CRAZY loud clacking/rattling noise from KA. Need help ASAP - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Anto · 03-17-2009, 11:33 PM

I just did the 248/232 cam swap on my 1993 coupe with a KA.
I redrilled the cam gear for +2.5 degrees of advance on the intake side, and rotated the cam gear 4 teeth CCW (per instructions).

I reassembled the timing chain per factory manual, lined up the silver links on the chain with the indents on the cam gears (with the exception of the 4 teeth CCW) and lined up the 3rd silver link on the chain with the indent on the lower idler pulley.

I then set TDC on the motor, and the distributor rotor at the #1 cylinder firing position. Reassembled everything back together, and cranked the motor. It spins perfectly fine.

When I start it, there is a LOUD rattling noise coming from the valve cover area. The sound is proportional to the engine RPM, if I rev it a little bit the rattling noise gets faster. The motor also runs choppy.

I pulled the valve cover and rechecked everything, it seems correct but I know somethings off. Fearing bent valves, I compression checked the motor and it's showing 230psi in all cylinders. Both the recalled factory chain guides are taken off.

WTF? Any ideas?

M11's · 11-03-2009, 11:57 PM

Did you set to TDC in the first place before removing everything it should be set to TDC before reinstalling the chain and matching up with cam gears.

geartech · 11-06-2009, 05:40 AM

Did you put new chain guides back in?
If not there's the problem. They're needed to keep the chain from hitting the timing cover case sides.

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03-17-2009, 11:33 PM	#1
Anto Zilvia Addict Join Date: Jan 2006 Location: California Posts: 835 Trader Rating: (0)	CRAZY loud clacking/rattling noise from KA. Need help ASAP I just did the 248/232 cam swap on my 1993 coupe with a KA. I redrilled the cam gear for +2.5 degrees of advance on the intake side, and rotated the cam gear 4 teeth CCW (per instructions). I reassembled the timing chain per factory manual, lined up the silver links on the chain with the indents on the cam gears (with the exception of the 4 teeth CCW) and lined up the 3rd silver link on the chain with the indent on the lower idler pulley. I then set TDC on the motor, and the distributor rotor at the #1 cylinder firing position. Reassembled everything back together, and cranked the motor. It spins perfectly fine. When I start it, there is a LOUD rattling noise coming from the valve cover area. The sound is proportional to the engine RPM, if I rev it a little bit the rattling noise gets faster. The motor also runs choppy. I pulled the valve cover and rechecked everything, it seems correct but I know somethings off. Fearing bent valves, I compression checked the motor and it's showing 230psi in all cylinders. Both the recalled factory chain guides are taken off. WTF? Any ideas? __________________

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11-03-2009, 11:57 PM	#2
M11's Leaky Injector Join Date: Nov 2009 Location: Liberty Lake, Wa Age: 19 Posts: 88 Trader Rating: (0)	Did you set to TDC in the first place before removing everything it should be set to TDC before reinstalling the chain and matching up with cam gears.

11-06-2009, 05:40 AM	#3
geartech Join Date: Aug 2009 Location: birmingham Posts: 13 Trader Rating: (0)	Did you put new chain guides back in? If not there's the problem. They're needed to keep the chain from hitting the timing cover case sides.