Broken Valve Spring

[mechaneck]

My '04 3.7L Liberty with 123,000 miles set code P0300 for multiple misfires. After checking it out I found that it had low compression on #4. It broke the #4 intake valve spring which was preventing the valve from closing fully. I applied shop air pressure to the cylinder and could not get the valve to seal even when I pried up on it. I've pulled both heads and everything looks good except the one spring. The broken coils bound up preventing the valve from dropping down far enough to it the piston or the rocker arm from coming out of place. The valve seat had a bit of carbon on it and once it was cleaned out the valve and seat have nice consistent contact all the way around.

My question is this: has Chrysler updated the springs? Is it worth it to replace all 12? Does anybody make a good aftermarket spring?

I searched and found lots of info on broken springs/valves but nothing much current on the repairs other than complete valve jobs or new heads. I don't think this is necessary in my case.

Thanks,
Keith

 

[MrMopar22]

I bought my '02 with the same issue; dealer said it burned up the engine and the owners didn't want to put any money in it.

I didn't pull the heads, just replaced the one valve spring. I've put 6,000 miles on it so far. Between all the vehicles I've worked on, this is the first valve spring I've ran in to, I'm going to run mine as is with the rest of the springs.

 

[k99jk99j]

the springs were updated for the 3.7L in 2005. they (the old) were made by the same supplier that made the valve springs in the lexus recalls. it is an industry wide problem that seems to have been rectified around 2005 in the industry. but for the 3.7L it had many valve train changes in 2005. mike

 

[mechaneck]

Thanks!

The only aftermarket springs that I found locally were Sealed Power and they listed the same part number for intake and exhaust while Chrysler shows them as 2 different parts. They were less than $3 each from Chrysler so I decided to do them all and use the OEM parts.

Also, surprisingly, the factory head gaskets and other gaskets from the dealer were only few dollars more than the aftermarket so she's going back together with all OEM parts. Should be good for another 123,000 ;-)