Andersonracing

I dont know to much about these cars yet. just got mine yesterday. i noticed a knocking feeling(a faint sound as well) with the clutch depressed at a stop revving 1-3k rpm, i feel/hear nothing with the clutch released and at speed i can hear no rod/main knock. i would hate to jump the gun and think its a rod/main bearing. it seems to be coming from the back of the engine or bellhousing. car is a year 2000 with 71,000 miles on it. no mods

Could anyone suggest a way to go about diagnosing the problem?

nissanfanatic

Press the clutch pedal in and out to try and manipulate the noise. Also, if the engine is rod knocking, it should take longer than usual for the oil pressure light to extinguish on startup. Past that, cut open the oil filter and examine for bearing material.

Andersonracing

The engine light turns off right on startup so its getting good oil pressure, is there a port that i can tap into to check the actual pressure, or can i read it through the OBD2 with a scanner?

and the knock happens only on revving the engine with the clutch depressed between the 1-3k rpm range, and also in take off from a stop. rolling at 1-3k rpm i feel nor hear the knock.

_brandon

Should record it, could be thrust washer issue. Unfortunately I do not think you can get the oil pressure from a scan tool, so you will have to hookup a gauge and try to do an oil pressure test. Also measure the lateral runout of the crank if possible. Billman has a tutorial on here somewhere on how to do so.

Andersonracing

I would imagine just a dial indicator on a magnetic block then "push" the crank either way?

Where is the port that i can attach a pressure guage to?

_brandon

Yelp, I dont remember the spec but its in the manual. Pull of the vtec solenoid if you are brave enough to and see if there is any metal debris in there. I dont know exactly where the gauge goes, but look around the forums and you should find your answer.

Andersonracing

Bump for some more info.

Diagnosed the problem. #4 seems to have the knock, so it looks like ill be putting in bearings. The knock is so faint so i think i caught it early.

As for changing them any way to do a rod and main bearing change in the car? or best to pull the motor. Ive done plenty of bearing changes just never any on a 4 cyl, especially on a motor like the F20C

Andersonracing

thanksssss. but my question is can i do the change in the car or do i need to pull the motor?

Billman250

Mains, motor needs to be removed and stripped to the bone.

Rods can be done in the car, if you are familiar with hand micropolishing. If you are not, the bearing wont make it a month.

Andersonracing

thanks for the reply, If im going to be doing bearings i might as well do mains and rods. and seeing as how i have a crankshaft lathe ill chuck it up and re polish all the journals. Anything else i should do while im elbow deep into the motor?