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Discussion Starter #1
Hey guys,

So this guide is on how to clean your throttle body. I thought this DIY might be useful because I had difficulty locating something like this.

What you need:
-Throttle body cleaner ($5 from any auto store)
-Hex wrench
-10mm socket w/ wrench
-Phillips screwdriver

Steps:

1. Remove the overhead manifold that goes over the engine (the same one you need to get off to remove the engine cover). (Pic 1)
2. Remove the black box sitting on the intake manifold. (Labeled 1 in pic 2) There are 4 hex screws, two are exposed and the other two can be uncovered by removing the rubber caps on top of them. Once you get the screws off, you just need to pull gently (it takes quite some force). (Pic 3)
3. Remove the cylindrical rubber extender that goes from the throttle body to the overhead manifold. It was tricky getting to the screw of the crimper. And then even after that, it was still hard to get off. The trick was to put your hand inside and push against the walls to try to loosen it.
4. Remove the 4 hex screws on the throttle body and take it off. Be careful when removing the throttle body since there is a spring, a lever, and a few other connectors that are attached directly to it. (Circled in Pic 4)
5. With the throttle body off, just take out your can of cleaner and spray it and wipe it off with a clean cloth.
6. You're done. Now just put everything back together.

Hopes this helps guys!

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Thanks! Picture worths a thousand words. Will give it a try next time.
 

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Just to clarify, step 4 calls for removal of bolts holding the throttle to clean it, do we also need to remove the springs and lever (in picture #4, it shows the springs are still attached) or can we just leave it attached since there is enough slack to move it out and clean it? TIA
 

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cleaning the throttle body

Big thanks, Racing Maven:thumbsup:
I'll be doing that as soon as I have some time.
Saludos
Fernandez
 

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Discussion Starter #7
Just to clarify, step 4 calls for removal of bolts holding the throttle to clean it, do we also need to remove the springs and lever (in picture #4, it shows the springs are still attached) or can we just leave it attached since there is enough slack to move it out and clean it? TIA
The springs, lever, and a valve have to be removed to clean it. The picture does NOT show the spring as it is still in the chassis, however the bolt IS attached to the throttle body. I also did not detach the cables to the wiring harness since there was enough slack to pull it out.
 

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Nice! I've done this.

Just a note: inspect some of the areas around the black box, and other mechanical attachments. sometimes a small crack in the plastic areas, and a dry o-ring causes lag in the operation of the delivery system. Underneath the little black box, I found a few small broken pieces(Dealer parts, I couldn't find anything available online).
 

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Many thanks! I was wondering if the TB could be removed without pulling the manifold itself. Now to attack the dreaded biodegradable wiring issue. (Hoping the internal wiring isn't kaput...)
 

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Removing the Throttle actuator on a car with an original wiring harness could cause a biodegradable wiring harness problem. I found this out the hard way. The isulation in the cable from the wiring harness connection to the throttle actuator is the same crappy stuff that the 93 to ~97 cars had in the main harness. If you have a car from the mid 90s and the original wiring harness be careful doing this or you could be out big bucks.

Greg
 

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This was very helpful, thank you! Anyone completing this project might deeply consider cleaning the EGR tube while the throttle body is off. Cleaning the tube will also resolve code #5 in port #3 of the w-124.

I had this code show up on my 1995 E320 (w-124). Research on this and other forums suggested it was most likely a clogged EGR tube. This indeed was the case.

Remove the tube to clean is quite easy if the throttle body is removed first.

Once this is off, remove the EGR tube:
1) disconnect the nut at the EGR valve (17 mm open end wrench, I think)
2) detach the small hanger attached to the oil filter housing (5mm alan nut with long extension on ratchet)
3) disconnect tube from plenum - the portion of the intake upon which the throttle body sits (two 10 mm hex bolts)

I was unable to remove the tube from the engine compartment because it was stuck in the EGR tube. Fortunately, with the throttle body off, I could move it around enough to stick a small flat head screw driver into the tube and scrape out the carbon deposits. Lots of chunks came out and this was sufficient to fully unclog the tube without going through the trouble of soaking it with chemicals or trying to ram a speedometer cable through it.

Replace gaskets for both the throttle body and the EGR tube.

This resolved the engine light and code issue.
 
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quest1966
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