Broken Valve Spring

[robausler]

Removed the passenger side valve cover and there it was...first spring smashed to bits. i could hear the tapping when I ran it but i figured it was the typical tap I normally got on start up, but louder since it was misfiring. I just need a few months out of it so ill replace the spring and maybe the rod(if the valve isnt bent).

 

I stay regular with changes (mobile one synthetic and lucas). Thinking about replacing both heads but what will that do to the bottom end?? will it blow it out? How can I tell if the Valve is bent. Once I have the spring off, should I be able to move/spin the valve. When the spring broke, it stayed in place. the valve is stuck open. how can I know if the valve hit the piston without pulling the head?

 

Original problem was code p0302 and p0101. Changed a bunch of sensors before I pulled the cover.

[DwayneJ]

Boroscope would be the easiest way to see if it hit the piston. Could get a fitting to apply compressed air to the cylinder and see if you hear it leaking past the valve.

 

If the valve is not bent I would just replace the valvesprings. You can replace the heads without hurting the shortblock. The "replacing the heads will hurt the shortblock" is 70s mentality, modern engines exhibit a LOT less wear and can handle a lot more power.

 

The Lucas you are simply thickening the M1 and diluting it's additive pack. Lucas is basically just thick oil with no additives.

 

Makes decent assembly oil but that is about it.

[robausler]

Boroscope would be the easiest way to see if it hit the piston. Could get a fitting to apply compressed air to the cylinder and see if you hear it leaking past the valve.

 

If the valve is not bent I would just replace the valvesprings. You can replace the heads without hurting the shortblock. The "replacing the heads will hurt the shortblock" is 70s mentality, modern engines exhibit a LOT less wear and can handle a lot more power.

 

The Lucas you are simply thickening the M1 and diluting it's additive pack. Lucas is basically just thick oil with no additives.

 

Makes decent assembly oil but that is about it.

 

Replaced the spring...runs like new. I found reman heads on ebay for 200.00. wondering if they are any good?

[rockcrusherrevived]

you would think anyone rebuiling heads would magnaflux them but you don't know for sure i would buy them locally

 

 

Boroscope would be the easiest way to see if it hit the piston. Could get a fitting to apply compressed air to the cylinder and see if you hear it leaking past the valve.

 

If the valve is not bent I would just replace the valvesprings. You can replace the heads without hurting the shortblock. The "replacing the heads will hurt the shortblock" is 70s mentality, modern engines exhibit a LOT less wear and can handle a lot more power.

 

The Lucas you are simply thickening the M1 and diluting it's additive pack. Lucas is basically just thick oil with no additives.

 

Makes decent assembly oil but that is about it.

 

Replaced the spring...runs like new. I found reman heads on ebay for 200.00. wondering if they are any good?

 

[robausler]

you would think anyone rebuiling heads would magnaflux them but you don't know for sure i would buy them locally

 

 

Boroscope would be the easiest way to see if it hit the piston. Could get a fitting to apply compressed air to the cylinder and see if you hear it leaking past the valve.

 

If the valve is not bent I would just replace the valvesprings. You can replace the heads without hurting the shortblock. The "replacing the heads will hurt the shortblock" is 70s mentality, modern engines exhibit a LOT less wear and can handle a lot more power.

 

The Lucas you are simply thickening the M1 and diluting it's additive pack. Lucas is basically just thick oil with no additives.

 

Makes decent assembly oil but that is about it.

 

Replaced the spring...runs like new. I found reman heads on ebay for 200.00. wondering if they are any good?

 

 

 

Do the springs get weak over time or do they just break? Since the springs are only 6 bucks a piece and so easy to change, thinking about just changing them all with the oil seals.

[rockcrusherrevived]

if the valve move up and down freely i would just replace the spring if the valve gets stuck it probably hit the piston so the head needs to be removed

 

 

you would think anyone rebuiling heads would magnaflux them but you don't know for sure i would buy them locally

 

 

Boroscope would be the easiest way to see if it hit the piston. Could get a fitting to apply compressed air to the cylinder and see if you hear it leaking past the valve.

 

If the valve is not bent I would just replace the valvesprings. You can replace the heads without hurting the shortblock. The "replacing the heads will hurt the shortblock" is 70s mentality, modern engines exhibit a LOT less wear and can handle a lot more power.

 

The Lucas you are simply thickening the M1 and diluting it's additive pack. Lucas is basically just thick oil with no additives.

 

Makes decent assembly oil but that is about it.

 

Replaced the spring...runs like new. I found reman heads on ebay for 200.00. wondering if they are any good?

 

 

 

Do the springs get weak over time or do they just break? Since the springs are only 6 bucks a piece and so easy to change, thinking about just changing them all with the oil seals.

 

[robausler]

if the valve move up and down freely i would just replace the spring if the valve gets stuck it probably hit the piston so the head needs to be removed

 

 

you would think anyone rebuiling heads would magnaflux them but you don't know for sure i would buy them locally

 

 

Boroscope would be the easiest way to see if it hit the piston. Could get a fitting to apply compressed air to the cylinder and see if you hear it leaking past the valve.

 

If the valve is not bent I would just replace the valvesprings. You can replace the heads without hurting the shortblock. The "replacing the heads will hurt the shortblock" is 70s mentality, modern engines exhibit a LOT less wear and can handle a lot more power.

 

The Lucas you are simply thickening the M1 and diluting it's additive pack. Lucas is basically just thick oil with no additives.

 

Makes decent assembly oil but that is about it.

 

Replaced the spring...runs like new. I found reman heads on ebay for 200.00. wondering if they are any good?

 

 

 

Do the springs get weak over time or do they just break? Since the springs are only 6 bucks a piece and so easy to change, thinking about just changing them all with the oil seals.

 

 

 

Runs great but now its throwing P0171 and P0420. From what I'm reading, I guess Ill be looking for a vacuum leak.

[DwayneJ]

Hopefully you just knocked a connection loose during the project.

 

Far as broken valvesprings, on a stock cam with stock rockers I would call it a fluke. One you get into upgraded camshafts and such though valvesprings become a wear item. On my street/strip car I expect to change them somewhere between 15-20K miles but the cam has pretty aggressive lobes.

[robausler]

Hopefully you just knocked a connection loose during the project.

 

Far as broken valvesprings, on a stock cam with stock rockers I would call it a fluke. One you get into upgraded camshafts and such though valvesprings become a wear item. On my street/strip car I expect to change them somewhere between 15-20K miles but the cam has pretty aggressive lobes.

 

Used the carburator cleaner to spray intake and listen for changes. Found a loose intake screw. cleared the code and it ahs not returned in the 100+ miles since.

[Westlotorn]

if the valve move up and down freely i would just replace the spring if the valve gets stuck it probably hit the piston so the head needs to be removed

 

 

you would think anyone rebuiling heads would magnaflux them but you don't know for sure i would buy them locally

 

 

Boroscope would be the easiest way to see if it hit the piston. Could get a fitting to apply compressed air to the cylinder and see if you hear it leaking past the valve.

 

If the valve is not bent I would just replace the valvesprings. You can replace the heads without hurting the shortblock. The "replacing the heads will hurt the shortblock" is 70s mentality, modern engines exhibit a LOT less wear and can handle a lot more power.

 

The Lucas you are simply thickening the M1 and diluting it's additive pack. Lucas is basically just thick oil with no additives.

 

Makes decent assembly oil but that is about it.

 

Replaced the spring...runs like new. I found reman heads on ebay for 200.00. wondering if they are any good?

 

 

 

Do the springs get weak over time or do they just break? Since the springs are only 6 bucks a piece and so easy to change, thinking about just changing them all with the oil seals.

 

 

Springs are made from wound steel, sometimes a spring gets made from a spot that has a weak spot. The Steel is produced and run out till they spot a weak spot, at that point they cut the run and start over. Sometimes a weak spot is missed and you eventually break a spring beacuase it was manufactured with a weak spot included. Very rare but it happens. If it is running great why even consider changing heads? If you are worried about your springs change all 16 and be done with it. If it was me I would be very happy to have it working perfect again and leave it alone.