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Ask Greg Your Own Question
Greg
Greg, Technician
Category: Jeep
Satisfied Customers: 6891
Experience:  maintain jeep wrangler's for a off road rental company,
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I own a 04 jeep grand cherokee with a 4.7 and it keep popping

Customer Question

i own a 04 jeep grand cherokee with a 4.7 and it keep popping a crank and cam sensor code and both have been replace
Submitted: 1 year ago.
Category: Jeep
Expert:  Greg replied 1 year ago.
Can you give me the codes that where read please .and any other codes that where read if any .Greg
Customer: replied 1 year ago.
The code is #1391 ..
Expert:  Greg replied 1 year ago.
Thank you, ***** ***** back .was this the only one ..
Expert:  Greg replied 1 year ago.
Another question where did you get the sensors ,OE / Aftermarket ?? Greg
Customer: replied 1 year ago.
They are both mopar sensors
Expert:  Greg replied 1 year ago.
Okay good best option . If this is the case then you need to check the crank and cam sensor reference signal is getting to the PCM if not then you have a connection or wiring issue , if you are then a possible bad PCM which is not that common..What is common if you are getting a reading is a bad crankshaft keyway damage ,this should be checked ,if this is the case you will notice at 3000 or more RPM the engine starts to miss.Lose timing chain is also a possibility, was any work done on the engine ?? Greg
Customer: replied 1 year ago.
Let's see where do I start this Engine has been completely overhaul new timing chain/ gears tensioner/ alll changed .. replace the driver side head at the Being overhaul because it was shaved below specs replace the tensioners again replace the fuel pump I replaced the PCM the issue with the jerking happens at 20 to 30 miles per hour then it's smooths out and drives like a dream . And then again at 70 to 75 miles
Expert:  Greg replied 1 year ago.
Looks like the work needs checking like the timing chain ,i suspect this could be off one toothor as i said the crank keyway as suggested .Have seen this happen ones where the passengers side cam timing was off one tooth .This is going to be a long job checking this ,the rebuilder will have to double check the work he has done if the two cams and crank sensors are okay and prove to be working using a scope making sure the two are working correctly . Please get back to me with the reply button, and not the poor or bad service, this way i can get back to you or suggest another expert if needed.Your deposit does not pay me until the answer is rated in a positive way,Not rating or a bad rating does not constitute a refund.If you are not happy or you have sorted out your problem before the answer then please let me know with the reply button .Kind regards Greg.