High RPM Engine knocks

[nojoke1981]

I really am hoping someone can tell me what my problem is. I have a 2005 Kia Sedon with the 3.5L V6. It has around 90,000 miles on it. This has been a great vehicle. Anyways just recently it has been very sluggish when accelerating which I was not too concerned with, but now when the RPM goes above 4000 I can hear these knocks and pings coming from under the hood and there is extreme loss of power beyond the 4000 RPM mark (almost non-existent). It only knocks and makes noises above that mark. The knocks and pings were my main concern. Has anyone else had a similar issue and could give me some insight. I plan on looking at it today with a mechanic I know, but would like to have an idea of what I am up against.

[PLP]

remove spark plugs and check them for wear.
the same with cables.
other than than - check all sensors (but if it was knock sensor engine would knock all the time)

In my opinion we are talking about spark plugs.
Also, check air filter.

And one more thing. Does your car take oil? It may increase the knocking.
When hot oil gets into the chamber and is being compressed it may ignite before itself before the spark would do it.

[nojoke1981]

I did look at it with a buddy of mine, but he was not familiar with Kia's. He told me it may be the timing belt, or a rev limitor issue or rev limitor sensor issue, but does not think it is a rebuild. Does this sound possible. If so any idea how much it would cost to have the timing belt changed? The noises it makes at high rpm is loud. The pinging/knocking does not sound good. Any ideas would be appreciated. It is a little odd to me that it only does it at high rpm and not at idle or in between.

[Bombardier]

Originally Posted by nojoke1981

I did look at it with a buddy of mine, but he was not familiar with Kia's. He told me it may be the timing belt, or a rev limitor issue or rev limitor sensor issue, but does not think it is a rebuild. Does this sound possible. If so any idea how much it would cost to have the timing belt changed? The noises it makes at high rpm is loud. The pinging/knocking does not sound good. Any ideas would be appreciated. It is a little odd to me that it only does it at high rpm and not at idle or in between.

Sounds like it is starving for fuel or the oxygen sensor/s have failed.

Replacing the fuel filter would be a good start.

Not sure on the O/S models but it is under the floor just in front of the second row of seats in the Australian model.

It is accessed through the floor by pulling back the flap of carpet there

The filter is contained inside the fuel tank in a plastic housing that needs to be gently unclipped to get at the fuel filter.