No crank after timing job on 3.7L

[edekok90]

Hello all, this is my first time posting. So I recently purchased a 2003 Liberty Sport 4WD. After driving for a while, I began hearing what sounded like chain chattering. After doing research I decided to it most likely was due to a bad chain tensioner. Long story short, I bought a replacement kit, stripped everything down and put the new chain on according to the service manual. In the process of torquing the camshaft sprocket on the driver side the crankshaft counter rotated and so did the cams. Me being a newb I thought I could rotate the camshaft back to where the v6 marks are at 12 o'clock then independently rotate the crankshaft back to the TDC location.

I put the chain back on, rotated the motor and the marks still all lined up so I figured it was probably back in sync. So I reinstalled everything and went to crank the motor over and I just here a clunk sound almost like the start is trying to engage but then power complete cuts out until I go and wiggle the negative terminal a bit then it comes back on. Does anyone have an idea why this may be the case/what's going on? I also should mention I disconnected the camshaft sensor when performing the job but forgot to do the same for the crankshaft sensor. One last thing I should mention as well is when I was disconnecting everything the alternator wire accidentally touch the negative post on the battery while the positive was stiil connected. Melted the post a bit. Quite the poop show tbh. Any help would be appreciated.

 

[DadOSix]

Hello all, this is my first time posting. So I recently purchased a 2003 Liberty Sport 4WD. After driving for a while, I began hearing what sounded like chain chattering. After doing research I decided to it most likely was due to a bad chain tensioner. Long story short, I bought a replacement kit, stripped everything down and put the new chain on according to the service manual. In the process of torquing the camshaft sprocket on the driver side the crankshaft counter rotated and so did the cams. Me being a newb I thought I could rotate the camshaft back to where the v6 marks are at 12 o'clock then independently rotate the crankshaft back to the TDC location.

I put the chain back on, rotated the motor and the marks still all lined up so I figured it was probably back in sync. So I reinstalled everything and went to crank the motor over and I just here a clunk sound almost like the start is trying to engage but then power complete cuts out until I go and wiggle the negative terminal a bit then it comes back on. Does anyone have an idea why this may be the case/what's going on? I also should mention I disconnected the camshaft sensor when performing the job but forgot to do the same for the crankshaft sensor. One last thing I should mention as well is when I was disconnecting everything the alternator wire accidentally touch the negative post on the battery while the positive was stiil connected. Melted the post a bit. Quite the poop show tbh. Any help would be appreciated.

sounds as if you have 1 cam 180 degrees out of time with the rest of the engine.

don’t force it over with a big wrench. most likely scenario is at least 1 valve is striking a piston.

If you are careful, you may not need to tear the heads off.

no more starter bumping.

disconnect the battery, and strip back to the timing components. remove the tension(er) and with chain loose / off, get the crank in the right place. there is a 50 / 50 chance that it will be on the tdc mark. reset your cams and then chain her up and tension. try and rotate by hand then, in the direction of rotation only. check for binding up as you crank by hand. if it freely rotates, you are hopefully good to go.

best of luck!

 

[edekok90]

sounds as if you have 1 cam 180 degrees out of time with the rest of the engine.

don’t force it over with a big wrench. most likely scenario is at least 1 valve is striking a piston.

If you are careful, you may not need to tear the heads off.

no more starter bumping.

disconnect the battery, and strip back to the timing components. remove the tension(er) and with chain loose / off, get the crank in the right place. there is a 50 / 50 chance that it will be on the tdc mark. reset your cams and then chain her up and tension. try and rotate by hand then, in the direction of rotation only. check for binding up as you crank by hand. if it freely rotates, you are hopefully good to go.

best of luck!

I’m an idiot. It was actually just loose connection thankfully. Runs fine so far. Hope it stays that way.

 

[DadOSix]

I’m an idiot. It was actually just loose connection thankfully. Runs fine so far. Hope it states that way.

Whew! Best possible out come!

 

[sleazy rider]

Whew! Best possible out come!

I was envisioning bent valves and kissed pistons. Great news.

 

[edekok90]

I was envisioning bent valves and kissed pistons. Great news.

Whew! Best possible out come!

Most definitely!

 

[edekok90]

I was envisioning bent valves and kissed pistons. Great news.

That was my concern when I went to crank it over! Lol

 

[AFT2008KK]

That was my concern when I went to crank it over! Lol

Congratulations! Sometimes the Jeep DIY gods do watch out.