Knocking sound

Knocking sound.. When I speed up it stops completely.. When I brake or start out slow it knocks.I believe the noise is coming from the lower part of the engine engine. Does that help?

Ok, I used to have a very quite running engine. The engine light came on so I took it in. Computer test found fault code p0340 and p0325. They replaced the p0340 but did not replace p0325. By the time I got home the engine was so loud I thought a helicopter was following me. Of course I called a shop and they said what you did, a rod knock going to cost $1800.00 to fix! Boo. Thanks for your help though I love this site

Ok, I used to have a very quite running engine. The engine light came on so I took it in. Computer test found fault code p0340 and p0325. They replaced the p0340 but did not replace p0325. By the time I got home the engine was so loud I thought a helicopter was following me. Of course I called. But I was told to bring it in if the light came back on. No light just louder and louder engine noise and now the knocks?

When I took it in and the 340 cam sensor code and
the 325 knock sensor code came up the car was not knocking at the time. The noise started after they repaced the 340. Should they have replaced the 325 since it came up also?

My 2002 Pt cruiser has a knocking coming from the engine, but it only seems to knock when idling, seems to run fine other wise. It only seems to knock when idling, seems to be fine other wise, it seems to go away when you rev it up, just knocks when idling.

Well it seems to get louder when the car warms up, it may be there when you first start it but it is hard to hear it over the fuel injection, but once it warms up it it very noticeable. And aain only seems to happen when it is idleing.

Hard to say, but the timing belt, and water pump were just changed about a month ago, and I just replaced the PCM about a week ago, and I just changed the sparkplugs 2 days ago, runs a heck of alot better but the knock is stil present.

I have an 01 PT Cruiser, chrysler, 58,000 miles. That has recently starting making an irregular knocking sound. For days I will hear nothing and then at times when I am stuck in traffic for a while I will start hearing and feeling a knocking sounds. I can feel it right under my feet and it does not knock faster or slower with excelleration. It seems to be without pattern. It does not knock when I am turning the wheel or anything - just in a straight line after being in slow or stop-and-go traffice for a while.

When I speed up it slows down or stops completely. But then I may not hear it again for days.
AT first it was so irregular that I thought I was dragging something - also because I can feel it under my feet when it knocks. But I am not dragging anything.

Chadd.

Well to answer your questions it usually begins on slow acceleration. After I have already been driving a while. I have gone weeks without hearing it at all - until yesturday when I heard it again - but not as bad as the last 2-3 times.
I have noticed something else that may be important. I have realized that the knocking is only an issue when I am or have just used the Air Conditioner. I know nothing about cars - so I don't know if this is connected or a coincidence. But maybe that is why I only get it once in a while.

What do you think?