knock in motor

[kgrantkey3]

knock in motor, sounds like a rod bearing, not heavy enough for a main, but it could be...

I have been reading about knock sensors etc...but my chevy's knock sensor doesn't make it go knock.

The car will run, but am afraid to drive it. It needs something done or parted out before it gets to old.....228,000 miles on it.

[Infinitiexpert]

Is that problem for an J30 or I30 model?

The knock sensor does not make noise, it just senses the knock and sends the signal to the engine control module (ECM).

If the problem is on the J30, it is possible that the one of the main bearing is worn out. Have you had the drive belts replaced or adjust lately? Over-tight drive belts can cause a premature main bearing worn out and make noise. The problem is very common on J30.

[kgrantkey3]

Originally Posted by Infinitiexpert

Is that problem for an J30 or I30 model?

The knock sensor does not make noise, it just senses the knock and sends the signal to the engine control module (ECM).

If the problem is on the J30, it is possible that the one of the main bearing is worn out. Have you had the drive belts replaced or adjust lately? Over-tight drive belts can cause a premature main bearing worn out and make noise. The problem is very common on J30.

J30, and i bought it used for 200.00 due to knock in motor. It came with a service manual, but it is somewhat lacking. I created a thread when i first joined about getting to the bearings from underneath. You answered " is there any other way" or something like that. That gave me new life as i have a good cherry picker but that's 1 monster of a motor to remove from above if you've never done it before. Thank goodness I may be able to get to it from below.

One other question, the book says the crank has marks indicating the correct bearing to use. If i have a bad bearing it should be obvious once in hand, and whether it's to thick or to thin.

Thanks for your comments as they are most helpful to an old SBC guy.

[kgrantkey3]

Originally Posted by Infinitiexpert

Is that problem for an J30 or I30 model?

The knock sensor does not make noise, it just senses the knock and sends the signal to the engine control module (ECM).

If the problem is on the J30, it is possible that the one of the main bearing is worn out. Have you had the drive belts replaced or adjust lately? Over-tight drive belts can cause a premature main bearing worn out and make noise. The problem is very common on J30.

Before I part it out I will try to fix the knock. It just has to be a main.

If nothing else the seats would be cool in my old 620 pickup truck....so would the motor...naw.

[kgrantkey3]

Can't get it to crank up and stay running. The fuel pump seems to be inoperative. I have the service manual that came with the car so it has a step by step procedure to check it all out. The hardest part is locating the parts and test points. It's simple enough to take a piece of 4pr phone wire and run it into the car so I can check voltages while cranking the car. I'll be working on this alone. The book is comprehensive on how things work, from the fuel pump relay, the fuel pump control module etc... Locating them is another thing. I have also discovered a security system that looks like it was installed by a rookie and no info on it. Found it tucked away under the steering wheel and driver-side kick panel.

The car did crank and drive when I bought it several years ago. The battery has been out but no work has been done to it. No question here just a remark now that I have the time and determination to fix it. The car will crank up and try to idle for 1/4 of a second, fuel pump connected or not. A squirt of either will cause it to run fast for 1 second (and knock).

No I just wanted to see, I'm not going to fix anything with a can of either, just had to know if the fuel pump was doing it's thing. It worked before sitting for so long.

[kgrantkey3]

12 volts to the fuel pump for 1 - 2 seconds when ignition is turned on...so I've got a bad fuel pump. Probably from sitting too long. At least it's easy to get at. Now I need to find a replacement pump on the cheap. Wish me luck.

[IlovemyFX]

Sorry, but you've been all on your own over here in the J section kgrant. Unfortunately I can't suggest a place for parts since the J is pretty rare around the forums and also pretty much unknown for the online retailers. Let us know if you find a good parts retailer for your J.

[kgrantkey3]

Originally Posted by IlovemyFX

Sorry, but you've been all on your own over here in the J section kgrant. Unfortunately I can't suggest a place for parts since the J is pretty rare around the forums and also pretty much unknown for the online retailers. Let us know if you find a good parts retailer for your J.

Will do.

I just wonder if there may be a fuel pump used on a Nisan that is the same as the one for the j30. I can't imagine they made a unique fuel pump just for the j30's. Maybe a maximum or something. When I replace the fuel pump I'll just be back to the original problem at hand...a knock in the motor. The book value on the car is not very much so I'm not going to put much into it.

My hope is I will be able to tell which bearing is causing the knock, the journal is in good shape and I can touch it up with a strip of fine grit emery cloth, replace the bearing and get some good use out of the car. they seem to be well built automobiles.

[kgrantkey3]

I'm going today to the local pull-a-part looking for a fuel pump. The lot has no J30's so I hope there is a Nisan with a pump that will work. I would never try this if the gas tank was hard to get at.

I should have attacked the knock issue long ago.

[kgrantkey3]

Nisan Maxima has the same pump.

Get at the fuel pump under the rear seat. Perfect replacement, sending unit and all. 17.50 @ pull-a-part 3.00 extra for 90 day warranty. These fule pumps are heavy duty compared to all I've ever worked with. 3 times the size as the one in my

Chevy truck.

I went by Napa and asked if the J30 was a match for another Nisan. They are able to cross

reference parts and that's how i found out about the Nisan Maxama fuel pump. The fuel pump alone was 120.00, if you wanted to get the bracket, sending unit and all it's over 200.00. Closer to 300.00