UPDATED broke down tonight....towed it home..

k99jk99j · **Posted:** Thu Sep 21, 2006 5:16 pm

Jeepjeepster wrote:

This isnt new guys, this has come up a few times now. I guess I get to look forward to a head job later on down the road. :roll:

Its a bad valve spring. :wink:

can't you change the spring with out removing the head. (if it is the spring)?

barhpr · **Posted:** Thu Sep 21, 2006 5:37 pm

Talked to Jasper engine today, and he told me the liberty 3.7 was a new engine and almost everyone hes seen comeback as a core had a bad head gasket, due to bad tollerences inbetween the head and the block.. and that the ez fix is remove the head and "true" them for a " tighter " fit.. gonna have the head off this weekend, and ill keep you posted.

Neatus · **Posted:** Thu Sep 21, 2006 5:39 pm

Might as well get a tiny shave and up the compression a bit :twisted:

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

There is a problem with the head gasket there. I found it at around 45k. Of course I was running over 300 hp out of it. Do not have the dealership do the work. The 5 star dealership that did mine told me that the block was cracked, and the heads were ruined. Not rebuildable. It took them almost a month to do a motor swap. They ordered and installed a remanufactured short block but told me they were getting a brand new long block. They had the heads machined and replaced the valves and springs. They did the timing completely wrong, but they thought it was my B&G computer that had partially failed and were trying to say that was where the failure was instead of the known problem area. They bent the housing on my transmission, which caused a scratchy sound from the transmission, and a slight shake at idle. They test drove it over 50 miles with the shark nozzle for the nitrous system in the air tube, and no fuel or nitrous lines connected to it, allowing it to suck in unfiltered air. They couldn't even figure out how to hook the K&N FIPK back up, and damaged the cone filter. The block was not cracked. Just 2 scorched cylinders. Easily rebuildable by boring it .030 over and ordering some custom pistons. It's in my garage.

Jeepjeepster · **Posted:** Thu Sep 21, 2006 6:28 pm

k99jk99j wrote:

Jeepjeepster wrote:

This isnt new guys, this has come up a few times now. I guess I get to look forward to a head job later on down the road. :roll:

Its a bad valve spring. :wink:

can't you change the spring with out removing the head. (if it is the spring)?

I fairly sure you cannot do that. The spring holds the valve and if you take the keeper off the spring, the valve would fail down into the block.

Cacher123 · **Posted:** Thu Sep 21, 2006 7:10 pm

Quote:

I'm fairly sure you cannot do that. The spring holds the valve and if you take the keeper off the spring, the valve would fall down into the block.

Even with the piston at TDC?
Also, how common is this problem with the valve spring? Something to look forward to? Approx how many miles?
(worried, worried, worried)

tjkj2002 · **Posted:** Thu Sep 21, 2006 7:15 pm

You can remove the valve spring while the head is still on the block,you need a adapter to hook up a air line where the spark plug goes and pump some air in the cylinder and the valve will not drop.

hillcountrykj · **Posted:** Thu Sep 21, 2006 7:22 pm

yes you can replace the spring with out removing the head. you fill the cylinder with air and it holds the valve in place while you replace the spring. as long as you did not bend the valve, then you would have to remove the head. but with 140k on the motor I would just rebuild it or replace.

Jeepjeepster · **Posted:** Fri Sep 22, 2006 7:17 pm

Thats cool, learn something new everyday.

barhpr · **Posted:** Fri Sep 29, 2006 11:51 pm

last thing I heard, it has no compression in #4 cylinder, they dropped the air box and passenger valve cover, it dropped a valve on #4, the valve is in the cylinder..
next is to see if it knocked a hole in the piston or not.

k99jk99j · **Posted:** Sat Sep 30, 2006 7:30 am

dropped a valve, sounds like the valve spring gave out. when they get that head off and find no damage you should be able to get her fixed for a reasonable price. one new head gasket (because of dissassembly) maybe some head work? and new valve springs on both sides. that would be alot cheaper than a reman motor.

was there any warning, like misfire codes? hesitations, backfire through throttle body? anything? or did it just go pop? mike :?:

hillcountrykj · **Posted:** Sat Sep 30, 2006 5:51 pm

time to stick a hemi in her :lol:

Jeepjeepster · **Posted:** Sat Sep 30, 2006 5:53 pm

So I guess the valve springs/keepers are the weak point in the 3.7...

PitViper · **Posted:** Sat Sep 30, 2006 7:02 pm

That can and does happen in any motor.

So far I have not heard of anyone else that droped a valve so i don't see a trend yet.

I have heard of head gaskets being a problem though.

Jeepjeepster · **Posted:** Sat Sep 30, 2006 7:27 pm

Ive heard a few now...

jeepskate · **Posted:** Sat Sep 30, 2006 10:38 pm

Yeah, the valve springs are suspect. My 2002 was trouble-free till I hit 100K miles. In quick succession thereafter: broken valve spring, blown a/c compressor and bad alternator/battery. Got about 113K on it now, and no money for a lift.

I had pretty much the same experience when the valve spring went: Stalled at the end of a freeway offramp, restarted and staggered to somewhere where I could pull over and wait for a tow. "Cylinder misfire." Got all new valves and springs now, so I've got that going for me.

At that mileage, I wrote the a/c and alternator off to the law of probability, but the valve spring I didn't appreciate. I'd done all the required maintenance up to that point and was counting on another 100K out of this engine.

UPDATED broke down tonight....towed it home..

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