Hey Vortec Guys! / Sierra pickup / Suburban / Yukon etc - Finally has Index!

[rayra]

INDEX for the topic -

Roster of GMT800 folks in ExPo - https://www.expeditionportal.com/fo...pickup-suburban-yukon-etc.155266/post-2302987
EGR Oil Ingestion, Remediation - page1
Heater Core connection Ts - page1
KNock Sensors - page1+
Idle Air Control (IAC) & rough idle - pg2, 23
Brake Fluid Flush/Change - pg2
Instrument Cluster Bulb replacement - pg2, 19
Oil Pump Pickup Tube O-ring replacement, Tahoe - pg2+
Vent Blend Door Actuator Repair / Replace - pg3
Torsion Key Leveling Kit Install - pg3-6
Discussion of H2 Springs - pg6-7
Mystery Coolant Loss / CasTech 706 heads cracking & repair - pg8, 17, 30 follow-up
Spark PLugs, platinum, iridium - pg9, 23, 49
Oil Pump Pickup Tube O-ring replacement, Sub - pg9
Toyota Tundra V-6 DOHC Timing Belt change - p10
Vortec Knock Sensors and Limp Mode - p10
Sub Rear Coil Spring replacement - p11+
Ignition Coil diagnostics - p11-12
Inner Tie Rod Sleeves - p12, 14
Rear brake Pad Replacement - p13
Driver window regulator and motor repair - p13
Rear Suspension Bump Stops - p15, 29, 48
Discussion of Scan and Temp gauges - p16
Steering Wheel 'clunk' / intermediate shaft - p17
Steering components and sway bar bushings - p18
PowerStop GMT900 Front Brake swap - pg18, 35 follow-up
Instrument Cluster Stepper Motors - p18-19
Rear Hatch and window releases - p20
Alternator Issues and mid-series design change - p21, 50-51
POtential Transfer Case wear-thru issues - p22, 31
Refueling early cutoff / purge valve / vapor cannister - p22-27
Throttle cable slack adjustment - p25
Fuel Pump Replacements discussion - p28, 32, 33 how to cut floor
Oil Pressure Switch / Sender - p29, 34 re-work
Radiator Crack, Patch, Replace, cooling system refresh - p29-31
Transfer case actuator / solenoid replacement - p34
front wheel bearings / hubs - p34-35
Torsion Key crossmember mount bushings - p35-36-37 temp shimming, 38 homemade bushings, 39 dorman, 40 replacement
Control arm wear and discussion - p35
CV joint dismemberment / reassembly - p36
Upper Control Arm and CV replacement - p42
Trans Cooler install discussion - p42

And my own build topic has a lot of installs and changes to my '02 Sub.


The 'Suburban Mafia' Roster - FIXED THE LINK
https://www.expeditionportal.com/fo...pickup-suburban-yukon-etc.155266/post-2302987


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This is a repost of some stuff I just put up in the 'project vanilla' topic, I've been meaning to get around to a dedicated posting about it, akin to the 'show us your adult rigs' topic and the idea of known problems and preventative maintenance.

I have some more pics and descriptions I'll add after

the repost, the context was in relation to knock sensor failure, and GM's placement of them under the intake manifold:


Recently had the wife's '05 Tahoe 5.3 apart for another reason*, had the whole intake etc off. Was staring at those knock sensors thinking long and hard about them, but at $50 apiece and no trouble and no visual issues, I let them be. Probably should have replaced them while I had the opportunity.

The issue - and I think it's 2003-2007 engines - GM in their inifiinite wisdom replaced a simple $5 PCV valve with a metal baffle integral to the driver side valve cover. And when the internal weep holes in this baffle plate crud up - her engine is crossing 160k mi - the engine starts breathing in oil. She told me about a puff of smoke, I dreaded a head gasket problem as she's had a small bit of heating and whiff of coolant in the last several months, but nothing I could ever track down. Couple days later, it's laying its own smoke screen on startup. She kills it, takes my Sub to work and leaves me a note. I fire up and it's plainly oil smoke. Some googling and some poking around confirmed this PCV trouble. The chambers in the intake manifold had puddles of oil in them.

This was the test, a swatch of paper towel on a spring / claw probe, shoved in past the throttle plate.

After much repeated swabbing, still no end of oil. Along the way I discovered the chamber is pinch-waisted with a quarter-sized hole into the back half. I swabbed back there and got even more sopping towels for my efforts. Then a towel slipped loose, lost in the intake. I pulled the throttle mechanism off, to get a better view trying to fish out the towel, you can see there was still oil puddling in the intake manifold.

Decided I had to pull the manifold to get the towel and all that oil out. This was after pulling the valve cover and cleaning out the clogged weep holes

The brownish blocks at both ends of the manifold are a later model factory revision, directly related to the corrosion failures of the knock sensors. The foam blocks seal both ends of the galley / void under the intake. Mostly. More about that in a bit.

So I pulled everything apart. It's a pretty straight forward and relatively easy job. The finicky injector solenoid connectors are the toughest part. Second toughest, more on that in a bit, too.

These dirty ports are the INTAKES. A before and after I cleaned things up a bit.

And that's a clear shot of the two knock sensors in an '05 5.3L vortec. Under those rubber disks. And their wire leads.

Anyway I cleaned it all up and got it back together, nice new intake gasket plates. Did a series of longer and longer test drives and called it good.

She's put about 1000mi on it since, still great and a recent swab test came out very clean. Problem fixed.


About a week later after learnign how easy it was to execute, I changed my own valve cover gaskets, all the stud bushings too. Mine had begun leaking noticeably after I mistakenly switched to synthetic blend oil at 120k mi. Wasn't dripping a drop until I did. Went very well.

Or so I thought. I'd sprayed degreaser and took some care (I thought) when hosing it clean, before pulling the valve covers. But here I am, scarcely a week later, and I am now throwing a 'Knock Sensor #2 / Bank #2' code. Apparently I got some crud in there and fouled up the ground path of the sensor. Despite also having the foam blocks on my '02 5.3.
So now I'm going to have to pull my own intake off and decide if I can just clean up and seal my sensors and put new intake gaskets, or spend $100 on sensors too and swap them while I'm in there.

oh the other complication was while I put the wife's intake manifold back in, I nudged the plastic compression T connector on the heater hoses high on the firewall. THAT turns out to have been the source of the whiff. When I bumped it I destroyed what was left of its internal o-ring. When I fired the engine up after the intake repairs, it started streaming fluid from that connector after the thermostat opened. %$%@&#! So I had to go get that T connector ($20) and man was that a PITA to change. Do it when your manifold is out, unless you have tiny hands. If you are nearing or past 100k mi, you really ought to change them anyway, they too are apparently a known source of trouble with these vehicles.

Apologies for bumping this all in here, but seemed relevant. I'd been intending to make a 'hey Vortec guys' topic about it anyway. Things that should be planned for. Intake gaskets, the oil breathing thing, the heater hose connectors. The internet and youtube are flush with people having troubles with these things on our motors. Fix them instead at a time and place of your own choosing, as preventative maintenance.

 

[rayra]

a few more pics / descriptions related to the previous post / issue

I used a plastic screwdriver handle to prop open the throttle plate / baffle, to keep from denting or marring anything, and the retrieval claw tool I was using as a 'probe'.

And down the hatch

The forward chamber wasn't anywhere near as bad as the back, despite the PCV breather tube entering the top of the manifold above the forward chamber.

Then like whathisname at Tut's Tomb, I spied a small hole at the back leading to another chamber full of wonders. And went for the 'full probe'

Anyway, the work is straightforward and readily done in a long afternoon, if it's your first time. Fuel connection, unplug the fuel injector solenoids, pull the top cover and pop the wiring harness hold down clips, unplug a sensor or two, and (10?) 8mm bolts and the whole thing comes right out.

-----

The heater hose firewall connection T. Giant pieces of excrement. it uses a compression connector that's obviously made for very quick assembly on the line. You just stab them on the pipe ends. Getting them off, getting them off after 100k mi, without a special tool and limited access for large hands, a bleeding nightmare. There are several hot to vids on you'tube, I ended up trying both the cheap line disconnector tool and ultimately used zip ties to apply enough crimping leverage force to the 'hand' connector to pry it loose.

Not so hot for this, find a better set.

The fitting, there are two, black and white. Again I presume to make assembly easy, 'the white is always on the right'.

ADDENDUM - the 'T' connectors are on the SUVs with rear heat / AC. SUVs without and pickups have a straight connector, but with a similar compression fitting and fragility in high-mileage vehicles.

In situ, the cursed thing. It's up under the cowl, pretty much over the #8 coil pack / exhaust port area. That filthy discolored brown is a result of heat, age and Dexcool dye

I think part of the culprit is the rigid hose holder that's attached to the engine, the hoses move with the engine, while the connectors are anchored to the firewall. The connector and its internal o-ring shift and rub until the o-ring degrades to nothing and then it's a beer tap at a frat party.

The black stuff on the pipe at the upper right WAS most of the o-ring.

And all pretty, ready for reinstall, took me 2 hrs to wrestle that sumbitch apart and 2 mins to put it back together.

Test drive, looking PappaWheely's way

Scene of my youthful exuberances and harassed fish and ducks. And many off-roading fiascoes.

 

[Jelorian]

Thanks for that write up and the detailed pics!

 

[ZMagic97]

Interesting...

Thanks for the info and write up. I have an 06 5.3 myself. I recently replaced my knock sensors: they were getting wet and causing a running rich SES light until they finally went and caused the knock code.

 

[justcuz]

My 2000 PCV valve was replaced with a factory replacement item that had nothing inside. Just a very small hole where the fitting went into the rocker cover.
I removed the foam blocks and sealed my knock sensors. The factory recommended dam does not work because it does not prevent moisture from getting into the knock sensor holes. The foam blocks will hold moisture in the area under the intake.
If the knock sensors ever go out again, I will retrofit later model ones that bolt to the exterior of the block above the pan rail. I bought the AC Delco knock sensors and little wiring loom for about $50.00 on Rock Auto online last time I did mine. My Autozone knock sensors only lasted a year, so I had to do them again. The AC Delco replacements have been in 3 years now with no problems.
Luckily you did not end up with a set of Castec heads that had internal cracks.
Good info and write up, thanks!

Years ago we used to spend a lot of time out in the Mt.Emma and Littlerock area. We were camping out in the Mt. Emma area after the 1971 San Fernando earthquake and woke up to a couple of after shocks. It felt like you were laying on top of a bowl of jello! One of the weirdest things I've ever experienced.

 

[rayra]

Just some notes on parts, probably doing my knock sensor exploratory surgery next week or the week after. Right now I'm thinking / hoping it's either a wire short or a bit of corrosion on the sensor that I can clean up on the cheap.

Really good prices on knock sensors
http://www.rockauto.com/en/catalog/...ion)+sensor,5108?a=Referer+www.bing.com+URL+/

And this section has got all the various wiring bits. The dealer wanted $57 for the harness
http://www.rockauto.com/en/catalog/...trical-connector?a=Referer+www.bing.com+URL+/

The full harness and rubber caps is $31 at Rock Auto

eta that pictured part is listed as serving a wide array of GM vehicles in the 2000-2007 range

I'll be back to this with pics and results after I fix it. Meanwhile I keep clearing the error code. It stays off until I get in a midrange acceleration condition on the freeway, when I'm presuming knocking is happening and knock #1 is reporting it and knock #2 doesn't, bam Service Engine Soon (SES) light comes on again and the computer curtails power output and my mileage goes to **** (from 15 down to 11 ish). I'm not driving a lot anyway, so I've been slow doing anything about it.

 

[Burb One]

Just some notes on parts, probably doing my knock sensor exploratory surgery next week or the week after. Right now I'm thinking / hoping it's either a wire short or a bit of corrosion on the sensor that I can clean up on the cheap.

Really good prices on knock sensors
http://www.rockauto.com/en/catalog/...ion)+sensor,5108?a=Referer+www.bing.com+URL+/

And this section has got all the various wiring bits. The dealer wanted $57 for the harness
http://www.rockauto.com/en/catalog/...trical-connector?a=Referer+www.bing.com+URL+/

The full harness and rubber caps is $31 at Rock Auto

eta that pictured part is listed as serving a wide array of GM vehicles in the 2000-2007 range

I'll be back to this with pics and results after I fix it. Meanwhile I keep clearing the error code. It stays off until I get in a midrange acceleration condition on the freeway, when I'm presuming knocking is happening and knock #1 is reporting it and knock #2 doesn't, bam Service Engine Soon (SES) light comes on again and the computer curtails power output and my mileage goes to **** (from 15 down to 11 ish). I'm not driving a lot anyway, so I've been slow doing anything about it.

I recently did my knock sensors (and wires) While in there I also replaced the plastic gaskets for the manifold. Was super easy, didn't take much time at all. Make sure to put some dielectric grease (if you can find high temp stuff, use it) and also, even more importantly, I used some red RTV around the seals of the knock sensor, so NO water could get in there. I really overdid the RTV lol. When replacing, my used rear knock sensor had some moisture and was corroded beyond belief. Front one looked brand new. I also left the foam inserts in between the manifold so no leaves could get in there, I figure with the RTV having some water trapped in there, unable to get to the sensor pockets, until it evaporates isn't the worst and is better than any other stuff that could get in there

 

[ZMagic97]

I recently did my knock sensors (and wires) While in there I also replaced the plastic gaskets for the manifold. Was super easy, didn't take much time at all. Make sure to put some dielectric grease (if you can find high temp stuff, use it) and also, even more importantly, I used some red RTV around the seals of the knock sensor, so NO water could get in there. I really overdid the RTV lol. When replacing, my used rear knock sensor had some moisture and was corroded beyond belief. Front one looked brand new. I also left the foam inserts in between the manifold so no leaves could get in there, I figure with the RTV having some water trapped in there until it evaporates isn't the worst

Same exact thing I did. The rear was wet and corroded causing a rich conditions on both banks. It wasn't until I washed off the motor that the rear finally failed and caused a knock issue.

 

[rayra]

Seemed to be exactly what triggered mine. I'd had it for just over year, ~6kmi, on top of its first 13yrs / 120k mi. Then I degreased the valve cover areas and sprayed it as minimally as possible and shortly afterward the rear has failed. Or it's a hell of a coincidence.

 

[Burb One]

Seemed to be exactly what triggered mine. I'd had it for just over year, ~6kmi, on top of its first 13yrs / 120k mi. Then I degreased the valve cover areas and sprayed it as minimally as possible and shortly afterward the rear has failed. Or it's a hell of a coincidence.

Coincidence(or not) for me too, first time I've had significant mud in the engine bay- from the trip where i got stuck- (these bays actually stay surprisingly clean through dirt, dust mud and water) and lightly hosed it out with the engine hot and running, hoping to have it all evaporate, making sure to avoid electronics, and the CEL went on a few days later.... of course a few days before the end of the month when I had a Smog deadline..., at least the fix is easy enough. Goodluck!

 

[justcuz]

Rayra,

Again good write up and info.

Seems like getting the engine wet buy use or cleaning is a common issue that is caused by water in the sensor wells evaporating and causing issues with the connectors.

5.7 engines use the same style sensor and connector mounted externally and you never hear of them failing.

If mine ever fail again I will either mount these outside the block or use the later model knock sensors that are now factory mounted outside the block. They are shaped like a little donut, with mounting bolt going through the hole.

 

[Martinjmpr]

Has anyone else had the leaky intake manifold gasket problem? Mine started throwing two codes right after I bought it. Fortunately for me the dealer was a stand-up operation, when I told them what was going on they told me to bring it in and they'd fix it (b/c it would not pass emissions with a CEL showing.) Apparently this is a well known enough issue with the 5.3 (not sure about other Vortec motors) that three's a TSB on it.
.
Been running great since then (actually it ran great even while it was throwing the codes.)

 

[justcuz]

I've heard of them, but don't know the codes or TSB's.

Had my 2000 not pass once and found loose exhaust manifold bolts causing it to fool the first O2 sensor into thinking the engine was running lean and it was adding too much fuel.

The intake manifold bolts have sleeves and rubber washers on them so it is kind of hard to over tighten them.
Must be coming loose since the torque is in inch pounds.

 

[rayra]

There's a TSB and an 'improved' gasket design. It's an easy job to do, if you've ever done anything like it. Just watch the hell out (SUV guys) for the heater hose connections on the firewall, or be prepared to replace those connections as part of the same maintenance evolution. In fact I'd strongly suggest doing both at the same time, as the heater connections are far easier to access and work on while you have the intake manifold etc out of the way. The connectors are ~$20 for both, via rockauto. About half the price of your local parts store. If you are getting morr parts, it's a good deal.

http://www.rockauto.com/en/catalog/...e+connector,6876?a=Referer+www.bing.com+URL+/

 

[rayra]

Well I did my Trifecta of Vortec / LM7 / 5.3L engine maintenance projects last Sun/Mon. Pulled the intake manifold off, replaced rusted Knock Sensor #2, cleaned and reinstalled Knock #1, cleaned both of their installation sites / wells / sumps as best I could and sealed them up tight against future water intrusion, pulled the passenger-side valve cover to investigate some excess oil thru the breather tube to the throttle body, and while the intake manifold etc was out of the way, went ahead and replaced both heater hose connection T's high on the firewall over cylinder #8. It's a 'T' on Subs with the rear heater / AC systems, it's a pair of straight connectors on similar pickups.


This was my third time pulling the intake manifold and attachments on this series of motors and practice makes perfect, it only took about 25mins to pull it all off.

The following are a lot of snapshots of what you'll likely find / see. I did some 'exploratory surgery' a week previously to confirm the knock sensor issue, so some of the tenses and references are a little odd, some of this was posted elsewhere as it was done -


The grungy galley. You can see the clean valve covers and clean blue valve cover gaskets I installed previously.

No4(?) intake, you can see how the prior leaking valve covers saturated and penetrated the intake manifold gasket line

The rear of the galley, the wire bundle is the leads from the two knock sensors. The little clean patch was where the bundle lay pinned to the galley cover plate by the foam wall at the rear of the intake manifold. I've be dissecting the wire lead to look for signs of arcing / insulation failure. The red lines are where he wire bundle was routed

Those two light-colored buttons are the breather ends of the transmission and transfer case breather tubes. They're routed up nice and high to the back of the top of the motor, to prevent water getting into them. You'd have to be fording up past the top of your wheel wells to flood these. And you'd be flooding the stock intake location to do so. Not sure where the front axle vent tube is routed ETA - found it, it's just inside the front left suspension, above the frame rail / upper control arm. The rear axle is routed up behind the driver side taillight, IIRC.

Lot of oil saturation in the breather portions of the intake and throttle body.

The injector tips themselves look ok, been running some injector cleaner additive every few tanks since I got it. But boy are those INTAKE runners backfilled with oil crud. Ungood.