Hi folks. So we got you looking up chutter in the thesaurus, eh? I've often used chutter to describe cold induced shudders. ch for chilly I guess...

I now use the lower weight oil in the winter. My dealer never got it in until 3/4 of the way through last winter. I wasn't impressed with them. My car still has the ocassional shudder immediately when starting up, but I believe less often and less shaking. I'm not sure if this improvement is since I'm using the 0w20 oil in the winter though. I wasn't impressed with the dealer. They're asking me why I want that oil when it's clearly recommended for the car in my climate. (Ottawa, Canada where we can hit -30 C for short spells.) I'm not convinced what exactly causes these start up shudders. I'm almost thinking it's not sluggish, viscous oil due to the inconsistency of it occuring. ie. It doesn't happen all the time and I've had stronger shudders on relatively warmer mornings. I've mentioned all of this to my dealer. - no response.

I was going to post about this very problem last month.

I've had this "shudder" happen at least 8 times, and only in cold weather after leaving the car parked over night. The shudders occured while the engine was trying to turn over about 10 seconds after I hit the ON switch. Here's a significant observation I made... Every time I got the "shudder" effect, it was during the following situation:

1) Hit on switch.
2) Shift into reverse and lightly press gas (4 sec. after on switch).
3) As I'm backing out of my spot in reverse, I lightly hit the brakes to slow my speed. (10 sec. after on switch)
4) The ICE attempts to start up at this point. I'm still moving backwards, but with the brakes lightly pushed. This is when I always got the shudder.

To me, it feels like the engine RPM isn't high enough when the fuel starts to flow and the engine is struggling to start (while under load).

Did anyone else notice this with their car?

Yes I have noticed this. Not quite the same but very similar. This is why I now give it a second before backing up.

I have had one very violent shudder but I hadn't put it in gear yet. I felt like the entire engine rattled.

This what happened to me the only time it has happened.

The violent shudder was the ICE starting before the car had been put in gear and it lasted no more than a second.

I think I have only had the violent shudder you described 1 or 2 times. I think this is just a ECU programming anomaly and doesn't indicate that something is failing (I hope)

Yes, while the ICE was starting the first time. I did not notice any odd smells or discolored exhaust either.

Someone else posted they thought it might be ice build up on the breaks or something. Could be since it was cold and moist. But I haven't had a car do something like that before.

I had this happen to me yesterday (it's the second time it's happened, each time it's been 30 +/- 5°F, at work, after being parked around 8 hours) It shuddered so bad that I thought I'd dropped the transmission, never mind that it was still in park!!!

The first time it happened, it felt and sounded like a chunk of ice sliding off the hood of the car, but this time I thought something was seriously wrong with the car... The whole thing shook. I was freaked out, to say the least.

I'll be incredibly disappointed if the engine goes in my car... although this one has lasted 2000 miles longer than the engine in my Envoy so I guess I don't have too much to complain about

So how many miles did you have on the Envoy before the engine failed?

I read that when the ECU tries to start the engine, it cranks the engine for a second without injecting fuel to get the RPMs up high enough to prevent a rough start. It almost seems like the RPM cannot get high enough in cold weather before that 1 second passes, causing the engine to aggressively shake for a second. When the RPM is too low, you will get major engine misfire which causes the engine to violently shake. When my Camry did this, I could tell with some confidence that the RPM was momentarily much too low to correctly start.

I am 95% sure that this does not represent a mechanical failure (or pending failure) in the engine.

I had this shake happen to me in my 1984 Corolla when the choke was stuck off in the cold. The engine would start to stall, I'd hit the gas to recover, and the engine would shake violently for a second as it recovered.

6000 give or take 30 miles