So on another site JimmyJam posted a detailed listing of the steps to remove a trans, does anyone here have that for the 4.2 engine? trying to get this to my son. Blown 4.2, found a parts car, bought and ready to start swap, any tips, tricks appreciated. Not a newbie, I have replaced and rebuilt motors, just new to the 2003 TB.
Remove and Replace 4.2, 2003 Trailblazer 4wd
- Thread starter rafterk
- Start date
Recommend that you consider taking the "Skeptical Mechanic’s" approach shown on this 'List of Freshening Up Actions' to be performed upon the Swap Motor BEFORE installing that Replacement Engine into the SUV courtesy the use of an EZ-2-ACCESS Engine Stand:
(1) Read the FAQ and Download the GM OEM Factory Digital Service Manual.
(2) R&R the Old Water Pump and Metal Gasket for an ACDelco OEM Unit.
(3) R&R New Cloyes Timing Chain Kit (New Chain, Hydraulic Tensioner, Chain Guides, Sprockets).
(4) R&R the Oil Pump Pick Up Tube to Clean the Pick Up Screen of excessive Carbon & Varnish.
(5) R&R the Gerotor Oil Pump-to-Pick Up Tube “O”Ring Gasket.
(6) R&R the Front and Rear PTFE Engine Oil Seals.
(7) R&R the Valve Cover, Throttle Body and Intake Manifold “O” Ring-Like Gaskets
(8) R&R the Exhaust Manifold and Replace any Broken Bolts/Stud Ends.
(9) R&R The Old Motor & Transmission Mounts with ACDelco OEM Versions ONLY.
This is a decent set of “On Topic” Engine Swap Videos that will give you a well-lit overview what these processes entail on a 4WD Trailblazer or Envoy:
Part 1:
Part 2:
Part 3:
Part 4:
If you are going to go any deeper into the GM LL8 4.2L I-6 Engine, there are a few more GMTN Threads around that are dedicated to providing images and information on all of the necessary Parts, Part Numbers and perhaps more insights into what that Engine Internal Work involves.
For FREE and OPEN access to many relevant Image Albums concerning THIS Motor and many other topics, Visit this Link to Browse around my "Flickr-Bucket" series of Albums for practically anything related to working on and repairing this LL8 Motor. You won't be disappointed... :>)
www.flickr.com
(1) Read the FAQ and Download the GM OEM Factory Digital Service Manual.
(2) R&R the Old Water Pump and Metal Gasket for an ACDelco OEM Unit.
(3) R&R New Cloyes Timing Chain Kit (New Chain, Hydraulic Tensioner, Chain Guides, Sprockets).
(4) R&R the Oil Pump Pick Up Tube to Clean the Pick Up Screen of excessive Carbon & Varnish.
(5) R&R the Gerotor Oil Pump-to-Pick Up Tube “O”Ring Gasket.
(6) R&R the Front and Rear PTFE Engine Oil Seals.
(7) R&R the Valve Cover, Throttle Body and Intake Manifold “O” Ring-Like Gaskets
(8) R&R the Exhaust Manifold and Replace any Broken Bolts/Stud Ends.
(9) R&R The Old Motor & Transmission Mounts with ACDelco OEM Versions ONLY.
This is a decent set of “On Topic” Engine Swap Videos that will give you a well-lit overview what these processes entail on a 4WD Trailblazer or Envoy:
Part 1:
Part 2:
Part 3:
Part 4:
If you are going to go any deeper into the GM LL8 4.2L I-6 Engine, there are a few more GMTN Threads around that are dedicated to providing images and information on all of the necessary Parts, Part Numbers and perhaps more insights into what that Engine Internal Work involves.
For FREE and OPEN access to many relevant Image Albums concerning THIS Motor and many other topics, Visit this Link to Browse around my "Flickr-Bucket" series of Albums for practically anything related to working on and repairing this LL8 Motor. You won't be disappointed... :>)
Mr. RSM Mr. RSM’s albums | Flickr
www.flickr.com
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Hiya @rafterk I believe you won't have too many surprises along the journey, especially since you will have the donor car to practice on before gutting the host vehicle.
The removal goes like most, you remove and disconnect what you need to do before hooking up a cherry picker. That includes the front of the car: headlights, grill, condenser and radiator. I will share a few of the many details relating to my method.
* I start by removing the front of the car, , battery, battery tray, horn assembly, air filter/washer fluid tank and coolant recovery tank. All for having room to see and access the engine better.
* The P/S pump can be removed from it's bracket and laid aside without opening the hydraulic hoses.
* I find it provides more room to access some vital bits by discharging the A/C and removing the radiator, condenser, hoses and compressor individually.
* I remove the exhaust manifold shield and use the #5 manifold runner as the rear lift point by wrapping a small chain around it and attaching the chain to my lift bar. I don't use the front lift hook. Instead I run a bolt deeply into a bolt hole in the front of the head.
* The engine wire harness can be stripped completely off the engine, but it continues back over the starter to the transmission. I find it easiest to disconnect each and every connection, remove the ECM and brackets, disconnect the harness from under the fuse block and other couplings, and then when it's clear of the engine compartment, I strap it up off the engine up over the firewall, onto the cowl.
I struggle every time with two of the transmission to engine bolts that are obstructed by fiddly brackets with bits attached to them. If you find an elegant method for dealing with those, good onya!
MRRSM made some spot on suggestions, and I second the idea of deep maintenance while the donor engine is on the stand. I don't agree with his suggestion of replacing the motor mounts. I have not yet seen one of them fail and would not hesitate to retain them if they pass a visual inspection.
If either the host or donor vehicles happens to be AWD, then there is a subset of details to share when contemplating an engine removal.
Cheers,
Rick
The removal goes like most, you remove and disconnect what you need to do before hooking up a cherry picker. That includes the front of the car: headlights, grill, condenser and radiator. I will share a few of the many details relating to my method.
* I start by removing the front of the car, , battery, battery tray, horn assembly, air filter/washer fluid tank and coolant recovery tank. All for having room to see and access the engine better.
* The P/S pump can be removed from it's bracket and laid aside without opening the hydraulic hoses.
* I find it provides more room to access some vital bits by discharging the A/C and removing the radiator, condenser, hoses and compressor individually.
* I remove the exhaust manifold shield and use the #5 manifold runner as the rear lift point by wrapping a small chain around it and attaching the chain to my lift bar. I don't use the front lift hook. Instead I run a bolt deeply into a bolt hole in the front of the head.
* The engine wire harness can be stripped completely off the engine, but it continues back over the starter to the transmission. I find it easiest to disconnect each and every connection, remove the ECM and brackets, disconnect the harness from under the fuse block and other couplings, and then when it's clear of the engine compartment, I strap it up off the engine up over the firewall, onto the cowl.
I struggle every time with two of the transmission to engine bolts that are obstructed by fiddly brackets with bits attached to them. If you find an elegant method for dealing with those, good onya!
MRRSM made some spot on suggestions, and I second the idea of deep maintenance while the donor engine is on the stand. I don't agree with his suggestion of replacing the motor mounts. I have not yet seen one of them fail and would not hesitate to retain them if they pass a visual inspection.
If either the host or donor vehicles happens to be AWD, then there is a subset of details to share when contemplating an engine removal.
Cheers,
Rick
Mooseman
Moderator
I believe that was covered in those videos by using a wobble adapter, 3-4 feet of extensions with a ratchet. Also covered in the video is to remove the engine mounts and drop the engine onto the frame for extra clearance. When I did my engine R&R, I didn't know about the extensions trick and was able to get my giant hoofs in with a wrench with the extra clearance but it was tight. Another thing that was covered in the video was removing the intake manifold for extra clearance.
One more thing to do with both engines out is to inspect the exhaust manifolds (if your replacement has one). Both of mine were cracked and needed to source a new replacement, which are usually reinforced on the crack prone areas.
I would be careful dicking around with the rear main seal. Mine was fine but replaced it anyway and wound up leaking. I haven't heard of a lot of these leaking there.
Like @MRRSM said, replace the timing system, or at the very least, the tensioner and guides, as they do have a slight history of failing. My tensioner failed later on and it was a b!tch of a job to replace with the engine in place. I wouldn't replace the cam phaser unless the interior of the engine shows signs of neglected oil changes. Mine was and wound up replacing it twice. I'd also throw in a new CPAS for good measure.
After the job is done, or if you have any questions, come back and post up your results.
We finally got the engine out of the 2004 envoy, looking it over, and getting ready to put back into the 2003 TB, are there any specific items to swap, or do these years meet? They seem to be the same but may be missing something small or inside.
Thanks for the videos and help above, you all are great. One more to pull and one to put in,
I'm too old for this stuff. Wish I was born rich instead of good looking.
Thanks for the videos and help above, you all are great. One more to pull and one to put in,
I'm too old for this stuff. Wish I was born rich instead of good looking.
As One who is perhaps a Bit Older... At this stage of Playing the Game, the object is to KEEP on getting Older and avoid taking the Inevitable "Dirt Nap" for as long as One possibly can... :>)
One other thing to Swap in between these Two Motors prior to dropping in the Replacement Engine is to Install The Starter while the Donor Motor is still mounted upon the Engine Stand.
The GM 4.2L Motor is one of those rare platforms that allows for this, since the access port to the Flex-Plate through the Bell Housing is above rather than below its ordinary mounting position for the LS Motors.
Just one less necessary Act of Labor towards finishing this PITA Mechanical Exchange once the New Engine has been Bolted In.
One other thing to Swap in between these Two Motors prior to dropping in the Replacement Engine is to Install The Starter while the Donor Motor is still mounted upon the Engine Stand.
The GM 4.2L Motor is one of those rare platforms that allows for this, since the access port to the Flex-Plate through the Bell Housing is above rather than below its ordinary mounting position for the LS Motors.
Just one less necessary Act of Labor towards finishing this PITA Mechanical Exchange once the New Engine has been Bolted In.
Removed two engines, reinstalled one. What a giant PITA. Running and driving, hopefully it last a while. Thanks everyone. Had a terrible time with the front axle seal we replaced, ended up putting a seal on the axle and then installing by tapping in. So nice to see others helping, and thanks again.
Mooseman
Moderator
You are very welcome. Glad to hear it went relatively well.
What was the issue with the axle seal? Was it the one on the differential? I know it's a bit harder to get it in because of those metal fingers but it's still pretty straightforward.
What was the issue with the axle seal? Was it the one on the differential? I know it's a bit harder to get it in because of those metal fingers but it's still pretty straightforward.
The axle seal was too tight, couldn't get the axle in to the splines, ending up with new seal set on axle, then sliding in to place and tapping seal in. The strut, etc was in the way I guess. Just a new learning curve.