06 3.8 Broken Valve Spring

[Risenranger]

Hey guys just wanted to post this incase anyone has questions or runs into this problem. Although extremely rare you can have a valve spring break. I had one go at 101K on a very well maintained 3.8. The springs are designed to never wear out but every once and a while you can get a weak one. This has nothing to do with driving style or lack of maintenence its just a bad spring. You can get one for 8 bucks and you will need a valve spring compression tool to remove/install. Just let me know if you need help on this topic.

[shipo]

Hey guys just wanted to post this incase anyone has questions or runs into this problem. Although extremely rare you can have a valve spring break. I had one go at 101K on a very well maintained 3.8. The springs are designed to never wear out but every once and a while you can get a weak one. This has nothing to do with driving style or lack of maintenence its just a bad spring. You can get one for 8 bucks and you will need a valve spring compression tool to remove/install. Just let me know if you need help on this topic.

I've been a member here for over seven years now and this is maybe the third broken valve spring I remember. Like you said, "Althought extremely rare, you can have a valve spring break."

[spacecoast]

Perhaps you could just write up the procedure anyway. I assume you must have the piston at the top of the cylinder and maybe even running air to the cylinder?

[andyg]

I still wonder why it seems isolated to the 4th gens. Maybe their increased output per engine comes from a different cam profile that stresses the valve springs? Happens in race cars with mismatched parts, but these are factory engines and highly engineered.

[beachlover4123]

Hey guys just wanted to post this incase anyone has questions or runs into this problem. Although extremely rare you can have a valve spring break. I had one go at 101K on a very well maintained 3.8. The springs are designed to never wear out but every once and a while you can get a weak one. This has nothing to do with driving style or lack of maintenence its just a bad spring. You can get one for 8 bucks and you will need a valve spring compression tool to remove/install. Just let me know if you need help on this topic.

What were the symptoms that made you suspect the valve spring?

[Risenranger]

OK, here is what happened... driving down the road to my house about 300ft or so before my garage the van started running insanely rough. I knew that something pretty bad had to have happened because there was no warnings and no engine light. Basically the engine will not throw a code if it is compression or fuel...I had a dead miss where one cylinder was not firing. Parked and popped the hood while it idled and you could hear the "fluttering" sound a valve can make when its not opening or closing properly. Shut it down right away and didnt dare to drive it anywhere for fear of more internal damage than had already happened.

Now here is how I fixed it... I wasnt sure if the messed up valve was in the front or the rear of the engine and I wanted to take a look under both valve covers anyway. I have found on these vans you need to take off the wiper assembly to really get to much of anything so it had to go. To do this you have to remove the wiper arms and some say they have been able to wiggle them off, I have done it twice now and needed a two jaw puller both occasions. Remove the top of the airbox, throttle body, and upper intake(unless your sure its under the front valve cover then you dont have to remove all that or the wiper cowl), there are several wire harnesses to unhook as well as hoses, im not gonna get into too much detail on that, this post is already long enough lol. OK, now you can get to your valve cover bolts (8mm, torque specs are 105in lbs and you can re-use the gaskets). I found that using 1/4in drive socket and 6in extension fit in the very tight space between the cast part of the upper intake and the valve cover the best. Boom there is was on the number two cylinder, it was the intake valve spring broken plain as day. Remove the rocker arm rail (10mm I think, torqued to 14 ft lbs) You will need a valve compression tool to remove the broken and replace the new spring. There are two small half-moon like clips that you must remove once the spring is compressed. Make sure you do not drop the valve into the head or its time to pull that too and thats not any fun. The valve is magnetic so you can use a magnet to hold it while you change the spring and clips. You can pull out the spark plug to check on the positon of the piston within the cylinder wall as well. I talked to several who know much more than I do about replacing all the springs and they advised not too. The valve springs are made to never wear out so if in the rare case you have one that does just fix the broken one and go on. I have been told that 99% of the time a spring breaks it will not bend the vale either. At any rate the van is running great now so my wife is super happy and that means I am too!
P.S. If your gonna change your pcv valve, do it when you have everything out... They are insanely hard to pull out of the van and almost impossible unless you remove the wiper assembly.
Hope this helps someone and thanks for the interest in the post.

[zero10]

As an alternative to using a magnet or using air pressure to hold the valve shut a trick I've used is to remove the spark plug for that cylinder then turn the engine until that piston is at the top, then turn it just a bit more until it has moved ~0.5-1" down the bore. You then feed in some cotton rope through the spark plug hole until the cylinder is full and turn the engine by hand back towards tdc until the rope is firmly holding the valves shut. It doesn't take much pressure to keep them from going anywhere. A bit of common sense does apply here - Only use a single piece of rope (don't try to feed one piece in after another, even if you tied them together... you'll never get the first one back) and make sure enough is sticking out the hole to grab to remove the rope later. Also, I suppose, don't turn it really hard towards TDC, you could damage a valve or damage the rope and end up removing the cylinder head any way.

This trick is great because you have full unrestricted access to the top of the valve, and you don't need a constant source of compressed air.

[shipo]

As an alternative to using a magnet or using air pressure to hold the valve shut a trick I've used is to remove the spark plug for that cylinder then turn the engine until that piston is at the top, then turn it just a bit more until it has moved ~0.5-1" down the bore. You then feed in some cotton rope through the spark plug hole until the cylinder is full and turn the engine by hand back towards tdc until the rope is firmly holding the valves shut. It doesn't take much pressure to keep them from going anywhere. A bit of common sense does apply here - Only use a single piece of rope (don't try to feed one piece in after another, even if you tied them together... you'll never get the first one back) and make sure enough is sticking out the hole to grab to remove the rope later. Also, I suppose, don't turn it really hard towards TDC, you could damage a valve or damage the rope and end up removing the cylinder head any way.

This trick is great because you have full unrestricted access to the top of the valve, and you don't need a constant source of compressed air.

Ahhh, the old rope trick; done correctly it beats all other methods.

[Dodgeboy77]

My Dad was an aircraft mechanic in WWII and worked on B-17's and such. That's where he learned the old rope trick that he taught me!

Bill

[shipo]

My Dad was an aircraft mechanic in WWII and worked on B-17's and such. That's where he learned the old rope trick that he taught me!

Bill

Yup, I learned it from an old WWII Navy mechanic (F4Fs and F6Fs).