Cleaning throttle body

biko

As a part of our series on DIY jobs on the car, today's pictorial is "how to clean the throttle body"
Car - generation one, Volvo S40.
Time - 20 mins.
Difficulty - easy if you're a bit handy.

The car had started to stutter when driving, particularly in 2nd gear pulling away. Engine would also sometimes die at red lights or when coasting downhill.
There was some white smoke from the exhaust but since it's been cold I didn't much think about it.

These are tell-tales of that the throttle body needs cleaning and I thought I might as well take some snaps.

I removed the neg from the battery for safety but it's not unheard of for people to do this while car is running (not recommended).

Under the cover with the Phillips head screw is the throttle body. Unscrew and remove. The hose from the air filter (big black thing coming in from the right in frame) is fastened with a hose clamp that has a regular screw head.

Unscrew this and push away the air hose. No other screws need loosening.


You can see all the gunk inside the TB (usually not this bad)


Close up


Inside the airhose


To clean, get TB cleaning spray, some use carburettor spray.
Have paper ready, napkins or kitchen towel works.

Wipe of as much gunk as you can using the napkins (got mine from McDonalds )
Give the inside of the hose and the TB a good wipe down to remove as much loose gunk as you can.
Once that's done, spray plenty of spray inside the hose and the TB and start working on it with an old toothbrush.
Use gloves and don't get spray on yourself or the paint.
Try to get the dirt out, don't push it in further.
It's recommended to wash the engine after job is done, to get any spray off that might have gotten on rubber parts in the engine.

When she's as clean as she will get, put everything together again and take her for a long drive to push the spray and the remaining loose gunk through the system.
Voilà, no more smoke or stuttering.

franksm

Good article ! I have used WD40 instead of carb cleaner in the past, it seems to disolve the varnish and cack pretty well.

Similar jobs (someone please do an article + pics !!) would be cleaning of EGR valve, and cleaning of cam/crankcase breather system

dirtydiesel

Good detailed post. An easy job with good results.

dnme

Just what I was looking for, gonna try this on my Corolla tomorrow. Many thanks

Plug

Anyone with a focus 99-02 1.4 or 1.6 sometimes the trottle body can get stuck and revs at idle seem high, spray in WD40 and it will sort it out.

dnme

Magnus wrote: »

As a part of our series on DIY jobs on the car, today's pictorial is "how to clean the throttle body"

Magnus, what other threads are there in this series? I tried a search of your posts but only found a thread about building a service pit. Are there any more tutorials? this one was great

unkel

gt112 wrote: »

Magnus, what other threads are there in this series? I tried a search of your posts but only found a thread about building a service pit. Are there any more tutorials? this one was great

This was Magnus' first tutorial. There are another 24 tutorials to follow over the next 24 days. Tomorrow he will fit a timing belt kit to his S40.

johndaman66

unkel wrote: »

This was Magnus' first tutorial. There are another 24 tutorials to follow over the next 24 days. Tomorrow he will fit a timing belt kit to his S40.

Seems like a fantastic idea to me. Anything that will potentially save us already hard pressed motorists a few quid would be much welcomed from many quarters. If I could make a suggestion though it would be that Magnus puts a disclaimer on each thread especially that such as changing a timing belt for example

mondeo

Would a dirty throttle body prevent a car from starting? Where does the dirt come from exactly?

biko

gt112 wrote: »

Magnus, what other threads are there in this series? I tried a search of your posts but only found a thread about building a service pit. Are there any more tutorials? this one was great

Hi, no I've only done this one so far. Volvoboy did one on servicing your car
http://www.boards.ie/vbulletin/showthread.php?t=2055422868

mondeo wrote: »

Would a dirty throttle body prevent a car from starting?

No, well yes if it's extremely dirty but not likely.

mondeo wrote: »

Where does the dirt come from exactly?

From outside. Remember to change air filter occasionally (see manual or inspect it for dirt).

kazul

I did this at the weekend. A bit more complicated on my car. I had to take nearly all the air intake apart, including removing MAF. All to reveal a lovely clean throttle body :rolleyes:

For my next trick I will be replacing an alternator belt tensioner/idler pulley. I finally figured ou that this is causing the rattle from my engine @ 1000 rpm. Relieved it's not the timing chain and/or chain tensioner

cornbb

Magnus wrote: »

The car had started to stutter when driving, particularly in 2nd gear pulling away. Engine would also sometimes die at red lights or when coasting downhill.

You've set alarm bells ringing. My Corolla has had this symptom for ages, I'm gonna try this at the weekend

Nonoperational

I could be wrong but I think one thing to be careful of if the car has an electronically controlled throttle body is to not move the flap with your hand as it can mess up the calibration.

biko

As far as I know you can push the throttle plate open and closed as you are cleaning on a ETM but don’t flood the ETM with cleaner spray, use it inside the throat only because there is a lot of electronics inside.

dnme

Magnus wrote: »

As far as I know you can push the throttle plate open and closed as you are cleaning on a ETM but don’t flood the ETM with cleaner spray, use it inside the throat only because there is a lot of electronics inside.

I fairly must have flooded mine, I sprayed it severalk times with carbourettor cleaner, toothbrush etc. It wasn't that dirty, just a little black when cleaning.

But now I'm worried after seeing the last few posts. I also wiped the end of the air hose with a cloth douse din carb cleaner. I ran the car for a good spin afterwards etc so I hope I'm ok. That carb cleaner seems to be lethal stuff.

JHMEG

franksm wrote: »

Similar jobs (someone please do an article + pics !!) would be cleaning of EGR valve

http://www.boards.ie/vbulletin/showthread.php?t=2055809200

Some should sticky these howto+pics threads

biko

There is a request for a "DIY mechanics" forum, hopefully it'll get approved and these threads can be moved in there.

nikolakaro

There is a problem with your engine (moisture probably). That yellow goo will keep coming back and for sure it’s affecting your engine’s performance.

biko

True, it's a daily runner in town so never really take it out for long runs, enough to burn the moisture out. It's a old car and I still get good mpgs so will look into it more some other time, atm I'm just keeping it "afloat"