urmajest

I have a 06 auto tC with 44000 miles.

Recently, my car is shaking after starting the engine.

It feels like driving through very smooth speed bumps put 5 feet apart.

I mean it is shaking when driving; it it not when stopped.

After a couple of minutes, the shaking slowly stops happening.

It appears to remain normal unless the engine cools down.

I have searched the forum but could not find any relevant information.

I hesitate to bring it to the dealership since they have charged me a lot for

unreasonable replacements a couple of time before.

Do you have any idea?

Thank you in advance.

Aphex13

It's hard to tell without a cel code, but mine did the exact same thing for about a month before I got an engine light. It turned out to be one of my coil packs. You could try trading them out with a friend to see if that solves the problem...

Datswhtshsed

Have you checked your engine mounts? also, try using higher octane fuel and see if that helps.

WillyB

I don't think it's anything to worry about. Especially if it's only when the car is cold. Sounds normal to me, unless it's a violent earth shattering shake. Then u have a problem

urmajest

Thank you for the information!

urmajest

What does it mean if higher octane fuel helps? Should I keep paying more on gas? Or does it help identify the problem?

Datswhtshsed

its usually the first remedy for a rough start. to be honest its kinda hard to diagnose your car right now. its hard to diagnose online. all we can do is try and check. have you check your air filter, MAF sensor, smell your exhaust, changed your oil, did you buy the car used? was it mod, is this a new problem or have you always had it and just decided o ask today?

TunerKid

Its deff not a motor mount, especially if it goes away and its deff not fuel, unless you got bad gas which i doubt is the case, because again, it wouldnt stop. I thinks its probably just the normal cold start stuff! Mine is a manual trans and idles at about 1500 until it warms up!

KyleL

What is the weather like where you are? Did you get your tc new or used?

The next cold start try letting it warm up for 5 minutes or until the rpm drops under 1K. Then drive around and if it's not shaking then I dont think it's something to worry about.

I have a manual and it handles differently in the winter on cold starts than on warm days.

urmajest

Thank you very much for the responses. I suspected it would be hard to analyze online
since it doesn't appear to be a common problem. As to some of the questions,

1) I bought this 06 auto tC NEW at 2005 summer. No options (except ipod integration), no mods applied. The only difference from the stock would be the tires; I replaced the old one with Kumho. I think the tires are not relevant since they ran fine for a year until recent.

2) I'm living in Indiana. The weather is fine. The symptom appeared very recently when the temperature became well above 50 degree. It survived the cold winter (w/o this symptom), but having this problem after the weather became warm.

3) I always used the cheapest unleaded gas at the same Speedways where three grades are available.

4) This symptom is recently appeared. I should say less than two weeks.

5) The engine oil is replaced about two months ago. It didn't have
many miles after the most recent replacement.

6) Since I rarely know the under-the-hood stuff, I'll google for them and let you know if I find more. So far, I didn't check anything under the hood.


Thank you again for great advices.

urmajest

If the problem does not rise by having 5 minute idle run, should I just ignore it? The car didn't have the problem before but developed it recently. I can live with it as a discomfort, but what I worry is what if this symptom is appealing for a greater problem or even a safety issue which will come in near future.
Thank you for your response!

KyleL

Letting the car warm up for 5 minutes on cold starts helps me. But your temperature is, as you said, well above 50. Keep searching. Good luck