cold weather = extra clutch pedal pressure needed to start

[kingwilliam]

Hi... to start my 1999 4Runner in cold weather, it requires extra pressure on the clutch pedal. The colder it is, the worse the problem.

Today was the worst. After sitting outside all day up here in Ottawa, Canada, at -20C (which is about -4 F), I had to step on the clutch with all my strength.

Moderately cold days require moderate pressure on the clutch. During mild/warm weather, it feels normal (to me, at least).

So my questions are...
-- anyone else have this problem?
-- could the problem get even worse?
-- any fixes? I know I could use the clutch cancel button, but I don't want to resort to that unless I have to.

The floor mats aren't interfering with anything. The carpet seems OK.

Cold weather sure can expose any car's weakness... crazy that they work as well as they do at this time of year.

thanks!

 

[02SE]

I'd check the clutch pedal switch. Not the "clutch start cancel" button, the switch that the clutch pedal arm itself depresses.

 

[bike]

Brake fluid is hygroscopic (absorbs water). If you haven't done a flush recently, I would start there.

 

[TheDurk]

You mean the pedal is hard to depress, so you have to push hard, or the key won't crank the starter unless you push extra hard to the floor? If the former, start with flushing the clutch fluid (which is brake fluid). If the latter, you can stick a furniture bumper on the tab that engages the clutch pedal switch to raise the contact point.

 

[02SE]

Brake fluid is hygroscopic (absorbs water). If you haven't done a flush recently, I would start there.

That's a good point, the brake fluid in the clutch system should be flushed periodically, as well as the brake fluid in the brake system. I do both every couple of years.

I assumed from him talking about the fact that the floor mats and carpet didn't seem to be holding the clutch pedal up at a higher than normal height from the floor, that he was having to push the clutch pedal down more firmly in cold temps, before the clutch pedal switch would close, and the starter circuit would be complete. Thus allowing the engine to crank.

Not that the clutch pedal was harder to push down in cold temps.

We'll have to wait for him to confirm the circumstances under which he has the problem.

If my understanding of his issue is correct, that would indicate worn clutch pedal switch contacts. When temperatures are cold, metals contract, so it takes that much more travel of the switch to close the starting circuit.

If that's the case the little adhesive bumper pad which Durk suggested, would close the switch sooner in the pedal travel, allowing the engine to crank without having to mash the pedal to get the switch to close.

Or just replace the switch.

 

[1blink]

I'd check the clutch pedal switch. Not the "clutch start cancel" button, the switch that the clutch pedal arm itself depresses.

I vote this way as well. Replace the clutch pedal switch.

 

[jasonoflivingston]

If you are talking about starting the vehicle, there may be more to this, but if you are just talking about when you are starting to drive your vehicle, my 2003 corolla had a clutch pedal that would harden up like a rock in cold weather which made driving a huge pain. My 2011 corolla does the same.

On a very cold day here in Ottawa, it can take the first 15 minutes of my drive before things warm up enough to bring pedal feel back to normal. I have talked to a lot of guys about it and most say they have some level of this issue with driving manual cars in this kind of cold weather. The more moisture in the fluid, the more effect, but part of it is just the viscosity of the fluid at cold temps. Changing the fluid would help to some degree, but I doubt it will ever eliminate the problem.

 

[TheDurk]

A couple of people have suggested replacing the switch as a better fix. This might not work if the root problem is wear in the pedal bushings or flex in the mounting. A new switch might do the same thing. So consider my 29¢ solution. Worked great for me.