Jeep Commander 06 4.7 head replacement

[baron1701]

Hi - My jeep ran hot a few times due to a leaking radiator. The last time I restarted it she imediatley ran very poorly.

I checked the compression and the Pas side head read zero on the first cylinder and low on the next. The drivers head was 157 to 160 for all cylynders.

I assumed a head gasket and hired a guy to do the job.

The person took my money and ran, more or less. Whether he got in over his head or was scamming me the whole time doesn't matter, the jeep was left in pieces.

He removed the intake and valve cover. He pulled the chain off the camshaft, broke the guide and didn't mark anything. He showed me a rocker arm that was floating around in the head before leaving the job.

I had some serious money trouble right afterwards so now I am going to try the job myself.
I plan to buy a new head from the junk yard. I bought the deluxe gasket set with bolts and everything included. I would just put a motor in but the prices around me are in the range of 1500 for a junk yard motor with 130+ miles. I figure I don't have much to lose trying to fix it.

I pulled the radiator and everything out of the way. The head bolts are broken loose. It looks like I have to take off the Harmonic Balancer to pull the engine cover off.

Im confused on a few things.

The engine ran great and then after it was started the last time it was missing and misfiring. I see how that's possible with the rocker arm bouncing around.
I am assuming that the timing is right where only the one cam chain was taken off does that make sense?

If I align the timing mark of the harmonic to the TDC on the cover how do i prevent it from turning while I use the puller tool?

[rhandwor]

You need to borow a manual or subscribe to alldatadiy. Timing is critical on this engine. All timing marks have to line up. Check all timing marks, Replace defective guides. While pulling harmonic balancer it will stay steady as you tighten the puller. This engine has a short timing chain that drives a pulley above the crank pulley. Both
camshaft chains are driven off this pulley. Their is a hole in the pulley have someone else hold a bolt in the hole align painted marks to mark on pulley. Otc makes a special tool for the job. Hole in block and pulley after the marks are aligned.

[baron1701]

I removed the head and it was a dropped valve seat. : (

The #2 piston now has a decent mark on the top of it.
I used a brass wheel and my drill to clean things up but now I don't know what to do?

I pulled a head from an '03 Durango. It looks good. I have cleaned it up and have to run a straight edge around It to make sure its ok. I was going for both heads but the other head had a sheared off cam sprocket so I left it in the donor vehicle.

Should I leave the piston in the engine? Its not cracked and it is moving properly.
The valve seat stayed in the head but it did imprint the top of the piston. The cylinder walls looked good. It looks like a crescent shaped mark. I will try to post pictures later. Im hoping I caught it in time.

I found a picture online that shows VERY similar damage. My engine was a lot cleaner but this picture can give you an idea.

[rhandwor]

I have pulled a head on a Volvo 960 with a interferrence engine. Most pistons were scarred I asked the machinist who did the head and he said it should be satisfactory for use. If under 1/4 inch depth at the deepest I think you could use the piston.

[baron1701]

Thank you. I think its worth a shot.

[baron1701]

Any opinions on whether or not to change out the drivers side head?
The problem was a dropped valve seat not a head gasket. The vehicle did overheat but the head checked out good in the compression gauge. I am worried about pulling it.

The machine shops here charge almost $100 to flatten the head and pressure test it.
I also believe that the valve seat is not something I can have preventively fixed or inspected.

[rhandwor]

It's cheaper to purchase a head set. Pull the head clean and use a straight edge. Look at the valve springs and reinstall.
If you don't want to pull it take a chance and save the spare gasket.
A lot depends on your time available and age.

[baron1701]

I looked over the bad passenger head that I pulled out of my Jeep and it seemed that one other seat was hanging out a little bit. I hit the valve and it pushed in with a few light hits from my ratchet.

I think I am going to pull the drivers head carefully and check the valve seats. If any are coming out a little bit I will have to go to the junkyard and pull another head. My worry is dropping another seat down the road and ruining a piston. I have found a few pictures online and I was very lucky to only have a scratch on my piston and not shatter it.

[rhandwor]

I think this is a good idea.

[baron1701]

I pulled the Drivers side head - looked great. The valve seats were flush, no sign of failure. The gasket was also in great shape. I checked with a straight edge and was very happy.
I re-installed it following the torque instructions.
I did have to guess on the torque for the 4 small bolts but I am pretty sure I nailed it.

torqueing down the 14 bolts in sequence took longer than I thought. I did it slow and steady.

The passenger head was removed from a Durango and the manifold flange was different so I stopped for the night. I will resume tonight after the kids trick or treat.

I also did the zip tie trick for timing. Im not sure how to remove them before I put the idler and crank pulley back on but I will figure it out.

At this point I will be very happy with my $100 repair ( other than the $ 450 the craigslist mechanic stole ) considering the valve seat failure usually results in Jeep death.

[rhandwor]

How did your job turn out?

[baron1701]

Hi - im still working on it - I expect to finish sometime next week.
I have both heads installed but I broke the Timing Idler Tensioner while getting ready to set the timing. The plastic piece cracked.
Better now than while running.

Im waiting on the parts. I may put the intake back on and get some other stuff ready but I cant do much at this point.

So far it has been a very easy going job. I got very lucky that the damage didn't get too bad.
The Jeep is from North Carolina so disassembling the bolts and part has been great, no rusted parts.

I did not send the heads out so I am worried about that part but everything else seems good. If the gasket doesn't hold - I don't see it being too difficult to pull one of the heads and do the job again now that I know what I am doing.

What is the foam piece that looks like it fits under the throttle body? I wasn't the one who pulled the throttle body off of the Jeep. The Durango I pulled the head off of in the junk yard didn't have anything like it. I looked up the part number online and I couldn't find a detail.

[rhandwor]

Originally Posted by baron1701

Hi - im still working on it - I expect to finish sometime next week.
I have both heads installed but I broke the Timing Idler Tensioner while getting ready to set the timing. The plastic piece cracked.
Better now than while running.

Im waiting on the parts. I may put the intake back on and get some other stuff ready but I cant do much at this point.

So far it has been a very easy going job. I got very lucky that the damage didn't get too bad.
The Jeep is from North Carolina so disassembling the bolts and part has been great, no rusted parts.

I did not send the heads out so I am worried about that part but everything else seems good. If the gasket doesn't hold - I don't see it being too difficult to pull one of the heads and do the job again now that I know what I am doing.

What is the foam piece that looks like it fits under the throttle body? I wasn't the one who pulled the throttle body off of the Jeep. The Durango I pulled the head off of in the junk yard didn't have anything like it. I looked up the part number online and I couldn't find a detail.

Look at http://www.rockauto.com/ Look at 2006 Jeep Commander throttle body gasket. They have pictures.
I would go back with these gaskets or equivalent.

[baron1701]

This weekend I finally got around to putting some serious time into the job and wrapped it up 95%. Once I put the front engine cover on I just went to town putting everything back. I expected problems but I didn't run into anything major. I put everything back together last night and changed the oil. I had no coolant but I was so excited so I fired it up twice and ran it for less than a minute and it started up just fine.

I have some loose ends. The 4 plugs in the boneyard head are from the old vehicle and my other plugs are toast. I am putting new plugs, thermostat and coolant in tonight before running it to temp and testing it.

I am having a lot of trouble with the EGR tube. The thing cracked at the flange where it tightens up onto the EGR. I cleaned it and filled it with JB Weld. I will try to put it on tonight. For some reason it did not want to fit into the throttle body - the angle was wrong. Do you have to take it off before you put the manifold on and then bolt it back on? I have to wonder it it got bent somehow. I intend to grab a used one off of Ebay. New was $68 at the Stealership ~ if it was 30 -40 I would probably bite but $68 for a flanged tube?

Time will tell the final outcome but I'm feeling a lot better about the job hearing the motor start.

Pics are shortly before putting cover back on.

[rhandwor]

You might get a better price at a junk yard with a scrap engine. Maybe where you purchased your heads.