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Need help, I'm on a road trip, temps are really cold -25C (-13F)
Car has been hesitating at cruising speed just when very little light ad on motor.
Twice it's gone into limp mode, first time left it overnight, cleared the codes and it started and ran fine.
Is my throttle body freezing up perchance? I'm stopped right now, after second limp mode, same 3 codes.
Btw when the hesitation happens no codes are being triggered.
Hope to get moving to a larger town at least.
Input needed!
Lucked out to get to a dealership, who says they can look at it this afternoon. Still interested in anyone's opinion, my initial research on the forum and some young mechanics was clean throttle body, possible pcv valve, possible upstream o2 sensor. Leaning towards PCV valve getting stuck open.
Those codes can be caused be extremely low ambient temps. If the vehicle doesn't show any symptoms once inside the warm shop, it's likely the low temps are driving the problem. Have them clean the throttle body, butterfly area, and sensor (or do it yourself if that's possible). Or, if the forecast is for warmer temps where you're traveling, then you could also consider doing nothing at all right now.
That's crazy low. At those low temps is the gas freazing once it leaves the injector?Quote:
Originally Posted by avguy
Dealership not much help.. (EDIT: correction- yes they were see below) said it's probably the CAI plugging up, but I disagree, I've been monitoring the MAP to see if it spikes to 14 when the hesitation happens and it doesn't. Still, I realize I shouldn't be using the CAI.. totally overlooked that as this is the first time in since it's install in 2011 that really cold conditions are encountered. IAT was down to -25C at one point (-13F).. hmm perhaps the fuel mapping hits a boundary there lol.
My first reaction was bad gas.. as this happened after a fillip at a small station in a small town. Do you think some bad gas with too much water or diesel mixed in could have started this off?
Lets say it's a coincidence and it's not bad gas.. even good gas with that much cold air might have issues at the injectors. Maybe bad gas and a it fouled a plug?
Dealership did 'defrost' the car in the heated shop for a few hours. Its still happening but not really bad that only happened the two times. Now it's not bothering super much as I don't think I'm damaging the motor, but still what are your opinions about perhaps a sticking throttle body and maybe a fouled plug(s)?
Thanks the input guys. Last night in temperatures close to freezing car ran like it normally does.. engine very smooth and much more power... once the temps drop to -10C (14F) or lower this issue seems to creep up.
What about that the 87octane gas is cut with 10% ethanol?
Also bought Lucas juice which I always use but stopped about 4 weeks ago when I ran out.
On the road for another two days I'll keep posting updates..
Well, after studying the behaviour for a day and causing two more limp situations, the tech at the dealership was correct- I'm now convinced the CAI air filter is plugging up with what is likely a combination of ice and re-crystallized road salt. Once you get into Northern Ontario they stop using salt and that in combination with colder temperatures and dew point conditions is likely the issue.
I essentially proved this by putting the scan gauge on IAT, WT, MAP, and TPS and studying the variables. I drove too fast on purpose to cause the 'limp mode' situation and sure enough at idle the motor was starving for air- normally revving the motor in neutral will see MAP around 3-4psi but this time it was at 12-13psi! Pulling a large vacuum just to idle, no wonder it would rev all chaotically.
So I hypothesize that if I pull over and wait ten minutes the heat from the motor will melt the ice crystals on the filter, and sure enough the car runs properly! I even figured out how fast I can go without plugging up the filter- above -12C (10F) the issue barely happens but as soon as temps get colder I have to slow down.. to 50mph if it's colder than -18C (0F).
So suspicions aside this issue appears solved- it's my fault for not switching to SRI before the road trip. SRI puts the air filter back in the engine bay to keep it warmer and dry.
Btw filter is K&N synthetic water resistant style so I can wash it when I get to my destination. I will follow up with pics of the filter and intake interior and throttle body.