knocking sound

The knock sensor only detect engine noise it does not cause it. It sounds like you have a rod knock or valve train noise can you tell if the noise is in the upper part of the engine or the lower?

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?

It sounds like you have a spun rod bearing. I would remove spark plug wires one at the time to see if you can get the noise to change.

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

Use 2CarPros anytime, we are here to help. Please tell a friend.

Cheers

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?

the 340 is a cam sensor code.
the 325 is a knock sensor code which may be set from the noise. in other words, it is doing its job but the knock is still there.

you need a shop to listen to the noise and give you an idea of what the issue is.

Roy

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?

no, the knock sensor has nothing to do with the noise but the sensor is coding because it cannot get rid of the noise.

Roy

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.

does it matter if engine is warm or cold? sound change at all?

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.

well 2 things might account for the difference. increased oil pressure above idle and a rotational balancing increase. usually it's the crankshaft that exhibits this kind of behavior.

a timing chain can also exhibit these symptoms. hard to diagnos over net.

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.

there was a TSB on 4cyl motors for cam knock. said it was not sychronous/rhythmic but erratic tap noise.

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.

do you notice it more when your braking or does it not matter....or does it just do it most while changing speeds wether it be speeding up or slowing down.... good luck :)

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?

check your knok sensor, harmonic balancer and timing chain/belt

theres rattling sound underneth the car

If this is not a constant noised, more so with body movement, have the suspension check, exhaust hangers, sway bar bushes, and engine mounts checked, start here.

I haven't had a car for five years.
My family scraped together the funds to do this for me.
I think of the car I own is really my families car.
I planned to keep the good conditions.
I did every oil change on time reasonably.
I hear a knock in the engine.
I went to the smog shop later that day to get smog.
The smog man tells me to get new spark plugs.
The man pushes the spark plug and the engine knock stops.
Is it okay to drive?
Should it stay in the driveway until I can pay for spark plug replacement?
Did I hurt my car by looking for work a whole day?
Should I use a treatment engine additive or special oil?
What do you recommend?

Did the knocking go away when the plugs were replaced? If so, everything should be fine. I do, however, recommend keeping the oil changed every 3000 miles and use a quality oil. There are many, but I'm not to push brands on this page. If you have a question about a specific brand, let me know.

engine knocks loudly when you start car and gas fumes fill the inside of car. you can also feel the knocking

does the knock go away when you drive? ever run out or low on oil?

no to both questions

when did knock start and has it always been same loudness?

i first started smelling gas mostly when idle and of course my husband couldn't smell a thing. the third day i could hear a low knocking when i started the engin but not when i drove off. day 4 loud knocking, strong gas fumes, and vibration from the knocking.

check your oil level and see if it has gas in it. your FPR may be leaking and getting into oil. this would thin the oil to where it would not lubricate/hold pressure properly resulting in engine noises.

we found the problem. when changing the spark plugs, one of them was completely unattachted. that must have been the knocking noise. the gas smell was comming from a cracked hose leading to the plugs. we changed spark plugs and their wires and engin now purrs like a kitten.