Bought my second car this week!

[Username1]

Well, Sorry I'm not up on the GM line. They are not my first choice, But I do like
this van A Lot, so I'm going to do what I can to keep it alive.

I'm not sure if you got away with anything not having "the spider" under your hood or not.
I never heard of it till a few weeks ago - Ha !

At any rate, it seems that with any used car, the new owner has some stuff to do to
get it up to standards..... Good Luck !

.

[Electronic M]

Thanks! I'm going to do my best once it gets consistently warm/tolerable to work outside.

Also hope my trivia/know-it-all-syndrome on what has what engine did not come across as being crabby....I did a bunch or research on this and the S10 SUVs when I was trying to buy a car and regurgitating it helps keep it in my mind....Though I'm not sure why I want to hang onto it...Guess I'm just a pack-rat for useless facts...

[MadMan]

Originally Posted by Electronic M

Mine is an inline 6 so hopefully is is not as bad as the V engines.

Oh, a later model Envoy. Good on you! While it's not a spectacular engine... in fact it is rather strange... I'd take a crappy one of those over a nice vortec motor any day. Because, you know, you actually can make the I6 run well.

I see you did the thermostat the hard way. I know I'm an experienced mechanic, but still, taking the alternator out of one of those is a walk in the park, and then the thermostat is right there in the open. So what code are you getting for the check engine light?

[Electronic M]

Got three codes according to AutoZone:
P0128 Low coolant temp....Either the engine has not cleared the codes prior to Saturday or the ECT temp sensor is bad (the other probable causes were dealt with by saturday's work).
P1481 cooling fan speed signal lost...Claims either bad electrical connection or bad fan clutch.
P0442 (evaporative emission system) small leak/no flow condition...I have a hunch that one is from completely filling my gas tank 3 miles before the diagnostic.

It actually was not all that hard changing the thermostat that way...Ignoring the parts runs it was ~1hour of work....Swapping/repositioning the capstan belt on a Realistic TR-3000 RTR deck is more of a pain (try doing ~8 screws that are out of hand's reach on one of 5 steps of disassembly just to get at the belt)...Heck tricks that working on that deck taught me were applied to the GMC.

[MadMan]

Well, it's usually 100 ignition key cycles to clear the codes. Just go back to AZ and tell them to clear the codes for you. Hopefully that takes care of the first code.

Sadly, the fan is where these motors start getting weird. It's a hybrid of an old school belt-driven thermostatic clutch fan, AND an electric fan. If I recall correctly, it's an electronic duty-cycle based fan clutch. (It's really stupid.) Don't think I've ever come across a bad one, though. If the code specifies it's lost the fan speed signal, either the fan isn't turning at all or the computer isn't getting the speed signal from the sensor in the fan. The wiring and plug should be on the drivers side of the fan shroud. Dig in there, unplug the plug for it and examine the pins and wires for corrosion. Gently tug on the wires on the back of each side of the plug to check if they're broken inside the insulation. If thats all shipshape, you'll probably need to replace the fan clutch, $112 on rockauto.com. If you want to get really into the nitty-gritty electronical diagnosis - which, you're here, so - you can put an O-scope across 2 of the 5 wires and you should get the speed wave while the fan is turning. I've never looked up the wiring on that, but 5 wires tells me: 2 for duty cycle command, 3 for speed sensor. 3 = pos, neg, and signal. A digital 3 wire sensor will need power to work (5, 8, or 12v) and make a square wave, so you'll have to test while it's on the car and while it's running, unless you feel like completely removing it and hooking it up to a power supply on your workbench, and spinning it (usually 100rpm or higher to register). But it can be done.

As for evap... it's a lot easier when you have a real good scanner and a smoke machine... but just off the top of my head, it's probably the vent solenoid valve at the back of the car. Most common problem, anyway. You can unplug it and apply 12v to see if it operates or not. Unless you just left the gas cap loose on one of those fillups.

[dieseljeep]

Originally Posted by MadMan

Well, it's usually 100 ignition key cycles to clear the codes. Just go back to AZ and tell them to clear the codes for you. Hopefully that takes care of the first code.

Sadly, the fan is where these motors start getting weird. It's a hybrid of an old school belt-driven thermostatic clutch fan, AND an electric fan. If I recall correctly, it's an electronic duty-cycle based fan clutch. (It's really stupid.) Don't think I've ever come across a bad one, though. If the code specifies it's lost the fan speed signal, either the fan isn't turning at all or the computer isn't getting the speed signal from the sensor in the fan. The wiring and plug should be on the drivers side of the fan shroud. Dig in there, unplug the plug for it and examine the pins and wires for corrosion. Gently tug on the wires on the back of each side of the plug to check if they're broken inside the insulation. If thats all shipshape, you'll probably need to replace the fan clutch, $112 on rockauto.com. If you want to get really into the nitty-gritty electronical diagnosis - which, you're here, so - you can put an O-scope across 2 of the 5 wires and you should get the speed wave while the fan is turning. I've never looked up the wiring on that, but 5 wires tells me: 2 for duty cycle command, 3 for speed sensor. 3 = pos, neg, and signal. A digital 3 wire sensor will need power to work (5, 8, or 12v) and make a square wave, so you'll have to test while it's on the car and while it's running, unless you feel like completely removing it and hooking it up to a power supply on your workbench, and spinning it (usually 100rpm or higher to register). But it can be done.

As for evap... it's a lot easier when you have a real good scanner and a smoke machine... but just off the top of my head, it's probably the vent solenoid valve at the back of the car. Most common problem, anyway. You can unplug it and apply 12v to see if it operates or not. Unless you just left the gas cap loose on one of those fillups.

The price of those scanners for OBC2 came down, since I bought mine. Owning a newer car and doing your own work, it's really a good investment. You can also use it the clear the codes, as well.

[Electronic M]

Well the check engine light went out after the repair, came back on at the end of the first week after the repair then a day later went out and stayed out....till now.

This morning I tried to start it up a few min before leaving for work (to warm it up), and everything on the dash behaved as normal...Only it did not even try to crank with the key in the crank position. The radio and accessories turn off in crank position so it I'd guess the ignition switch is still good. Multiple tries and pushing the gass pedal down did nothing, and when I got home tonight it still refused to make an attempt to crank. Battery voltage is fine, hell I jumped it to my Lincoln with the Lincoln running and even with the Envoy showing 14V on it's volt meter it refused to try to crank. The check engine light is back on. My guess is the crank signal runs through the computer and the computer is not happy for some reason.

It did something similar to me about a week ago when leaving work...Would not crank the first few key movements (check engine light was out IIRC). I waited a minute or two then retried and it started fine then so I shrugged it off...Seems it definitely needs help now.

I guess the first thing to do is see what Chillton's has to say about the starter motor circuit... A friend has a code reader so I may borrow that to see if I can figure out if/what's makin the computer angry...

This car may end up sold before the ETF...I need a good TV hauller, and this thing seems to have more chewing gum and drywall screws than actual automobile left in it.

[Eric H]

Is the Theft Light flashing? On a GM I think it's a little Lock symbol.

[Electronic M]

Originally Posted by Eric H

Is the Theft Light flashing? On a GM I think it's a little Lock symbol.

Nope. The only lights that are on (aside from the bulb test where all warning lights come on for a sec on first time keying to run position) are the Check Engine light and the battery light.

IIRC on mine the security light reads security...It has keyless entry, but the ignition key is NOT a chip key so it has a security feature where it goes into panic mode if it was locked with the remote but not unlocked with the remote before opening a door...IIRC it will start in panic/security mode.

[MadMan]

Ok, well iirc, even the chipless keyed ones of those still have a quasi-passkey system. There is a sort of switch on the key cylinder that is hooked up to security. But anyway, if the antitheft light is not on while the ignition is on, it's probably not a security issue.

Common causes for a no crank at good battery voltage would be the ignition switch, neutral switch, starter relay, starter itself, or ground wire.

The ignition switch may still have burned contacts, just because it disengages the accessories in the crank position doesn't mean it's engaging the start connection. To verify this, try rapidly turning the key between the run and crank positions, which may clean the contacts and eventually make a connection.

The neutral switch should be easy to eliminate as a problem, just look at the PRNDL indicator on the dash. It should have P underlined. Even so, with one hand, hold the key in the crank position, while simultaneously moving the shifter through the gears, particularly neutral and park.

This car should have a starter relay, which'd be in the underhood fusebox. It should be labeled as such. Have someone else sit in the car and turn the key between run and crank, while you listen or feel if the particular relay is clicking. Note that a couple other relays will also click at the same time. You could also remove the relay while someone holds the key on crank, and plug the relay back in to see if it clicks. Either way, try swapping that relay with another one in the fuse box.

If it's the starter, you can try hitting the starter with a hammer while someone holds the key on crank. Or, sometimes I get away with sitting in the driver seat and rocking the car while cranking it. That'll jar the armature hopefully enough to move past a dead spot and start cranking.

A bad main engine ground wire can sometimes (but not always) be successfully bypassed by putting a jumper cable from the car's battery negative terminal to the engine ground. If it starts then, it's probably a ground wire.

If I had to guess, though, I'd say the starter has a dead spot.

[Electronic M]

I swapped out the relay then the starter yesterday. I could not initially find the starter, and was trying to check if the relay was firing. I pulled the relay had some one crank it and plugged the relay in and it started...I swapped the relay for a new one thinking it was the cause and then it would not start again...At that point I found the starter motor and was able to confirm correct crank voltages to it while it was refusing to crank. Swapped in a new motor (amazing it costs as much as the one in my Lincoln despite being under half the size), and it now seems to be starting reliably (knock on wood). Check engine light is back out too(IIRC this car leaves it on till the engine starts). The old starter had one of the big terminals on the plastic terminal board rip out as I was removing it.

They gave a decent amount of space to work on it, but it still is awfully cramped. A few times I wished I had an air wrench where the bolt was nice and loose, but the ratchet only had 2-4 clicks of swinging range...That is the kind of work that cramps one's whole arm especially in ~45 degrees.
The back ache from servicing a friend's TV Saturday flowed right into Sunday and got fed then.

[MadMan]

Originally Posted by Electronic M

At that point I found the starter motor and was able to confirm correct crank voltages to it while it was refusing to crank.

Well hey, that's a perfect confirmation. Glad you found the problem. A starter with a dead spot can have very weird intermittent problems like you had. I've had lots of terminal lugs break out of starters. It's usually bakelite, made extra brittle by years of high temperatures and hot/cold cycles. New ones don't break easily, but it's always important to know your medium when you're tightening a bolt.

[Electronic M]

Well the red albatross has worn out it's welcome...Back in early June on the way to a swap meet I spun it on a sharp turn a block from my house. It started to slide putting me on a collision course with a phone pole, I corrected hard to avoid taking it out (I hear phone poles are expensive), which resulted in my avoiding it* and colliding with a guard rail on the other side of the road. *I avoided the pole, but it's guy wire hooked the rear fender folding it back and hooking under the rear bumper cover ripping that cover off and messing it and the tail gate (bottom edge was mostly painted bondo) up a good bit. The front bumper cover and grille sustained damage. Not to mention damage to the dial bezel of a radio I had fixed for someone (it's always the thing you feel most guilty about that gets it worst).
I think what I blame most for the accident is the driver side front sway bar linkage being broken (it likely was before I owned it given the rust on the break) and the rear tires being baldy. I was only going 30 (the speed limit there) and there was some morning dew on the pavement.

This accident at once makes me like the vehicle platform much more, and like the particular specimen I possess much less. The frame and metal bumpers are remarkably solid and the vehicle took the impact well (the guard rail and plastic parts took all the damage). (Contrast that that to my parrents' previous honda CR-V that did not even have a bumper under the cover as sold from the factory)

I recovered rear the bumper cover (minus a light mounted in it) and after beating the hidden fender metal it mounts over back roughly into shape me and a friend got it back on...It ain't pretty, but it looks better with it on.

All that body damage pretty much kills the resale value...
As much as the new linkage makes it about as drive-able as it was; I've lost all faith in it....Doing the repairs I did made it obvious this was not it's first front end collision....Doing a very thorough inspection of the front end reveals that this was not it's first front end crash, and the last was much worse....On top of that whoever the previous owners hired to fix the front end last time did an appalling job...Most of the visible front end body parts were affixed with zip ties and or drywall screws (where they bothered to fasten it) EVEN in the places where the factory mounts still lined up right! With how much old work that I can see was done wrong I'm too concerned about the stuff I can't see to want to fix it.

I actually decided I was done with it before the accident when changing the front pass wheel bearing did not fix the bad grinding sound on low speed 90 degree right turns....Between that, the worsening air suspension issues, the 4DW issues, the bad door seals creating noise, drag and a drivers floor foot soaking pan when parked on an incline in the rain, and a dozen or so other issues of varying import I decided it ain't worth the time/money to bring it up to my standards.

I've been and still am saving up for a better SUV. Once that is done, I'm either going to sell the GMC cheap (as is), or if a dealer has a good Push-Pull-Drag sale, trade it in on the next one. ....If both of those options fail I have half a mind to park it in the middle of the previous owner's (cough*swindler's*cough) gigantic lawn late at night, set fire to it, and walk away.

I may end up buying a better example of the same model....I can tell it's a great platform despite owning the worst (cared for) example of it I've seen on the road.

[dieseljeep]

Originally Posted by Electronic M

Well the red albatross has worn out it's welcome...Back in early June on the way to a swap meet I spun it on a sharp turn a block from my house. It started to slide putting me on a collision course with a phone pole, I corrected hard to avoid taking it out (I hear phone poles are expensive), which resulted in my avoiding it* and colliding with a guard rail on the other side of the road. *I avoided the pole, but it's guy wire hooked the rear fender folding it back and hooking under the rear bumper cover ripping that cover off and messing it and the tail gate (bottom edge was mostly painted bondo) up a good bit. The front bumper cover and grille sustained damage. Not to mention damage to the dial bezel of a radio I had fixed for someone (it's always the thing you feel most guilty about that gets it worst).
I think what I blame most for the accident is the driver side front sway bar linkage being broken (it likely was before I owned it given the rust on the break) and the rear tires being baldy. I was only going 30 (the speed limit there) and there was some morning dew on the pavement.

This accident at once makes me like the vehicle platform much more, and like the particular specimen I possess much less. The frame and metal bumpers are remarkably solid and the vehicle took the impact well (the guard rail and plastic parts took all the damage). (Contrast that that to my parrents' previous honda CR-V that did not even have a bumper under the cover as sold from the factory)

I recovered rear the bumper cover (minus a light mounted in it) and after beating the hidden fender metal it mounts over back roughly into shape me and a friend got it back on...It ain't pretty, but it looks better with it on.

All that body damage pretty much kills the resale value...
As much as the new linkage makes it about as drive-able as it was; I've lost all faith in it....Doing the repairs I did made it obvious this was not it's first front end collision....Doing a very thorough inspection of the front end reveals that this was not it's first front end crash, and the last was much worse....On top of that whoever the previous owners hired to fix the front end last time did an appalling job...Most of the visible front end body parts were affixed with zip ties and or drywall screws (where they bothered to fasten it) EVEN in the places where the factory mounts still lined up right! With how much old work that I can see was done wrong I'm too concerned about the stuff I can't see to want to fix it.

I actually decided I was done with it before the accident when changing the front pass wheel bearing did not fix the bad grinding sound on low speed 90 degree right turns....Between that, the worsening air suspension issues, the 4DW issues, the bad door seals creating noise, drag and a drivers floor foot soaking pan when parked on an incline in the rain, and a dozen or so other issues of varying import I decided it ain't worth the time/money to bring it up to my standards.

I've been and still am saving up for a better SUV. Once that is done, I'm either going to sell the GMC cheap (as is), or if a dealer has a good Push-Pull-Drag sale, trade it in on the next one. ....If both of those options fail I have half a mind to park it in the middle of the previous owner's (cough*swindler's*cough) gigantic lawn late at night, set fire to it, and walk away.

I may end up buying a better example of the same model....I can tell it's a great platform despite owning the worst (cared for) example of it I've seen on the road.

You don't need another one of those dogs! Stay away from Craig's list!
If you're going to buy another used SUV, go to a licensed used car dealer. They're required to, at least look over the car to see if it's road worthy.
PM me and I'll let you know the name of the dealer where I bought three good used cars, reasonably priced. I drove each one a good long time.

[dieseljeep]

Originally Posted by dieseljeep

You don't need another one of those dogs! Stay away from Craig's list!
If you're going to buy another used SUV, go to a licensed used car dealer. They're required to, at least look over the car to see if it's road worthy.
PM me and I'll let you know the name of the dealer where I bought three good used cars, reasonably priced. I drove each one a good long time.

No replies!
I hope, our man MR. Carlson isn't PO'ed at me! I always like meeting with him and his Father at the WARCI meets.