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07 commander 4.7 help

591 views 9 replies 3 participants last post by  Archie102281 
#1 ·
I have 2007 commander 4.7 the check engine light came on yesterday and the codes were p2302 and cylinder 1 and 5 missfire so I changed the plugs and all cleared except the p2302 so I made a tester for the coil and checked cylinder 1 coil and I get power but no spark all other cylinders I get power and spark. I checked the coil from 1 on 3 and got spark so the coil is good. Im getting 14v to the coil on 1 but no spark. Any help would be greatly appreciated.
 
#3 ·


This statement does not make sense. A head gasket should not have any impact on generating a spark unless the air/fuel ratio is so far off in one cylinder that the engines computer shut down the injector and coil. I do not believe the computer on a Jeep will do that for an individual cylinder though. It could be a wiring issue on the ground side, electrical connector issue on the ground side, or a bad ecm signal on cylinder #1.

How many miles are on your vehicle?

Are you losing any radiator fluid?

Did you or the Dealer perform a compression test on all eight cylinders?
 
#5 ·
They said there was coolant in cylinder 1. Yes im lossing coolant. But im also having a problem with it over heating once a week. After I changed the thermostat so I didnt think to much ofit thought it was just an air bubble. They are saying that it is grounding out thats why there is no spark
 
#7 ·
You very likely need a new head gasket if you are losing coolant and over heating. Do not wait on this repair if you plan on keeping the vehicle. Coolant in the engine is bad for the piston and crank bearings. If it is grounding out, there must be a significant coolant leak in cylinder #1. Yes, this can happen.

Changing the head gasket is not a difficult task, however, it requires a lot of labor removing and replacing all of the parts to get the head off the engine. A full gasket kit costs about $100. Labor is what will be the most expensive part. Book time is 14 hours for both heads, probably 10 hours for one engine head. It took me almost 10 hours to remove and replace my left cylinder head and I am an advanced DIYer.
 
#9 ·
A couple of tips.
1. Replace the timing chain while you are in there. I got mine from summitracing for $250. Do not purchase a Chinese made chain. You will be sorry if you do. My gears were fine.
2. Use new head bolts and follow the torque guidelines. I like to put a small paint mark on each bolt so you know how much you have turned each on the last torque phase.
3. I like to remove the rocker arms before putting the timing chain back on. That way you can easily install the chain. There is a special tool for this that makes it easy. Freedom racing has the tool to purchase or rent for half the purchase price of $90.
4. If you do take the rocker arms off make sure you mark them and put them back in the places where you took them. Each of them wears uniquely and should stay with the cam lobe they came from.
5. Do not forget that there are ground wires behind and screwed into the cylinder heads. These need to be removed before taking off the head or you will break the wires.
6. You can rent a large flywheel puller from Autozone part 27271. You will need this.
7. I used a short chain and lock attached to the sway bar to hold the flywheel in place while removing and tightening the flywheel bolt.
8. Check to make sure the cylinder head surface is flat using a ruler and very small feeler gauge. You may have to have the head re surfaced at a machine shop to make sure it is flat. If you do not have the tools, a machine shop can tell you if the head surface is flat. This is most important. If the head surface is not flat you could blow a new gasket on start-up.
9. Get a new bolt set for your exhaust manifolds and down pipe connections. The old bolts will be too rusted to re install.
10. Be prepared to use a cut off tool on the two bolts that connect the exhaust manifolds to the down pipes. They may be too rusted to remove with tools.
11. Consider changing both head gaskets while everything is apart.
12. I had to pull the inner plastic front fenders off to get to all of the exhaust manifold bolts. If you do this you will need new plastic rivets to reinstall the fenders. I prefer installing the exhaust manifolds AFTER the heads are installed. That way I know for sure that the head was installed perfectly and sealed perfectly. The front fenders on my 2005 WK used Marson 48150 plastic rivets at $7.50/ box plus the cost of the rivet gun. Marson 48000 rivet setter $20.00.

Good luck. Budget a minimum of 14 hours plus machine shop time.
 
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