Throttle stuck this morning! Help!

**Car guy** · 01-15-2009 11:57 AM

This happened two years ago (or maybe it was last year)...driving to work today on the highway and noted that I did not touch the gas in a few miles. I got off the peddle and the car did not slow. Throttle stuck.

Hit the brakes and it slows a little but I hit a stop light and it wants to push right through the brakes!

Issues:
1. Engine sloppy to rev up...like running in sand
2. It is -1 below zero today.
3. The engine is a 98 2.8 A4
4. I cleaned the throttle body out after it happened last time, but it was warm when I did it...I do have a K&N-will that gunk up the butterfly?
5. Is it my tps sensor?

Help.....take care...."cannon ball"

**Tigu** · 01-15-2009 12:22 PM

Häähäää,
sorry, I had to,
the problem lies in the stupid system of throttle body and everything that is connected to it.
2 Years ago I almost toasted the engine on my V6 engine in winter with -25 degrees Celsius. The throttle stuck open after driving on snowy streets in finland.
Fix: dismantled the vacuum connections and breather system of the engine and cleaned the whole thing. Then I plugged the breather system from the TP side and installed 2 breathers for both sides. Never had the problem again...

**Car guy** · 01-15-2009 12:34 PM

Yeah! You should have seen my face...I wish I could...no coffee needed this morning. I was puckering up pretty good in rush hour this morning (Kansas city really has no rush hour though!).

You had me at vacumm lines...when you say breather-do you mean air intake (where it meets the throttle body) or am I way off.

If you have pics great, if not let me know do's and dont's as I try to clean this baby tonight in the cold.

Thanks!

Just drove it at lunch...worked fine...16 degrees now. WTF.

Clean I WILL!

**Car guy** · 01-15-2009 02:52 PM

Any cleaning recommendations....or should I say, what not to do?

Thanks-Bump!

**quattro16** · 01-15-2009 06:20 PM

There was a big recall on throttle bodys in A6's while back for this reason. What is happening is the air being sucked in the throttle body has condensation and starts to freeze when very very cold out and will eventually keep the throttle plate open. There is a coolant pipe that runs around the bottom half of the throttle body to prevent this, but when so cold out and cruising on the highway it dosent work so good. The recall was to replace the throttle body which had fittings on the body to run coolant through and around the throttle plate, internally. So theres your problem but i dont think the recall pertained to A4's for some reason. Maybe you can rig something to warm up the throttle plate.

**4A Play** · 01-15-2009 06:30 PM

Maybe just clutch and neutral until the TB un-sticks?

**Tigu** · 01-16-2009 12:30 AM

Open the thing up and clean it.
The condensation will happen also more if there is the hot breathing air in the intake that comes from the engine.
sorry, i'm not an english-talking person actually - kinda hard for me to explain, but the work is easy and can be done with minor (brakings) ohh,
another thing, there should be an oval rubber sealant on the back of the TP.
look really carefully, maybe it needs engine silicone to make it ok again. mine held no air going in or out, made the fuel consumption go

.
ok, hope you have a nice

**ghost6303** · 01-16-2009 10:12 AM

when i had my 2.8 there was a similar situation once in it, although the cause was different. it was a nice sunny 60F degree day out and me and a friend were taking a 100 mile road trip. i let him drive, which i almost never do. so we were cruising and he says to me, 'i cant slow down'. he had to ride the brakes in order to not smash into the car infront of us. this was going like 75mph on the highway. i told him to get over to the shoulder which he did, but then, being a little freaked out, he pulled the trans out of gear and the engine bounced off the rev limiter a few times before i freaked out and grabbed the keys. we let it sit there for a few minuits before trying to start it. started up fine, continued with the drive, never had the problem again.

i say different cause because it was a nice warm day out and it wasnt the TB freezing shut. i never found out what happened actualy. we looked at the gas pedal to see if it had stuck on anything and it hadnt. throttle cable was nice and smooth. so i dunno but thats my story.