GMC Sierra: Problems & Solutions

mailman2

I have a 2001, 1500 Z-71, 5.3 with 35,000. I'll be changing the AF and trans. fluid. Should I stay with GM'S dexcool or go to Prestone? Any suggestions on changing tranny fluid, What kind, should filter be changed or power flushed? ANY HELP? Also, is there a drain plug for tranny fluid?

rayt2

I would stick with the dexcool which has a longer useful life (5yrs. or 100k) and is available at auto parts stores. Not sure if standard antifreeze will cause any issue, I would think not but hey this is a GM vehicle subject to it's own little quirks.
The tranny pan does have a drain plug if I recall but you should change the filter if you change the fluid. Curious as to why your changing the fluid? is there a problem? These systems are closed and not subject to outside contaminents, owners manual says not to touch it for 100k unless used for towing or heavy service then do it @ 50k.
My buddy who owns transimission repair business says the same thing, unless there is a problem don't mess with the tranny. He also stated that these quick oil change places push for the "flush" and change because it's a money maker not a necessity. They use questionable scare tactics in getting you to do it similar to selling you a "motor flush" because of sludge build-up. All smoke and mirrors to the unsuspecting or uninformed consumer.

Ray T.

sticks2117

I did a full front brake job on my 95 gmc and know when I press the brake it takes a lot of effort to stop the vehicle and I have a like a hissing sound coming from under the dash Any suggestions as to what it might be I did all the test for the booster and they all check out fine the booster shows to be solid

obyone

Did you bleed the brakes? Top off the fluid?

rayt2

Bleed the brakes again, sounds like you still have air in system. Start at right rear then left rear then right front and left front. The idea is to work from farthest point from master cylinder to closest point.
Let us know the results. There is nothing under the dash that would cause a brake system air leak.

Ray T. :shades:

weels

Man! I know you checked the battery terminals but this really sounds familiar. My old 96 was doing that and every thing looked fine on the terminals till I peeled back the insulation over the connectors. I ended up replacing the battery cables and it was fine after that. Sometimes its good to undo the battery and soak the ends of the cables in baking soda and water for a while. I never cared for the side mount connectors. You can't inspect them like the top mounts. I hope you get it figured out without too much more cash. Good luck!
- Tim

phaedrus411

Don't use DexCool unknowingly. This antifreeze, though marketed as "sterile", has been shown create a residue in the cooling system that can block flow and even eat away at the gaskets. This is not smoke and mirrors; there are several class action law suits being brought against GM at the moment for their continued use of DexCool and supposed knowledge of this problem. As GM has used DexCool exclusively for a decade or so, a recall is not going happen as it would most likely cost the company in the billions of dollars.

Continuing to use DexCool probably will not harm your vehicle. Just understand that the 100,000 mile slogan is bogus. When you have your coolant changed, get the system fully flushed to remove the residue and continue change it every 2-3 years.

larryd27

Hi, I have a 91 GMC sierra, For some reason my fuses keep melting inside the fuse box and the headlight switch it's self is almost impossible to touch from being so HOT. What would cause this?? any help would be nice! Thanks in advance!

dion2me

Towards the end of the day my truck starts to struggle with gas. I can push pedal to metal with no effect. Has shut down 2x. Even parked I am unable to give it any gas. Runs fine an hour later and in the AM.

HELP??? :lemon:

KCRam

Sounds like an overheating or failing fuel pump... probably want to get that checked/replaced.

kcram - Pickups Host

oilyrag

Can any help me with step by step instructions on how to remove and replace the Electric window motor and regulator on my 1999 GMC Sierra 1500 series (New Body Style) pickup?
This is the motor with the cable type regulator.

obyone

Removal
1. Raise the window. If the window motor is inoperable, remove the window to gain access to the window motor retaining screws.
2. Remove the door trim panel.
3. Remove the water deflector.
4. Remove the door speaker.
5. Support the window.
6. Disconnect the wiring harness from the window regulator motor.
7. Remove the 3 bolts (1) from the window motor located on the front side of the motor. IMPORTANT: Do not allow the cable gear to come out of the housing. A failure will result with the cable coming off the spool.
8. Separate the motor from the cable housing by wiggling the window motor. Observe the orientation of the window motor.
9. Remove the motor from the door regulator assembly.

Install
1. Install the motor to the cable housing by wiggling it into place. NOTE: Refer to Fastener Notice in Service Precautions.
2. Install the 3 bolts to the window motor. Tighten Tighten the bolts to 5 N.m (44 lb in).
3. Install the window, if removed.
4. Connect the wiring harness to the window regulator motor.
5. Remove the window support.
6. Connect the wire connector to the switch to inspect the operation of the window. After inspection disconnect the wiring harness and continue the installation.
7. Install the speaker.
8. Install the water deflector.
9. Install the door trim panel.

shiftless

I have a 2000 Sierra 1500 Std. Cab, Short Bed, 4WD, 40000 Miles. At about 30 to 50MPH there is an apparent "grinding" noise that appears to come from the left front wheel. The "grinding" seems to be in time with the wheel rotation and can be felt through the steering wheel. All symptoms completely dissappear when turning to the left (at speed). All indications are pointing to a failed left front wheel bearing as the cause. The wheel bearing was replaced but the noise is the same. Any ideas out there as to what the source of the problem might be?

Ed

weels

maybe a cv joint?

weels

If you have too big a fuse it will allow more current (heat) through the entire circuit including the switch. I would start looking that you are using the correct rated fuse and are the headlights stock or high powered aftermarket or are there add - on lights in the circuit?
If all that stuff looks right, start looking for a short somewhere. I've had trailer harnesses go bad internally to the plug and cause this sort of thing even though the plug looked fine on the outside. Good luck.
- Tim

j_appleseed

I have 2000 Sierra 1500 and the driver's side mirror (OEM) vibrates excessively. I ordered a new one three weeks ago and received and installed it today. It's from CIPA Mirrors. After a test drive I've decided that's it worse than the OEM one I replaced. The passenger side mirror is as solid as a rock. Maybe I just received a bad mirror. Any info is appreciated.

KCRam

Check the mirror-door mount... it could be the cause of the vibration. 1994-2002 Dodges were notorious for the driver-mirror vibes as well.

kcram - Pickups Host

dryodt

Anyone out there experiencing a clunk, clunk sound like an electric motor hitting a stop in the 2005 GMC Sierra? Mine has less than 4200 miles on it and this sound has surprised me twice in the last two weeks. Other than that the truck is/has been excellent. Even medium towing.

ghamilton

Hi, New Guy Here

I just bought a 2000 GMC Ex-Cab 4.8L and already it has been taken back to the dealer twice for repairs all before my first payment!

I will tell you what has been done and then let you know my most recent problem.

1. Fuel Gauge Sensor Replaced -
2. PW - Window Regulator -
3. Power Steering Unit and Steering Shaft -
4. Heater Fan -
5. Alignment, Rotate Tires -

Now - Has anyone had this problem...

In the rear-end, Take off and not only hear a clunk noise, but feel it go through the driveline. Really notice it when taken off at an angle (forward or reverse) such as from a bottom of a hill.

For the most part, it when taking off from a stop.

The dealer has checked the universal joints, yoke, springs, shocks, u-bolts etc...
Dealers response? "This is normal"

I know when you shift gears from say, reverse to drive - yes it does make a "normal" noise, but what I am hearing is LOUD.

Note; This was not happening when I first bought the truck, maybe 3-4 weeks after.

Does anyone else have this problem?
Any suggestions?

Thanks All

weels

I have an '04 2500hd and it makes a small clunking noise under the floor near my feet. It only does it on semi-bumpy or inclines. I can't be sure that it might be making the same noise on the passenger side too. I haven't noticed it when shutting down though. I'm not following the electric motor coming to a stop description. Does it make a wind - down noise and also a clunk? Let us know if you find it.
I'm not having much luck with mine. I'm almost suspecting body flex at a seam but it's too difficult to diagnose unless I got a little guy to ride underneath when I go four wheelin'. Any takers?
Good luck. - Tim

tenga

Tenga here. Been a while, the forum is like my CB, I only use it, when I need it.
Just got back from a 2 week trip, with out the 2002 2600HD crew cab. I went to move the seat backwards and only one side (rail) would move. The seat was then moved forward and again only one side would more (same side that moved to the rear). When I say moved, the movement is only 3/4 to an I ".
I look under the seat to see if the seat was catching on anything. As far as I could tell there was nothing on the rail or anything snagging the seat.
Your help would be appreciated. Tenga

peekamoose

When I change modes (floor, vents, defroster, etc.) on my 2004 Sierra 1500, nothing happens. It seems like the air diverter door is stuck. Anyone else have this problem?

gmcducati

I had the same problem, there is a missing washer in your transfer case that when you take off from the start slams into the backend of the transfer case. Its a factory flaw. I would take it to a differential specialist, mine cost me $1,400. Mostly labor. Also my '99 GMC Sierra 1500 got stuck in 4wheel drive which caused me to take it in. The banging I thought was the rear diff, but it was coming from the transfer case.

Good luck. Watch out for those differentials, mine has 95k and both have been replaced.

herefordman

My 5.0 Vortec has been giving me lots of grief with ignition problems, it will run super for about an hour, and then regular as clockwork it starts to run like its only on two cylinders, It happened about four months ago and I replaced coil, distributor,wires, plugs, cap, rotor.
And this fixed the problem, but now its back, my manual shows a coil driver in the manual but no description what it does, does anyone know if this could be the problem ?.
Its the small black thing on the same bracket as the coil, not sure if this is the problem or not, but I've replaced everything else.
I could set my watch with how this truck runs, almost right on an hour of running time it really starts stumbling and grumbling almost undriveable, if I stop and turn the truck off and wait five minutes, it runs fine when I start back up, but goes bad pretty quickly after that.
Any help would be appreciated, thanks. :sick:

billbus

My old 89 3500 R/V rust bucket dump has another rusted steel brake line with a hole just as it enters the power brake booster (?) near the back of the truck. My Chilton's Guide doesn't really show a good diagram of what is back here, so I'm guessing that this is what it is!

The line that is leaking is the long hose which leads from the booster toward the front of the vehicle along the frame. I wish it were the 6 inch line which ran just underneath this longer line!

I'm trying to find an illustrated parts diagram showing or info about how and where this Intermediate brake line connects to other hoses at the front. This line looks very long, appearing longer than the standard 60" steel brake line length, and while the back connection to the booster is easy to get to, I've not yet found the front connection fitting.

Can anyone point me in the direction of a parts diagram - perhaps at an online catalog site, or even print catalog - showing the steel brake lines for this truck? Also, I'd welcome any suggestion on how to make this repair a bit easier. Due to all the rust, replacing the rear brake line attached to the left rear wheel was a killer. I'd like to find the most efficient solution to this challenge before I jump in.

Any suggestions are appreciated!

Bill B.
Pittsboro, NC

keith11

I have a new 2005 Sierra crew cab Z71 with about 2400 miles. On both left and right turns there is a single clunk or bump sound that appears to come from under the front of the cab. It can be felt in the floor on the passenger side and easily heard. It usually doesn't occur when the truck is cold, and becomes nearly 100% repeatable after driving for a while. A mechanic suggested it was the exhaust mounted too close to the floor under the front passenger seat. Anyone have any ideas?

noobie1

Congratulations keith, your in luck if it's 100% repeatable. Now the dealer can't wiggle out of fixing it if it becomes problematic by saying "could not duplicate customer's complaint".

-David

tjboatboy

Hi,
I have a 1999 GMC Sierra SLE 4X4 Exteneded cab with a 5.3 engine. In April I noticed an engine noise that turned out to be piston slap. Very annoying. The engine had 45000 miles on it at that time. I had purchases an extended warranty 6/60. The dealership went to bat for me and I ended up with a new engine. I had the choice of a Texas rebuilt or a goodwrench engine for an additional $1300.00 I went for the GM engine. The problem is this: After the engine had been in for about 500 miles I had a flowmaster 50 series converter back exhaust installed. At about 1500 miles the truck developed a hesitation at take off. It has been to the dealer 6 times and still has not been repaired. New fuel pump, PCM, O2 sensors, Mass air flow sensor, Cleaned the fuel rails, New fuel filter, I have a K&N Air filter. The dealership flashed the PCM and things were fine until I turned on the A/C where the hesitation has returned. It has never logged a code. Fuel mileage is about 12 mpg.
Do you have any suggestion the the dealership might try?
Thank you for any help on this,
Tim

roberts64

I've got a 2001 GMC SLE 1500 and when I put the truck in park and it idles for more than a minute or so, the fuel gauge drops to E and the Low Fuel Warning light comes on. As soon as I shift into drive, (or reverse) and move, the fuel guage goes back to the right place, and the Low Fuel Warning light goes out. Occasionally, it will come on when driving, but that's not very often. However, when I'm in park, it will do that almost every time.

Any ideas??

Thanks a million!

keith11

David, I hope you're right. The dealer has now had my truck for one full day on two occasions. They have removed the nerf bars and tightened, loosened, and retightened all the cross members on the frame. The only thing they've accomplished is make the problem more obvious. I've got a bad feeling about how long it's going to take them to find this. The dealer that sold me the truck (in another town - couldn't find the model/color locally) said it was the exhaust too close to the floor under the passenger area, but the current dealer said that wasn't the case. Would love to hear suggestions from anyone or confirmation from others who have this problem. So, I continue to have a clunking noise when turning. Thanks.

weels

It's enought o drive you nut isn't it? My '04 2500hd does a similar thing. I have a pit in the garage and every time I'm under it I try to bounce the truck to try and duplicate it but never can. There are so many sheilds and guards and stuff under there that it's tough to see anything. I almost suspect it's up behind the inner fender. I 'm tempted to yank it off too see what I can.

ghamilton

I had the same problem with my 2000 GMC SLE -

The problem is a Fuel Sensor.

It's located on or around the Fuel Pump - I had the dealer fix mine. The day I bought the truck, the dealer filled the tank for me, before I drove off the lot, the Low Fuel Warning light came on and the fuel gauge dropped to E.

I believe they had to drop the gas tank to fix it.

It will probably cost you more for labor than parts.

This was just the begining of problems for my truck. See #1136 above.

Good Luck to Ya!

mturcotte

I have a 2003 Serria Denali with 95,000 miles on it. When under a load or acceleration I get what I would call / sounds like engine flutter. I have had the plugs, wires, coil to # 6, muffler, cat all replaced. Any suggestions on what this could be?

mailman2

How do you change the fuel filter on a 2001 Sierra with the 5.3? Do you pull the fuel pump fuse and the turn the ignition key to on? Does this de-pressurize it?

kingle1

I've got a weird problem -- when you accellerate hard, there is a "gurgling" noise like running water behind the center of the dash. It goes away after a few seconds, but it really bothers me! Any thoughts?

tunajack62

Has anyone noticed thier 5.3 ('00) seeming a little meek, I drove an '04 5.3 the other day and noticed a big difference in power. I've recently replaced the fuel press. regulator due to hard starts when hot (leaking into the vacuum line). It runs about 48lbs pressure at idle under vacuum and jumps to around 58 without vacuum.Think that's a sign of a weak pump? I've also put a Gibson dual exhaust on her recently. More fuel needed? Hope not, It's not bashful about using gas.

tunajack62

I'm hearing alot of these complaints, and everyone is saying a fuel pump/sending unit replacement (about $350). I'll be checking the wiring at the pump, since I've noticed some replacement pumps come with new wiring harnesses. Mine's doing the same. I've also noticed sometimes it's hard to start cold. Watching a pressure guage, the pump doesn't always work when the key is turned on to the ignition position. I'll post if I find anything goofy with the wiring.

noobie1

kingle, do a word search for "gurgling" here and at "Chevy Silverado Problems Solutions". It should give you enough to go on.

-David

obyone

Sorry to say I had the same problem when I installed my Gibson catback....down on power especially on the low end. Replaced the gibson and all was fine.

carp2

ive got 2000 that is doing the same thing. It only happens when im idling, as soon as i put it in park the giage reads properly. dealer told me im looking at about $800 to fix ,told me its a sensor in the tank.

carp2

Has anyone had problems with there transmission, only to find out the panitary gears where all in the bottom of pan. I thought it was something in my brakes like a rock grinding on disc or something. never thought it was the tranny till i took to garage. I thought that they fixed there trans. problems in 1999. anyway $3500 later back up and running. Emailed gmc head office and told them what i thought. there taking it to board meeting to see if ill get something back.

weels

I've had a few pumps go bad on me and it's usually in the winter and it ends up being a nasty job to drop the tank. The last two we did was pretty slick. Although some might not want to do it, the easiest thing is to cut an access panel in the floor of the bed. Last winter our plow truck went through two pumps and the second change out was a breeze - just unscrew the plate and eveything is right there. Most folks have bedliners so it isn't even visible.
Just thouht I throw that out there.
- Tim

pdana

I have a 1998 GMC Sierra with a 4.3 v6 and manual transmission. When I push the clutch in when coming to a stop or while changing gears my rpm will either surge or stay where it was at while the truck was in gear, only coming down to a normal range when the truck comes to a complete stop. I recently replaced the IAC valve and it seemed to fix it for a little while and then I slowly started having the same problem again. It's also more noticeable when the a/c is on. Is there anything else I can check/replace, or do I possibly have another bad IAC valve? Thanks for the help.

weels

Throttle cable / linkages all ok?

pdana

I think so. I looked at them and they looked ok. I also gave them a squirt of WD-40. I think I may have another bad IAC valve, because when I first replaced it the problem went away, but it slowly came back.

lisalmu

Hi all..

I just bought a '91 GMC 2500 5.7 Liter V8. Its a nice truck in and out. Excellent condition. great running condition. Lots of power. Smooth running truck. Idles nicely even at startup. No hiccups. Nothing to indicate anything was wrong. Its been very well cared for over the years.

Except. I'm getting 5 MPG!!! yes FIVE! I dont know what's wrong. It was just smogged on thurs. It passed. I can go 30 miles and use up a 1/4 tank of gas. Its a 22 gallon tank. If its getting 5 MPG empty, I'd hate to see it pulling a loaded horse trailer!!!

Does anyone have any idea why its such a gas hog?? Its killing me. I'm just glad this truck isn't my main transportation. I wouldn't be able to afford to even go to work!

Lisa

sprintcar1

ive had several eletrical problems:first side mirrors will not adjust electrialy :second pass. door lock will not work electrically but will work manually. third heat control problem can turn up or off but not down now the most serious last night i was woke by watch dogs to find the truck trying to start it self. meaning the starter was cranking the engine but since the ignition switch was in the off position it would not start. then the starter got hot from cranking and began to smoke ALOT. to stop this from happening i had to diconnect the battery. after i but a new starter what should i check next so this does not happen again? the starter has been replaced with a new starter due to previous accident :mad:

gmboy1

FYI
Just a note for the Do_it_Yourself'ers. I just finished changing the internal Filter in my 2003 GMC Allison Transmission, actually a piece of cake, no external attachments to remove, drain plug in pan actually works and all pan bolts are easily accessible. The internal filter is about $29.00 and the external spin_on was about $20.00. I could not find the capacity listed anywhere, but to let you know, it was approx. 10 quarts.

noobie1

The fluid amounts as stated in the Service Manual are:
"Fill after rebuild, 12.7 qts." and
"Fill after fluid and filter change, 7.4 qts."
Don't know why the discrepancy. You might double check the level being sure to use the procedure as stated in the Owners Manual. Kinda complicated.

Curious about the internal filter you mentioned. Can't find anything about it in the S.M. Is that its official name?

BTY - If there's an Allison dealer near by, you can get those spin-on filters for about $9.00.

-David

weels

That's terrible. I don't know how long you've had it or what's involved in the smog test, but if it runs that good and passed the test, that don't jive. Don't rule out that the guage might be bad. I guess you can tell when you go to fill it how much it takes. I wish I could help but everything I'm thinking of would also make it run like a pig. Did they sniff the exhaust as part of the test? Usually if it's running real rich the exhaust pipe will be black and sooty and smell like fuel. Does it have a catalytic converter?
- Tim