Hey Vortec Guys! / Sierra pickup / Suburban / Yukon etc - Finally has Index!
- Thread starter rayra
- Start date
Engine replacement or rebuild?
Getting close to 200,000 on my 1999 Sierra so I'm starting to think about the possibility of dropping in a new(er) used engine or having the existing rebuilt, probably doing the same with the transmission as well.
This is my primary work vehicle, 4wd, V8, automatic trans. Sees some off-road usage, mainly dirt and fire roads.
What says the collective?
Getting close to 200,000 on my 1999 Sierra so I'm starting to think about the possibility of dropping in a new(er) used engine or having the existing rebuilt, probably doing the same with the transmission as well.
This is my primary work vehicle, 4wd, V8, automatic trans. Sees some off-road usage, mainly dirt and fire roads.
What says the collective?
rayra
Expedition Leader
Depends how much work you can or are willing to do yourself. The rebuild and machining work (and attendant labor costs) will wind up costing about as much as a crated / new short block. and the latter would still need valve work on your old heads.
And bringing in a new short block would be a big jumpstart on the project. You can pull the heads and send them off for rebuild and while they are out you can pull and transfer everything else and be finishing the motor reinstall by the tim ethe heads come back. Minimal down time for the vehicle. (and rental econo cars are cheaper by the week, once you are over 3-4 days rental, if you don't have an additional vehicle available)
I'd say a coin toss for me, but I do all the work I can do myself.
speaking of which, my new water pump, coolant crossover gaskets and valley cover plate gasket have all arrived. Soon I'll be draining the coolant, pulling the water pump and the intake manifold assembly and trying to conquer a persistent oil leak coming off the top rear of my block somewhere. IT's about the only oil gasket I havent changed, since my synthetic fiasco. And since I want to go after the rear crossover anyway, necessitating the intake pull, I figured I'd do it all at once. Knock sensors previously done, shame I'll need to re-mount and seal those again. Thinking this time I'll deliberately leave out the foam blocks under the vortec intake when I reassemble things. Given I'm in the southwest; that I've used a total sealing method on the knock sensor caps, and I'd rather have that engine top space 'breathing' in my desert crawls, it seems like a reasonable thing to do. Especially since they are a water trap as-is and already harmful to the rear knock sensor in the factory config.
I've also got some 2" wheel spacers to install.
And bringing in a new short block would be a big jumpstart on the project. You can pull the heads and send them off for rebuild and while they are out you can pull and transfer everything else and be finishing the motor reinstall by the tim ethe heads come back. Minimal down time for the vehicle. (and rental econo cars are cheaper by the week, once you are over 3-4 days rental, if you don't have an additional vehicle available)
I'd say a coin toss for me, but I do all the work I can do myself.
speaking of which, my new water pump, coolant crossover gaskets and valley cover plate gasket have all arrived. Soon I'll be draining the coolant, pulling the water pump and the intake manifold assembly and trying to conquer a persistent oil leak coming off the top rear of my block somewhere. IT's about the only oil gasket I havent changed, since my synthetic fiasco. And since I want to go after the rear crossover anyway, necessitating the intake pull, I figured I'd do it all at once. Knock sensors previously done, shame I'll need to re-mount and seal those again. Thinking this time I'll deliberately leave out the foam blocks under the vortec intake when I reassemble things. Given I'm in the southwest; that I've used a total sealing method on the knock sensor caps, and I'd rather have that engine top space 'breathing' in my desert crawls, it seems like a reasonable thing to do. Especially since they are a water trap as-is and already harmful to the rear knock sensor in the factory config.
I've also got some 2" wheel spacers to install.
rayra
Expedition Leader
well, 3hrs wasted on the Tahoe today, trying to diagnose and correct an oil pressure reading fault. I went ahead and pulled the intake manifold apart, to gain better access to the oil pressure sender and get a better look at things. The sender is on the back top deck of the engine block, behind the intake manifold. With everything in place I cannot see it directly and can just barely get my fingertips on it. Last time I used a jury-rigged ratchet / extensions / universal joint setup to get it in. The sensor worked for a short time and then seemed to crap out. Dash gauge went back to 80psi (failure position when no reading / voltage is present. I was concerned that I might have fouled the opening on the sender by rubbing it across the schmutz on the top back of the motor, when I was trying to thread it in.
So I pulled it all apart and found the teflon tape I put on the sender splayed all over the outside - apparently I wrapped it around the wrong direction and it peeled off as I threaded it in. But none of that was in the hole or blocking the sensor. center of the sender rattled like an old-school PCV valve, don't recall if it did before. So I cleaned it all up, put some pipe dope on it and re-installed that sensor - they're $40-50, I figured it was worth a shot to put if back in and see what happened.
And speaking of PCV valves, I once again found a good quantity of oil in the intake and evidence of same in the intake runners in the heads and intake manifold. So I took some time to clean all that up again. It's been a while since I went thru all that, I'll have to check how long ago. What a mess.
I started this topic 2-1/2yrs and 40k mi ago for this Tahoe with this oil saturation problem. I guess the weep holes in the intake manifold is crudded up again.
I was having fiddly trouble disconnecting the fuel injector wiring clips, actually broke a bit of plastic off of one. Couldn't remember or quickly find the proper technique for disengaging the two-part clips. So I circumvented that by simply removing the entire fuel rail assembly. A tubular fuel rail on each side and a crossover pipe. (4) 8mm bolts, two torx screws and a little pull / wiggle and the whole rail comes out. There was enough room and loose wiring to tuck them to both sides, out of the way of removing and installing the intake manifold.
Before reassembly I cleaned up all the fittings (and found an o-ring that tried to run away). I used some silicone lubricant on pieces of paper towel to scrub all the crud off both the injector ends and the ports / holes in the intake manifold. And some Q-Tips soaked in silicone lube to swab those ports before pressing the injector / rails back in.
The part highlighted in red is one of the injector ends.
Anyway, cleaned everything up, put it back together and sad trombone. Oil pressure gauge is still failing high. At this point I can only hope that it is a failed sender. And I get to do today's evolution all over again next week, after I mail order a new oil sender. Been doing some early morning maintenance and minor repairs on this Tahoe, it's finally time to sell it off.
So I pulled it all apart and found the teflon tape I put on the sender splayed all over the outside - apparently I wrapped it around the wrong direction and it peeled off as I threaded it in. But none of that was in the hole or blocking the sensor. center of the sender rattled like an old-school PCV valve, don't recall if it did before. So I cleaned it all up, put some pipe dope on it and re-installed that sensor - they're $40-50, I figured it was worth a shot to put if back in and see what happened.
And speaking of PCV valves, I once again found a good quantity of oil in the intake and evidence of same in the intake runners in the heads and intake manifold. So I took some time to clean all that up again. It's been a while since I went thru all that, I'll have to check how long ago. What a mess.
I started this topic 2-1/2yrs and 40k mi ago for this Tahoe with this oil saturation problem. I guess the weep holes in the intake manifold is crudded up again.
I was having fiddly trouble disconnecting the fuel injector wiring clips, actually broke a bit of plastic off of one. Couldn't remember or quickly find the proper technique for disengaging the two-part clips. So I circumvented that by simply removing the entire fuel rail assembly. A tubular fuel rail on each side and a crossover pipe. (4) 8mm bolts, two torx screws and a little pull / wiggle and the whole rail comes out. There was enough room and loose wiring to tuck them to both sides, out of the way of removing and installing the intake manifold.
Before reassembly I cleaned up all the fittings (and found an o-ring that tried to run away). I used some silicone lubricant on pieces of paper towel to scrub all the crud off both the injector ends and the ports / holes in the intake manifold. And some Q-Tips soaked in silicone lube to swab those ports before pressing the injector / rails back in.
The part highlighted in red is one of the injector ends.
Anyway, cleaned everything up, put it back together and sad trombone. Oil pressure gauge is still failing high. At this point I can only hope that it is a failed sender. And I get to do today's evolution all over again next week, after I mail order a new oil sender. Been doing some early morning maintenance and minor repairs on this Tahoe, it's finally time to sell it off.
rayra
Expedition Leader
Been struggling lately, trying to complete the pre-sale work. Ive been hit with a recurring bout of positional vertigo and nausea. Makes it REALLY difficult to crawl around and under a vehicle.
Anyway, been working on a 4WD failure to engage. Tried removing the transfer case modulator / actuator to ********** the solenoid around a bit, found the transfer case fluid to be super gooey and can't really determine if its EVER been changed. And it's been on my 'to do' list for a year.
Pulled the actuator off cleaned it a bit, bumped it around a bit and got something moving in the solenoid. But then while trying to re-mount it in the midst of fighting the vertigo and dry-heaves I failed to properly align the actuator pack onto the keyed splined shaft in the transfer case. I SEEMED to get it on, had less than 1/8" gap between actuator and transfer case, thought it was on correctly and then set about alternately tightening the three mounting bolts. ... and then the back of the actuator case ruptured.
The black cylinder in the lower part of this image is the solenoid that drives the geartrain in the actuator. It projects under the transfer case proper.
From the driver side, the actuator module is covered in oil seep / grit, with the front driveshaft in the foreground
You have to remove the driveshaft to get the clearance to removed the actuator. The part looks like this. The face in the image goes against the transfer case.
Off the vehicle
And here it is, damaged. The gear in the actuator was pushed thru the pot-metal looking casing, from my trying to draw it on with the mounting bolts. Blew a circular section right off. I heard it ping as it ricocheted off of something but could find no trace of it anywhere.
I got my fingers on the shaft in the tranfer case and gave it a jiggle, things seem ok on that side.
No great loss as the actuator seems to have been my 'service 4wd' fault anyway, this removal and re-install was a rehearsal of sorts and an experiment in freeing the solenoid - if that was the trouble originally. I was previously able to troubleshoot somewhat, swapping in a known good 4WD dash switch with no transfer case switching afterward. And the same computer error generated.
I've since received the replacement actuator from rockauto.com. Just waiting to get a handle on this bout of vertigo before I do the install. And I'm pickup up 2qts of Delco Auto Track II fluid for the transfer case, after I get it functioning and can drive it enough to get the fluid warmed up to flow well.
fyi, the mid-series model split of the GMT-800s bites here. Same transfer case, NP8 / 246, but the actuators and 4wd dash switches are different parts. My fiendishly clever plan of owning two GMT800 SUVs let me down, here.
Anyway, been working on a 4WD failure to engage. Tried removing the transfer case modulator / actuator to ********** the solenoid around a bit, found the transfer case fluid to be super gooey and can't really determine if its EVER been changed. And it's been on my 'to do' list for a year.
Pulled the actuator off cleaned it a bit, bumped it around a bit and got something moving in the solenoid. But then while trying to re-mount it in the midst of fighting the vertigo and dry-heaves I failed to properly align the actuator pack onto the keyed splined shaft in the transfer case. I SEEMED to get it on, had less than 1/8" gap between actuator and transfer case, thought it was on correctly and then set about alternately tightening the three mounting bolts. ... and then the back of the actuator case ruptured.
The black cylinder in the lower part of this image is the solenoid that drives the geartrain in the actuator. It projects under the transfer case proper.
From the driver side, the actuator module is covered in oil seep / grit, with the front driveshaft in the foreground
You have to remove the driveshaft to get the clearance to removed the actuator. The part looks like this. The face in the image goes against the transfer case.
Off the vehicle
And here it is, damaged. The gear in the actuator was pushed thru the pot-metal looking casing, from my trying to draw it on with the mounting bolts. Blew a circular section right off. I heard it ping as it ricocheted off of something but could find no trace of it anywhere.
I got my fingers on the shaft in the tranfer case and gave it a jiggle, things seem ok on that side.
No great loss as the actuator seems to have been my 'service 4wd' fault anyway, this removal and re-install was a rehearsal of sorts and an experiment in freeing the solenoid - if that was the trouble originally. I was previously able to troubleshoot somewhat, swapping in a known good 4WD dash switch with no transfer case switching afterward. And the same computer error generated.
I've since received the replacement actuator from rockauto.com. Just waiting to get a handle on this bout of vertigo before I do the install. And I'm pickup up 2qts of Delco Auto Track II fluid for the transfer case, after I get it functioning and can drive it enough to get the fluid warmed up to flow well.
fyi, the mid-series model split of the GMT-800s bites here. Same transfer case, NP8 / 246, but the actuators and 4wd dash switches are different parts. My fiendishly clever plan of owning two GMT800 SUVs let me down, here.
rayra
Expedition Leader
Thanks. I found a thing called the Epley maneuver that seems to help a good bit with my positional vertigo. It seemed to manifest a couple years ago with a left ear infection. Came back without an apparent infection every several months. This time it was a couple weeks of home renovations and vehicle mechanical work in the heat that seemed to set it off again (along with some gout trouble) and I haven't taken enough rest days in a row to get over it. About a week ago I tilted my head over to look down the back of a rack of canned goods and I piled myself into a corner of my garage interior. Body just threw me into a corner, thinking that was 'up'. Hit me again laying on my back under the Tahoe when I turned my head up and left to look at the front driveshaft. Even laying flat on the ground I swore 'up' was a different direction and had some really violent nausea about it.
There's a couple other medical maneuvers that help, but most focus on getting the stones in your inner ear back where they belong and then require you to rest in a reclined position for a couple days to get them to stay there. I haven't been doing the last part, this time. But need to. Meanwhile I'm walking around like Herman Munster, neck muscles stiff from trying to hold my head still.
There's a couple other medical maneuvers that help, but most focus on getting the stones in your inner ear back where they belong and then require you to rest in a reclined position for a couple days to get them to stay there. I haven't been doing the last part, this time. But need to. Meanwhile I'm walking around like Herman Munster, neck muscles stiff from trying to hold my head still.
Hillbilly Heaven
Explorer
A few minutes riding one of these will fix your vertigo.
Seriously I do hope it gets better. I worked with someone that had it and know how disturbing it can be.
Seriously I do hope it gets better. I worked with someone that had it and know how disturbing it can be.
rayra
Expedition Leader
That machine would help, you know, by getting those few moments of bliss AFTER you vomit.
I'm taking some OTC motion sickness meds which takes the edge off the violent nausea. I'm still getting the swoon if I move my head just wrong. But I went ahead and got in the driveway again this morning to work on vehicles.
Tahoe 4wd is fixed. Installed the replacement actuator. Sussed out the gear misalignment. Transfer case shaft was in a 'neutral' position, about 10-12deg out of alignment with the resting position of the engaging gear in the actuator. And there's not enough clearance with the transfer case front driveshaft extension to pivot the actuator enough to engage the shaft. So I carefully grasped the transfer case shaft with some slip pliers and rotated its guts into alignment sufficiently enough to seat the actuator on it properly, proper depth, before bolting it in. The shaft 'clicked' (guessing into neutral, as that's what the dash switch indicated when I fired things up. It felt a great deal like a motorcycle gear shift.
One last bit on re-installing the front driveshaft. Put the yoke end up forward and above / beside the front axle yoke BEFORE re-inserting the splined shaft into the transfer case. Doing so with the yoke end low, I couldn't seem to get enough clearance to get the shaft yoke past the crossmember to get it mounted.
Time to road test it and drive it to the local GM dealer to buy some Auto Trac II for a fluid change of the transfer case. And that will warm that goo enough to get it to drain as well as possible.
I'm taking some OTC motion sickness meds which takes the edge off the violent nausea. I'm still getting the swoon if I move my head just wrong. But I went ahead and got in the driveway again this morning to work on vehicles.
Tahoe 4wd is fixed. Installed the replacement actuator. Sussed out the gear misalignment. Transfer case shaft was in a 'neutral' position, about 10-12deg out of alignment with the resting position of the engaging gear in the actuator. And there's not enough clearance with the transfer case front driveshaft extension to pivot the actuator enough to engage the shaft. So I carefully grasped the transfer case shaft with some slip pliers and rotated its guts into alignment sufficiently enough to seat the actuator on it properly, proper depth, before bolting it in. The shaft 'clicked' (guessing into neutral, as that's what the dash switch indicated when I fired things up. It felt a great deal like a motorcycle gear shift.
One last bit on re-installing the front driveshaft. Put the yoke end up forward and above / beside the front axle yoke BEFORE re-inserting the splined shaft into the transfer case. Doing so with the yoke end low, I couldn't seem to get enough clearance to get the shaft yoke past the crossmember to get it mounted.
Time to road test it and drive it to the local GM dealer to buy some Auto Trac II for a fluid change of the transfer case. And that will warm that goo enough to get it to drain as well as possible.
rayra
Expedition Leader
Calling all GMT-800 Subs, Calling all GMT-800 Subs, can I get a first-thing in the morning multimeter / voltmeter read of your Starting battery at its terminals, before you've run your vehicle, after it has sat overnight?
I'm trying to diagnose what seems like a parasitic voltage drop, I'm losing about half a volt in the afternoon / overnight.
Details are in this topic in the 12V forum -
https://www.expeditionportal.com/fo...y-wanderer-pwm-with-a-flooded-battery.199671/
I've removed just about everything I've added. I don't know if it's my aftermarket stereo / DVD or if a rat / squirrel has chewed something important. I've looked repeatedly can't find any wiring damage. About the only thing left to do is start pulling fuses and see what stops the loss.
At this point I'm wondering / hoping it's a systemic problem built into the vehicle. Not that that would be a good thing.
I'm trying to diagnose what seems like a parasitic voltage drop, I'm losing about half a volt in the afternoon / overnight.
Details are in this topic in the 12V forum -
https://www.expeditionportal.com/fo...y-wanderer-pwm-with-a-flooded-battery.199671/
I've removed just about everything I've added. I don't know if it's my aftermarket stereo / DVD or if a rat / squirrel has chewed something important. I've looked repeatedly can't find any wiring damage. About the only thing left to do is start pulling fuses and see what stops the loss.
At this point I'm wondering / hoping it's a systemic problem built into the vehicle. Not that that would be a good thing.
Greetings from Colorado.
I have been chasing some parasitic drains in my 2004 Yukon XL 1500 5.3. for a long time. I found this YouTube video that seems promising. I have several auxiliary batteries and have been using a Ctek mppt controller. The vehicle sees limited use as its mainly a tow vehicle. I am chasing a drain to the starting battery. The auxullary battery stays charged, while the main battery goes flat. I have been laying a couple of solar panels on the roof when parked and that will keep both batteries charged and ready. Without the panels the main battery goes flat in about 2 days of non use.
George T
rayra
Expedition Leader
Thanks I will check it out, Humble Mechanic does some good stuff, I found his channel via the ErictheCarGuy vids. Checking each circuit is what I figured this would come down to. Early on I was suspecting a bad cell in my starter battery or a voltage leak via the crud on top of my combiner solenoid, but I've since swapped my Starter and Aux batteries (same Interstate Grp 78) and cleaned up all the dual battery connections. And the problem pretty much remained associated with the Starter battery side of things.
rayra
Expedition Leader
wellll sheeeeit
Been some clunking going on durign braking, going up driveways, any start and stop. I've been poking and prodding to no avail, unable to find anything worn or showing shifting movement I've felt.
Lately it's been worse and I've also been hearing a whine that was hard to distinguish from teh new slightly different road noise of the tires swapped in from the Tahoe, late last summer.
All along, I've had a long list of 'refreshing' parts that I've slowly been replacing, mostly as targets of opportunity. Preventative maintenance / 'baselining'. Chief among them upper and lower ball joints and new front transaxles.
Now one of the background 'watch for' items in my suspension alternations was looking out for increased or accelerated bearing wear due to a change in suspension angle / geometry, brought on by the aftermarket torsion bar keys for added lift. So the recent higher-pitched road noise that developed at about the same time I swapped tires had me worried about bearings and upping my shopping for replacements. So after my recent wild toad ride upstate and over the grapevine and continued clunk-clunking as well as some squeaking I took to be a brake pad issue, I determined to take advantage of a break in our rain and get to the bottom of things...
[flash=200,200]
it would appear that my front wheel bearing(s) are shot. I'm not driving much of anywhere until I make this repair.
Browsing around Autozone and rockauto there's a massive disparity in pricing. I'm already using a Powerstop drilled and slotted front brake upgrade kit, it's actually a GMT900-series with larger diameter rotor and caliper / pad setup. Works great, very happy with them, will eventually get their same type replacement rotors for my rear. Their branded replacement hub and bearing assemblies are a ridiculously inexpensive $30 for each front. Delco Advantage is $112 / wheel. Timken's $96, Moog $109, Delco OEM $133. Autozone wants $180 for the same Moog assembly. And $120 for Duralast. Per wheel.
All along I've been erring on the low-budget end of these replacements figuring a new (cheap) part is still way better than a worn out OEM part. And other for my penchant for excessive speed on the highway when I can get away with it, my demands on this vehicle are low. I'm barely clocking 6,000 mi/yr on it. I am definitely NOT of the 'buy once cry once' camp.
Been some clunking going on durign braking, going up driveways, any start and stop. I've been poking and prodding to no avail, unable to find anything worn or showing shifting movement I've felt.
Lately it's been worse and I've also been hearing a whine that was hard to distinguish from teh new slightly different road noise of the tires swapped in from the Tahoe, late last summer.
All along, I've had a long list of 'refreshing' parts that I've slowly been replacing, mostly as targets of opportunity. Preventative maintenance / 'baselining'. Chief among them upper and lower ball joints and new front transaxles.
Now one of the background 'watch for' items in my suspension alternations was looking out for increased or accelerated bearing wear due to a change in suspension angle / geometry, brought on by the aftermarket torsion bar keys for added lift. So the recent higher-pitched road noise that developed at about the same time I swapped tires had me worried about bearings and upping my shopping for replacements. So after my recent wild toad ride upstate and over the grapevine and continued clunk-clunking as well as some squeaking I took to be a brake pad issue, I determined to take advantage of a break in our rain and get to the bottom of things...
[flash=200,200]
it would appear that my front wheel bearing(s) are shot. I'm not driving much of anywhere until I make this repair.
Browsing around Autozone and rockauto there's a massive disparity in pricing. I'm already using a Powerstop drilled and slotted front brake upgrade kit, it's actually a GMT900-series with larger diameter rotor and caliper / pad setup. Works great, very happy with them, will eventually get their same type replacement rotors for my rear. Their branded replacement hub and bearing assemblies are a ridiculously inexpensive $30 for each front. Delco Advantage is $112 / wheel. Timken's $96, Moog $109, Delco OEM $133. Autozone wants $180 for the same Moog assembly. And $120 for Duralast. Per wheel.
All along I've been erring on the low-budget end of these replacements figuring a new (cheap) part is still way better than a worn out OEM part. And other for my penchant for excessive speed on the highway when I can get away with it, my demands on this vehicle are low. I'm barely clocking 6,000 mi/yr on it. I am definitely NOT of the 'buy once cry once' camp.
vintageracer
To Infinity and Beyond!
"Clunking" in the front end can be the result of the lift keys you installed.
Check the distance between the upper control arm and the frame pad below the upper control arm that limits the lower movement of the upper control arm. To much lift with a stock control arm and you can be riding or very close to riding on the frame pad under the upper control arm resulting in a big "Clunk".
You need at least 1 finger worth of room between the two when sitting still.
Check the distance between the upper control arm and the frame pad below the upper control arm that limits the lower movement of the upper control arm. To much lift with a stock control arm and you can be riding or very close to riding on the frame pad under the upper control arm resulting in a big "Clunk".
You need at least 1 finger worth of room between the two when sitting still.
Last edited:
