GM 3800 Series-II Exhaust Cross Over Pipe

Status
Not open for further replies.
Joined
Jan 30, 2007
Messages
17,501
Location
Clovis, CA
I just read the service manual and it says to remove the exhaust cross over pipe before attempting to remove the throttle body. Those 4 bolts that hold it on look pretty dry and rusty. I'm thinking I need to start some kind of bolt oiling regimen for awhile before attempting to break those bolts loose. You guys got any suggestions as far as the type of oil or a way to apply it? I was gonna squirt some SuperTech penetrating oil in there unless you guys got a better idea.
 
Iv always had good success with PB blaster.

I try to remove bolts and screws as they age generally just replace them all if I have to fix something.

A little bottle of anti seize can be handy for future repairs.
 
+1 for PB. Spray every day for 5 days. The bolts will walk out as if they were just put in.
 
PB also works great on really old O2 sensors. The trick is to start spraying it a day or two before you plan to do the work...
 
Merk I don’t think you need to remove that cross over pipe just to R&R the throttle body.
 
Just had the throttle body off my BPAU last week. Three 10mm. New gasket. Nothing to do with the exhaust.

Excellent advice on PB Blaster in advance of work and anti-seize when reinstalling.
 
You don't need to remove the crossover pipe to remove the throttle body. Aside from the wiring harness connection, there are the three nuts and one 8mm headed bolt underneath that connects a brace. Remove the bolt and take a small pry bar/screwdriver and pry it back a little bit for clearance (before removing the nuts at the throttle body). It doesn't bend, but pivots on the bolt at the intake.
 
True. I have a 3800 in my Impala too and I pulled both upper/lower intakes without removing any exhaust components. I pulled the throttle body off (very dirty), cleaned and reinstalled with a new gasket. I couldn't believe how dirty it was but did not feel a sticky gas pedal. My Silverado's pedal starts to get noticeably sticky with just a little oily buildup on the throttle plate? I don't know why.
Originally Posted By: ron350
Merk I don’t think you need to remove that cross over pipe just to R&R the throttle body.
 
Not necessary to remove exhaust pipe on my oldsmobile 88 with the 3.8 liter(3800series) but it is an older 1997.

perhaps you have a variant?
 
As a mechanic in the 70's I used and preferred CRC penetrant products for EXHAUST bolt and nut loosening - if they needed to be preserved. Otherwise it was the Alabama Hot Wrench and/or the air power chisel.
 
Originally Posted By: The_Eric
You don't need to remove the crossover pipe to remove the throttle body. Aside from the wiring harness connection, there are the three nuts and one 8mm headed bolt underneath that connects a brace. Remove the bolt and take a small pry bar/screwdriver and pry it back a little bit for clearance (before removing the nuts at the throttle body). It doesn't bend, but pivots on the bolt at the intake.


I know exactly which brace you're talking about. It's the brace that supports the tube for the secondary air injection pump and it's in the way of pulling the throttle body off. I was looking at it last night and the bolt that holds the brace on is not accessible with the crossover pipe in the way. I have all kinds of tools and I don't see any way to get at it.
 
Originally Posted By: mjk
I wonder how AeroKroil would work on that issue... got a free can with my Kreen, this past winter.


That's all i use and prefer it over the others living in a high salt area. Its good stuff, i buy it by the gallon.

BTW it makes a good cutting fluid also when used for low speed metal drilling and tapping.
 
There was a test of the various penetrant oils in one of my hot rodding mags. Kroil was the best, but it is hard to get and expensive. However, a 50/50 mix of standard dex/merc atf and acetone worked just as well. I have had awesome luck with this homemade stuff. Certainly works better than liquid wrench, which also works. Just takes longer of a soak.
 
I loosened some nuts on the bracket retaining a failed igniter in my old kitchenAid oven with a few drops of Liqui-Moly I had nearby. Better there than in the filtered engine
smile.gif
 
Status
Not open for further replies.
Back
Top