nissan pickup help

[q_r86250]

hey guys i gotta 93 nissan hardbody 4wd truck for 4wheelin' and the guy claimed it didnt run so we investigated it further and the fuel pump was unplugged, we asked him why it wouldnt run after we figured it out he replied the fuel pump blew yet it runs now. heres the tricky part.......

sounds fine at idle yet when accelerated it has a knock , we thoght it was a valve sticking so we checked it out.....still it knocked after we replaced gasket and checked valve spacings and put all new oil in.......but when it is accelerated heavy.....it sounds like a diesel engine at about 4500 rpm or so
with that knock. now someone told me it was a crank bearing but could that really be it? i dont wanna tear it down for nothing and have to hoist the motor back in with no progress you know?

i also found lucas oil under the seat which also is a good indicator that it may just be the crank bearings, yet the guy says that when it did run there was never any knock.????????????

really stumped on this one guys and i figure someone could help if they have ever dealt with these.

by the way this truck is a 4 cyl 2.4 litre

any info will be appreciated thanks guys

ryan

[Jim mac]

is it pinging? not sure on your particular motor but if your cam chain tensioner is going bad your timing chain can make a knocking sound. Jim

[q_r86250]

it kinda pings but makes a knock at highmid and high rpm's

ill check it out but how do i know if the cam chain tensioner is going bad?

what do ilook for?

[3 weelin geezer]

A good indicator of what may be wrong is giving it a pee test. No, don't pee on it. Take an oil sample and send it to a lab. They can tell you what kind of metals are in the oil and where they most likely came from.

[q_r86250]

well i actually drained the old oil that was in it, and got rid of it. so did i screw myself?

and if not where are these labs?just curious because it must be new technology eh?

sounds neat though

[q_r86250]

still at a stand still if i should take the motor out and replace the bearings on the crank, but like i said, people claim its the lifters on the valves but it cant be i used a feeler gauge and the play was the within the haynes manual limits.

someone also told me that they think it may be the cam chain tensioner but upon inspection it seemed very tight and chain looked newer.

well if anyone has any experience with these trucks please help.

for reference this is a 93' nissan hardbody pickup with the ka24e engine which has 4wd. these ka24e engines came on the mid to late 80's sentra's and 240 sx cars. this engine was not a swap it was stright from factory.

thank you guys

ryan

[PowerTrike]

Have any oil pressure numbers? Does pressure seem to drop significantly when the oil warms up? Sounds kinda like it could be one or more bad rods or mains...

Good Luck!

[G-MAN-1]

check your timing chain and guides thats what was wrong with my nissan 2.4. i have a good feeling thats the problem here. the guides seem to lose there buffers on the 2.4 . from i have read thats a common problem. check it out...

[q_r86250]

but the the buffers on the cam chain guides would make the truck sound like a diesel when accelerated in neutral? not sure, you guys are the experts on this stuff but tell me if your 2.4 nissan engine did that noise before hand and had that knock.

to powertrike:
i will check to see oil pressure, and if it is that means bad rod or bad rod bearings?

thank you guys for the info and iappreciate it very much as this may be my ride to tf 06 , i thought back in jan i couldnt make it but god has done wonderful things for me since my dad died last year.

once again thanks for all the info guys, and if you have anything more to add it will be appreciated:beer

[PowerTrike]

to powertrike:
i will check to see oil pressure, and if it is that means bad rod or bad rod bearings?


I'm really not an expert and do not have experience with the nissan 2.4 but no, if you have low oil pressure that doesn't neccisairily (sp?) mean that you have one or more bad bearings but it is a common sign. If you have good inital pressure on startup and it slowly drops as your oil thins out and runs off the bearings faster it is a sign that they are getting pretty worn. If your oil pressure drops when you hit the gas, there is a good chance that your oil pump pickup is clogged....

Can you pinpoint where the "diesel" (rattling i'm assuming) is coming from? Bottom end or otherwise?

The main bearings on my ford 302 are worn out of tolerance and I have low oil pressure and some noise at high rpms. But at idle and low rpms I can't hear any knocking at all. I'm just running heavy oil to get by until I can rebuild it a new oil pump didn't help me much.... I would have attempted putting new bearings in underneath the truck but on my f150 they would be a major PITA to replace without pulling the motor, maybe your nissan's would be doable in the truck?

[q_r86250]

that makes sense about the oil thinning out and making the sound.

the oil pump could be clogged, in return making that sound?

but the sound can not be identified whereabouts its coming from, by this i mean that every where i listen, it sounds like its coming from. if im in fron i hear it there, if i listen underneath i hear it there so i can't pinpoint it.

but with the nissan engine, i have to take the whole thing out because the crossmembers and so forth so thats why i have been hesitant to do it. it would also be a P.I.T.A. to do so.

but ill surely findout soon. im a ford fan and this is the first "feather hauler" for me so, im kinda lost but thanks for the help. and i will let you know about the oil pressure.

[darrel632]

Mech. friend of mine has one, the knock sounds like the engine, he swears its the tranny, flywheel / throwout bearing area he's put 65,000 kms on with the knock waiting for it to blow up, and its still running.

[q_r86250]

so if it is that, that means that he has put crazy miles on it with the knock, which means that he also couldn't exactly pinpoint it either like me. i never know where because it sounds off wherever you check, it seems like it doesnt ever get located no matter how hard i concentrate!!!! but engines are relatively cheap, and stuff so i guess thats how it is for now!!! but i may pull it still and have a friend of a friend rebuild it who is also a mechanic, but the trouble is he is 200 miles away, so he hasnt been able to look at it .

well you say your bud has the same truck? 93 nissan hardbody 4wd with the 2.4 ka24e engine?

let me know

ryan