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3.2 V6 Throttle Body Clean - How To

25K views 68 replies 28 participants last post by  godisadj00  
#1 ·
There's been a few posts about cleaning the throttle body recently, and as I'd been experiencing similar symptoms (unsteady idling, hesitancy, jerkiness) I thought I'd give it a shot.

I have to say, I'm really pleased with the result - the response and running is silky smooth now, just like when I first got it.

If anyone hasn't had this done .... DO IT! It certainly won't hurt, and almost certainly will make a world of difference to your car's running. Don't be frightened off either. I'm a complete noob and I found it was really quite easy.

To give something back to the forum I made a photo log of my experience to provide a step-by-step guide for everyone's benefit. I hope it's useful.

3.2 V6 Throttle Body Clean - How To

This procedure must be carried out on a cold engine, because the throttle body needs to reset itself once reassembled and a cold engine is a requirement for that to happen.

The whole thing takes around one to two hours to complete

What you will need:

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1. In order to remove the air hose you'll need to undo a spring hose clamp. A pair of channel lock pliers like in the photo will do it

2. The throttle body itself is attached by 4 hex bolts. I found that a 5mm hex bit on a long screwdriver (like the one that I bought especially) worked best because I couldn't access the very bottom bolt using an allen key, not even a long one

3. When re-assembling you should seal the O-ring gasket with a smear of Silicone Grease. I found that Maplins sell small tubes of it for about ÂŁ5 (Maplin product code RE90X)

4. To do the actual cleaning you will need a can of carb cleaner, such as the one I got from Halfords (product code 294918-0) for about ÂŁ5

5. A clean lint free cloth

6. Cotton buds

7. Plain white paper

8. Since you will need to disconnect the battery, make sure you have you radio code so you can re-activate it afterwards. The 4 digit code should be in your car handbook or other documentation that you received with it

Step 1 - Disconnect Battery

Unlock the car and open the boot - in the V6 the battery is in the boot, underneath the carpet with the toolset, the latter of which has a spanner that fits the nut on the negative terminal of the battery. Disconnect the negative terminal and tuck the disconnected wire away from the terminal.

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Place a towel across the latch of the boot so that it won't engage if you try to close the boot. Since the boot latch is battery operated, you won't be able to open the boot again to re-connect the battery so this will prevent that happening. Having said that, there is an escape mechanism that can be used to manually open the boot but it can be a bit stiff to operate.

Step 2 - Unclip The Air Hose At The Airbox Side

To get the best access to the 4 bolts holding the throttle body, you need to remove the air intake hose. Start at the end shown in the picture and either use the pliers to undo the clip and pull back the pipe, or if you prefer you can undo the two screws that attach it to the air box. If you do the latter, you'll need a short philips-head screwdriver so that you can access the bottom screw easily, and I would advise to cup you hand underneath the bottom screw so that it doesn't drop into the engine when undoing it.

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Step 3 - Unclip The Throttle Body Power Cable

Before undoing the other end of the air hose, unclip the power cable that attaches to the throttle body housing. You'll need to insert a small flat-head screwdriver and gently depress the catch while pulling the plug to remove it. You may be able to just do this by hand, as I did.

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Step 4 - Unclip The Air Hose At The Throttle Body Side

With the power cable un-plugged and tucked out of the way, use the pliers again to release the air hose clip and pull the hose back to reveal one side of the throttle body internals.

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(Extra points to those who note how clean it looks inside already... ok, I admit I forgot to take a photo of this so I took one after cleaning LOL)

Step 5 - Undo The 4 Hex Bolts

The two top bolts can easily be accessed, but the ones on the left and at the bottom are more tricky to get to, and can potentially drop into the engine bay unless you're really careful. Use the screwdriver with the 5mm hex bit to undo the bolts and while doing the bottom two use your free hand to guide the bolts out so you don't lose them in the engine bay. Once the bolts are fully undone pull them out and put to one side.

Step 6 - Remove The Throttle Body

Now remove the throttle body by giving it a slight twist, then gently pulling it towards you (it's not held on by anything now) and this will reveal the air intake chamber on the other side of the throttle body.

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If anything gets into this open hole it could cause a lot of problems, so me being paranoid I would advise to block the hole temporarily to be on the safe side. I used a scrunched up plastic carrier bag and gently inserted it a little into the hole

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Step 7 - Cleaning The Throttle Body

Now onto the business :)

As you can see, my throttle body was pretty gunked up

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It's very important to note that during the cleaning process you should keep the cleaning solution away from the electronics of the throttle body, or you may damage it. To that end, always keep the electronics parts at the top so that the cleaning solution naturally drains downwards and away from the components. In the photo below, the electronics are housed inside the black part of the throttle body.

Also note that the throttle butterfly (the round bit in the middle) is driven by a sensitive stepper motor, so do not use any force on the butterfly or try to open it as otherwise damage may result.

Holding the throttle body in one hand with the electronics side upwards, carefully spray the carb cleaner into and around the throttle butterfly. Wait for a few secs then gently use the clean cloth to wipe away the majority of the gunk. Now gently use the cotton buds to wipe around the circumference of the throttle butterfly.

Now take a clean piece of paper and tear off a small strip. You can then feed the paper through the gap around the top and bottom of the throttle butterfly to dislodge the gunk trapped where we can't get to. Be very careful not to get too close to the hinges of the throttle butterfly or the paper will become stuck in there! And make sure to only use the cut edge of the paper to do the actual cleaning as the torn edge will be ineffective and is likely to get stuck in there. With the gunk dislodged, use a cotton bud soaked in carb cleaner to wipe around the edge and clear it up.

Repeat this process for both sides of the throttle body, then repeat the above steps until you can't get any more gunk out.

Once you're satisfied it's all clean, and still holding the electronics upright, give a final spray around with carb cleaner, let it drain off then dry off with the cloth and cotton buds. Put the whole throttle body down with the electronics upright and leave it to dry off for a while.

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The finished result should look something like this

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Step 8 - Prepare For Refitting

Remove the inserted carrier bag from the hole and give the O-ring and mating surface a quick wipe around with a clean cloth to remove any muck that's accumulated so there is a clean surface to use. Then apply a smear of Silicone Grease to the O-ring in preparation for re-fitting of the throttle body.

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Step 9 - Refitting The Throttle Body

It's fairly tricky to re-attach the throttle body without making a mess of the Silicone Grease, so insert the top two throttle body bolts into the throttle body and use them as alignment assistants while you carefully bring the two mating surfaces together. Once the two top bolts are inserted into their holes on the other side just do them up a couple of turns to keep the body in place while you carefully insert the remaining two bolts at the bottom, then do these two up a couple of turns.

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Once all four bolts are in, work around each bolt in turn gradually tightening each one up so that the two mating surfaces are naturally drawn together. This keeps the alignment of the throttle body straight so that the Silicone Grease doesn't get displaced and can do its job.

Finally tighten all four bolts - but don't over do it!

Step 10 - Refit The Air Hose & Power Supply

Quite simply the reverse of the procedure to disassemble, use the pliers to re-attach the air-intake side air hose, making sure it is fully seated into its original position, then plug the power supply cable back in. Then re-fit the air box side of the air hose.

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Step 11 - Re-connect the battery

Once you're certain everything is back in place and done up correctly, re-connect the negative terminal of the battery.

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If, like me, you closed the boot then you won't be able to open it, so you' you'll need to open it using the plastic loop hidden in the centre tunnel:

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Step 12 - Throttle Body Alignment

The throttle body must be re-aligned. This will happen automatically - just insert the key into the ignition and turn it until the dash lights are on... but do NOT start the car. Leave the key in this position for 5 minutes. During this time you should hear some clicking going on in the engine bay. This is the throttle body alignment doing its stuff.

Step 13 - Radio Code

While you're waiting for the throttle body alignment to complete you may as well re-enable your radio by entering the code from your handbook. The unit will display SAFE on the front. You need to simultaneously hold down the RDS and SCAN buttons for a couple of seconds until the display changes to four zeros. Then you can use the radio station buttons from left to right to enter the four digit code - button one changes digit 1, button two changes digit 2 and so on. When you've entered your code simultaneously hold down the RDS and SCAN buttons to set the code.

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Step 14 - Set The Date & Time

The clock will also be reset to your car's dash pod manufacture date, so this is another job that can be done while waiting for the throttle body reset to take place.

On the dash, pull the left silver knob (under the rev counter) towards you until the Hours flash, then turn the knob to the right or left to increase or decrease the hours. To advance to minutes pull the knob again and set the minutes, again for year, month and so on.

Step 15 - Enjoy!

By this time the throttle body reset will have taken place. Remove the key from the ignition, re-insert and start the engine. Now drive off and have fun! (Oh, and make sure the bonnet is closed first!)
 
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#2 ·
Cheers Marty, the sticky has been added to the V6 page.
One thing..can you amend your guide to say "put a towel over the tailgate lock once the battery has been disconnected" this will save peeps from trying to open the tailgate with the wire as it is very stiff to operate.
Well donenmate.
Steve
 
#3 ·
V6RUL said:
Cheers Marty, the sticky has been added to the V6 page.
One thing..can you amend your guide to say "put a towel over the tailgate lock once the battery has been disconnected" this will save peeps from trying to open the tailgate with the wire as it is very stiff to operate.
Well donenmate.
Steve
Done!

Cheers dude :)
 
#5 ·
Excellent write up mate!

Im going to do this today, rain permitting...

What improvements did you notice after doing this?
 
#6 ·
antcole said:
Excellent write up mate!

Im going to do this today, rain permitting...

What improvements did you notice after doing this?
Thanks, I'm quite proud of my efforts :p

I went down this route because I had some issues with the running, so there's no benefits as such, it just fixes up the problems. So, if you're already running smoothly then you might be wasting your time doing this.

The issues I had were:

1. Unstable idle - not by huge amounts but enough for me to notice
2. Jerkiness - especially with light operation of the throttle (like in traffic)
3. Hesitancy - put my foot down and I would get flat spots

All these problems have disappeared now. It's back to how it was when I first bought it two years ago - silky smooth power delivery all the way up. It's much more of a pleasure to drive again 8)
 
#7 ·
Marty said:
antcole said:
Excellent write up mate!

Im going to do this today, rain permitting...

What improvements did you notice after doing this?
Thanks, I'm quite proud of my efforts :p

I went down this route because I had some issues with the running, so there's no benefits as such, it just fixes up the problems. So, if you're already running smoothly then you might be wasting your time doing this.

The issues I had were:

1. Unstable idle - not by huge amounts but enough for me to notice
2. Jerkiness - especially with light operation of the throttle (like in traffic)
3. Hesitancy - put my foot down and I would get flat spots

All these problems have disappeared now. It's back to how it was when I first bought it two years ago - silky smooth power delivery all the way up. It's much more of a pleasure to drive again 8)
Superb, well i have pretty much all of those symptoms....
Idles fine but theres a disgracefully monumental flat spot that is not unlike a badly tuned vauxhall viva from 20+ years ago!!!
Hesitancy - YES
Jerky in low throttle driving - YES
Flat spot - like Ace Ventura inhaling before his exhaustive explanations!!

I might give the exterior a bit of a buff up while im there, your first class write up explains very nicely on how to remove and re-fit, so thats good even if not needing the clean up.

Thanks again mate.
 
#8 ·
antcole said:
Marty said:
antcole said:
Excellent write up mate!

Im going to do this today, rain permitting...

What improvements did you notice after doing this?
Thanks, I'm quite proud of my efforts :p

I went down this route because I had some issues with the running, so there's no benefits as such, it just fixes up the problems. So, if you're already running smoothly then you might be wasting your time doing this.

The issues I had were:

1. Unstable idle - not by huge amounts but enough for me to notice
2. Jerkiness - especially with light operation of the throttle (like in traffic)
3. Hesitancy - put my foot down and I would get flat spots

All these problems have disappeared now. It's back to how it was when I first bought it two years ago - silky smooth power delivery all the way up. It's much more of a pleasure to drive again 8)
Superb, well i have pretty much all of those symptoms....
Idles fine but theres a disgracefully monumental flat spot that is not unlike a badly tuned vauxhall viva from 20+ years ago!!!
Hesitancy - YES
Jerky in low throttle driving - YES
Flat spot - like Ace Ventura inhaling before his exhaustive explanations!!

I might give the exterior a bit of a buff up while im there, your first class write up explains very nicely on how to remove and re-fit, so thats good even if not needing the clean up.

Thanks again mate.
LOL - go for it! Please do report back on how you got on :)
 
#9 ·
Hi - Newbie here

Just to say that I followed your how to guide and took everything apart and managed to clean the throttle body (man it was filthy - must have taken about 20 cotton buds to get it really clean).

Whilst I was at it I gave the MAF a clean with specialist MAF cleaner and put a new Pipecross panel filter in as well, just to make a proper job of it.

I managed to do the throttle reset also - heard the buzzing and clicking with the key in the ignition.

Initially after taking the motor out for a spin I didn't really notice any difference and if anything it felt a bit bogged down on occassions when pulling away,say from traffic lights, but having given it a good 10mile run yesterday I have to say that from start up today the car drives much, much better than before and it's really worth doing - throttle response has deffo improved and the engine in general feels a lot smoother and stable than before. (ECU must have needed to re-sort fuelling etc out)

So would like to say thanks for the write up, as I probably wouldn't have even attempted it without the info and pics - so once again thanks! :p

Regards
Daniel
 
#10 ·
I did mine too, following Martys excellent instructions.

There was one difference with mine in that the one shown in the write up doesnt have cooling hoses to and from it.... mine does.

I just de-pressurised the engine coolant and carefully disconnected each hose. Didnt lose a drop of coolant and apart from the wriggle of re-fitting the hoses, all went well.

Cant say i noticed a big difference but it just felt good to have cleaned a filthy throttle body.
 
#11 ·
markwartd said:
Hi - Newbie here

Just to say that I followed your how to guide and took everything apart and managed to clean the throttle body (man it was filthy - must have taken about 20 cotton buds to get it really clean).

Whilst I was at it I gave the MAF a clean with specialist MAF cleaner and put a new Pipecross panel filter in as well, just to make a proper job of it.

I managed to do the throttle reset also - heard the buzzing and clicking with the key in the ignition.

Initially after taking the motor out for a spin I didn't really notice any difference and if anything it felt a bit bogged down on occassions when pulling away,say from traffic lights, but having given it a good 10mile run yesterday I have to say that from start up today the car drives much, much better than before and it's really worth doing - throttle response has deffo improved and the engine in general feels a lot smoother and stable than before. (ECU must have needed to re-sort fuelling etc out)

So would like to say thanks for the write up, as I probably wouldn't have even attempted it without the info and pics - so once again thanks! :p

Regards
Daniel
Welcome to the forum BTW
 
#12 ·
Thanks for the welcome.

Your quite right - forgot to mention that I also had the two hoses connected. i just left the hoses connected as access looked a bit tight and I didn't want to damage anything (bit of a wuss I know :roll: ) and cleaned the Throttle Body in place with a large rag under to make sure no cleaner went over the engine bay around and below the area - managed to do it without getting any cleaner near the electronic part of the Throttle Body.

Regards
Daniel
 
#13 ·
markwartd said:
Thanks for the welcome.

Your quite right - forgot to mention that I also had the two hoses connected. i just left the hoses connected as access looked a bit tight and I didn't want to damage anything (bit of a wuss I know :roll: ) and cleaned the Throttle Body in place with a large rag under to make sure no cleaner went over the engine bay around and below the area - managed to do it without getting any cleaner near the electronic part of the Throttle Body.

Regards
Daniel
Hey Daniel,
Any chance of some decent pics of your steering wheel and paddles as I've not seen a DSG with a comfort pack steering wheel.

Ps welcome by the way
Steve
 
#14 ·
Here you go - The Red Leather really isn't as red as the picture - I wasn'too sure about it at first (maybe a bit poncy), but I love it now - it's something a bit different.

I could only attach a photo via attachment - sorry.

Regards
Daniel
 

Attachments

#16 ·
@markwartd and @antcole

Hmm, odd about the cooling hoses. Mine does not have them. But then, mine's a manual... and yours are both DSG. Maybe that's why? Now my article is incomplete! [smiley=bigcry.gif]

@antcole I'm really sorry to hear that all that effort didn't really pay off for you. I'm still grinning with the difference in mine! :p
 
#17 ·
Marty,

Im not sure what the hoses are either I thought best to leave them well alone.

But once again thanks for the clear and concise write up it was really helpful and the cleaning has made a big difference to my car.

Regards
Daniel
 
#18 ·
markwartd said:
Marty,

Im not sure what the hoses are either I thought best to leave them well alone.

But once again thanks for the clear and concise write up it was really helpful and the cleaning has made a big difference to my car.

Regards
Daniel
I'm really pleased to hear that! You're very welcome

Welcome to the forum btw :)
 
#19 ·
Marty said:
@markwartd and @antcole

Hmm, odd about the cooling hoses. Mine does not have them. But then, mine's a manual... and yours are both DSG. Maybe that's why? Now my article is incomplete! [smiley=bigcry.gif]

@antcole I'm really sorry to hear that all that effort didn't really pay off for you. I'm still grinning with the difference in mine! :p
It did make a difference, definately a bit more perky.... i think my issues are more related to my mechatronic unit.... which, again, you wont have the stress of!! :lol:

While mine was out i gave it a soft detail brush off and coated with an aluminium etch primer before a nice spray of smooth silver hammerite.
Looks the dogs dusters all brightened up.
You gave me the confidence to remove it and it did need a clean!

I only removed the hoses because i wanted to give it a spray up, otherwise your instructions still stand... its easy enough to give it a clean while its attached to the hoses.
Thanks again mate.
 
#20 ·
Heres the puppy back in place... i like shiney stuff see....

Image
 
#22 ·
antcole said:
Heres the puppy back in place... i like shiney stuff see....

Image
Unfortunately, in cleaning the TB the rocker cover looks a little sorry for itself now.
Check my latest posts on my build thread for options..
Steve
 
#23 ·
antcole said:
Marty said:
@markwartd and @antcole

Hmm, odd about the cooling hoses. Mine does not have them. But then, mine's a manual... and yours are both DSG. Maybe that's why? Now my article is incomplete! [smiley=bigcry.gif]

@antcole I'm really sorry to hear that all that effort didn't really pay off for you. I'm still grinning with the difference in mine! :p
It did make a difference, definately a bit more perky.... i think my issues are more related to my mechatronic unit.... which, again, you wont have the stress of!! :lol:

While mine was out i gave it a soft detail brush off and coated with an aluminium etch primer before a nice spray of smooth silver hammerite.
Looks the dogs dusters all brightened up.
You gave me the confidence to remove it and it did need a clean!

I only removed the hoses because i wanted to give it a spray up, otherwise your instructions still stand... its easy enough to give it a clean while its attached to the hoses.
Thanks again mate.
Yea, I was reading some of your posts and wondered if the mech unit might be more of the cause rather than anything else :?

I still think the DSG is awesome and even now sometimes wish I had one, but I'd made my decision to go manual for the reliability and I think it was a wise decision to make.

Anyway, I'm very glad to hear it wasn't an entirely wasted effort! 8)

Now just to clean the rest of the engine to make it shiny ... :wink:
 
#24 ·
V6RUL said:
antcole said:
Heres the puppy back in place... i like shiney stuff see....

Image
Unfortunately, in cleaning the TB the rocker cover looks a little sorry for itself now.
Check my latest posts on my build thread for options..
Steve
Youre spot on there mate!
Ive got to pluck up the courage to remove the inlet manifold and do the cam cover... :-|

Its a bit like picking at a piece of loose wallpaper.... once you start its all gotta go or it looks rank!! :lol:
 
#25 ·
antcole said:
V6RUL said:
antcole said:
Heres the puppy back in place... i like shiney stuff see....

Image
Unfortunately, in cleaning the TB the rocker cover looks a little sorry for itself now.
Check my latest posts on my build thread for options..
Steve
Youre spot on there mate!
Ive got to pluck up the courage to remove the inlet manifold and do the cam cover... :-|

Its a bit like picking at a piece of loose wallpaper.... once you start its all gotta go or it looks rank!! :lol:
yeah, tell me about it..
Steve