L36 replacement or swap to L26
- harofreak00
- Administrator

- Posts: 26022
- Joined: Mon May 19, 2008 6:04 pm
- Year and Trim: 2004 GXP - plus a handful of other Bonnevilles
- Location: Browerville, MN
- Contact:
Re: L36 replacement or swap to L26
Its been a while since I ripped a block apart, but I remember the plate just coming out with a simply pry. Have you tried that?
Andrew - owner/operator of Bonnevilles Unlimited

2004 Bonneville GXP | 60k | White Gold Tricoat | custom built supercharged 3800 hot rod | garage queen
1997 Corvette | 57k | Silver Metallic | Z06 wheels | Date-night Hauler/Parts runner
2014 Town & Country Limited | Cashmere Pearl | 115k | Family Hauler
2002 Ram 1500 Quad Cab Sport | Black| 280k | Official Bonneville Hauler

2004 Bonneville GXP | 60k | White Gold Tricoat | custom built supercharged 3800 hot rod | garage queen
1997 Corvette | 57k | Silver Metallic | Z06 wheels | Date-night Hauler/Parts runner
2014 Town & Country Limited | Cashmere Pearl | 115k | Family Hauler
2002 Ram 1500 Quad Cab Sport | Black| 280k | Official Bonneville Hauler
Re: L36 replacement or swap to L26
Sorry if I wasn't specific enough, the seal is my issue. I know how to get the plate out, all ready played around with the bad motor. Didn't have any luck getting the seal out without putting a couple scratches in the plate.
Re: L36 replacement or swap to L26
Well I've been able to get some work done, heres the before and after shots.






Theres still plenty of work to be done but I'm a little closer to the end.
The rear main seal and back plate are up next on the list. I've got a tee for the oil pressure sending unit, and for the gauge I'm adding. Gotta clean and reseal the oil pan before putting it in. Plus while the car is just sitting here I'll do the tranny filter, fuel filter, and flush the power steering fluid.
I know most of the paint will burn off, or flake off but at least it looked nice for a little bit. I'll keep you guys posted on the progress.






Theres still plenty of work to be done but I'm a little closer to the end.
The rear main seal and back plate are up next on the list. I've got a tee for the oil pressure sending unit, and for the gauge I'm adding. Gotta clean and reseal the oil pan before putting it in. Plus while the car is just sitting here I'll do the tranny filter, fuel filter, and flush the power steering fluid.
I know most of the paint will burn off, or flake off but at least it looked nice for a little bit. I'll keep you guys posted on the progress.
Last edited by Bing on Wed Mar 09, 2011 9:47 pm, edited 1 time in total.
- sandrock
- Retired Gearhead

- Posts: 4753
- Joined: Mon May 19, 2008 2:14 pm
- Year and Trim: '00 SSEi (proj), '99 Tahoe & '05 Bonne GXP
- Location: Orlando Fl
- Contact:
Re: L36 replacement or swap to L26
Looks nice!!
OH yeah...Coolant temp sensor needs to be changed. L26s only used the two-prong sender since the gauges took the info directly from the PCM. L36s used the three-prong...one for ground, one for pcm, and the other for gauges.
OH yeah...Coolant temp sensor needs to be changed. L26s only used the two-prong sender since the gauges took the info directly from the PCM. L36s used the three-prong...one for ground, one for pcm, and the other for gauges.
2005 GXP - White Gold Pearl, no mods...yet.
2000 SSEi - Resurrection in progress. Built L67 w/L32 fuel rail, ported heads, and cam. Camaro front brake system, GXP cluster, and much more in planning.
2000 SSEi - Resurrection in progress. Built L67 w/L32 fuel rail, ported heads, and cam. Camaro front brake system, GXP cluster, and much more in planning.
BonneMe wrote:Looks like a Volt, Sonata, and Taurus got it on.
Re: L36 replacement or swap to L26
Thanks I got that swapped right before pics. I ended up just clicking the sensor into the abandoned wiring harness. One benefit of doing the valve covers, oil pan, and rear plate is getting to see just how clean this thing is internally. Plus the added bonus of the rear cover coming off, is that pretty much all of the dexcool is gone.
-
00Beast
- Retired Site Developer

- Posts: 20960
- Joined: Tue May 27, 2008 10:30 pm
- Year and Trim: '17 Silverado 1500
- Location: MN/IA
- Contact:
Re: L36 replacement or swap to L26
Looks great!!!!!
Bye Bye:

RIP sandrock

RIP sandrock
Sirius wrote:Think about it. You’re tooling down the road in your Prius, knowing full-well that this thing being green is as big a sham as federally mandated ethanol-enriched gas, Russia pulling out of Ukraine, and Obamacare.
Re: L36 replacement or swap to L26
Thanks guys for the feed back. Its taken longer than what it should to do this swap but I'm just to picky. Working on finding a good route for the oil pressure line. Then probably do some cleaning up and sorting out of what I have and what I can't find.
-
00Beast
- Retired Site Developer

- Posts: 20960
- Joined: Tue May 27, 2008 10:30 pm
- Year and Trim: '17 Silverado 1500
- Location: MN/IA
- Contact:
Re: L36 replacement or swap to L26
Just to check, your UIM is an APN sleeved unit, correct?
Bye Bye:

RIP sandrock

RIP sandrock
Sirius wrote:Think about it. You’re tooling down the road in your Prius, knowing full-well that this thing being green is as big a sham as federally mandated ethanol-enriched gas, Russia pulling out of Ukraine, and Obamacare.
Re: L36 replacement or swap to L26
Yeah, the UIM is the APN sleeved intake. That was just part of my frustration with this whole motor swap. I only had the L36 together for about 500 miles or so before knock, knock, knock... . That was after doing the LIM, UIM,180* thermostat, series I AC Delco water pump, all new hoses, plugs & wires, & Good Year gator belt.
Sorry for the rant, at least I could swap these parts over.
Anyway, a little side track for the L26 motor install. Was able to find a route for the oil pressure line from the motor to the gauge.
Here's a drivers view of the finished product. The gauge is from JEGS, I put a red bulb cover on and tied it into the dash lighting. That way it should look and function similar to the others.

I ended up using some 3/8" o.d. nylon tubing for a chase/protection for the oil line.
This view is at the pass. side, went through the top portion of the plastic wiring connector going through the firewall. Made sure I didn't drill through any wires. I ended up chosing this location because it ended up being closest to the oil filter adapter.


In this shot I'm trying to show the tubing going through the plastic above the wires inside the cabin.
Then routed the tubing to the gauge.

Well thats it for tonight, more work ahead of me.
Sorry for the rant, at least I could swap these parts over.
Anyway, a little side track for the L26 motor install. Was able to find a route for the oil pressure line from the motor to the gauge.
Here's a drivers view of the finished product. The gauge is from JEGS, I put a red bulb cover on and tied it into the dash lighting. That way it should look and function similar to the others.

I ended up using some 3/8" o.d. nylon tubing for a chase/protection for the oil line.
This view is at the pass. side, went through the top portion of the plastic wiring connector going through the firewall. Made sure I didn't drill through any wires. I ended up chosing this location because it ended up being closest to the oil filter adapter.


In this shot I'm trying to show the tubing going through the plastic above the wires inside the cabin.
Then routed the tubing to the gauge.

Well thats it for tonight, more work ahead of me.
Re: L36 replacement or swap to L26
Well I did the rear main seal, and it actually went pretty well. I used a scrap piece of wood to pound the old one out. Then went about cleaning the plate up for the new seal. I ended up just cleaning/scrubbing it in the kitchen sink with some dish soap and hot water. Dried it all off and then put it in front of my heater to dry it even better and heat it up a little (I think it expanded just enough). So I took the new seal that was cold (contracted) from being in the garage and left the plastic ring in place to install the seal. It basically pushed right in, used the old seal to counter sink the new seal in place, it worked great. Ended up leaving that seal protector on until I installed the plate. I let the crank shaft just push the plastic protector out of the way. I checked the plate clearance to bottom rail with my straight edge and it all checked out. Torqued everything down and checked the gap. Again all good.
Then while I still had the pan off I cleaned it up and cleared it to protect the aluminum. A side note here about the splash shield in the pan IT'S SHARP! I know,I know what an idiot lesson learned for the night. That aside I was able to get it all cleaned up and bolted back in place. The flywheel was next and is done and torqued. Installed the new O2 sensor (AC Delco) and decided was good enough for tonight.
I know its early but I'm running on 4hrs of sleep from last night, oh well.
Then while I still had the pan off I cleaned it up and cleared it to protect the aluminum. A side note here about the splash shield in the pan IT'S SHARP! I know,I know what an idiot lesson learned for the night. That aside I was able to get it all cleaned up and bolted back in place. The flywheel was next and is done and torqued. Installed the new O2 sensor (AC Delco) and decided was good enough for tonight.
I know its early but I'm running on 4hrs of sleep from last night, oh well.
Re: L36 replacement or swap to L26
Ok it's been awhile since I posted an update on my project. Well I didn't do very well with pictures along the way but I do have some before and after shots. I did manage to fire up the new to me used L26 tonight!
I primed the oil before firing it up. No leaks and sounding good!
Before (old L36): A little to much silver in this pic..

After (newer L26): Little bit different paint scheme this time.



As you can pretty much see by the pictures there is no physical difference between the 2 motors. The L26 runs so much smoother and has better internals than the L36. Also with the L26 you can almost be guaranteed that it didn't have a coolant leak before you got it. With the updated gaskets all ready installed, it takes away some worry. Then when you use the updated UIM from APN for the L36, plus a 180* thermostat you've got a reliable motor ready for service, that shouldn't have the UIM problems. The swap wasn't all that bad for my first time, at least I think so. The amount of time it took on my part was not having a lot of spare time to work on it. I could very well see this getting done in a weekend as long as every thing was lined up ahead of time and ready to go. I did a lot of extra and not necessary work on my part but I like the overall outcome.
New parts I used for this swap:
Valve cover gaskets, exhaust gaskets, UIM gaskets, oil filter adapter gasket, rear main seal plate gasket, rear main seal, water pump gasket.
Series I AcDelco water pump, Belt tensioner assembly, spark plug wires, APN UIM, 180* thermostat, motor mounts, larger oil filter (the one for 4.3l V6).
Accessory parts I was able to keep on the L26:
starter, aluminum oil pan, front exhaust manifold, valve covers, LIM, ICM and the coils too.
Some of the extra work that I did along the way:
I cleaned the engine bay up while it was empty.
Drained and flushed the power steering fluid.
Drained and changed the tranny filter while it was sitting.
Changed the fuel filter which made more work for me. The o-rings are not sealing on the filter, found that out tonight. I'm now contemplating just doing the o-rings or splicing in a new end.
Flushed cooling system and switched to Prestone "mixes with any".
Hopefully this is a story that will eventually end "happily ever after".
Before (old L36): A little to much silver in this pic..

After (newer L26): Little bit different paint scheme this time.



As you can pretty much see by the pictures there is no physical difference between the 2 motors. The L26 runs so much smoother and has better internals than the L36. Also with the L26 you can almost be guaranteed that it didn't have a coolant leak before you got it. With the updated gaskets all ready installed, it takes away some worry. Then when you use the updated UIM from APN for the L36, plus a 180* thermostat you've got a reliable motor ready for service, that shouldn't have the UIM problems. The swap wasn't all that bad for my first time, at least I think so. The amount of time it took on my part was not having a lot of spare time to work on it. I could very well see this getting done in a weekend as long as every thing was lined up ahead of time and ready to go. I did a lot of extra and not necessary work on my part but I like the overall outcome.
New parts I used for this swap:
Valve cover gaskets, exhaust gaskets, UIM gaskets, oil filter adapter gasket, rear main seal plate gasket, rear main seal, water pump gasket.
Series I AcDelco water pump, Belt tensioner assembly, spark plug wires, APN UIM, 180* thermostat, motor mounts, larger oil filter (the one for 4.3l V6).
Accessory parts I was able to keep on the L26:
starter, aluminum oil pan, front exhaust manifold, valve covers, LIM, ICM and the coils too.
Some of the extra work that I did along the way:
I cleaned the engine bay up while it was empty.
Drained and flushed the power steering fluid.
Drained and changed the tranny filter while it was sitting.
Changed the fuel filter which made more work for me. The o-rings are not sealing on the filter, found that out tonight. I'm now contemplating just doing the o-rings or splicing in a new end.
Flushed cooling system and switched to Prestone "mixes with any".
Hopefully this is a story that will eventually end "happily ever after".
Last edited by Bing on Wed Jun 15, 2011 5:31 pm, edited 1 time in total.
Re: L36 replacement or swap to L26
Alright just need to confirm my oil pressure readings hear to calm my nerves. At start up it's 61 psi and then as it warms up it settles down to 40-41psi. When I shift it into gear and the tranny loads the engine a little it goes down to 32 or so psi, this is at 176* coolant temp. I have not driven it around yet (no hood on yet) or some other misc stuff.
Are these readings in an acceptable range?
These readings were taken from my mechanical gauge. The stock gauge in the dash was reading higher (never went below 40psi). I did install a new oil pressure sending unit when I did this swap.
Any input would be appreciated.
Thanks guys as always.
Are these readings in an acceptable range?
These readings were taken from my mechanical gauge. The stock gauge in the dash was reading higher (never went below 40psi). I did install a new oil pressure sending unit when I did this swap.
Any input would be appreciated.
Thanks guys as always.
- harofreak00
- Administrator

- Posts: 26022
- Joined: Mon May 19, 2008 6:04 pm
- Year and Trim: 2004 GXP - plus a handful of other Bonnevilles
- Location: Browerville, MN
- Contact:
Re: L36 replacement or swap to L26
It's acceptable, but not ideal. I'd expect more out of lower mileage engine.
Andrew - owner/operator of Bonnevilles Unlimited

2004 Bonneville GXP | 60k | White Gold Tricoat | custom built supercharged 3800 hot rod | garage queen
1997 Corvette | 57k | Silver Metallic | Z06 wheels | Date-night Hauler/Parts runner
2014 Town & Country Limited | Cashmere Pearl | 115k | Family Hauler
2002 Ram 1500 Quad Cab Sport | Black| 280k | Official Bonneville Hauler

2004 Bonneville GXP | 60k | White Gold Tricoat | custom built supercharged 3800 hot rod | garage queen
1997 Corvette | 57k | Silver Metallic | Z06 wheels | Date-night Hauler/Parts runner
2014 Town & Country Limited | Cashmere Pearl | 115k | Family Hauler
2002 Ram 1500 Quad Cab Sport | Black| 280k | Official Bonneville Hauler
Re: L36 replacement or swap to L26
Well at least I have a 1yr warranty on the motor, not that I want to use it. Just really didn't want to pull it out ever again. I guess I'm just going to monitor it and see how it goes.
I just wanted to say Thank you to the following members for all their help and guidance.
Harofreak00, 00Beast, Sandrock, Jrs3800, Lesabreinbuffalo, and Myfirstbonnie.
Without you guys I would have ended up putting in another L36 or just giving up on the car.
So thank you to all of you!
Bing
I just wanted to say Thank you to the following members for all their help and guidance.
Harofreak00, 00Beast, Sandrock, Jrs3800, Lesabreinbuffalo, and Myfirstbonnie.
Without you guys I would have ended up putting in another L36 or just giving up on the car.
So thank you to all of you!
Bing
Last edited by Bing on Sat Mar 26, 2011 11:50 pm, edited 1 time in total.
- sandrock
- Retired Gearhead

- Posts: 4753
- Joined: Mon May 19, 2008 2:14 pm
- Year and Trim: '00 SSEi (proj), '99 Tahoe & '05 Bonne GXP
- Location: Orlando Fl
- Contact:
Re: L36 replacement or swap to L26
No probs at all.
I just skimmed through the list you did with the install...did you install a new oil pressure sending unit? And if so, what type? Different sensor makes will give different readings @ the same oil pressure. There is also an off-chance that the sending unit caught an air pocket.
Glad you like the engine. Yes, the L26s are a smoother operating engine. It'll make you fall in love with your Bonne all over again
I just skimmed through the list you did with the install...did you install a new oil pressure sending unit? And if so, what type? Different sensor makes will give different readings @ the same oil pressure. There is also an off-chance that the sending unit caught an air pocket.
Glad you like the engine. Yes, the L26s are a smoother operating engine. It'll make you fall in love with your Bonne all over again
2005 GXP - White Gold Pearl, no mods...yet.
2000 SSEi - Resurrection in progress. Built L67 w/L32 fuel rail, ported heads, and cam. Camaro front brake system, GXP cluster, and much more in planning.
2000 SSEi - Resurrection in progress. Built L67 w/L32 fuel rail, ported heads, and cam. Camaro front brake system, GXP cluster, and much more in planning.
BonneMe wrote:Looks like a Volt, Sonata, and Taurus got it on.
Re: L36 replacement or swap to L26
The sensor was an Original Engine Management one from Rock Auto. The readings still make me uneasy especially the hot idle reading in gear. Would the bigger oil filter affect the reading. I'm paying attention to my mechanical gauge reading for my worries. The motor doesn't knock or clatter at all even when it has the low pressure reading. I did drive it around a little yesterday and it seems to stay right around 55-58psi going down the road. It is funny all the looks you get driving around without a hood.


