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Due to the nature of my problem I've had little success on Google. I appreciate any help.

  • I have a 2001 Honda CR-V EX with 130000 miles on it and I'm the original owner.

  • The week prior to my problem the engine temperature indicator started rising near the red zone so I checked the radiator fluid which was low. I added fluid and that solved it.

  • The next week the car wouldn't start. There was no clicking associated with normal starting. The battery seemed to have power because the accessories all worked. I hooked it up to a jump start charger anyway and then when I turned the key there was a loud clank as if the engine was mechanically stuck on something and the extra amperage from the car starter helped it break loose and it started up and seemed to run fine.

  • Later that day it started running rough and dying at stops. The engine was clicking loudly. I thought maybe the alternator went out but it tested fine and so did the battery.

  • After some Googling I found that the valves often need adjusting. I popped the valve cover and set all the valve clearances. One of the intake valves was tilted to the side and when I undid the lock nut it popped back into place and seemed fine. I also changed all the spark plugs, changed the oil and oil filter, changed the pcv valve, and the fuel filter. It started up and ran great but still had the loud clicking that seems to occur on every revolution of the crankshaft (now seems inconsistent, see edit2). I hear the clicking best from near the front driver side of the engine (now seems center of engine, see edit2) although it is hard to pinpoint.

  • I just opened the valve cover again. The timing belt is in good condition and seems tight enough. I am about to double check everything.

Thank you for your time and any ideas.


(EDIT1) Valve Control Assembly Inspection

  • I double checked the valve clearances and checked the rocker that was originally popped to the side and it seemed fine.

  • The clicking does not happen when I hand crank the engine or when turned by the starter.

  • It doesn't seem to be a problem with the camshafts or rockers or anything I can get to with the valve cover off. I am hesitant to go deeper into the engine.


(EDIT2) Clicking Description and Location

I put the engine together and ran it to try to pin-point the noise. It doesn't seem as constant as before.

  • Sometimes it is "1111111111" sometimes "101010101010" and sometimes "11010110101101" (the ones are clicks).
  • The click is sharp and loud when driving or just giving the engine gas but still sometimes intermittent.
  • The click is quiet or loud at idle with no discernible reason.
  • At first when the engine warmed and settled into normal idle it stopped clicking for maybe 20 seconds.
  • The sound seems to be coming from the center of the engine but I can't really tell.
  • I pulled the spark plug wires one by one and ran the engine but I didn't notice any real difference as far as clicking.

(EDIT3) Video of My Engine Running

I posted a video of my engine starting, idling, and revving a little on YouTube.

Ignore the lifter noise. The click is louder later in the video. Sorry about the extreme close-ups, it's to try to pin-point the click in the video.


(EDIT4) Exhaust System Inspection

I decided to check for an exhaust leak. I duct taped a shop-vac to the tail-pipe and set it to blow in the exhaust. Then I sprayed soapy water on the exhaust system. The connection between the catalytic converter and the "A" pipe gave me soap bubbles indicating a leak.

Hoping to solve the clicking I disconnected the exhaust where it was leaking. I checked the gasket and there was a lot of exhaust deposits on the inside of the gasket leading me to believe that maybe the connection wasn't tight enough or the gasket isn't very good. I ran the engine with the exhaust disconnected from the catalytic converter to see if that stopped the click noise but it only sounded slightly louder. Would that indicate a damaged exhaust valve?

So, I ruled out exhaust leak as the cause of the noise even though there is an exhaust leak that I need to fix.


(EDIT5) Leak-Down Test

I rigged up a "mirror" and an LED small enough to put through my spark plug openings. It was a little hard to make out the valves but, they all looked fine except one intake valve on cylinder 1. I couldn't tell if it was damaged or just partially discolored.

I decided to rig up an attachment that screws into my spark plug openings for my air compressor so that I could do a crude leak-down test. I set each cylinder to TDC before testing. Then I set my compressor at 80psi and then plugged in the air hose and measured what the psi dropped to. Not an ideal test but, I figured that all the cylinders were subjected to about the same variables and so, if one were leaking, it would show up different from the others.

Here are my results:

  1. 71/80 psi
  2. 73/80 psi
  3. 72/80 psi
  4. 72/80 psi

They are all within 1% of the average result. Am I correct that this means there isn't a major leaking issue with any of the cylinders?

I think I might have to pull the oil pan and check the rod bearings next, unless there's a better suggestion.


(EDIT6) Removal of Accessory Belts

Prompted by Anthony X's comment, I decided to test the engine with the accessories disconnected.

  • The A/C belt was already removed from a previous A/C compressor failure.
  • I removed the power steering belt.
  • I removed the alternator belt.

Those are the only belts visible in the engine compartment. I ran the engine with those belts removed and the engine sounded the same and ran the same with the same clicking noises. So, it isn't one of those accessories. I'll have to look up if there is anything else I can disconnect to test.

On to checking the rod bearings I suppose.

Back to the valve assembly for a second. If the valve controls and cams all function well and look good and the cylinders hold pressure well with a leak-down test, does this indicate that the valves are functioning properly or is there still something that could be wrong with the valves that would make the noise while they function correctly?

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I've decided to put it together again to try to pinpoint the reason for the noise or at least a more precise location of the noise. I'll edit any findings into my question afterwards. –  Seminecis Aug 21 '13 at 22:15
    
I took it to an auto parts store and they suggested Motor Honey or Lucas Oil. I don't want to treat the symptoms. I want to figure out the cause so quieting the engine is not going to help. I'm not sure what to do so I am going to start pulling accessory belts of to see if they are loose or if the accessories are going out. Again, I will edit anything I find into my question. –  Seminecis Aug 23 '13 at 18:11
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Do you know if this engine uses oil pressure to adjust valve timing and/or tension a timing chain or the like? If so, sometimes the oil inlet to the hydraulic tensioner/adjuster gets plugged, and the tension will not be as high as intended, which can cause valve noise. I'm thinking of some VW/Audi experience I have. –  mac Sep 4 '13 at 15:05
    
@mac The engine is a fairly simple DOHC style. Honda switched to a iVTEC in 2002 which introduced variable valve lift, timing, and dwell. My engine uses a simple spring tensioner for the timing belt. My Volvo uses the system you mentioned. I'll need to make sure it doesn't develop the issues you describe. Thanks. –  Seminecis Sep 4 '13 at 18:06
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Playing the video, I heard what I thought were: (1) an out-of-adjustment or sticking valve (the rapid ticking), and (2) something loose or worn on the front (water pump or other accessory or pulley) - a slower deeper knocking sound. Bear in mind that I'm not an automotive expert, just based on informal experience. –  Anthony X Sep 6 '13 at 2:50
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1 Answer

Clicks and Knocks are really hard to determine without actually looking at the car itself. There are a lot of things that can cause them. Transmissions, AC, Valves, Exhausts, etc.

However I found a problem similar to yours on Honda-Tech that might be something to check. They appear to think it has something to do with the Engine Valves. I know you adjusted them but perhaps they need replacement here is the link I found.

http://honda-tech.com/showthread.php?t=2740192

Hope that Helps

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Thanks for the suggestion. Not sure if you saw but, I added a video of the problem which might make it easier for internet help. –  Seminecis Aug 25 '13 at 16:07
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Yeah I looked at it, I own a 99 CR-V of the same style. Does it make that sound while in driving or just when it idles? –  wmfrancia Aug 26 '13 at 3:07
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This is more of a comment, than an answer. You have plenty of rep to leave a comment. –  theUg Aug 26 '13 at 4:50
    
@wmfrancia It makes that noise pretty much all the time. It seems louder when driving or under load or above a couple thousand rpm. Somewhere in the middle of the video I move to the inside which cuts out the normal engine noise and the clicking is very audible at that point. Thanks. –  Seminecis Aug 26 '13 at 6:47
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made changes to the answer –  wmfrancia Aug 26 '13 at 13:48
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