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Timing belt change complete, won't roll over

Discussion in 'Neon' started by coltmac, Jan 16, 2017.

  1. coltmac

    coltmac Active Member

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    While working on my 05 Neon to repair it after hitting a deer, I thought it would be a good time to go ahead and do the timing belt and water pump. Car was nearing 100K and seemed like the thing to do. Now I'm regretting this decision. So new timing belt, water pump, serpentine belts were installed (and radiator and headlights from the deer damage). Also replaced the oil sensor (leaking) and changed oil/filter. Now job all done and car back together, but car wouldn't roll over. I knew the battery was rather week before starting the work, so went ahead and put in a new battery. Then when it rolled over the starter seemed to struggle and alternated between rolling and grinding. So hoping that it was a bad starter and not anything worse, I bought and new starter. Now it only starts to roll if I roll the engine to a non compression point. The new starter won't even roll it over. So now I'm running thru all I worked on trying to determine what I've screwed up and not knowing where to begin. This is the 1st time I've attempted this job and of course did a little research before beginning. I know it is an interference engine and tried to be very careful not to mess up the timing. I aligned the two timing marks like instructed at TDC, and once the belt was removed, did not move the crank or the cam independently except the crank back three teeth and forward two to give some slack for putting on the new belt. after installing the new belt and adding tension, I rolled the crank clockwise 2 rev's and found the cam mark was 1 tooth off. Made the adjustment and rolled the crank again and the marks were aligned correctly. At this point, I keep thinking that I've got it out of time and am really screwing up the engine every revolution, but don't know how I could've done it or how to check it. I've turned the crank with a breaker bar and socket and it seems to roll pretty easy, but that is relative since I don't really know how hard it should be. Any ideas on what this could be or what I should be checking would be greatly appreciated. Thanks in advance.
     
  2. AllanC

    AllanC Well-Known Member

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    Even if you had the crankshaft - camshaft timing off by 1 tooth, I believe that would NOT cause a piston to hit an open valve. Try this. Remove all 4 spark plugs, With no spark plugs present the engine should turn relatively easily and evenly at the crankshaft pulley. Have a helper turn the crankshaft slowly in a clockwise fashion 2 complete revolutions. Listen at each spark plug opening for any strange sounds like metal / piston hitting a valve.

    If it turns smoothly and without any noise or sound of metallic content, then you should be satisfactory and correct with installation of the timing belt. Then go to the starter and fashion a jumper wire to momentarily connect the battery terminal at the starter solenoid to the smaller terminal at the solenoid. That should engage the starter and allow it to spin the engine. With no spark plugs and compression, the starter should spin the engine at much higher speed than during normal engine start.
     
  3. pt006

    pt006 Active Member

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    Mac; if you have the 2.4 liter DOHC engine you're in luck. It is not an interference engine. I like Allan's idea. On a PT, there is a plug in the right front inner fender panel that gives a straight shot to the crank pulley bolt. By using a 3/8" ratchet/long extension and with the plugs out, it should turn over smoothly.
     
  4. ImperialCrown

    Level III Supporter

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    If it isn't an SRT-4, then it is a 2.0L. To check for bent valves, I remove the valve cover and loosen the rocker shaft bolts until all valves should be closed.
    With a compression gauge hose screwed into the spark plug hole, the cylinder should hold air pressure. If air is heard at the throttle plate, the intake valves are leaking at that cylinder. If air is heard at the tailpipe, the exhaust valves are leaking for that cylinder.
    By not 'rolling over', I assume that you mean not 'firing'? If not rolling over means not cranking over, then you may have mechanical interference of some kind that must be located?
     
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  5. coltmac

    coltmac Active Member

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    It's a 2.0, forgot to write that. I removed the spark plugs, and turned the engine at the crank by hand, and hear a noise coming from, I think, cylinders 2 and 4. I did this alone, so I used my phone to record sound while rolling the motor, so I'm not sure exactly where it was coming from, but it is a distinct low whistle sound. Also with the plugs out I thought it would be easier to roll but it still was difficult at times. This would be the mechanical interference keeping the starter from rolling the engine over. So I assume this means I've bent some valves somehow and am now going to have to do a much more extensive motor work. Work that ironically enough is what I was trying to avoid by doing this proactive maintenance. Just shoot me now please. Can you give me a quick rundown of what I'm in for? I really appreciate the time for your responses.
     
  6. AllanC

    AllanC Well-Known Member

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    This is discussion for an inline 4 cylinder engine that is 4 cycle (intake, compression, power, exhaust) and that has a 1-3-4-2 firing order for the Neon 2.0 liter. When #1 cylinder is approaching TDC (top dead center) for timing, it is completing its compression stroke so both intake and exhaust valves are closed. So there is no interference / bent valves on #1 cylinder. Cylinders #2 and #3 are 180 degrees opposite in rotation from #1 so those pistons were at there farthest travel from the cylinder head. So no piston valve interference on #2 and #3. Number 4 is the culprit.

    When #1 piston is approaching TDC on its stroke, #4 piston is in exact phase and is approaching the head on its stroke. Cylinder #4 is completing its exhaust stroke so #4 exhaust valve(s) are open and then must close before the piston reaches the head or there will be valve interference. In addition if the camshaft rotates independent of the crankshaft with #1 (#4 also) at TDC, #4 intake valve(s) attempt to open and can interfere with that piston. So you will find bent valves on #4 cylinder.

    Here is a link to chapter 9 of factory service manual, engine section, for the 2.0 liter Neon engine. This is for a 2004 model year Neon but should be identical for 2005 models. Timing belt removal discussion starts at page 9 - 83 and head removal at page 9 - 25.

    Dropbox - 2004 Neon Engine
     
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  7. chuzz

    chuzz Well-Known Member

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    Probably a couple of stupid questions, but I'm just the guy to ask them. Is the car automatic or stick? If it's automatic, do you have it in park or did you leave it in gear. If it's stick, is it in neutral? I'm asking for the reason that you say it's difficult to rotate even with the plugs out. The whistling sound you're hearing may just be the normal compression of the cylinder. I'm just surprised the nobody has suggested that you make sure your battery cables are clean and tight on both ends. Did you clean the posts on the new battery and the cable ends before you installed it? Sometimes it's the simple things that we overlook that lead us to over analyzing a problem. I'd suggest you check those things first and then see if it will rotate with the key switch when you try to start it. Keep the plugs out. If it cranks with the key, then start checking other things. If the car was running before you hit the deer and started the belt replacement, I simply don't understand how you could have bent valves now. Do any of the rest of you guys get what I'm trying to understand? I'm not a mechanic and have had two brain surgeries in the past and don't have very good cognitive thinking anymore, so please forgive my stupid questions.
     
    #7 chuzz, Jan 20, 2017
    Last edited: Jan 20, 2017
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  8. coltmac

    coltmac Active Member

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    It's an automatic. I think you might be right about the whistling. The 1st time I tried it, I was by myself and listening from the side of the car. I tried it again last night with my 11 yr old. He was turning the engine slower and it didn't make the noise. And I noticed that each cylinder was moving air in and out like it should, and thought maybe it was the shape of the hole making it sound that way. So I placed my hand over each hole and noticed it pushing and pulling air against my hand. It was actually pulling a little vacuum against my hand. If I had bent valves could it do that?
    Yes I did clean the terminals on the new battery. And yes I feel like I'm overanalyzing and still holding out hope that I'm overlooking something that is simple. I did pick up the harmonic balancer puller back up from Autozone today, so hopefully have time to start taking it apart again this weekend. I figured I would take a few things apart looking for an interference and turn the engine to see if it still turns hard. Another thing I thought about doing was marking the crank to determine how often I feel the interference, and maybe putting a rod in each cylinder to determine if there is a correlation between the interference and the cylinder location. If I get all the way apart to the point of the timing belt and it is in time, I will probably do the pressure test that IC suggested. but that will take some tools that I don't have. Thanks for the input.
     
    ImperialCrown likes this.
  9. AllanC

    AllanC Well-Known Member

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    I was thinking that if you removed the camshaft cover and measured the height of the closed intake and closed exhaust valves and compared the height to other valves on different cylinders, a discrepancy would intake a bent valve which is not closing due to spring pressure alone.

    But this would be a tricky measurement because if you have a bent valve, the piston is probably hitting the valve and forcing it closed. Measuring valve height might be misleading. Others might have an opinion on this idea???
     
    #9 AllanC, Jan 21, 2017
    Last edited: Jan 21, 2017
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  10. coltmac

    coltmac Active Member

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    crank turns hard every half revolution. Timing marks still lined up. Removing valve cover next.
     
  11. AllanC

    AllanC Well-Known Member

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    Where is the timing mark on the crankshaft timing sprocket when rotation becomes difficult? At TDC? 45 degrees beyond TDC? 90 degrees beyond TDC, 180 degrees beyond TDC? Assume that when the crankshaft sprocket mark is aligned with its timing mark on the oil pump housing , that is 0 degrees rotation.

    Have you checked and their is no interference or rubbing on the crankshaft belt pulley, alternator pulley, power steering pulley, A C pulley, idler tensioner pulley?
     
    #11 AllanC, Jan 21, 2017
    Last edited: Jan 21, 2017
  12. coltmac

    coltmac Active Member

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    loosened rocker shafts till everything was loose, and added compressor air to each cylinder, one at a time. #2,3,&4 cylinders held some pressure, #1 did not. With air going into #1, you could hear and feel air coming out of the tailpipe. So apparently bent exhaust valves.
     
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  13. AllanC

    AllanC Well-Known Member

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    I like this test to help identify a specific area which is the culprit. But what is puzzling to me is how #1 cylinder has bent valve(s)??? As stated previously with #1 piston at TDC (top dead center) and the crankshaft sprocket aligned with its timing mark on the oil pump housing and the camshaft sprocket aligned with its timing mark on the housing cover, #1 cylinder is finishing its compression stroke and readying for the power stroke. Both intake and exhaust valves are closed and have been for 180 degrees of crankshaft rotation before and after TDC. Cylinder #4 would have an intake valve open when #1 piston is approaching TDC or exhaust valve open after TDC.
     
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  14. coltmac

    coltmac Active Member

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    Is there any other explanation for an open air leak into the exhaust with the rocker shaft completely loosened? I'm trying to make sense of it too. At TDC, wouldn't the very next valves to open, be the exhaust valves on #1. I did have to remove the cam sprocket to remove the water pump. I must have moved the cam when putting it back on. That's the only thing I can figure. Can they be bent that easy? Unless there's another explanation, I guess I've got a head to remove.
     
  15. AllanC

    AllanC Well-Known Member

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    When #1 cylinder is at TDC, the air fuel mixture is compressed. The spark plug fires, the mixture burns and expands and drives the piston. This piston moves downward in its bore and the crankshaft rotates 180 degrees. It is only after the crankshaft rotates 180 degrees does the #1 exhaust valve open. So that is why I am thinking that #1 cylinder does NOT have a bent valve.

    If the camshaft moved more than 1 or 2 teeth and the crankshaft stationary with #1 at TDC, then it is highly likely that a valve is bent. But it would have to be #4 that has a bent valve(s). The valve(s) are canted at an angle in respect to piston travel. If a piston hits a valve there is a side force applied and it can bend easily.

    Here is a modified procedure that I have used when replacing a timing belt on a 2.0 liter 4 cylinder that avoids any potential damage if the camshaft rotates unexpectedly with the timing belt removed.

    Rotate the crankshaft clockwise at the crankshaft bolt. As the timing mark on the crankshaft sprocket approaches TDC and its reference mark on the oil pump cover, stop rotating when the mark is 90 degrees BEFORE TDC. The timing make on the camshaft sprocket will be 45 degrees BEFORE its reference mark on the timing belt cover. Use a white marker and make a new, temporary timing mark on the crankshaft sprocket adjacent to its reference mark on the oil pump cover. Likewise put a new, temporary mark on the camshaft sprocket next to its reference mark on the timing belt cover.

    Doing this places all 4 pistons in the midpoint of their travel in the cylinder bore. No piston is at the end of its travel and next to the head. Remove the timing belt from the camshaft sprocket. With this arrangement if the camshaft accidentally rotates either clockwise or counterclockwise and a valve opens, no damage will occur because no piston is near a valve.

    Upon installation of the timing belt, you are using these temporary timing reference marks. You tension the belt properly and then slowly turn the crankshaft clockwise 90 degrees. You check the original timing mark on the crankshaft and camshaft against their reference marks and all should be good.
     
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  16. chuzz

    chuzz Well-Known Member

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    I agree with AllanC. There is NO WAY you could have bent a valve by simply moving the camshaft when you pulled the gear. I am also a believer that you have it in the wrong position or maybe what you think is a timing mark, isn't really the timing mark. Any way you can take some photos of what you have right now? Post them with what you consider all of your timing marks lined up and let us have a look. Either that or just remove the timing belt, rotate that cam 180 degrees and put the belt back on and check your compression on #1 again.
     
    Bob Lincoln likes this.
  17. pt006

    pt006 Active Member

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    I changed a belt years ago on a different engine than yours. Maybe a 2.2 or a 2.5 L Mopar. When aligning the marks, the camshaft wanted to snap back because of valve spring pressure. I turned the cam with a pair of vise grips to the correct position, then used another pair of vise grips to lock the cam at that position. The vise grips handle was resting on the valve cover surface of the cyl head to prevent the cam from turning. I'm not familiar with your engine, but is it possible that spring back of the cam would be strong enough to bend a valve?
     
  18. coltmac

    coltmac Active Member

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    Reluctant to tear into it any further, until I know for certain I have to, I decided to tighten the valve train and check compression. The starter was still having problems rolling it over consistently, even with just one cylinder making compression. So I'm back to this being a starter, battery or wiring issue. The question I have is why does it take sometimes multiple revolutions before the cylinder starts holding any pressure? It was hit and miss with the starter kicking in and out, but with each cylinder we let it turn over at least 3 times. Cyl #1 wouldn't move the needle at all, so we moved to 2 which pumped right up to over 160, #3 nothing, and 4 nothing. Decided to let it crank some more and #4 started showing compression and looked good. Back to #3 and it was then showing good, so back to #1, and it took many more revolutions before it started showing compression. In the end they all showed sufficient pressure that it should run. It's like something needed to pump up with oil pressure before the cylinder or valves would seal. The car has set for over a month now without running. I would just like to understand the reason it is like this. Thanks.
     
  19. AllanC

    AllanC Well-Known Member

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    The engine uses hydraulic valve lash adjusters. Due to sitting for this lengthy time without running, all adjusters would drain down and be empty of engine oil. So the clearance on the adjusters would be slightly more than normal (few thousands of an inch) but that would not affect the compression of the engine. Once the engine is up and running for a few seconds, sufficient oil pressure invades each lash adjuster, the excessive gap closes and everything is normal. On an engine with high miles (100,000+) sometimes leaky or worn lash adjusters manifest themselves as being noisy (clicking sound) and then quiet down as the engine warms up. That explains the theory but this is NOT the source of the problem.

    You have replaced the starter motor and the battery. So starter motor is not the issue. Have you charged the battery? There is always a parasitic draw ( 10 - 20 - 30 milliamps) on the battery when the positive and negative battery cables are connected. Even though the battery was fully charged at installation, sitting without a recharge would deplete its capacity. You need to attach a battery charger and get it fully restored to 100% capacity. Then repeat your compression test. Are you making sure you have a good seal where the compression tester adapter threads into the spark plug hole?

    How are you conducting your compression test. You need fully charged battery. What is the air temperature around the vehicle? If it is very cold (winter time temperatures near or below 32 deg F) then the thicker oil viscosity will slow engine rotation. But all compression readings would be affected equally. While conducting compression test you should remove the fuel pump relay from the PDC (power distribution center) to prevent the fuel system from pressurizing. No need to dump fuel through the injectors into the engine and cause oil dilution.

    Have you removed all 4 spark plugs and then testing each cylinder individually? When checking an individual cylinder, you want to remove as much resistance to crankshaft rotation from all of the remaining cylinders. You want to crank the engine
     
  20. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
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    And, was it a screw-in type of compression tester, or the kind with the bulb that you shove in the spark plug hole? The latter gives unreliable results, often doesn't seal tight.
     

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