1990 Nissan 2.4L Engine Knocking

[jebuschrisco]

I was driving home today and halfway the engine started to make a knocking noise... I thought it was the exhaust pipe until I got out and noticed it coming from the engine.

I took off the air cleaner and found oil around the perimeter of the filter.

Any ideas what happened? Rod, piston, gasket, thermostat issues?

1990 Nissan D21 2.4L 118k miles. Just bought it a week ago and drove it maybe 5 times.

Havent taken off the valve cover yet to see if there are any clues...

Any suggestions are appreciated.





http://youtu.be/-6Z9Yj5VqOo video of the sound it made before I noticed it was overheating and quickly ran to shut it off.

[whomadewho]

Listened to the you tube. Hard to tell,almost sounds like a cracked exhaust manifold. What happens when you reve the engine? A couple of things to try. With the engine running at idle,unscrew the oil filler cap and look for a large amount of blow by. Take a listen at the tail pipe,listen for a miss. You can also disconnect the plug wires one by one to rule out a bad rod bearing. Not always true,but if it was a bearing issue one would think the oil light should come on unless the PO unpluged the wire. You can try a master oil gauge to rule this out.

[jebuschrisco]

When I rev the engine the noise increases in pace and sound.
Yesterday I took the radiator cap off and ran the engine for a couple minutes to see if the fluid would gush out (one way to tell if a head gasket is bad?). Nothing bubbled or gushed out and only a slight movement was seen. I also drained some of the oil and didnt notice any milky oil or water and the dipstick also looked normal.

Would a cracked exhaust manifold cause an overheating of the engine, or the other way around? I guess I neglected to mention in the first post that when I parked at home and lifted the hood I noticed the boil over reservoir for the radiator was steaming and then I ran to check the temp gauge and it was all the way in the red zone. I dont know how long I was overheating but my drive couldnt of been more than 15mins.

Thanks for the suggestions.

Just tried the filler cap... I could see oil being tossed around and being tossed out of the filler hole. But I didnt definitely see smoke. There was a change in the noise when the cap is on and when it is off.

I unplugged each spark plug wire, one at a time, and started the engine and the noise persisted.

[jebuschrisco]

I tried the radiator cap thing again... oil spots appeared and the fluid bubbled...

Blown head gasket was the first problem then? Second I drove and overheated the thing.. and now something internally is damaged.

[jebuschrisco]

found this piece of plastic in the timing gear... I think one of the guides must of broken off. Which makes me wonder more and more about that noise I am hearing. I took the piece of plastic out and the noise persisted. I didnt rotate the whole engine to check the whole chain but I assume more plastic pieces are somewhere...

[jebuschrisco]

not my picture but you can see where the right end of the timing chain runs close to the water/coolant passage... I read somewhere that the chain can eat through the engine block and expose the passage.

This is what I think happened to me.

[whomadewho]

With everything that went on,I would shop around for a rebuilt or a core that can be rebuilt. Chances are good after the engine may have a internal crack in the combustion chamber or a crack in the water jackets. You can go online to Car parts.com. Which gives a list of used auto parts and auto salvage yards, you maybe able to score a rebuild able engine core near you.

[whomadewho]

The site is called - car-parts.com.