L36 to L26 Intake Swap

[jiminnc]

Was wondering if anyone has experience replacing a L36 UIM with a L26 alluminum UIM. I'm working on 1998 SE w/3800 series II. It's my wifes daily driver so not looking for HP gains just keeping it running good. It has 189K on it and still has the original UIM/LIM. The radiator just cracked on the left side and I know the intake needs to be replaced so it's time to tear into it. Any help is appreciated.

 

[blueguy]

You will need an adapter plate for the throttle body...not sure if the Lower Intake Manifold is the same...if not, you'll need another one of those...you'll also have to modify and block off some vacuum routings if I remember right.

 

[jiminnc]

Yeah I found an older post that led me to the adapter plate from zzp, but everything I've read has been on 2000 to 2003 models and from what I can tell the L36 LIM is the same as the L26 on these models. I'm wondering if the 1998/1999 L36 LIM had some minor difference. Are the improved composite UIM's reliable? If so I'll just go that route.

 

[blueguy]

Not sure about the '97's or some '96's...but all the '98-'03 plastic UIM's are the same. All the '04+ ones are the aluminum ones...so no...not the same.

 

[jiminnc]

After doing some research and alot if reading on this forum I decided to go with the Dorman replacement UIM. I finished it yesterday, and it runs great.

Here's a list of everything I did:
-New radiator
-Thermostat
-Hoses
-New LIM gaskets
-New UIM&gaskets
-Fuel injector o-rings
-Spark plugs and wires
-Valve cover gaskets & grommets
-Coolant temp sensor

The old LIM gaskets were broken in several places. I don't know how the coolant wasn't getting into the oil. Cleaning the 189,000 miles worth of crud off of the parts was probably the hardest part. But know maybe my wife can get another 100K out of it. This forum was alot of help. Thanks.