't trust one shop get a second estimate from a front end alignment shop (sorry but some tire giants may be alittle quick to make work/$$).
  • repairdogrepairdog Member Posts: 948
    CPI injection under the upper intake is a known problem leakage area and theres a CPI and nut kit (actually the 2 fuel lines) that fix internal leaking and if you smell fuel thats it so search on this and see the many posts. If you test the fuel pressure at the rail its 60 psi key on engine off and 54 running. If when off the pressure drops quickly its the CPI/nut. Pump could be running as fuel dumps in manifold so check this out so don't trash the cat convertor (excess fuel in it) or dilute the oil with gas.
  • james2006james2006 Member Posts: 6
    ok i was told that the timing chain could be causeing my truck not to run right is that true i am doing a fuel pressure test on thursday morning and putting a new fuel filter. then go from there .
  • jpmccrjpmccr Member Posts: 31
    Good point on the battery and alternator. However I thought the same thing and replaced both already thinking the problem would be solved. NOPE. :confuse:
    Did I mention that I got his one used and the folks that had it previously put a battery in it that was bigger than the tray! I liked to never got it out and when I did I almost dropped it. Luckily it landed on the plastic shroud cover (yeah right). The corner of the battery punched a hole in it! CRAP!!! :cry: Oh well. I did notice with the battery out the tray had acid on it (cleaned it up with baking soda and some water) and there was some caustic damage to a cover for the hot lead from the battery to where ever it went. If you want I could send you a picture and let me know what you think. My wife seems to think it might be the ignition cylinder. Not sure. . . :confuse:
  • marcanddulsiemarcanddulsie Member Posts: 2
    I have recently replaced coil pack and fuel injectors. Now it wont start. it is firing through the coil but not the plug wires. :mad:
  • repairdogrepairdog Member Posts: 948
    Reread the original and now with the acid point did you pull the battery and tray out and look at the juction under it - you have to look at it and the cable - that cable is multi piece and runs to the starter so pull that out and look and use an ohm meter and flex the cables around and see it reading change - if so replace. Also easier is make sure those side terminals to the cable are clean by pulling the insulator back - it just slides back.
    Wife could be right but unless she has a really haevy key chain full of junk doubt it. When this happens is the shifter in park for sure all the way cause these do have an adjustment on the trans and if off slightly won't start so next time it won't start with the key on (engine off) and your foot on the brake move the shifter to N and then back to P and see if that allows it to start.
  • cwboatmancwboatman Member Posts: 4
    I've got the same problem with my Blazer. Has anyone heard of a fix. This is becoming a pain, I need to disconnect the battery at hight so the truck doesn't unlock itself. :confuse:
  • repairdogrepairdog Member Posts: 948
    There is an electronic module that controls the remote/FOB so would guess its defective or a wire in the door control panel has a short or the door switch - you can pull the door panel and check or just pull the fuse to the locks.
  • blaze4x4blaze4x4 Member Posts: 29
    About when will a radiator on a 2001, with 101,000 miles go ? And what should I expect to pay for a replacement? After idling for approximately 10 minutes yesterday with the A/C on, I traveled 20 miles then stopped for dinner. Upon returning to the vehicle, I noticed about two pints of Dex Cool under the left front cornor of the blazer. Monitoring the temp gauge (never got above 210), I had to travel another 80 miles home while running the A/C. This morning, there is a damp spot in the same location, however the level in the radiator isn't very low at all.
  • repairdogrepairdog Member Posts: 948
    Could be several things so it was drivers side up front.
    1. Look at the water pump it has 2 holes in the bady that drip when the seal starts to go. Look at the small bypass hose on WP too.
    2. Intake manifold gaskets all leak on the 4.3 motors by 100k so look above the water pump where the engine block and intake meet - any leaksge - usually when hot running and the reservior will slowly drop and often you hear the lifters tap on startup. Could also be leaking out the top area in the V between the intake and valve cover and then runs down - seen both before.
    3. Radiator hose leaking.
    4. Plastic tank cracked below that rad hose - just did a 98 with that. Cost is $150-200 for a new one then you install.
  • repairdogrepairdog Member Posts: 948
    Cap and rotor mounted correctly? All the wiring and other connectors solidly clipped on?
  • marcanddulsiemarcanddulsie Member Posts: 2
    I found # 3 cylinder wire off at plug replaced and check all others. Should I replace rotor and cap?
  • cwboatmancwboatman Member Posts: 4
    Thanks for the tip. I'll try check the items you mentioned. Just as an FYI, The dealership said one of the relays maybe bad. I replaced all three and it did not correct the problem.
  • guestguest Member Posts: 770
    You never said what year and model but one of mine is an LT with 2 button memory and 8 way and that one had a short in the seat wiring and took out the remote and seat drive modules - love that quality engineering.
  • wgochwgoch Member Posts: 4
    Finally got a chance to work on it a bit and removed shrouds, covers etc. to expose wiring in steering column. There is a large junction box about 18" below steering wheel. Appears to be straight through and has continuity (including to the battery on the side towards the firewall. Is the switch you are talking about just under the ignition keyhole?

  • repairdogrepairdog Member Posts: 948
    So before you did these did it run? Basis question I should have asked. Cap and rotor at 100k or when pitted or arced inside. Same on plugs and wires. 97 had problems with the ignition module often called the switch but not the key/tumbler portion that causes most no start and stalls on 97 only. All power runs thru it and had bad/loose connections internal and most owners change and find it fixes it. Search on 97 blazer ignition switch.
  • repairdogrepairdog Member Posts: 948
    Yes, in the upper column so go to online lookup sites like autozone or advance (parts america) and look at the part so you will know - or go to the store and they will let you see it. Have to take the column covers off to reach.
  • james2006james2006 Member Posts: 6
    hey 95 gmc jimmy 4.3l vort does not want to start right seems its not getting fuel i did a fuel pressure test . with key on motor off 60psi then it drops slowly . with engine running its at 50psi and is jumping around . so not sure if its the fuel pump or the injectors and what is the cpi nut i called gmc and they did not know what i was talking about . any help . thanks
  • repairdogrepairdog Member Posts: 948
    Here's the info on it from an eariler post:
    Leaking CPI regulator and hoses/fuel lines (called a nut kit by GM) under the upper intake manifold. You can remove the IMTV (Intake Manifold Tuning Valve) from intake manifold. Once the IMTV unit is removed, visually inspect the inside of intake manifold. The manifold and injector unit should be very carboned up and dirty. Any clean areas indicate a fuel leak internal to the manifold plenum. Most times this is caused by the fuel pressure regulator leaking fuel from vent hole in the regulator body. Other factors may be present (such as a cracked inlet fuel line) but usually the regulator unit has failed. If no leak is detected through the IMTV hole, but a faulty unit is still suspected then you must pull the upper plenum to get a full view of the inside of the intake.

    CPI was used until 96 when the newer spider type injection was introduced that has its own problems. Good luck.
  • cwboatmancwboatman Member Posts: 4
    The year is a 98. From reading your comments, this issue can be caused by a number of different electrical failures. I think I've found my problem. While doing my P/D, I started with the rear door/tailgate. The reason being, thats when the problem started, I had the tailgate opened for a couple of hours, thats when I heard the silinoids engaging and disengaging by them self. When I removed the back panel I noticed the windshield wiper, water supply tub was disconnected (spraying water inside the door. There are about (5) different electrical plugs/connection controlling all the little silinoids and latches. I started isolating/disconnecting one at a time and waiting to see if the issue re-occured, which happened every 5 seconds to 1 minute in intervals. Once I disconnected the plug going to the rear door key/switch assemble, the issue stopped. It has been 12+ hour and the issue has not returned. To test my results, I plugged the key/switch back in, the issue started within 30 seconds. I disconnect key/switch connection and plugged the other 4 connection back in and it appears to be working. The only thing I loss by leaving the key/switch disconnected is the ability to lock/unlock rear door with key. I works fine with remote. Looks like I'm heading back to the parts house. :surprise:
  • canadianblazercanadianblazer Member Posts: 2
    Hi everybody,

    I was hoping that someone could shed some light as to diagnosing 4WD problems on my '98 Blazer LT.

    Here's the problem:

    When the 4Hi button is pressed, the light on the button flashes and I here clicking noises from the TCCM but don't here the encoder motor activating. All it does is go back to 2Hi, All the buttons light when I start the engine and the 2Hi light stays lit. I've tried changing when moving slowly, in Park and in Neutral.

    I can get into 4Lo by being in Neutral, hear clicking from the TCCM and also hear the encoder motor shift, and the 4Lo light is on. So this seems to be normal.

    If I try to shift from 4Lo to 4Hi, and again, the 4Hi light flashes but it shifts back to 2Hi.

    Off hand, I would think that the TCCM and the encoder motor are fine, but can anyone point me in another direction as to why it does'nt like 4Hi

    Thanks in advance for any help.
  • repairdogrepairdog Member Posts: 948
    The encoder motor is the low gear in the xfer case engaging. If you get in 4 Lo you should be able to get into 4Hi. Both need to engage the front axle coupler on the pass side and there is a sensor on the axle to send a signal to the TCCM. So, pull the battery cable off for 30 minutes and see if the TCCM reboots and all works OK.
  • cwboatmancwboatman Member Posts: 4
    I had the exact same problem. There is a separate electronic control module that controls the shifting between 2 & 4 wheel drive. The control module is located behind the side kick plate on the passager side under the dash board. Be sure to disconnect the positive side of the battery before connecting the new module or you will blow it. I'm not sure what the cost is now, but I paid aprox $150 at the dealer about a year ago.
  • canadianblazercanadianblazer Member Posts: 2
    First off, I'll thank repairdog and cwboatman for thier replies.

    I tried pulling the fuse fuse for the 4WD rather than disconnect the battery. Did'nt work so I will try the battery disconnect next. What it did do though, is when I engaged 4Lo and then pressed 4Hi, both lights stayed on and when I moved the truck, I was'nt getting any tire chirping that you would get on dry pavement in 4Lo. I did'nt want to drive at any kind of speed thinking I'm in 4Hi in case 4Lo engaged.

    But on a good note, I can hear the axle coupler that repairdog mentioned activating on the passenger side as well as the encoder motor shifting. That would indicate that mechanically, every thing seems to be O.K. (I think). Then again, the TCCM might not be sending all the signals it should be.

    Thanks again for the help :confuse:
  • repairdogrepairdog Member Posts: 948
    There is a sender unit on the front axle coupler that tells the TCCM its engaged or not, same on the xfer case so one of those may be sticking - ball type that as the shaft moves pushes the ball up - had the front one stick on one of mine before and its a $15 part so if in doubt change it.
  • kaphilkaphil Member Posts: 1
    I had this same problem and was told my the dealership it would cost 500 to fix. To it to a local shop and it turned out to be a vacum hose had a dle in it. So, check the vacum hoses before you invest any money.
  • gmc2000gmc2000 Member Posts: 1
    My 2000 Jimmy will not start and the key is stuck. Cannot put it in gear. The lights on the dashboard or anywhere else do not work. What's going on?? Anyone help?!
  • steverstever Guest Posts: 52,457
    Will the key turn at all or will it just not come out of the cylinder?

    If it's not turning, sometimes you can free it by gently moving the steering wheel a few degrees left or right.

    Steve, Host
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