[ElisiansBane]

I have a 2007 Kia Spectra Ex with 86k miles on it. I just had the brakes, full throttle body, spark plugs, transmission fluid and filter, and oil changed/cleaned/replaced. The radiator was recently replaced after a minor accident.

I noticed that when I accelerate from a stopped position the tachometer will slip very slightly and then speed up just fine. The car holds speeds fine and I did not have any problems with a month ago. I took it to two different mechanics who test drove it and read the codes and they said that everything was fine, but it still bugs me.

So I wanted to know, is this a common thing with the 2007 spectra? Or should It take it back and have them check again? Could a dirty idle air valve be the culprit?

 

[DavesSpectra]

The engine and transmission are controlled by microprocessors and they "talk" to each other and when there are "problems" in eiither unit they can effect each other...Minor problems may not "set" a trouble code but sometimes can be felt by the driver.

I have been told that KIAs do not like transmission fluid made by other manufactors.
The fluid is a "type3" fluid and other manufactors "should" work but I have read about problems going with different brands than the Hyundai/KIA spec'd type.

You might want to ask what "brand" fluid was put into your car and if it was not Hyundai/KIA brand ask to have the fluid replaced again.

The transmission in your car is a modified Mazda/Ford design (F4EAT) and is known also to have problems "if" the transmission fluid is not changed every 30k miles.
The fluid can become thick and clog up passage ways...Changing old fluid can break loose some of this gunk and cause problems (usually not major) if it clogs the torque converter or valve body in a tranny that has not been maintained (every 30k).
A regular poster (Loyale 2.7 T) has a 2001 Spectra and had problems with his tranny. His posts offer insite into how to "cure" a misbehaving transmission...

Some of it is covered in ...
http://www.kia-forums.com/kia-cerato-shuma-spectra-forum/77522-kia-spectra-shifting-problems.html
Also do a search on Loyale 2.7T for his posts..

As for a dirty IAC (idle air control) valve ...it's "possible"....also a BIG problem you have not mentioned in your post is the timing/cam belt. If you haven't replaced it at 60k it is ready to break at ANY time and at 86k miles most have either slipped teeth or broke causing MAJOR engine damage... There are many posts about Spec owners "crying" about how their KIA failed them when it broke..
Dave