Third Gen Prius Surging on Highway in Cold Weather

Update: This seems to be related to cold temps. It happened last two days on way into work, with the outside temp being in the single digits farenheit. But, did not happen on the way home, temp in the 15-17 degree F range. Will keep you posted as I learn more...

Monday Update: Still seems to be temperature related. It was warmer this morning, and no sign of surging. Fingers crossed...

 

I got my in to garage Monday. dealer said nothing wrong. its still doing it. call Toyota today to file complaint. like I told fellow on phone today at Toyota ,how does this car get 50 mpg when the motor is running the whole time from start up till I shut it off. I just don't understand the prius at all, as far as running wise. I would think going down road at steady speed 50 the electric motor should be powering you and not the gas motor the whole time. electric motor keeps shouting on and off going by the screen and that is went I feel the surge and the mpg gauge drop from 50 to 35 and then back up to 50mpg and 30 seconds later repeat the same thing.
we will see when dealer calls Friday.

 

I just had an experience like this with my Gen II 2006 Prius with 168K miles. It was indeed a cold day, morning temps in the single digits F, and the car was parked outdoors overnight. I got on the interstate and put cruise on, and after a couple miles started noticing a very pronounced surging - the gas engine would rev way up, then drop off, then way up, repeating every 2-3 seconds. Then it would go back to normal for a while. It happened on cruise control and off. I switched the display to Energy mode with the arrows, and noticed that the hybrid battery charge was low and getting lower. It went all the way down to 1 bar and stayed there. After 10 miles I was off the interstate and in city traffic for 5 min. The battery stayed low.

45 minutes later I was returning home. The hybrid battery started charging, and it got to full charge and stayed there all the way home, again not normal. I was worried at the time that the battery was going, but reading some of these other posts makes me think it could be just an effect of the cold weather. This is the first winter the car has spent outdoors - before this it's been garaged every night. I looked at the referenced threads on the Gen II Prius and the surging they describe is much more subtle - this was really noticeable. I guess I'll drive it some more and see what happens, but I'll be very interested to hear others' experiences on this.

 

well got to dealer . they said there's nothing wrong with it. All I told them is every week I will have it in shop till it's fix. I can't believe its my first (and last Toyota) if this problem is normal. We took car out on road at dealer and of course the car only acted up a couple of times. Tech said it was fine. I drove today well over 100 miles each way and it did it the whole time. We are planning trip to SC in two weeks and told wife by the time I get there I will be jerk off so many times the way this thing drives. I'm going to try another Toyota dealer close by.
Another thing I brough to tech was that my (big battery I call it) as never moved from full since I brought car and drove about 1500 miles now. He told me it should drop down and then charge back up. I don't know.
When car acts up it feels just like your running out of fuel for 1-2 seconds and picks up fuel again. But I don't know if its coming from gas or electric motor that the little surge comes from. Don't get me wrong I love the car and I getting from 41 to 49 mpg. I evn when out today and installed 4 new pure contact tires on it today and the ride is a lot better then the tire that came off it. But I only got about 45 miles on new tires.

 

I'd be curious to know what the mileage was.

I had similar experiences and it turned out my EGR valve was all blocked up - at just shy of 80k miles!?!

New EGV and car is running much smoother and the transition between engine and electric is smooth again too. Apparently there was also a fault code stored that it was the EGR.

 

mileage is 47k miles.
they told me no codes showed.
but then again I don't believe any of the computer code shit. because wifes car (Hyundai) as been in shop 5 times for stalling out of the blue sky and she was told no codes we cann't do anything. Now there is a reason car stalls out when it feels like it. I'm sorry but mechanic's are not mechanic now days, they are computer robot. do only what computer tells them. That's one thing wrong in this world.

 

Hmmm sounds like dodgy petrol then. Your car is surging and your wifes is stalling and mechanics can't solve either.

 

Prius has been doing it since I brought the pile of junk.
I think its the egr valve on each one of them.

 

What miles?

 

47k miles

 

Mine did this today. Temperature out side was 60°F. I had started the ICE to see if I still had the cold knock (still there) and stayed in HV for the trip shopping. On the highway at 55mph, the engine did exactly as you described in post #1. The glaring difference was the outside temperature and my EV range was still above 10 miles, though I wasn't using EV at the point of surging. I have a SG but didn't have HP or Batt Amps showing, and quite frankly was so taken back by the incident, I didn't even think to check it.

I had no codes showing in the SG and still got 67MPG on the way to the store and 71MPG on the way home I haven't bought any gas since November and what's in there is E0.

6 month/5K service id due next month. Like you, I'll keep a close eye on it and report it when I get to the dealer.

 

I when to dealer today for recall and told dealer about problem having and was told everything is ok and engine lite and no codes. this was another Toyota dealer in area,not were I brought it. so today called Toyota for another complain filed along with giving them attorney name.
I can't believe over 25 vehicles I have owe and this TOYOTA has taken the cake. Its the first and last Toyota.
post #29 wife wifes car was a spark plug not firing all the time.. I asked service adviser NO ENGINE LITE OR CODES NOW WHAT. They didn't know what to say.

 

Fascinating thread, but like a movie that ends when the power goes off, no conclusion...

Does anyone know what this problem was?

OP's - any updates?

 

Gumming up EGR valve?

 

Mind reader!

Just wanted to know if my own psychic powers are working or not!

How's the weather in the UK at present? Winter coming for you...