frozen throttle or fast idle?

[bryanthompson]

It's about 5 below zero right now with 6 inches of snow on the ground. I was on my way to work about an hour ago, when my throttle appeared to freeze open. At first i didn't notice, but when I started slowing down for my turn, my rpms stayed at 2200ish rpms. A lady I work with lives right where it happened, so I coast into their driveway and check for snow in the engine area. I found just a little... up by the windshield and battery area, and I know there was some underneath I couldn't get to. Anyway, after 10 minutes, i start it back up and make my way back home... the problem's gone for now.

Now... did it freeze, or is there a fast-idle for when it's this cold? Strangely, I could give it more throttle when this was going on, but when I let off it backed down to the 2200 rpms.

[Zero10]

Lol I had the same thing happen, 4 times.
Every time mine went somewhere between 3500 and 5000, which is more than a little quick.
The throttle wheel is frozen, I popped the hood, and gave it a turn back to the proper position, and it was fixed, but it will keep coming back.
Hopefully somebody can suggest something, it actually looks like frost is accumulating on the inside of the throttle body, causing it to stick open.

[fast924S]

check the coolant passage in the throttle body. It sounds like its clogged. they run coolant threw the throttle body to try to keep throttle body "frosting" from happening.

[Zero10]

Really, I had no idea.
Could you explain that a little more?
Do they just run a coolant line up and into it?
As far as I know, my entire cooling system is clean as a whistle, but I suppose that passage could be plugged.
Wouldn't that lead to heating the intake air when the engine gets warm?

[fast924S]

I am almost sure that Porsche does it, I know toyota does it. I will check my throttle body agian and see if there is any coolant lines to it. BUt there will be 2 lines a supply line and a return line and a little passage machined threw the throttle body. This keeps the throttle body warm so it wont freeze. And yes it does heat the incomming air a little but without this u could have a throttle body freeze wide open.

[TCMdocs944]

Nope on the coolant thing for the N/A....Maybe the turbo has it.

This idle thing can also happen from a bad vacuum leak..my guess under the intake manifold or the large one from the manifold area to the brake booster.
Cold and old hoses don't mix too well.

If it is your throttle actually sticking you may want to spray a little PBblast on the mechanism....coats, sooths, releives..

Good luck.

[bryanthompson]

It's definitely a freezing issue of some kind. I bought a spray can of Silicon, and i'm going to spray some of that in the cable and see if that helps. This does seem like a really odd problem... but i guess 20 below temps will do strange things.

[ronin]

yep, it's just like carburetor icing on a piston engined planes. you need a carb heat hose

[TCMdocs944]

Careful with the silicone......Isn't it a No No with O2 sensor cars?

[bryanthompson]

I can put it there without causing any chaos, can't I? I haven't done it yet, so let me know if i can or not. If not, what can I do?

[TCMdocs944]

I might pick a different lubricant. One hotrodder I know said that you just have to make sure that it dries completely...

but you know the hotrodder type....I am not sure he has ever even seen an o2 sensor.

If your car is chipped I understand that the sensor is "turned off" anyway so it wouldn't be a factor.