Ill start by letting you know the yr and such. I have a 00 neon 2.0 5spd. Has about 140k. I was cruising down the highway going 65 when my rpms went crazy nd the car bogged down. I managed to keep it going at 2500rpm in 4th gear. Once I stopped at a light it stalled... got it started nd it was running with a severe misfire(had to over rev to get going). I managed to get the codes with my bluetooth obdII Scanner. 0391 and 0390. Cam crank not in sync and timing skipped 2 or more teeth. What are the odds of this happening considering timing belt nd water pump were replaced less that 30k miles ago. Ppl tell me my motor is blown but I dont want to accept it. Is it possible that the cam or crank sensor failed on me...or the cam magnet broke??? I need this as a daily driver. The car wont start now and I have the will power to open the timing, I just want some insight as to what may have caused this. Is there any type of shortcut to diagnose this issue or do I start dissassembling my motor. I have a parts car so I pulled sensors but have not had the time to put them in. Any type of feedback is greatly appreciated

 

Do look just above your posting the OBD II code and what it means for help. On the top of the plastic timing belt cover there should be a little plug. Try pulling the plug and see if you can look at the cam gear and alignment marks. at TDC they should line up if the timing belt did not jump teeth.

 

I can check that... but wouldnt I also have to see the tdc for the crank sensor also to ensure? Or does the cam always end up lined up when the motor is shut off? If I crank a pulley till it lines up or is the compression supposed to make it land at tdc once its shut down? Thanks for a response ill check when I get home.

 

Ok, so I ran a diagnostic test of my own, just want to make sure im right. I removed the cap that exposes the timing mark of the cam. I pulled out spark plug on cylinder 1. the put a 1ft metal pipe(about 3/8" round) into the hole to rest on the piston. I then cranked the crankshaft bolt until the pipe stopped going up and was about to go down. Looked at the cam and did not see a TDC mark at all. So I continued cranking until the pipe went all the way down and back up to the top. the TDC mark was back exactly 1 tooth from lining up with the mark on the timing cover. What I'm asking is... is that the right way to determine top dead center and that the timing belt skipped 1 tooth on the crank? If so I guess ill probably pull the timing cover and go ahead and reset the timing and put a new belt and tensioner in. Timing belt and water pump(and seal) were done 25k ago so I don't think I need to replace the water pump again but since im in there and the belt is cheap... and the mechanic that did it last probably didn't change the tensioner because its not the hydraulic one. Also since the belt did not break or skip more than one tooth, do I need to do a cam/crank relearn or will the car figure out that its fixed. I do not have the expensive scan tool with that feature. I had neon in the past that skipped 4 or more teeth and I tried to fix it, and the timing was perfect but would not even crank over more than quick click because I did not do the cam/crank relearn

 

There is a youtube video that shows a guy putting a compression gauge on #1. Then he used a wooden dowel to find TDC. If you go that route once you reach the highest point on compression you should be at TDC and the 2 cam marks should be aligned. I did the Timing belt in Feb. I got the kit from amazon for about $100. Belt was a Gates, tensioner was Canadian with alignment marks for proper tension and the water pump is made in China. I borrowed the pulley puller from O'reilly's. It's a pain to do and if you go for it take your time. It's also a good time to inspect all you engine, transmission, and strut mounts.

 

Sometimes when people don't do the tensioner idler pulley, it comes back to haunt them, especially on high mileage cars. Also if any debris wasn't cleaned out, it gets trapped inside the cover and can jump the belt.

 

Thanks for the responses. Based on what you both said im on the right path. I have dealt with the oh so fun timing removal in this car before so im not afraid to open her up. Just waiting to have the funds to afford the tensioner pulley and belt. I wont take it apart until I have the parts on the way. Im not going to replace the water pump since it only has 20k or so on it. I believe they did the crank oil seal when they were in there last as well. I will order a new timing belt and tensioner. Found them on ebay, $58 for the tensioner and $13 for the belt. Can someone read the diagnostic procedure I did and tell me if TDC is for sure at the top stroke of piston number one?