Last post on Apr 05, 2011 at 5:11 PM
You are in the Jeep Cherokee and Jeep Grand Cherokee
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Jeep Grand Cherokee, Jeep, SUV
#1 of 42 02 Jeep Grand Cherokee died suddenly at 50mph
Jan 18, 2008 (3:36 pm)
Today I was driving along at 50mph in my 2002 Jeep Grand Cherokee Laredo 4.0L when suddenly it felt like I lost half the power. A few seconds later the engine died. I coasted to a stop and was able to restart the engine numerous times. It would idle fine but as soon as you gassed it the engine would start misfiring again, sputter and stall. It did this a few times and now it won't even start at all.
I did the key trick and received 5 error diagnostic codes:
P0340 Camshaft position sensor circuit malfunction
P0351 Ignition coil A pri/secondary malfunction
P0352 Ignition coil B " " "
P0353 Ignition coil C " " "
P0455 Evaporative Emmission Control System Tank Detected (gross leak)
I believe the the P0455 was present before this cut off. I think that code is due to an aftermarket gas cap.
The other four codes are what have me concerned. Can anyone offer any ideas as to what would make those codes all come on at once? Seems odd that all coil packs would fail simultaneously.
Where should I begin? At first I suspected a fuel filter, but now after seeing the codes I don't think that is it.
Jan 19, 2008 (12:41 pm)
Today I inspected the camshaft rotor sensor. I couldn't understand why Jeep would build a vehicle with the wire connection jammed up against the block. I noticed some metal shavings just below the sensor. I put 2 and 2 together and realized that the piece that holds the sensor (maybe called rotor?) had spun about 1/4 turn. I asked someone to watch the small rotor under the camshaft sensor to see if it spins when I bump the engine over and it does not....CRAP! I pulled out the rotor assembly that goes down into the engine block and I find a seized rotor with large metal teeth that have sheared off into my engine somewhere. Has anyone experienced this before? I am assuming that this means I have to drop my oil pan to at least fish out the metal teeth. My other concern is that the teeth on the other end (in the engine) may be damaged as well. PLEASE HELP!
#3 of 42 Re: follow up [blanblan]
Jan 19, 2008 (12:54 pm)
not to worry bout cam not turning has chail to drive cam
sound as if distrubator has frozen
#4 of 42 Re: follow up [tuggajb]
Jan 19, 2008 (1:07 pm)
Is it still called a distributor on the cam sensor rotor doohickey? This is an 02 GCL and has no other distributor that I can see (coil packs).
#5 of 42 Re: follow up [blanblan]
Jan 19, 2008 (2:10 pm)
It looks as if it is called a camshaft synchronizer. It looks like a tiny distributor for the camshaft position sensor.
I am hoping a Jeep tech will tell me the best way to go about changing this item out...mostly I want to know how I can be sure that whatever gear this connects to has not sheared as well. It is impossible to see from the top.
#6 of 42 Re: follow up [blanblan]
Jan 19, 2008 (4:03 pm)
more than likley didnot shear gear, from jeep service manual not any harder than dis to change only thing that is a bear is making sure that you have timed it right (they dont use a timing light with this but turn and adgust timing with the computer reader on the engine computer)
#7 of 42 Re: follow up [tuggajb]
Jan 21, 2008 (9:42 pm)
Is this the type of thing that I can get the timing close and the computer will take up the slack or is this a dealer only timing fix?
#8 of 42 Re: follow up [blanblan]
Jan 22, 2008 (5:54 pm)
prob dealer only as computer has to have the timing real close to even stare (sure not like the olden days )
#9 of 42 another update...getting closer
Jan 24, 2008 (7:48 pm)
I managed to fish out each piece of metal teeth by removing the oil pan. Can anyone tell me how the camshaft synchronizer is put in mechanically...meaning how (where) should the gears line up? I realize that it has to be fine tuned (timing) by the dealer, but I still have to get it somewhat close mechanically because you only have so much rotational adjustment. I can't see any timing marks anywhere. My best guess by looking at it is to maybe put the engine at TDC for the #1 cylinder and install the synchronizer with a "set pin" in the small hole (in the side of the sychronizer). Can a Jeep expert confirm this for me? SOS PLEASE HELP! I am desperate here and I think I'm the only guy on the planet whose sychronizer seized up. Even the Jeep dealer sounded baffled.
Jan 26, 2008 (4:41 pm)
I got my 02 Jeep Grand Cherokee running super again. I'm sorry to say that forums were of little help but that is why I'd decided to post a how-to for others who experience this problem (seized camshaft synchronizer). There was very little help anywhere with this problem, so it is no offense to this particular forum. Obviously if teeth broke of of your synchronizer down near the oil pump drive you are going to have to get those out of your engine somehow before continuing.
Now for how to replace your camshaft synchronizer. If your vehicle was running when this device seized, then you have lost the timing relationship between your cam and the camshaft sychronizer. In order to get it back you first need to get your #1 cylinder to TDC (top dead center) of the compression stroke. If you aren't sure how to do that, then you probably shouldn't be attempting this job yourself.
When you purchase a new camshaft synchronizer you may or may not notice a temporary plastic set pin which passes through the aluminum casting into the small rotor (on the top part of the casting which stays outside the block). If it is not there, you will have to put something there to keep that position. I used a small piece of scrap 12 gauge household wire.
The goal is to put the new camshaft synchronizer into the block so that it ends up with the position sensor wire connection facing straight back towards the firewall at 0 degrees from the block (basically straight back towards the oil filter). This may take you a couple tries since the gear on the synchronizer that meets the gear on the cam itself match up diagonally. This means you have to start farther counter clockwise from your ultimate goal of 0 degress and rotate clockwise as you push it into place. You may also have to move the oil pump slot a couple times with a long screw driver to line it up. When you get it to seat fully with the wire connection straight back, #1 cylinder at TDC (compression stroke) and temporary set pin in the camshaft synchronizer, then you have finished the hard part!
At this point, I replaced the hold down clamp which anchors the synchronizer, put the small plastic camshaft position sensor back on and reconnected its wires and removed my temporary set pin (wire). You may still have to bring it to a dealer to have the timing fine tuned, but if you get it right, you can drive it there. I could tell when I first started my engine that I was one tooth off (advanced). I just lifted the camshaft synchronizer up just far enough to spin (retard) it one tooth. On my second try, the engine sounded terrific. If you don't know the symptoms of timing being too far advanced or too far retarded, then you probably don't want to attempt this job because you could cause engine damage...especially if your timing is way too advanced. If you were truly at TDC on #1 cylinder, you should be good to go. If it doesn't start you may have to repeat the procedure. You may have been at TDC of the exhaust stroke instead of the compression stroke meaning you were 180 degrees off.
Hope this helps...it took a great deal of digging to get the right instructions.