Cadillac Owners Forum banner
  • BEWARE OF SCAMMERS. Anyone trying to get your money should be checked out BEFORE you send anything anywhere.
195K views 93 replies 56 participants last post by  hotboimack  
#1 ·
A common problem for Cadillacs, and many other cars at that, is their reputation for getting a dirty throttle body due to carbon buildup. Dirty throttle bodies would eventually produce what many people would refer to as a "sticky gas pedal" and frequent stalls at stops. The simple fix for this common problem is one that can be done by anyone with the proper tools.

By now you may be wondering, what is the throttle body? In simple terms, the throttle body is a round opening that controls airflow. For a further explanation on how this works, read the article in the yellow box on this page: http://www.popularmechanics.com/automotive/sub_care_sat/1272341.html?page=3&c=y

Now, down to the nitty gritty...how can I clean the throttle body? Cleaning the throttle body is a simple process that this walkthrough will demonstrate. Let's start.

Tools Needed:
Ratchet with 9/32" bit.
Carb Cleaner (Top Gum Brand is used in this walkthrough)
Rag or Toothbrush (to clean)

Step 1: Remove the Air Intake. This can be done by simply pulling it off at the round opening at the top.

There is one sensor that may have to be unplugged (it should have red lining). In this walkthrough, there are a total of 3.

Image


Specifically, this is the air intake:
Image


Step 2; part 1: The removal of the air intake will expose the MAF screen.

Image


Specifically, this is the MAF screen:
Image


Step 2; part 2: Remove the MAF screen with a ratchet. (You will need a 9/32" bit)

The red outlines indicate where you should remove the screws. The blue outlines indicate sensors plugs that can/may be removed for easier access as previously mentioned. There are 3 screws, one is under the MAF screen, remove this one first to make things easier (it is the hardest to loosen because of its location).

Image


Step 3: The throttle body and throttle body blade ("blade" does not indicate that it is sharp) are now exposed.

The throttle body blade opens when the accelerator is pressed. It will need to be kept open in order for proper cleaning. In order to do this, you may lay something heavy on the accelerator (manually keeping it open will tire your hands).

Image


Step 4: Proceed to clean the throttle body with Carb Cleaner.

You may either spray some on the actual blade and bore, or spray on a toothbrush and clean. DO NOT FORGET to clean the blade perimeter as well.

Image


After you are done cleaning the throttle body, reassemble everything by following these steps backwards. REMEMBER TO RE-CONNECT ALL UNPLUGGED SENSORS.

The total amount of time required for this task depends on how well you are aware with the location of certain objects. It may range from 30 minutes to 2 hours including cleaning.

-SL1CK
 
#6 ·
Thanks for the great pics and instructions. That's exactly the problem I was having, sticky gas pedal and stalling at 30mph when slowing down from high speed. I was shocked how much crap was in my throttle body at 66k miles for my 99 deville. It looked like a used car's motor oil which was never changed. I went through 5 cotton rags to clean all that black junk out.

For that bottom screw, I had to use a 2 inch extension. And I don't know what it's called, but the lever where the wire is being pulled on that connects to the blade... I opened the blade then placed a wrench on the lever which kept the blade open. Oh, I was a bit concerned for a moment after I finished my task and attempted to start the car. The engine struggles like as if it's been flooded and revs up the engine multiple times like as if it's a misfire or something. After 45-60 secs, it calms down and runs fine.

For a guy who does decent amount of maintaince and repairs on his car... this project took me 1hr. Taking it all apart, cleaning, re-assemble, and turning the car on to purge the remaining cleaner out of the engine.

Thanks guys, this forum kicks ass.
 
#11 ·
I cleaned my TB last nite. 98 STS 130,000 miles. This stuff/gunk/cabon was an 1/8" thick on the back side of the throttle blade and a 1/8" thick rim of it behind the throttle blade!! Inside the intake looks way thick with the gunk, I'm thinking of taking the intake off and cleaning it too! The best part was throttle responce I got after just cleaning it back to the intake!!!! Off idle throttle responce is awsome now!!! Now what will happen when I clean out the intake, my guess would be more power!! Port matching & porting an intake on hot rod V8 can be as high as 20hp! Maybe we need pictures/instructions how to remove and clean a North star intake?
Guy
 
#12 ·
My mom's 97 FSM states that this is a 30K mile cleaning interval.

I have tried to keep up on this on most of my cars that are EFI. I just installed a oil separator on my LT1 that should reduce this oil residue buildup from the PCV system.

http://collop.cz28.com/custom2.html gives a good description of it and why this is a good idea.

Excellent post SL1CK!
 
#13 ·
Great information...very easy to do on the 2000 STS as there is no MAF screen to remove. Mine was not that dirty, but no question it needed a cleaning. It took me about twenty minutes. So far the idle looks to have steadied out. I'll see over the next few days how critical this was to the idle problem. Thanks again. :burn:
 
#14 ·
Great post. Mine was identical to the pictures... did it Saturday, was a piece of cake.

My car started right up, but blew some smoke for about 30 seconds.... then cleared up.

Nice write up, nice pics. Thanks a million.....
 
#15 ·
SL1CK said:
A common problem for Cadillacs, and many other cars at that, is their reputation for getting a dirty throttle body due to carbon buildup. Dirty throttle bodies would eventually produce what many people would refer to as a "sticky gas pedal" and frequent stalls at stops. The simple fix for this common problem is one that can be done by anyone with the proper tools.

By now you may be wondering, what is the throttle body? In simple terms, the throttle body is a round opening that controls airflow. For a further explanation on how this works, read the article in the yellow box on this page: http://www.popularmechanics.com/automotive/sub_care_sat/1272341.html?page=3&c=y

Now, down to the nitty gritty...how can I clean the throttle body? Cleaning the throttle body is a simple process that this walkthrough will demonstrate. Let's start.

Tools Needed:
Ratchet with 9/32" bit.
Carb Cleaner (Top Gum Brand is used in this walkthrough)
Rag or Toothbrush (to clean)

Step 1: Remove the Air Intake. This can be done by simply pulling it off at the round opening at the top.

There is one sensor that may have to be unplugged (it should have red lining). In this walkthrough, there are a total of 3.

Image


Specifically, this is the air intake:
Image


Step 2; part 1: The removal of the air intake will expose the MAF screen.

Image


Specifically, this is the MAF screen:
Image


Step 2; part 2: Remove the MAF screen with a ratchet. (You will need a 9/32" bit)

The red outlines indicate where you should remove the screws. The blue outlines indicate sensors plugs that can/may be removed for easier access as previously mentioned. There are 3 screws, one is under the MAF screen, remove this one first to make things easier (it is the hardest to loosen because of its location).

Image


Step 3: The throttle body and throttle body blade ("blade" does not indicate that it is sharp) are now exposed.

The throttle body blade opens when the accelerator is pressed. It will need to be kept open in order for proper cleaning. In order to do this, you may lay something heavy on the accelerator (manually keeping it open will tire your hands).

Image


Step 4: Proceed to clean the throttle body with Carb Cleaner.

You may either spray some on the actual blade and bore, or spray on a toothbrush and clean. DO NOT FORGET to clean the blade perimeter as well.

Image


After you are done cleaning the throttle body, reassemble everything by following these steps backwards. REMEMBER TO RE-CONNECT ALL UNPLUGGED SENSORS.

The total amount of time required for this task depends on how well you are aware with the location of certain objects. It may range from 30 minutes to 2 hours including cleaning.

-SL1CK
What a great tip. Like many others I had a sticky gas pedal. Just thought it was normal stuff. Such an easy fix. Many thanks.
Dave,
1997 concours
 
#17 ·
I find my LT1 tends to get stickier in the winter months, primarily if I have the throttle body coolant bypassed.

Cleaning helps a lot. I don't recommend the throttle body coolant bypass due to the sticking in the winter. It doesn't do much if anything at all anyway.

David Jenison said:
What a great tip. Like many others I had a sticky gas pedal. Just thought it was normal stuff. Such an easy fix. Many thanks.
Dave,
1997 concours
 
#19 ·
If you take a good monitor of your idle IAC counts before and after you will see the improvement.

IAC counts around (I believe) 128 show no need to perform it, but anything outside of that, it is needed.
 
#21 ·
#25 ·
This instruction works on a 1991 seville as well. It is a little easer to get too. Remove the air intake elbow and open the throttle. Alternate spray and swab the two ports untill clean. (A small swap about the size of a gun cleaner and you are in business.) The car now runns like it should and the gas millage is back where it should be. Thanks for the post.
 
#26 ·
I know how to clean throttle bodies, but when I did mine, the car started kind of hard as usual, but then the throttle seemed to be sticking slightly. It wasnt doing that before. I used to work at a Cadillac dealer and was always told to just place a screwdriver inside to keep the blade open (obviousely dont pry on the metal). Anyone have this probelm also? Maybe I just have to go drive it to let it settle out.