Ka timing chain rattler(SOHC)

[xsublimefrekx]

I know this has been covered alot for the DOHC but i have searched and no one has really said anything about the SOHC. IF there is a guide somewhere that i havent looked and someone knows please give it to me. I was just wondering if it is pretty much the same thing that needs to be done for the SOHC. Thanks

[xsublimefrekx]

no one can help?

[Arrow]

IIRC in the SOHC timing chain rattle is due almost exclusively to a clogged/weak/disfunctional chain tensioner, due to the fact that there is no upper guide (let alone a need for it) that rattles against the valve cover. Also you might want to check to see if your lifters are making the noise instead of your chain (they can sound similar until you know the difference)

[xsublimefrekx]

thanks for the help ill check that.

[rogoman]

The 89 - 90 SOHC chain assemblies used chain guides that had a plastic backing; these failed early in the life of the motor. The replacement guides are metal backed.

Another problem area of the SOHC motor is the oil pump. It seems to have a short life in a lot of instances. This causes a very low oil pressure issue in these motors which ends up with timing chain noise due to the tensioner not working correctly; also hydraulic lifter noise and possible rod/main bearing damage.

[xsublimefrekx]

the rattle gets much louder around 3k. I dont know if that helps any.

[rogoman]

Take the valve cover off and look down alongside the timing chain at the guides to see their condition.

Also check the oil pressure by installing a temporary mechanical oil pressure gauge. You would remove the oil sensor which is located next to the oil filter and install the mechanical oil pressure gauge in it's place; you may need to get an 1/8 BSPT to 1/8 NPT adapter to hook up the gauge. With the engine fully warmed up, the pressure should be as follows:idle - at least 11 psi3000 RPM - 60 to 70 psi

If the oil pump needs to be replaced, it's easy to do so on a SOHC as it bolts on externally.

[xsublimefrekx]

ok ill have to look at it this weekend i have class all day tomorrow.

[xsublimefrekx]

i checked the timing chain guides and the one where the tensioner is looks fine but the one that is supposed to be across from it isnt there. The chain felt tight and didnt seem to have any slack in it. I havent tried the oil pressure i need to get a gauge.

[rogoman]

If the chain guide that's on the driver's side is missing, then don't operate the motor because the chain will most likely skip several teeth and you'll end up with some bent valves.