1989 Nissan Pickup Z24 Questions

[massey461]

I have an 89 nissan pu with the z24 engine and its got 180,000 miles. i bought it with an oil leak at 167,000 miles and. when i got it it ran great but a had a pretty bad oil leak. and i had to add about a quart every two days of drivin it. i never change the oil filter because it always had fresh oil in it. but one day out of nowhere it started knocking a little so i shut it off and added just a little bit of oil. and it didnt help, it just kept getting louder. the noise sounds like its coming from inside the block. but it doesnt knock at idle only on accelerations. so i figured it was a rod bearing. so i pulled the engine and pull the oil pan and valve cover. and nothing seems to be broke and the rod bearings dont seem bad either. If any body has any ideas on what to check next or what it could be, please respond. Thanks everyone. -justin

[Saudade]

Well, it's a bit late to try and diagnose the problem.

Did the knock improve after warming up? What weight oil have you been using? How did you check the rod bearings? Did you measure them? Have you changed where you buy your gas? Did it knock on acceleration in neutral or only in gear, under load?

[massey461]

lol ya i probably should have asked before rippin it apart, but too late now.........it did it warm or cold. and i have been using 10w 40 since i bought it. i didnt change the kind of gas either, just 87. It would knock in gear, in neutral and during acceleration, but the knock got louder the higher the rpm and more throttle i gave it. ......but heres the thing. I couldnt find anything wrong in the bottom end so i went ahead and pulled the head off and found that the head gasket was blown, inbetween the first and second cylinder. so would that possibly be making the knocking sound, and also it was starting a lot easier after the noise started, maybe cause by lack of compression? thanks for the response saudade!

[Rev_D21]

Either have the lower end reconditioned or swap at this point. You are already there. If you decide to keep this engine I would do rings and bearings. Have everything checked for cracks. Deck the block and replace all o-rings and gaskets. Taking measurements and blueprinting the engine will reveal what you knock was.