re: valve leak/cross-firing

**conzky** · January 29th, 2006 04:04 PM

I need your help gurus. I went to baguio yesterday to visit my daughter, upon reaching Baguio, i noticed a sudden loss of power, erratic idle and harsh engine sound. i pulled over and checked the engine-1 by 1, i removed the hi tension cable of each cylinder and found out that cyls 1 and 2 are no longer functioning because even when removed, there's no change in the idle at all, while when 3 and then 4 are removed, the engine stops. i concluded that there's valve leak in 1 and 2. i consulted a mechanic and he said not necessarily valve leak, it can be cross-firing. Probably correct, nevertheless in both situations, my car needs top overhaul. Am i right? What are the necessary parts to be replaced for top overhaul? Details if possible, pls. How much will it cost me for parts and labor? Thanks in advance.
btw, the car is 90 corolla gl.

**afrasay** · January 29th, 2006 10:07 PM

it could also be a dead sparkplug.

**sirkosero** · January 29th, 2006 11:12 PM

might be a dead spark plug, sirang high-tension wire na tumatalaon na ang spark... distributor rotor and cap might also need replacement. pero malamang gastado lang yung spark plug.... u must have been running rich kaya naging gastado yan... kung ang spark plug naman ay covered with oil, thats the time u need to change valve seals and top overhaul.

**conzky** · January 30th, 2006 01:55 PM

Originally Posted by sirkosero

might be a dead spark plug, sirang high-tension wire na tumatalaon na ang spark... distributor rotor and cap might also need replacement. pero malamang gastado lang yung spark plug.... u must have been running rich kaya naging gastado yan... kung ang spark plug naman ay covered with oil, thats the time u need to change valve seals and top overhaul.

i've already changed the plugs. it didnt change anything.

**theveed** · January 30th, 2006 02:06 PM

Since Corolla naman, why not drive up to your nearest surplusan and try a different set of plug wires... di usually nasisira ang plugs itself unless sa loob ang may problem (fouling, flooding, etc.)

Check the cheap stuff first like dist cap, HTwires, rotor then move up to the ignition coil and distributor itself.

**jim** · January 30th, 2006 02:23 PM

di naman kaya clogged fuel filter iyan???? check mo na rin. since wala kang sinabi na oil sa old sparks plugs mo, di pa kelangan nyan ng top overhaul. palit ka na rin lang ng HT wires.

**speedyfix** · February 5th, 2006 02:36 PM

if the car is carburated then hindi sa fuel filter yan.

actually, even if efi yung engine, the fuel filter will not affect only half the cylinders.

**Betz** · February 6th, 2006 11:08 AM

Hi Ten wires most probably!

**jim** · February 6th, 2006 11:12 AM

Originally Posted by speedyfix

if the car is carburated then hindi sa fuel filter yan.

actually, even if efi yung engine, the fuel filter will not affect only half the cylinders.

pag kulang ang pumapasok na gas dahil clogged ang fuel fuel filter ganyan din ang symptoms (loss of power, erratic idling, harsh engine sound) nyan from my experience. no harm done naman kung i-check na rin.

**afrasay** · February 6th, 2006 01:01 PM

Originally Posted by jim

pag kulang ang pumapasok na gas dahil clogged ang fuel fuel filter ganyan din ang symptoms (loss of power, erratic idling, harsh engine sound) nyan from my experience. no harm done naman kung i-check na rin.

pero it should manifest on all of the cylinders, not just one or two.