Motor shakes when it first starts up or takes off

Suppose the motor mounts harden in the cold and transmit more vibration thru to the cabin. Could this be a theory that explains it. Might have to wait till spring to see if that cold is causing it.

 

This happened to me with my Prius V the other morning. I hadn't run the car since just after the hurricane hit. I recognized the symptom because it's happened to other cars I've owned over the years. Basically, not all cylinders are firing and it's always been attributable to damp spark plugs. This was understandable because my car had been in a very damp area right after Sandy and didn't run for several days while in that high humidity. I turned off the engine, waited a moment and restarted and all was fine.

I also own a Prius C and that has run smooth in the same environment but I was driving that car immediately after the hurricane. It never sat for the length of time the V did.

 

I've noticed this happening as well, but only since the weather started getting really cold. I use the same gasoline as the OP. I think it's just the car shivering from the cold ;-)

 

Please describe the problem. Is the engine running rough? For how long? Does the engine smooth out after "XX" seconds?. How long was the engine running before it was shut off prior to the rough engine idle?

 

For me, the engine, in the *cold*, runs "rough" for only a very short while (less than a minute), but I have experienced the shuddering at first start up. As if the engine, like me, is uncomfortable with the coldness.

 

I owned a 2010 Prius Gen III which had an engine vibration problem at start up. This was (is) is a widely known problem. It occurs when the Prius engine is cold (soaked at ambient temperatures below 50 degrees F) and it is started for only a few seconds in order to move the car from one location in the drive way to the garage (or something similar). The car is then left to sit for several hours (typically overnight). When the vehicle is then later "started", the engine shakes, sometimes violently, for up to 15 seconds before it smooths out. Toyota has a TSB for this problem. Toyota attributes the Gen III engine shake to water condensation on the inside walls of the intake manifold -- water that gets into the cylinders and obviously does not burn like gasoline. Personally, I have owned my C4 for only a week, so I have had not experienced a problem with engine shake at start up. However, having owned a Gen III, I know exactly how to test the C4 to see if it does the same thing. As a side note, I owned a 2002 Gen I Prius and it never, ever, had this problem.

 

I had this happen about 2 months ago so it did not coinside with cold weather so I am not sure why it happened. It seemed as if it was possibly flooded a little and was stumbling until it burned off the excess gas or maybe even not getting enough.Hasn't done it since so I think whatever the condition was that caused the problem is fairly rare; having said this it was a little alarming notheless for the 30 sec or so that it ran rough. Also get the traction light flashing on occassion while waiting at the drive thru but goes out as soon as foot is taken off the accelerator and a little gas applied.Anyone else experience this strange condition?

 

The infamous Prius coldstart issue sounds like this:

and is quite unnerving when it happens especially if you are unaware of the issue.

 

I've never heard that knocking noise from either of my Prii.

 

But now that I think about it, my Gen2 does at times idle rough for a few minutes after start up.

 

I had that issue also and I did get a POP sound. I upgraded to a 89 or 91 octane gas every other fill up and the problem resolved. It may have had alittle water in the gas tank. I'm back to 87 Octane but use a Big company for example Shell or Chevron and all is well.

 

I'm using 91 from the first tank (two bars when I bought my C4 at the dealer and got a voucher to fill up with 91) and just got that sound the first time last Sunday at about 8:00 PM when the temp here in SoCal was about 60+. My C4 is in the garage so it's not very cold and that was the first time in cold (?) weather start outside.

 

I would monitor it. 60 degrees F is not cold and not freezing which is 35. You have perhaps the best manufacturer warranty in the business so you have peace of mind. The car has a long history of trouble free use. The Prius makes strange sounds and plenty when it is new and it may be part of the break in process. My car has only has 2,200 miles and is 2 months old. I still get a few noises, but with time they either deminish or I just don't notice it. The cold weather start may have plenty to do with it. Can't fathom the guys in Minnesota who use block heaters. If you get a error code bring it back to the dealer without hesitation. I'm not a mechanic so if one chimes in add value to that opinion more than mine.

 

That is exactly what my car does. Do you know what the fix is? I am leaning toward a lemon