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Chad
Chad, Lead Master Tech
Category: Chrysler
Satisfied Customers: 1114
Experience:  Electrical master,Diesel Specialist,Lead tech/ shop foreman
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Chrysler 300 C: My engine acts like it's hitting the rev limiter

Customer Question

My engine acts like it's hitting the rev limiter under heavy acceleration, or around 3500 rpm in any gear, any suggestions…
Submitted: 2 years ago.
Category: Chrysler
Expert:  Juan Crespo replied 2 years ago.
Hi there. Welcome to our site. MAP signal and/or CMP signal out of parameters and even a restricted exhaust can make your engine run like you describe. What model Sebring are you working on; 2D coupe, convertible, 4D sedan? What size engine? Do you have access to test equipment?
Customer: replied 2 years ago.
It's not a Sebring, it's a 2005 Chrysler 300c 5.7l. Getting a p0016 and p0137 code on the scanner. I changed the cam sensor but didn't want to mess with the crank sensor until I got more information
Expert:  Juan Crespo replied 2 years ago.
Thanks for the clarification. I thought I had seen "Sebring" under the category - clearly a glitch. Code P0137 should be easy to check as it points to a short to ground on the Oxygen sensor heater return signal circuit. This usually happens when that part of the harness rubs against a sharp bracket or comes in contact with an exhaust pipe.Code P0016 is not that much harder to diagnose, but requires using a lab scope to do so - single channel will do for these tests. If you need to, give me the brand name and model number and I'll "walk" you through the procedure.We'll need to "look" at the signals from both cam and crank sensors to determine why the PCM thinks they're not synchronized. Once we do that, we can know for sure whether the issue is caused by bad sensors, connectors, wiring or even a worn timing chain.
Customer: replied 2 years ago.

I definitely DO NOT have nor have access to a lab scope... is there any other way to diagnose the problem?

Expert:  Juan Crespo replied 2 years ago.
I wish there was a simpler way, but unfortunately there is none. You see, the lab scope is a voltmeter that shows a voltage signal over time so we need it to look at those two signals (CMP and CKP). Other than that, you could try a scan tool capable of reading sensor data to see what values the PCM is seeing from those two sensors, but that kind of scan tool is usually much more expensive than a single channel scope and would be much harder to use for someone who is not a pro.To give you an idea of what prices are, laptop-based lab scopes start at less than $100 on ebay, self contained units go for about $400. On the other hand, good used scan tools like the one we would need go for around $800.I've got both the knowledge and the desire to help you out, but please understand that you got to have the right tools to work on this type of issue or things can get very expensive very quickly. Please let me know how you'd like to proceed. Best Regards.
Customer: replied 2 years ago.

I'll change the CKS, and see what happens from there. I'll get back to you tommorow...

Expert:  Juan Crespo replied 2 years ago.
I understand and agree with your decision; since lack of tools forces us to guess, changing the CKP sensor is the the least expensive option.I'll be back online tomorrow after 2PM. Hope to hear good news from you then. Best Regards.
Expert:  Chad replied 2 years ago.
Hello, new expert here. Do you still need assistance?
Customer: replied 2 years ago.
Changed both camshaft and crankshaft position sensors, still seems to have the same issue as before
Expert:  Chad replied 2 years ago.
I have seen this same thing a dozen times, all on your style car with the 5.7 hemi in it.I have changed all the sensors and had engineering come down and ride with me on a few of them. Luckily, I have actually found and fixed all of the ones I have seen. the only problem is that there is only one fix that will take car of the problem.The repair to fix the concern that you are having is to replace the engine wire harness.I have not been able to find the same bad spot in the harness, but ever one of the ones I have seen is the wire harness has been stretched by the torquing of the engine and damaged the harness.Like I said you will need to replace the engine harness on your car to repair the concern that you are having.
Customer: replied 2 years ago.
Is it hard to change the wire harness?
Expert:  Chad replied 2 years ago.
I don't think it is hard to change. But I don't know your technical abilities. You have to be able to get to the bottom of the engine to disconnect some of the sensors.You also have to route the harness correctly to get all the connectors to fit back where they go.