How to get rid of knocking in engine 98 caddilac

Could be injector timing issues. Too far retarded will give poor response and a knocking sound, a bit like the old Commer Knocker engines.

Could it be an engine mount

Code 325 is for a knock sensor failure.
The sensor looks for spark knock and if that happens the engine computer slows down spark timing.
The problem could be the sensor, the wiring, or something other than spark knock the sensor is finding. A bad valve or rod knock can mirror the spark knock traits.

http://engine-codes.com/p0325_nissan.html
The P0325 code means that the Knock Sensor is not working properly. Problems with the knock sensor will not cause an engine performance problems. Replacing the knock sensor usually takes care of the problem. The link above will help you track down what you need to do to fix the issue

It is on the lower left side of the engine (side towards firewall - see picture).
Knock sensor failures are pretty rare, why are you looking for it?

The water pump is in the back of the motor on this one, it requires a special socket to remove and replace. If you have been scratching your head on this one, Cadillac had head gasket bolt issues, the bolts stretch and the gasket leaks internally.

Well, for starters, your problem got posted under 1985 Oldsmobile 98 - then you said it was a 95 Oldsmobile 98 Regency Elite (HUGE difference between 85 and 95)...then it would be REALLY nice to know which engine we are talking about.

I'll just go with what you said last: 1995 Oldsmobile Regency Elite (Two engine possibilities)

If you have the 3.8L Supercharged engine (VIN CODE "1") it is on the left side of the engine near the oil filter.

If you have the non-supercharged 3.8L (VIN CODE "K") there are TWO of them. One is near the oil filter and the other one is in about the same location on the other side of the engine block.

Please also note that MOST fault codes for knock sensors are not caused by the knock sensors themselves. (they do fail, but it is very rare.) Usually there is either a wiring problem to the knock sensor, or the engine has internal problems causing a "knocking" or "ticking" noise which causes the engine computer to "think" that there is a problem with pre-detonation causing an "ignition ping". The code sets when the computer has retarded the ignition timing as far as it can and the "knock" or "ping" does not go away....usually it doesn't go away because it is not caused by ignition timing. The knock sensor is just doing its job and reporting the knock. It does not know the difference between a knock caused by ignition and a knock caused by internal engine problems.

You have carbon build up on the valves and pistons to get rid of this you will have to buy some Top engine cleaner and hook a vacuum hose to the can where it pulls the fluid into the cylinders say a brake vacuum boost . or a line in from the throttle body. After you get it to **** it all the way in shut the engine off for 30 minutes and let it soak. then fire up the engine and run it till it quits smoking, this should get rid of the engine knock. Since the carbon builds up inside the compression chamber it raises the compression ratio to a point that the knock sensor can adjust the timing to keep it from knocking, this is a problem for GM cars but also for all cars that have to burn Alcohol or ethanol and it's the only way to get it out without tearing the engine down. also once you are done you will need to change the motor oil and filter cause the carbon will plug up the filter.

have truck scanned for trouble code most auto stores such as auto zone/ advanced auto do it for free code gives u start point as to knock which is where code is coming from most knock noise is lower engine problems rod knock-wrist pin -main bearing going

the knock sensor tells the car's on board computer/PCM that the engine is pinging/knocking from poor fuel or the wrong octane or other engine related faults, they seldom fail, most likely the connector to the sensor is making a poor connection, the knock sensor is located on the engine block, it screws into th water jacket, do u hear any engine ping or spark knock?.