Is your car jerky when cold?

[JakePSD]

I've been noticing that when I first start driving my car, if I don't let it warm up much before driving (gently of course) it is kinda jerky when accelerating. It's not my right foot doing it, I know that, it is definitely that car. It runs great once it starts warming up, its just when the engine is cold. Has anyone else noticed this with theirs? I'm not really worried about it, I figure it probably just has to do with the VCT system and cold oil. No CEL or anything, and like I said, runs perfect once it starts getting even just a little bit of heat in her. Just curious if this is normal or maybe I really do have an issue.

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[vernonator]

Yes....asked the same question when I got mine. I called it "lumpy" just give it a few minutes to warm up and you are golden (either driving or sitting idle).

 

[Evil Minion]

Yes....asked the same question when I got mine. I called it "lumpy" just give it a few minutes to warm up and you are golden (either driving or sitting idle).

Ditto. Done it since day 1. 25,000 miles later and no issues.

 

[15wile]

Yes, mine does this. First few shifts in the morning are kind of clunky no matter how gently I ease the clutch. Not sure if motor or tranny or both. Either way, it goes away after a minute or two of driving. 26k miles and no issues.

 

[JakePSD]

Good to know. Thanks for the replies. Like I said, I really wasn't worried about it, I know things run different before the computer goes in to closed loop (or is it open?) mode. Just wanted to see if mine was different or if its normal.

Wanna talk about things running strange when cold, my 2000 F-250 with a 7.3L diesel... Sounds like a pulling truck when started around 20 degrees F. That is until it stalls and has to be cranked again. 5-40 synthetic oil helped that a lot, but with 15-40 dino oil, holy crap...

 

[Agent_S550]

Its misfire protection kicking in. The actuators are retarding the timing, the cylinders are fattening up, and it's trying to regulate cold fluids and prevent detonation. I believe it's mostly a function derived from the fact it can run non 91-93 fuel. Most tuned cars report back that theirs no longer does it after going to 93.

 

[timd38]

Same here!

 

[JakePSD]

Its misfire protection kicking in. The actuators are retarding the timing, the cylinders are fattening up, and it's trying to regulate cold fluids and prevent detonation. I believe it's mostly a function derived from the fact it can run non 91-93 fuel. Most tuned cars report back that theirs no longer does it after going to 93.

That actually makes quite a lot of sense.

Makes one wonder though, if tuned cars no longer exhibit this, are they actually doing slight harm to their engine? If the detonation protection isn't as effective, it could be causing damage. That or the tuners just did a better job at it than Ford did...

 

[Jay-rod427]

My PP car did that, this auto not so much or maybe just not as noticable. Stuttered and stumbled a bit until warm.

 

[JakePSD]

My PP car did that, this auto not so much or maybe just not as noticable. Stuttered and stumbled a bit until warm.

I'm sure an auto would be harder to notice. As long as the torque converter is unlocked, you won't feel nearly as much engine fluctuations as you would with a manual that has a direct lock from the engine to the wheels. By the time everything is warmed up enough to allow TC lock, the jerkiness I'm sure is all gone.

It never hit me til now, but maybe that is part of the reason almost every automatic transmission in recent years will not lock the TC until things have warmed up. Obviously being unlocked helps with warming the fluid, but now I wonder if part of the TC lock strategy isn't to mask rough running cold engines...

 

[Agent_S550]

Well engine load and detonation are two very related variables. The motor is not doing any harm to itself by being tuned. Most motors have a minor amount of detonation when cold. If you run 93, have a 93 tune in, drive the car when cold and no longer have a overly sensitive cold start mode, nothing will change. The car will run off of base map tunes and adjust accordingly regardless. I wouldn't worry about it.

 

[QRK]

Yes, mine does this. First few shifts in the morning are kind of clunky no matter how gently I ease the clutch. Not sure if motor or tranny or both. Either way, it goes away after a minute or two of driving. 26k miles and no issues.

I see the same thing especially while shifting into 3rd when I'm accelerating out of my complex and the car is cold. I would say I've never been able to make that first shift into 3rd smooth no matter how hard I try haha.

I'm thinking it has to do with the trans being cold because my engine has plenty of time to warm up before I exit my complex since I live all the way in the back.

 

[Hack]

Yes.

 

[jasonstang]

I don't think it's denotation because of cold engine. It mostly runs rich when cold and I think it's just how the engine runs when cold. The variation in the parts is causing un-even burn.
There might be some moisture in the cylinders not helping the burn too.

 

[JakePSD]

I don't think it's denotation because of cold engine. It mostly runs rich when cold and I think it's just how the engine runs when cold. The variation in the parts is causing un-even burn.
There might be some moisture in the cylinders not helping the burn too.

Solid point as well.

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