Engine won't turn freely!!!

TxBxSx · **Joined:** Mon Mar 24, 2014 6:22 pm **Posts:** 10

So, I've been chasing what I thought was a battery/starter issue. My wife parked the jeep on a Friday, we left town for the weekend, and when she attempts to start it on Monday....click.

The battery was about 6 years old and has required a jump from time to time over the past few months....but wouldn't respond to a jump this time. The jeep would just give a slight bump of the starter..and that would be it...I have since changed the starter and put a new red top in it, only to find that I get a more aggressive bump of the starter... This had me worried.

I pulled the fan and shroud so I could get a socket on the crank shaft and try to turn the motor over freely. Nope. It will rotate in the opposite direction(counterclockwise), and no I didn't go far, just enough to note that it wasn't seized...but once I get to the same spot trying to rotate clockwise, it stops...

I had done the timing belt and waterpump a few thousand miles ago, and am worried that the cam pullies my have loosened. The fact that they weren't keyed I thought was really strange and made me rather nervous, but it obviously works. The strange thing is that if they valve timing is off...it would have had to have happened either just as the jeep was being shut off, or as it was attempting to start that morning. If this is true, there may be hope that no damage was done to the valve train, and I may be able to reset it.

Is there a prcedure for checking the timing or resetting it? During the timing belt change, the procedure was more about maintaining the existing timing, so I'm not sure hot to go about verifying it if it is off.

jws84_02 · **Posted:** Thu Jun 30, 2016 8:26 pm

Chances are if timing did get messed up than 1 or more rockers are broke. Something in there isn't allowing the motor to turn. Only way to know is open it up

geordi · **Posted:** Thu Jun 30, 2016 8:57 pm

You are going to have to disassemble the top of the engine to the rocker arms (removing the valve cover) to find out exactly what has happened.

If any of the injector tips are bent / impacted, then that strongly suggests that you instead have had a valve failure. Not being able to rotate the engine is not a good sign unfortunately. There have been some situations where the rockers have gotten into the exact perfect place to hold a valve open - But if that has happened, then that also means that if it did this while the engine was turning, piston has met valve anyway.

Prepare yourself for the potential of needing to pull the head entirely. It is a good possibility that you will need to do this.

B4NGER · **Posted:** Fri Jul 01, 2016 2:33 pm

couple other things to check would be hydro locking from fuel or coolant/water leakage when it was sitting idle. Maybe pull injectors or or glow plugs and try and turn over? Mechanical damage from the rockers could be a definite possibility but the fact that it was driven to where it sat just fine(if it was running good when parked????) Also you could pull the serpentine belt off and make sure that none of the accessories are locked up (mainly thinking alternator or ac compressor) by turning them all individually by hand then trying to rotate the engine again from the crank with the belt off before digging straight into the engine.

TxBxSx · **Joined:** Mon Mar 24, 2014 6:22 pm **Posts:** 10

Hydro lock!

I pulled my glow plugs....but before I even got there I noticed some water had collected in the low spot of the intercooler hose before the throttle. This had me suspicious. Plugs 1,3 and 4 were dry, but #2 had some moisture on it. Once all the plugs were out I put my socket on the crank shaft (crank still being exactly where it was not wanting to rotate past before) and SPLOOSH! A fairly substantial amount of water shot out of the second cylinder plug port!!

Now...where did it come from??

I have had cool and disappearing for a lonnnng time. But thought all the while it was the water pump. I replaced it a few thousand miles ago when the bearings went out, but I've since still be loosing coolant. No smoke out of the tailpipe. But every once and a while I catch a slight scent of it when we first start the jeep up in the mornings.

Thoughts?

geordi · **Posted:** Sun Jul 03, 2016 6:32 pm

No guesses - Head gasket leak, and you have a big one. It is bleeding back into the cylinders when the engine is off - cooling engine creates negative pressure which draws water into cylinder.

You will want to get a fresh head gasket at this point, it would suck to do all the labor for ARP studs only to find that it didn't completely seal the leak. You will want the two-hole gasket, ARP studs, metal glow plugs (if you don't already have them) and the intake elbow kit. I'm SUPER HAPPY that you didn't have a valve drop! This is a fixable situation, I do not think the starter has the power to have hurt the rods, so be very happy that this didn't happen catastrophically or that the engine was able to fire off even once, b/c that most likely would have bent a rod and trashed it.

If you need help, I can provide that, but it sounds like you are in a good place to tackle it yourself.

TxBxSx · **Joined:** Mon Mar 24, 2014 6:22 pm **Posts:** 10

Update...

Cylinders 2 and 4 are spitting water, and #1 doesn't seem to be building any significant compression. I can feel some as I cover the hole with my finger and turn the crank, but it's not enough to push past.

jws84_02 · **Posted:** Sun Jul 03, 2016 7:19 pm

Man on man. How often did you have to add coolant? Sounds like a pretty substantial head gasket leak

geordi · **Posted:** Sun Jul 03, 2016 7:42 pm

TxBxSx wrote:

Update...

Cylinders 2 and 4 are spitting water, and #1 doesn't seem to be building any significant compression. I can feel some as I cover the hole with my finger and turn the crank, but it's not enough to push past.

Ok... That is starting to seem more like you maybe DID lose a valve. I've never seen 2 cylinders hydrolock together. You need to just pull the top, sadly there won't be more information to be gathered until you can see the tops of the pistons.

B4NGER · **Posted:** Tue Jul 05, 2016 8:23 am

Since the coolant was in 2 different cylinders I wouldn't put all my money on a head gasket failure, as Geordi said he has never seen 2 cylinders fail like that, apart from each other. You said water had collected in the low spot of the boost tube after the inter-cooler. Seeing water/coolant here makes me think 2 things, somehow it has leaked past the intake valves back down into to the boost tube from the cylinders, or that if you have an EGR still hooked up that it may have failed internally and is leaking/pushing coolant into the egr return gas stream, perhaps it had failed awhile ago (like you said missing coolant for some time), and on your wife's way home it failed worse and leaked a lot more coolant into the intake, maybe with the engine running it was able to still run and make it to where it was parked. I just would worry about you doing the head gasket and possibly not doing a Weeks elbow/egr delete and locking up the engine again after all that work. With the water ingestion possibly coming from the EGR it could have filled one of the cylinders just enough to break one of the rockers before it was shut off/parked, or a massive head-gasket failure happened in 2 non adjoined cylinders.

diesel_guy86 · **Posted:** Tue Jul 05, 2016 9:00 am

A junk cylinder head i have on the shelf has cracks in the intake valve area on i think 3 cylinders. This would not only leak coolant into the intake system, but also into the cylinder once the valve is open. Seeing how it was running when parked, its most likely not a dropped valve, but cracked waterjacket around the valve area. I can get pics when i get home.

This is somewhat starting to resemble the cummins "53 block" where they found that a certain casting number had cast/design flaws and would crack.

geordi · **Posted:** Tue Jul 05, 2016 11:13 am

Well - That would be interesting too. Can you post the stamped datecode from the head? It is on the intake side, just behind the #1 cylinder.

Engine won't turn freely!!!

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