Yes a compression test has been done and it goes into limp mode just past 2000 rpm and throws the cam sensor code. Thats been the issue right after he replaced the belt and replaced the head with a used head (for unbent valves). They have tried replacing the cam sensor 4 times and they have even repositioned the belt. No change. My uncle said before handing it over to the shop that it was running on all cylinders.

 

If it is true that there is somehow a different number of lobes, it would cause a problem because valves wouldn't be opening/closing when they should, or at all if there isn't a lobe for the valves. The lobes are along the camshaft though...they are the teardrop looking things. They aren't just on one end of the camshaft. If the camshafts were different, I would have changed it out anyways to the original one before installing the head.

 

Yeah thats what my fiance said too. My uncle said they are identical except for the one he replaced it with has less lobes the my original one. He didn't think it was an issue and the guy at the shop said he didn't think it was an issue either but they've done everything else they tell me and it doesn't change anything. After replacing the cam sensor 4 times and realigning the belt with a professional shop don't know what else would continue to throw that code and neither do they. Their getting an intermittent cam sensor error code so logic is telling me that its because the cam isn't sending the right number of pulses to the ECU do to the lack of lobes on the "new" cam. I'm no mechanic but it makes sense to me. I'm just hoping this does it, my uncle has my car back at his shop and is gonna try and swap the cams today/tomorrow. I just hope it works, I really don't know what else it could be...I can't see my car being totally shot due to a broken timing belt? My fiance said he's never seen a timing belt be this much an issue before.

 

Well, the head itself is interchangeable. That doesn't necessarily mean that everything else is. In 2003, certain sensors are read differently by the computer...this was due to the new computer system dubbed "NGC." When people swap in a 2003-2005 engine into an older Neon, they have to switch over the sensors as well. It would make sense that by having a complete, older head in a newer engine could potentially cause problems; at least in my mind based on the above.

The trick before swapping things for older and newer year vehicles is to make sure everything is indeed the same before doing it. While the 2.0L SOHC stayed the same over the years, there were "improvements" to certain systems.

 

Its fixed!!! Actually I guess my uncle found the issue finally! He said what it was, wasn't the cam lobes (even though my original one did have more) he didn't even have to swap the cam! He said it was a magnetic cam screw on the end of the cam? He said my original one was different from the one put in on the new head. So its almost like you said the computer was trying to read an older model cam screw and didn't like it. He said as soon as he put the old one back on, No more CEL and it revs up great without issue! I can't wait to get my car back! Now all I have to figure out is whether or not I request a refund of the 400.00 I was charged by the other shop for basically doing nothing. Even though they gave me a break on the labor a little they didn't fix it and they didn't even have an answer as to what was wrong so now I'm wondering if I should get that money back? And thanks for all the suggestions and help!

 

Did you use a credit card? Dispute the charge. I use my CC anymore for big things/services because if I get charged a lot for a service that goes bad, you're CC co. will help fix it. My experience with it was getting a full-refund of $750 from a shop that butchered some things they were installing on one of my cars. Congrats on getting the car fixed BTW!

 

Hi, My timing belt broke about two weeks ago. Unfortunately the worst was true, and the valves were bent. I bought a used Head from the local pick a part, and installed it. We had a tough time getting the timing belt on and making sure everything was lined up but finally did.

I now have the same problem that the rwebber16 had, The car goes into limp mode over 2000 rpm. I changed the Cam magnet yesterday after reading this, but am still having the same issue. This time the car was able to get to 3000 rpm and 30mph before throwing a P0016 error.
I have changed the CPS already, and we cannot seem to figure out what to look at next. The issue points to timing being off, but The marks line up. After the engine is run the timing appears to be off by one tooth, but I have been through 3 belts and 2 tensioners and am still having it correct to one tooth off, so...?

Did I miss another Sensor some where that is faulting because of the different head? I have heard that swaping heads can cause issues, but I am kind of stuck at this point. Thanks for any help.

RWebber, I am glad that your car is helping. Thanks for posting.