89 240sx valve lash maybe? need advice

[240midohiofan]

my sohc 240sx seems to be having from what some one told me was valve lash... its a very loud ticking noise that speeds up when the motor revs up. it sounds like it is hitting the valve cover and i need to know how to fix it or if that is even the problem. i searched only only found stuff on the dohc ...thanks in advancedNick

[Sygerwulf]

You should get a vehicle stethiscope *dunno what the real name for it is* A piece of hose or pipe or the very least a long screwdriver and listen around the top and bottom of your engine for the sound.

Does it do it at idle or only when you give it gas? If you're like me then you either have wrist pin slop or a rod bearing going bad. To find out if it is pull each spark plug one at a time and see if the sound stops. if it does, then it's the before mentioned problem. If not then it could be your timing chain slapping against the guides. I haven't heard many cases of 240's having valve lash. You could have a bent valve though. Did it just start all of a sudden?

[240midohiofan]

it does it at idle. it did just start all of a sudden. ill take your advice and try that. what is wrist pin slop? thanksNick
Modified by 240midohiofan at 10:38 AM 9/28/2005

[Sygerwulf]

The wrist pin is what holds the piston head to the piston rod. When it gets worn or warped it allows space inbetween and the piston head doesn't sit tight against it anymore. When the crank turns and the rod pushes the piston up and it reaches the top of it's cycle, the piston head moves up higher then it's suppose to due to the "slop" in the wrist pin, then when the fuel/air is ignighted it slams the piston back down on top of the wrist pin, the rod pushes down and rotates the crank, and it starts all over again.'It's hard to say how long a car will last with this. I've hard of people driving years with a bad wrist pin (no nissan owners though) and then I've had personal experience when my mom's buick started to knock and blew a piston through the head lol. My car has been knocking due to the wrist pin or rod bearing for a year now, so who knows? Do the test and find out if its that. If it's a wrist pin you'll have to remove the head to get the top of the piston out, if it's a bearing you'll have to drop the oil pan and possibly have your crank machined or replaced. Lets hope that this isn't your problem lol

[240midohiofan]

thanks for the help. the thing is it doesnt sound like a knock, more like a tick, it just sounds like maybe my valve spring collasped or something im gonna take of my valve cover and have a look

[Prelude Guy]

I had the same exact problem with my 89 when I bought it. The car runs, but it had this VERY loud tick. It sounded like an early 80's Mercedes Benz diesel. All I did was change the oil and it went away. It is as quiet as it should be. However, the engine does not perform well at all. I can barely accelerate fast enough to merge into traffic.

I think there is something wrong in the head too. Once I move into my new house (with a 2-car garage) I am going to swap an SR20 in it. I will disassemble the KA to see what is wrong with it.

[240midohiofan]

hmm well i will try changing the oil but when i drive it, it doesnt seem have lost power, maybe in time but oh well. let me know what u find out if u dissassemble it.thanksNick

[ricebike]

the sohc engines have hydraulic valve lifters & doesn't have shims to adjust for valve lash like the dohc engines do... so mebbe changing oil to help get some of those sticky/varnish covered valve lifters to free up...