Edmunds Answers questions

1999 Suburban 7.4L all sensors operating. what is the ignition timing at idle with a code reader set to "monitor'

chuckster57 — Tue, 05 Feb 2008 23:37:24 GMT

1999 Suburban 7.4L . Replaced head gaskets. installed dist. with # 1 at TDC and put rotor "button" at "8" mark. Hooked up autoxray code reader and at idle runs rough and says timimg is at 23-24 degreees. Seems way to advanced. Can't fnd anything that says what it should be. getting P1345DTC (crank/cam correlation out of range) all marks seem to be lined up.

99 7.4 Chevy 1500 first crank of the day runs fine. After that hard to start every time. Please help,

fio2 — Mon, 26 Jan 2009 14:36:06 GMT

start a runs fine but every start after that for the rest of that day are hard starts. checked throttle body, iacv ,looked at the egr didn't look bad and replaced the pcv. It seems to be fuel related I am about to pull my hair out.

2003 GMC with Duramax started then went dead and would not crank back up.

unionman1 — Sat, 13 Jun 2009 16:03:02 GMT

I have a 2003 GMC with the 6.6 Duramax. Yesterday I started it up before work and walked in the house. On my way back to the truck it just died. It would not start back up. That afternoon I tried again and still no luck. I sprayed starting fluid in the air cleaner and it cranked up and ran fine. After shutting it down it was hard to get it started again (with no spray). I don't know if it's losing pressure through an air leak or it's the fuel pump. Anybody have an ideas?

Help with speedometer reading 20 mph to slow on 92 GMC 2500 2 wheel drive

tommytee — Thu, 24 Jan 2008 12:19:57 GMT

My 1992 GMC speedometer reads 20mph to slow. When I drive 65mph being clocked by my wifes car my truck speedometer reads 85mph. The temperature gauge also reads low. I have replaced my temp. sensor with no changes noted.

Can anyone tell me if it would be a problem with my instrument cluster or something else?

Does anyone have a wiring diagram? Do I have to take the truck to a dealer to find the problem?

Thanks

Trying to find out the horsepower of the 1996 7.4l GMC engine- mine is port injected but has distributer

wecomb — Sun, 17 Feb 2008 08:51:37 GMT

Same as above

What's difference in towing capacities Chev 5.7 vortec K2500 vs newer 6.0?

dulrich — Mon, 18 Feb 2008 12:36:34 GMT

Trying to determine if a 1999 K2500 w/5.7vortec is sufficent enough to tow my horse trailer or do I need to go to the newer 6.0?

'02 Chevy Silverado 4x4 Encoder Motor Change

crash1963 — Sat, 15 Mar 2008 19:03:08 GMT

Hi... anyone know how to install an NP8 encoder motor? The cam on the transfer case is nearly, but not quite lined up for installation. I've heard not to turn the motor electrically while it's off of the truck, so somehow I have to turn the cam on the transfer case. I put the truck in neutral off of the ground but this cam won't move much.. .feels mushy. Am I doing something wrong? I just need to move it a little bit.. :) Thanks!!

I have a 2005 GMC 2500HD 8.1 6 speed manual. There is a rattle coming from the base of the shifter? Dealer can't fix.

fiberguy — Mon, 31 Mar 2008 14:19:32 GMT

This rattle only seems to be when under load or acceleration, does it in all gears. My Dealer can not tell me if this is Normal or not as they do not see many of these transmissions. This rattle started around 20,000 miles, I now have 32,000 and it has not got any worse. Can anyone tell me if this is normal with these transmissions?

Thanks

Is a 1994 Chevy 454 block the same as a 1979 454 block? Are the heads just different?

turkeyjac — Tue, 17 Feb 2009 20:43:30 GMT

are the blocks the same or do they differ from tbi and carb

GMC catalytic converter heat shield rattle fix? 1995 GMC Vandura G2500.

lobosays — Mon, 04 May 2009 20:54:46 GMT

What is the FIX for a 1995 GMC Vandura G2500 5.7 TBI catalytic converter heat shield rattle?

Thank You.

30K service items for an GMC 2500 diesel 4WD.

ted38 — Fri, 24 Jul 2009 19:20:33 GMT

I need a list of items that require service at 30 thousand miles on my 2006 four wheel GMC diesel.

Replacing GMC 2500HD Duramax belt tensioners.

buddyboy5 — Sat, 25 Jul 2009 16:00:35 GMT

I have an '01 GMC 2500HD with Duramax 6.6 diesel and I've replaced the serpentine belt tensioner 3 times in the year I've had it, twice while on the road pulling a 35 foot 5th wheel camper. The last one only lasted about 4 months. They usually break right in half, through the cast aluminum. I've had a couple of people look at it and none of us see anything obvious. Any ideas?

I have 1995 Chevy 6.5 turbo diesel and the truck needs TDC offset done how do i go about this.

rodman4 — Thu, 10 Sep 2009 12:57:55 GMT

Need timing done on my 6.5 turbo. Is this something I can do?

Different Front and Rear Tire Pressure on 2008 GMC 2500HD pickup?

ronp50 — Sun, 27 Sep 2009 19:13:55 GMT

I have a 2008 GMC 2500HD PU. The door sticker calls for 72PSI in the rear tires and 50PSI in the front tires.

The PU is used to tow a 8500# trailer but 85% of the time is run empty.

While running empty, should I reduce the rear tire pressure to 50-60PSI to save on rear tire wear? If I continue to run the rear at 72PSI while empty will I prematurely wear out the rear tires.

Thanks

Dies>vortec-2-11-08,fuel injected,70lb's fuel pressure@check valve,supposedly there's a fuel pressure regulator ?

ebob1 — Mon, 18 Feb 2008 00:31:00 GMT

Vortec won't stay running unless i pour fuel manually into it. via under the air filter assembly where the butterfly choke assembly is. as long as i continue to pour fuel in it stays running

I CAN'T LOCATE THE REGULATOR AND THE FUEL LINES DIP INTO A PLASTIC RECTANGULAR BOX ON THE INTAKE MY GUESS IS THE INJECTORS ARE UNDER THE INTAKE BUT I DON'T WANT TO REMOVE IT JUST FOR GIGGLES

I have a 2002 Chevy 2500 HD 6.0 and i need the security system reset does any one know how this is done.

kobelco269 — Sat, 08 Mar 2008 14:14:02 GMT

it will start then the security system flashes and it will shut down

GMC 2500 HD Allison transmission not going into gear.

mattred — Mon, 24 Mar 2008 13:55:34 GMT

2002 GMC 2500 HD. Duramax with allison transmission. It will just act like its in nuetrual at times. Other times it shifts into drive, reverse and park very hard. Harsh noise from tranny heard also. When acting up the 3 low light flashes. Replaced TCM and still have the same problem.

I have a 2004 GMC 2500 HD extended cab and the back doors squeak. Why is that!

allen24 — Sun, 30 Mar 2008 15:16:03 GMT

The back doors squeak during turns

I need to know how to locate the vacuum lines on my 2006 Chevy Silverado work truck Vortec v-8.

dhost — Sun, 01 Jun 2008 22:48:04 GMT

I am installing a fuel enhancer system and need to tee into the strongest vacuum line. I don't know enough about todays engines to locate the vacuum lines that I need to tap into.

95 Chevy 2500 Cheyenne locks in to park.

cab14 — Thu, 17 Jul 2008 10:58:52 GMT

Before I inherited this truck it was having shifting problems in that it wouldn't shift into 1st gear, but would run in all other gears fine. Some switch on the tranny was replaced (Nov). I've had the truck since Dec and now it is locking into park and takes about 10-15 minutes to get it out of park.

What might the problem be. Is there a sensor on the brake that I should be able to locate that could be bad? Is it something to do with the shifting mechanisms by the steering column?

I've got the panels off around the steering column and I can't find a problem, nothing appears broken or loose.

Chevy Silverado starter activates with gear selector in 3rd.

rgavaldon — Sat, 02 Aug 2008 00:36:25 GMT

I have a 2002 2500HD. With the key on and shifting the gear selecto to 3rd gear the starter activates What is the problem and how to fix it?

I have a 2002 GMC C/K 2500 crew cab that stalls out frequently.

codaddy5 — Tue, 19 Aug 2008 10:53:54 GMT

The truck will just loose power and fuel supply. I have already had the fuel pump and filter replaced. The web site has said some people have heard of a recall on 2001. Can anyone let me know if there has been a diagnosis on what causes this, and what can be done to fix it for good. It is the 8100 series engine.

1998 Chevy 2500 transmission problem

jeff109 — Fri, 29 Aug 2008 00:10:31 GMT

i have a 98 2500 chevy truck had the transmission redone top to bottom and when i drive fr about 20 miles i loose overdrive. when i stop and turn the truck off for about a minute it will barely crank and the problem is gone for a another twenty miles hghway miles..they hace rebuilt from top to bottom all new hard parts pump and torqu conv. and tcc switch and it still does . what do i do they are lost for word...

Dash problems on Chevrolet 2500 Silverado Duramax.

mag11 — Thu, 04 Sep 2008 12:49:32 GMT

I have a 2003 Silverado 2500 duramax and the dash ie speedomoter tach temp and all of the guages doesnt work I have narrowed the problem down to the connection to the dash unit is there a way for me to tighten the connectors so they will make contact all the time?

How do I program a keyless entry or remote key for a 2004 Chevy Silverado?

mag11 — Sun, 12 Oct 2008 19:14:21 GMT

2004 Silverado

I have a 6 liter that is backfiring and flooding out. I replaced fuel and air filter and plugs/wires and no luck. Chevy 2500.

deereboy — Thu, 16 Oct 2008 20:23:25 GMT

i have a 2000 chevy 2500 4 wheel drive that hesitates at 1000 rpms and going down the road it floods out and sputters and backfires. I have replaced fuel/air filter and plugs/wires and still problem is there. Any help?

How difficult is it to repair front differential bearings in my 2002 Suburban K2500?

filiatrault — Fri, 17 Oct 2008 19:13:06 GMT

I have been told that I need significant repairs - as much as $1,0000+ to repair and possibly replace my front diff. My truck has only 110,000 miles on it so I have a hard time beleiving that the entire front diff is shot. It sounds very much like bearings to me which are relatively inexpensive but I am not sure how difficult the repair is.

We have a 2000 2500 series Chevy pickup and I would like to know how to drain the radiator fluid.

jakey1946 — Wed, 29 Oct 2008 17:28:29 GMT

I would like to know how to darin the radiator so I could put fresh fluid in my 2000 Chevy pickup

GMC Sierra 2500. 4WD will not engage. Actuator good. Fuse good. What else to check? Relay/switch?

egglebl — Mon, 03 Nov 2008 11:29:10 GMT

GMC 2500 1994 Sierra 4X4. Was in 4WD. I disengaged but it would not re-engage. Checked the Actuator on the bench with 12VDC and it extends. Replaced fuse. Lever in Cab is in 4H but light will not light and front end will not engage.

I have a 2004 Chevy 2500 4x4 that won't shift into 4 hi. It will shift into 4 low with no problem. Any suggestions?

tneg — Sat, 20 Dec 2008 15:46:51 GMT

The 4wd shift is on the floor. It shifts fine into 4 high but doesn't engage and the light on the instrument panel doesn't come on. Now when i shift into 4 low everthing including the light works fine.

99 Chevy 2500 7.4 crew cab is hard to start after engine is warm.

fio2 — Thu, 22 Jan 2009 09:56:48 GMT

the engine starts fine when cold. if the truck sits for a while it turns over a lot before it cranks. when the engine does run it seems to run fine. the fuel filter has been replaced

99 Chevy 7.4 hard start after engine is warm.

fio2 — Fri, 23 Jan 2009 09:02:10 GMT

hard start after engine is warm changed the fuel filter any suggestions?

I have a 1995 Chevy 2500 2WD that locks the tranny into 2nd.

eraddatz — Thu, 29 Jan 2009 03:04:36 GMT

It does it only in winter, so far? Also torque converter locks and unlocks when it wants to. For example it will unlock going down a hill, yea I know backwards of what it should be. the 2nd thing starts out in 2nd, not first. I have 2nd and reverse. I have to shut it off for at least 20 to 30 minutes for it to come out of it, so far. no codes and no check engine light Oh yea 4le80 trans Any Ideas?

By the way If I go out and PLAY in the snow, where the tires are spinning, it seems to do it, if that helps. not something I do, but the shop had no idea without a code.

1994 GMC 2500 4WD not engaging.

simpleman2 — Fri, 30 Jan 2009 18:43:37 GMT

I have a 1994 GMC 2500 that will not engage the 4wd. Actuator is new and the fuse is not blown.The clutch was replaced about a month ago.It worked this morning (indicator light,front axle engaged)Now it will not.Sure its electrical but not familiar where to look. Switches,relays etc.It is electric. Going to snow on Monday. I know it is possible the knuckle heads could have pinched or have a loose wire on transfer case if there is any.I need to know where the switches are that engage the 4WD. Thank you your help is appreciated.

Poppet location for fuel injectors? Chevy K series pickup.

chives10 — Sun, 15 Feb 2009 20:40:26 GMT

1999 chevy k series pickup replaced spider injector and i want to check which way to wire poppets. any help would be great thanks.

If I travel down the road my vehicle tracks straight. If the wind blows it will throw me into the other lane? GMC K2500.

jlinemn4 — Tue, 03 Mar 2009 13:42:04 GMT

i have a 1994 K2500 Suburban the front end has been completely rebuilt including steering box, if i am traveling down the road my vehicle tracks strait but if i get a slight wind or a gust it will throw me into the other lane. It's as if i can't control the vehicle. any ideas. the only thing that has not been replaced is the sway bar. i have also replaced tires.

What's the turning radius for '94 Chevy C2500 crewcab and an '03 2500 Suburban?

rimler — Sat, 21 Mar 2009 09:36:32 GMT

How close can I turn into a garage near the corner of my building?

99 Chevy 2500 4WD pickup lowbeams and daytime runnning lights don't work but highbeams work.

mdrdavies — Thu, 26 Mar 2009 16:09:13 GMT

99 Chevy 2500 4WD pickup lowbeam headlights and daytime runnning lights don't work but highbeam headlights work.

Thinking of buying a 97 Chevy 2500 6.5 diesel. Is this truck a good one to buy ? Heard it had problems?

ekh1 — Fri, 27 Mar 2009 07:47:55 GMT

220,000 miles. In good condition.

95 Chevy K2500 6.5 turbo diesel. EGR and other problems. Help!

dirtslinger — Tue, 14 Apr 2009 17:49:02 GMT

Well, Ii have a 1995 k2500 chevy, with a 6.5 turbo diesel. The check engine light shows a DTC 33. Saying MAP high input. I replaced the map and baro sensors, still have a problem. With the engine at idle its fine, under acceleration at about 3500 rpm or so the engine is rough firing it seems. The glow plugs have been replaces 2 days ago. And also in the summer months, the truck seems to build pressure sometimes after a long sit, when you crank it, it makes it about 1 mile down the road or so and goes dead, like it sucking air or something. I have no clue, I do believe that its getting fuel tho. It does it the most in the summer, and I don't have any problems it seems during the winter.

If you need me to explain anything else I will, this truck has been getting on my nerves super bad, and now getting to that point where I'm growing tired of working on it, so any help would be greatly appreciated..
THANKS.

2000 GMC Sierra 4x4 with 260KKm. When accelerating get buzzing like valve chatter from transmission at 80km/hr and 1700 rpm.

ontheflybri — Wed, 15 Apr 2009 23:46:45 GMT

GMC 2000 Sierra 4x4, 3/4 tn, 6 l with 260KKM. When I accelerate I get a buzzing from the transmission like valve chatter at 80 Km and about 1700 rpm. If I punch the gas and downshift the buzzing stops and I can accerate to higher speeds fine and then continue in overdrive at 110 km/hr. Occasionally this also happens at 100KM/hr and about 2000 RPM.

A transmission flush has not fixed the problem and Mr Goodwrench recommends transmission replacment. Help.

The auto gear selector locks into P on my '04 GMC 2500. What's up?

dhoogen — Fri, 08 May 2009 22:33:45 GMT

My '04 2500 auto gets stuck in "P". This happens more and more frequently. If it's not a fuse, what else? I only have 30K on it.

I have a 95 Chevy 2500 and it shifts good and goes good in drive but not in reverse. What's wrong?

bezza — Sat, 06 Jun 2009 08:41:01 GMT

It catches every gear just doesn't pull in reverse until you give it a lot of gas. It makes noise from the rear end. Can it be the gears?

88 Chevy 2WD 2500 tbi dying.

woodster1 — Sun, 07 Jun 2009 18:02:57 GMT

Truck started dying yesterday leaving stop. Would restart but die. Once got up to 35mph ran fine. Got home, changed out fuel filter.

Didn't help, still did same. Now won't start. Undid fuel line at back of tbi at engine. With key on and also cranking, no fuel comes out. Can hear fuel pump run for couple seconds with the key on, so pump must be good? Can't locate fuel regulator. Does this year have one? Any suggestions?

GMC 2001 4X4 Suburban when in 4LO, the front end engages but when shifting to reverse it disengages? Why would it drop out?

dean32 — Sun, 28 Jun 2009 05:29:22 GMT

When in drive front end is locked up, shifting to reverse the front end disengages and only the rear wheels turn.

I have a 93 Chevy 2500 series truck and can't figure out why I cant get it in time. What is the trick to do this?

rucuss — Fri, 03 Jul 2009 08:44:51 GMT

How do you time a 93 Chevy 2500 series truck? Is there a brain that needs to be reset? Or what?

1994 GMC 2500. When I turn the key on or off there is a banging sound near the heater fan area? Thanks

lippy16 — Fri, 03 Jul 2009 09:59:12 GMT

When you first turn the ignition switch to start the pickup there is a banging sound down by the heater fan area. After having the key on for 10 seconds or so the sound stops. When you turn the key off-engine quits-the banging sound starts again. You can turn the climate control off-which turns the fan off-the banging still continues. Could it be the device that changes where the air flow is directed-defrost/floor?
Thanks

2000 Chevy Silverado 2500 HD jerky transmission.

dhaynes1 — Sun, 05 Jul 2009 11:04:02 GMT

I have a 2000 Chevy Silverado 2500 HD - when I tow my boat, trailer, etc., the transmission will begin to shift really hard after I've been on the road for about 30 minutes. It always shift to the next gear, but you can feel the truck "jerk" when it shifts and the transmission makes a popping noise.

Again, it will shift normally at the beginning of the trip but, once the hard shifting begins, it will continue through the remainder of the trip. Any Suggestions?

I have a 2002 GMC Sierra with over 200000 miles. Truck runs then low fuel light goes on and it won't rev over 2000 rpm.

alspringoak — Tue, 18 Aug 2009 14:38:14 GMT

I have a 2001 GMC Sierra with over 200000 miles. Truck has been serviced. Don't have history. Ran strong, then low fuel light came on and truck won't go over 2000 rpms. Changed fuel filter, truck ran ok then did the same thing.

Is it a sending unit? How do i access it? Low fuel light is on ,runs at 2000 rpms and does not stall. Is there a pump on the sending unit or is it a bad fuel pump? This truck has a Duramax diesel with Allison transmission.

I want to check all major ground points for the sending unit and other electrical components that effect fuel delivery can anyone help.Thanks

My Chevy 2500 5.7 hesitates off of idle until 3000-ish and then cleans out. New tune-up. Looking for ideas, kinda lost.

eraddatz — Sun, 06 Sep 2009 17:34:27 GMT

I don't know to do. Hesitation and backfires off of idle. So bad I can't even go through a stoplight anymore. Ideas anyone?