Broken valve spring - need help

I sent my jeep in to get the cylinder head replaced a month or so ago, ended up getting the wrong cylinder head from everdrive, sent it back and ended up getting a new one from Clearwater Cylinder Head. Great customer service and quick shipping, but after having it installed and the jeep being driven by my mechanic for about 150 miles, I picked up the jeep and drove it about 20 miles until something went wrong. All of a sudden the jeep lost power and started to stutter and shake, finally dying when I came a stop. I started it back up and was able to limp home. My mechanic look at it this evening and said the #5 exhaust valve spring had broken.

Is this something that is common to have an exhaust valve spring break? Should I be worried to damage to other areas to the engine? The cylinder head has a warranty on it, so I'll be calling tomorrow to see what the next steps are.. But they are probably going to just send me a new head, should I be concerned about the springs or is it probably just a defective spring?

I've had a defective spring although not on a XJ. It was on my 91 S-10 4.3 with a GM crate motor that had about 200 miles on it. It did not cause any damage but the minute it happened it ran like crap I shut it down and had it towed home. They told me to get it to the closest GM dealer and it was replaced for free.

I don't think its that common, but it has happened. The head should be pulled and checked for a bent valve and piston damage.

what kind of piston damage? this has me worried. I drove it less than 10 miles to my house once it broke.

With no spring pressure the valve could have made contact with the top of the piston.


That shows there 4 valves made contact with the top of the piston. That is a mild out come.

I'd be more worried about the valves in a pic like that.

It could look like this:

how hard/what is the process to replace a valve spring?

Fairly easy. You just need the correct tool.



However, if the valve did bend from contact with the piston you may have valve seat damage, piston damage, and/or valve guide damage.

If there is no other damage you have to secure the valve in the head some how. If your head is off its easy. If its on you can try compressed air or compress a piece of rope in the chamber.

thanks..I'm wondering since I had one break, wondering if I should have him replace all of them

I really don't know. Its a rare problem with stock Jeep springs. What many of there rebuilding companies do is strip the used heads and throw all related parts in one batch then clean them an use them. So they will have a container for exhaust valves, retainers, locks, etc. Not that there is anything with used parts. They then assembly the head with the clean used parts. So you may have springs from various heads. I would have the installed height checked and the bind height checked. I wouldn't replace all the springs. But also talk to your machine shop as he may have a different opinion and has seen a lot more cases like this than me.

I talked to my brother who stopped by to take a look at the jeep while it is in the shop. The mechanic is waiting on getting an adapter in order to put air in the cylinder and check for compression. He said that the metal on the springs had a different tint to it, almost as if it was from a part made in China not using US steel.

I called Clearwater Cylinder Head - when I orginially bought the head he said it was brand new, never mentioned that it had refurbished parts on it. When I called to say I had a warranty issue, the guy said that they are refurbed parts and that he'd be happy to send me a new spring, otherwise I'll have to remove the head and send back to them for further investigation before they cover the warrant.. Personally I think it's bullsh*t. If there is no valve or piston damage, I'll probably replace all the springs with new ones and get compensation from Clearwater.

Emerscape said:

I talked to my brother who stopped by to take a look at the jeep while it is in the shop. The mechanic is waiting on getting an adapter in order to put air in the cylinder and check for compression. He said that the metal on the springs had a different tint to it, almost as if it was from a part made in China not using US steel.

I called Clearwater Cylinder Head - when I orginially bought the head he said it was brand new, never mentioned that it had refurbished parts on it. When I called to say I had a warranty issue, the guy said that they are refurbed parts and that he'd be happy to send me a new spring, otherwise I'll have to remove the head and send back to them for further investigation before they cover the warrant.. Personally I think it's bullsh*t. If there is no valve or piston damage, I'll probably replace all the springs with new ones and get compensation from Clearwater.

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IF you bought the head with a CC you might have some clout.

Getting them to pay for a full set of springs, unless you can prove that they are all bad, is not practical. Read your warranty and see what it covers.

yeah I buy everything with my AMEX specifically for the strong customer service and customer backing. I read the warranty, they don't necessarily have to send me a new spring, but I can send the head back to them for investigation and give me a new cylinder head. The warranty also includes labor, but does not cover any other damage caused by a failure of the cylinder head.

Emerscape said:

yeah I buy everything with my AMEX specifically for the strong customer service and customer backing. I read the warranty, they don't necessarily have to send me a new spring, but I can send the head back to them for investigation and give me a new cylinder head. The warranty also includes labor, but does not cover any other damage caused by a failure of the cylinder head.

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Ouch!

Know anyone with a bore scope? Might save having to pull the head.

I personally do not but I know my mechanic has a lot of friends that do engine work. Hopefully he'll be able to find one

One thing nobody mentioned yet is the possibility that you burned the valve seat. You can test this with a compression tester. It all points to more problems. Seems like it would end up being better to pull the head, while your supplier is still liable.