SOHC Tapping sound, Not the chain (already fixed)

[slakker]

I have the SOHC and I have a tapping problem at and above 3500. Sounds pretty horrific. It varies the speed according to the engine speed of course. Should I expect it to be valve(s), Lifter(s) or the cam shaft. I have never had the head off and I am changing the gasket tomorrow. Which of course is blown. (Another thread I started). This noise, which seems more than just a tapping, Kinda like hitting your knuckle against dense wood. It has to be either of the above listed. My question being how can I tell. Will valves be njoticably bent. Any help would be great.

[silencer.1]

A connecting rod bearing is pretty much gone. That sound is the connecting rod whacking the side of the block internally. The engine is worthless. It'll need at least a new crank, connecting rods, piston's etc. Buy a new engine. Seriously.

[slakker]

is this true.?. Anyone else

[slakker]

I dont understand how that would be possible. If the rod were to be in contact with the block then it definitely wouldn't be this subtle. For the rod to come in contact with the block it would have to free itself from either the crank or the piston and I would have a huge hole. It has ot to be a lifter ir a valve.

[gumby]

off topic it helps it you list the mileage

[slakker]

105,000 240's are pretty stout, but when I got this car it had cooling problems and a susceptible head gasket failure. Well the head gasket has gone south (bubbling in the radiator, exhaust leaving the cylinder into the cooling system). I was going to replace the gasket tomorrow along with trying to find the tapping noise. Replace that also. Just need some information

[slakker]

Any ideas. I am going to start this project and honestly I dont want to do this twice.

[silencer.1]

I'm not joking in the least. This just happened to me 2 months ago. Started off as a faint hollow tapping at around 2k-3k and slowly progressed to a snapped connecting rod that:

A: broke at the bolts, sending rod pieces plus a bolt through the oil pan andB: broke at the piston, slamming the rod through the side of the block and making a 2" hole along with a piece of block bouncing along behind me

It's kind of unusual for it to go at only 105k miles, but if the engine wasn't properly maintained, it's a definate possibility. My bearing went at 175k miles after a lot of abuse. Also known as 8000 miles in a month. 50%-60% of which were in the top 1/3 rpm.

Edit: Got to thinking about it and it makes more and more sense. If the previous owner ran it hard enough and maintained it so poorly that it blew the head gasket, I'd be very worried.

Messengers:AIM: nukesunlimitedMSN: [email protected]: [email protected]

I'll be up for another 30-45minutes if you want to IM me.

[smokin240]

I have a tapping like yours in my DOHC KA 167k and was told by 2 people who know there stuff that it was crankshaft bearings. Thats a big project to start on so I don't know when i'll get it done.

[hachibroku]

that sounds like main bearings to me too. my engine only lasted a month knocking but my boys lasted a whole year and he wasnt nice to it. might as well think about a rebuild.

[Altiman94]

find a used motor, put the new chain on it and youll be good to go.

[hamsterball]

Mine makes the same noise.. it's not that bad, and not really horrific.It's only on like one area of the valve cover.On cold start ups you can hear it go tap-tap-tap-tap while idling, then when it's warm the noise goes away and becomes a little faint tap-tap-tap noise which isn't audible really..when driving at half-throttle or more, you can hear the noise come -tap-tap-tap and tap faster.sometimes it goes away, sometimes it comes back.one time, i was on a run, and when it was tapping at like 5500RPM, it went away for the rest of the run... and i just heard the engine noise without tapping.

Is yours coming from the top part of the valve cover? or is it in the middle area or what?

If it's from the top, it's probably your lifter/valve/camshaft.Lifters are $24 each from Nissan (here in CA), and you have 12 of them. A camshaft is like $180.

If it's in the middle area, it's probably like the above people mentioned.

Some one looked at mine and heard it, and told me it's not that bad of a valve tap... and I have heard of a few different stories with our KA's and other nissan engines running with the tapping noise. And when we opened the cover to check the condition of the valves, they were all clean and pretty decent looking for 160K miles.

It depends on how bad it is.. on mine it's only coming from like 2 or 3 lifters, but not all of them and goes away with some swift 6000RPM take ups.. so I will be able to run on it for a few more miles i would assume.

The sucky thing about our SOHC motors is that you can't do adjustment with shim replacements like you can with the DOHC KA. if you have tap on the DOHC, you can actually buy adjusted shims that clear your lifter/valve.Argh.

It's basically not worth it unless if your compression on the engine is good.. I would just get another single cam motor or DOHC replacement.I'm already saving $$ up for a DOHC replacement.

Good luck with the car, and let us know what you find out it is.

[240yo]

I know it may sound dumb.. But check your oil.. I had the same tapping sound when I got my 240.. checked the oil level .. refilled it .. drove it for like 2 minutes, and the sound was gone.

[hamsterball]

I know it may sound dumb.. But check your oil.. I had the same tapping sound when I got my 240.. checked the oil level .. refilled it .. drove it for like 2 minutes, and the sound was gone.

yeah. we wish it was that easy...

[Liquidus]

It really could be just your oil, i had the same problem on my SOHC when my headgasket was blown. Correct me if im wrong, but isn't the timing chain tensionor powered by oil pressure. The leaking head gasket contaminates the oil and stops it from running the timing chain tensionor correctly. Try fixing the headgasket and putting in some of the engine cleaner and changing the oil. My SOHC also taps if i'm a little late in changing the oil, it could be just your oil.

[HaveBlue]

I have the same problem. My ticking is located at the top of the engine right under the valve cover. The SOHC has hydraulic lifters with oil in them. if one gets clogged with oil gunk it will start to tick. Try running some engine cleaning solutions in with your oil to clean out any gunk. this is good to do right before an oil change. Pour in some cleaner, run the car for a while and then drain the oil and fill it up again like normal. Then do another oil change within 1000 miles. This way any extra loose crap will come out too. And when you do this oil change you can see how dirty it comes out. if its clean you are probably ok. if not repeat the cleaning. I also ran 2000 miles with synthetic in the engine (i normally run regular oil) because it has more detergents than regular oil. this got rid of my ticking sound. for now

[slakker]

I dont think it is anything that simple. It isnt a slight tapping, and it only happens after 3500 rpm. I dont want to spend the 100 buckas and all the time changing the head gasket, if it could be something else. ust to have it blow anyways. I dont know what I am going to do. It sounds worse than just valve tap, like a bent valve or something. I am just not sure. If I dont change the head gasket itll blow. If I change it it might blow anyway. Time, effort and money????? I did just run seafoam through the oil. It didnt help. Thanks though

[nyckanny]

i dunno if its because non synthetic was used in the past prior to owning my first used s13, but, the engine tapping noises went away after i put synthetic in, a short while after. dohc. my friends mx6 had the same effect using synthetic on his v6.

ken

[YOUNG240SX]

MY S13 SOUND LIK WENT I START COLD IT TAP,TAP,TAP,TAP AND LESS THAN 3MIN IT STOP AND ONLY MAKES WENT IT LIKE 20 DEG. OUTSIDE

AND SOHC ARE BEST FOR WEIGHT LOSE ON YOUR CAR