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Chevy Blazer GMC Jimmy Maintenance and Repair



  • fast72ssfast72ss Posts: 2
    It goes into 4 wheel high no problem and works great but when i HIT THE BUTTON FOR 4 wheel low nothing it stays in 2 wheel.
  • fast72ssfast72ss Posts: 2
    1996 gmc jimmy thanks
  • Had already reset the code before I read this. Will give it a whirl as soon as it comes on. Thank you for the response. Will let you know if it works.
  • auto9999auto9999 Posts: 86
    To engage 4LO you need to bring the vehicle to a full stop. It is written in the manual.
  • repairdogrepairdog Posts: 948
    Check the fuel pressure at the fusl rail (metal lines rear of compartment) at the test port and to start requires 60 psi and to run 54 psi. Low means replace pump - do the filter first located under drivers side frame rail about where the front door is. Do you have a good spark/coil/wires/cap/rotor/plugs? Any codes read out? Mileage on this 98? Could be several things.
  • repairdogrepairdog Posts: 948
    As stated must be not moving more than 3 mph and in neutral and you should hear the encoder motor in the transfer case engage the lower gear with a clunk. 96 have a vac assembly on top of the transfer case that leaks and won't allow 4Lo - sensor sends signal to control module that low is engaged and dash light goes on solid. Check all vac lines as first step front the intake down and GM uses 5/32 and 7/32 size. There is a reservior believe in drivers side front fender on 96 so check to that too.
  • repairdogrepairdog Posts: 948
    99 up were first years with factory alarms I believe so unless its a GM remote (FOB) you need to determine the aftermarket brand and search for their instructions. Check the remote battery first and most also have a valet switch under the dash installers mounted that deactivates alarm if you let someone park it - reactivate sequence also specific to brand.
  • mstafformstaffor Posts: 4
    Did you get this resolved? I have a 93 PU and it idles rough, misses once in a while. I have changed everything and this is a new GM engine (less than 2000 miles) my old engine did the same thing. I have a new distributor, coil, cap, rotor, wires, plugs, O2 sensor, TPS, MAP, and throttle body. No codes, and it runs fine except at idle.
  • Well. I tried the fix for the P0404 code and it didn't seem to work. Works after the reset for about 2 starts, then after about 1/2 mile on the road, SES light come on again. Code is still the same. Know of any other fixes or is it dealer time?
  • aallen2aallen2 Posts: 5
    I am having a similar issue where my check gages light comes on and my oil gage falls to '0' when the car is idle - when I am moving it moves up fine...what could this possibly be because the shop I had it in this morning told me the only option is to replace the motor mind you it was not an issue until they did an oil change.

    Also my ABS light is continually on - could you provide insight as to why?

    I will like to know possible issues and solutions so I sort of know what I am talking about when I take it in -- any advice is very much appreciated.

  • repairdogrepairdog Posts: 948
    If the oil is at the correct level and the filter is new and the correct one (if this just happened I would change both again somewhere else) then I would change the oil pressure sending unit first to make sure thats not the bad item - you did not state the year but all 98 up are loacetd behind the distributor on the stand pipe back there and they are fairly cheap. At idle common is 20 psi then up to 50-60 at full throttle.

    As to ABS light you have a sensor in each front hub (98up) and one on the trans (2wd) or transfer case (4wd) that are required to work - so if the light is on get the ABS codes read out (special scanner) and that should tell you why.
  • repairdogrepairdog Posts: 948
    Only other item I have is that if the cat converter is clogged then the readings can cause this but the vehicle would also be a dog and bog down. Sorry all I got.
  • blu99blzrblu99blzr Posts: 14
    left front makes popping noise when going over speed bumps, railroad tracks... can't afford to take to a shop, so I want to ask all of you what you think.

    unrelated - had rear end rebuilt about 3 months ago due to a failed pinion bearing. (It in turn munched the whole diff.) $1640 - a rip off? new gears, carrier, shafts, bearings, seals but old axle housing... now rear brakes surge. Could they have failed to clean the rotors after working near them?
  • repairdogrepairdog Posts: 948
    If 4wd check the lower ball joints as they are the #1 Blazer failure and noise area - give all fittings up front a good greasing - upper and lower ball joints, tie rod ends and the id;e arm under the skid plate, and all steering linkage (4 places - that makes 10 zerks to find).
    Also if you look back up and search the posts GM has small hood cone washers because the hood shifts and clunks. Try those first then I have many others to look at.

    Rear brakes surge - assume you mean pulse/grab when the brakes are applied. Are you sure its the rears and not the fronts, and if so the rear calipers are single piston lightweight with a special plastic piston and on geting new pads should be replaced with rebuilts due to sticking internally often occurs after the piston is pushed back in. Rotors can only be turned once on most and are the main cause of the pulsing as they get hot - the calipers slides need to be greased too a thing lots forget and they bind and can eat the rotors and cause this too. Bottom line is the rears need to be taken apart and examined and repairs made accordingly to correct. To do it yourself is loaded calipers with pads $55 eacd x 2 and rotors $35 each x 2 so under $200. If you destroyed the rear end you could have effected those brakes.

    Rear ends are expensive to rebuild totally as yours was. I would have gotten a used at the junk yard and put in for under $400 - but I do most of my own and have tools and jacks. You can look up the parts prices online and see.
  • blu99blzrblu99blzr Posts: 14
    had I known it'd be a $1600+ charge, I'd have had the tow truck take it to my home and done exactly as you said - replace the whole mess from a yard. Too late now I guess. I just did the front brakes - pads and had the rotors turned - about a month ago. Hadn't thought to replace the calipers since they looked good and seemed fairly easy to compress. Haven't done anything with the back brakes yet - will have to tomorrow and let you know. Will hit those zerks while I'm at it. Chilton's says those lower ball joints can have up to .125" (about 3 mm) play before needing replacement. Is this true? I remember something about them not being pre-loaded.
  • redblazerredblazer Posts: 2
    I have a 93 s-10 blazer 4.3 with 82,000 miles on it, over the past year every time I let it sit for more then a day or two it runs fine at first but about 5 miles it begins idling extremely rough, backfiring, extreme hesitation and smelling like rotten eggs. If i let it set for several hours it is fine again and can be driven anywhere until i let it set for a few days. Does anyone have any ideas? Thanks
  • repairdogrepairdog Posts: 948
    Front calipers are fine they are dual piston cast units that can be reused many times - only the rears are cheapos.
    You never said 2wd or 4wd and mileage, but the 2wd zerk tells if ball joint bad and the 4wd requires loading to see (old pull top and bottom of wheel only works in extremely bad joints) - many posts on 4wd lowers being bad and high speed vibration and the clunk are tell tale signs.
  • repairdogrepairdog Posts: 948
    Read post #2208 on CPI and then look up fuel pressures for this and that should help. If you smell gas or on dipstick then the cat converter may be getting loaded with it and very hot so be careful. They are also known for clogged EGR problems. Hope you have turned this one up too with cap/rotor/plugs/wires/filters etc due to the year too.
  • blu99blzrblu99blzr Posts: 14
    Push button "Auto" 4wd, 4L60E tranny. 154,000 miles - still riveted upper ball joints, so I'm thinking nothing has been done out front since it left the factory. Noticed high speed vibration today - 60-65 mph. Can't (legally) go any faster around here. I go to work pretty early - 5 AM, so I'm gonna catch a nap before tackling the Blazer. Thank you for your help.
  • repairdogrepairdog Posts: 948
    I crank my 99 like yours up to 80 all the time in flat FL. Did they put new u-joints in yet, another vibration area at that mileage. Hope you have done the trans filter a few times and the transfer case requires Autotrak II blue fluid from the dealer (manual was published befor GM had the clutch pack problem causing chatter in transfer). Look at the CV boots cause both mine went by 120k and rebuilts put in and if you have the knuckle and hubs off for lower ball joints its easy. That inside CV has an internal snap ring so with a block of wood hit it to the out direction a few times and it unsnaps. My idle arm was also so loose that had alot of steering play. Good luck.
  • I am trying to drop my gas tank to replace the fuel pump. 1st i am having problems draining tank by siphon from gas fill tube. There is a stopper of some sort blocking my hose. Next I am wondering how to get to gas lines to disconnect. I assume thay are on the top of the tank. Do I drop tank and then disconnect?
  • repairdogrepairdog Posts: 948
    Yes they have an anti siphon or overfill ball in there so you can disconnect the inlet fill hose at the tank top and put hose in or remove the filter and pump thru there. If you remove your spare tire you can access all the hose connections on tank top and they are snap type either squeeze together or the electrical with retainer snap/pull connector. Be careful the hoses get brittle and are expensive. Mark them for install so you don't mix up (sometimes I get confused under there).
    Easier if you have the rear high enough up as on ramps cause just jack stands is kind of low. Enjoy.
  • Thanks for the good advice. I have a 2dr with the spare on the back. I checked to see if there was a way to get at an access panel and there doesn't appear to be any, is there a way to access on a 2dr. Other wise how do I disconnect lines?
  • I have a 1998 GMC Jimmy with 148K miles. It start clicking from under the dash. It sound like the turn signals are always on. I have replaced the multifunction unit thinking it was bad but no luck. I have noticed that when I step on the brakes the clicking does stop. Do I have a bad sensor in my brakes? How do I find out what is causing the problem? I went to the auto store and I had no error codes in the computer.
  • repairdogrepairdog Posts: 948
    Never done a 2dr before - all mine are 4dr.
    Haynes is outdated as always on 98up but says to disconnect the filler and drop till access to top. See if there are disconnects from the metal lines on the frame to the tank while the tank is installed (where changes from metal to flex).
    Anyone done a 2 Door gas tank out there???
  • repairdogrepairdog Posts: 948
    So, is it under the dash or the front brakes? Listen as someone else drives it by you and determine. Brakes could be many things such as rotors (any pulsing), caliper slides needing grease or frozen, the metal disc pad slide shims that clip between the ends of the pads and the mounting brakets contacting the rotors, even worn hubs but these usually start to grate or grind. The hubs each have an ABS sensor in them but if bad the yellow ABS light will come on and not noise source usually. If not brakes , is the sound under dash or in engine compartment - open the hood and listen. Got more to check after you determine.
  • auto9999auto9999 Posts: 86
    Here is my 2000 Blazer's (Trailblazer trim, 4WD) troubles so far since it was bought new:

    1. all four (upper, lower, right and left) ball joints replaced (2002-2003), fixed by new car and extended warranty
    2. idler arm replaced (2002), fixed by new car warranty
    3. multi function switch replaced (2004), fixed by extended warranty
    4. lower intake manifold gasket replaced (2006), fixed by extended warranty
    5. heater core replaced (2006), fixed by extended warranty
    6. serpentine belt replaced twice (2004 and 2005), own expense
    7. driver-side front door hinge being loose (not fixed yet)

    Since the replacement parts were supposedly of the identical quality of the original parts, I expect that the same problems will recur in the similar intervals in the next several years. As my extended warranty expires in October, 2006, the recurring problems above alone would cost me about $2500.

    Blazer's many common problems seem to have happened already and were fixed in my vehicle by now. When the next cycle of troubles begins, I would have to trade in this Blazer for something more reliable. I wish Blazers had more reliability, as I like my Blazer very much and wish to keep it longer.
  • It is coming from under the dash behind the glove box. It is the multifunction flasher unit that has a three prong connector into circuit board behind the glove box. It sounds just like the turn signal is always on. I removed the multifunction flasher and the clicking stopped. It is my understanding that this switch has many purposes besides just the turn signals.

    The brakes and rotors have been replaced. and the clicking sound it under the dash when the GMC is moving or parked. While moving it is clicking but when you apply the brakes the clicking under the dash stops. Could this be that my ABS control module is having a problem?

    Thanks for the help
  • repairdogrepairdog Posts: 948
    There are 2 relays back behind the glove box - 1 for the turn signals and 1 for the flashers (they are on the brake circuit). The multifunction switch is in the steering column and includes the harzard switch (or flashers) and thats the bad part of it. Until that is replaced the noise will continue. Search this forum for "multifunction switch" and you will see that many have had the same experience (or pain).
  • dju91001dju91001 Posts: 1
    Im new here but im stomped on this diagnostic. Maybe i can get some help. I have a 96 gmc jimmy with the 4.3L H.O. I had a code for the mass flow sensor, camshaft sensor, and the abs light stays on. I replaced the mass flow sensor. The jimmy has a really rough idle, and it cuts out when climbing hills on the highway. I was told that the camshaft sensor and the crankshaft sensor are out of sink with eachother. If i were to advance the timing which way would i need to turn the distributor? Would the fuel pump be going bad? It has 170,000 miles on it. As far as the abs light, what would i need to check to solve that? Any help would be greatly appreciated.
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