disepyon Posted May 19, 2012 Share Posted May 19, 2012 (edited) I adjusted my valves according to this: http://www.picturetrail.com/sfx/album/view/1803105 http://www.atlanticz.ca/zclub/techtips/valveadjust/index.html After I adjusted it I began to hear a ticking noise, very loud as if something is clinging against something else. Its constant, I hear it on idle and through the rpm range. However everything else seems ok, engine idles super smooth (better than before), revs fine, no hesitation. I did a compression check and I got starting from 1-6(165 165 170 170 165 165). I thought maybe the oil tube next to the rocker arms might be rubbing against, but all is fine and I have clearance. I found out that while the engine is running and I unplug spark plug wire to piston 1, the noise stops and of course the engine starts to idle rough like it should. So I swapped the spark plug wire and same symptom, i changed the spark plug it self and same symptom. I dont get it. Whats wrong? Did i bend a valve for piston 1? bad valve spring? I dont get how that would affect that noise if there is no spark. Shouldnt the noise still persist since the cam shaft is still spinning and the rocker and valve/valve spring would then have to move? Edit, this is for a stock l24 240z. Edited May 19, 2012 by disepyon Quote Link to comment Share on other sites More sharing options...
nash542001 Posted May 19, 2012 Share Posted May 19, 2012 I remember reading something about a case like yours in the "how to rebuild OHC nissan engine" book. It was in the troubleshooting section and said that by killing the spark on a cylinder, if the noise went away it was most likely ____________. I can't remember, but I thought it was a sign of a bad main bearing. I will go home soon and read the book to find out. Then again if you just did something and it started making a noise I would look over what I did. Quote Link to comment Share on other sites More sharing options...
disepyon Posted May 19, 2012 Author Share Posted May 19, 2012 I remember reading something about a case like yours in the "how to rebuild OHC nissan engine" book. It was in the troubleshooting section and said that by killing the spark on a cylinder, if the noise went away it was most likely ____________. I can't remember, but I thought it was a sign of a bad main bearing. I will go home soon and read the book to find out. Then again if you just did something and it started making a noise I would look over what I did. Thanks for the help. My brother said it could be the exhaust/intake manifold gasket. I am missing a nut and a stud on the first exhaust runner. The stud snapped off in the head and I never could get it out, so a while back I just said whatever. I dont get how it could be making a noise all of a sudden. My brother said he had a similar problem that made the same noise and it was his exhaust gasket. The gasket is only about 6 months old and i hardly drive the car. Could it be now that my valve clearance is adjusted more proper, there is more air moving out of the exhaust runner causing that noise in a leak in the exhaust gasket? Quote Link to comment Share on other sites More sharing options...
dexter72 Posted May 19, 2012 Share Posted May 19, 2012 The gasket could have broken off or the manifold could be starting to warp at #1. I would definately pull the valve cover again just to make sure the valve adjustment is correct on #1 cylinder. Quote Link to comment Share on other sites More sharing options...
nash542001 Posted May 19, 2012 Share Posted May 19, 2012 Yes, it could very well be an exhaust leak. I have had that happen before too. I would check that first and then double check your lash adjustment. The book says "that if it is a piston-pin noise it will be a double click. Piston slap or noise at the pin or rod bearing can be checked by grouding the plug at the cylinder while the engine idles. The clicking noise will diminish or stop when the problem cylinder is disabled. A connecting rod will knock or pound if oil pressure is low or connecting-rod bearing-to-journal clearance is excessive. A main bearing with excessive clearance will knock at half engine speed. The noise will usaully occur when the engine is first started, hot or cold, before oil pressure builds. Disabling a cylinder on either side of the problem bearing should quite the noise" (How to rebuild your Nissan & Datsun OHC Engine p.9-10). Hope that helps! Quote Link to comment Share on other sites More sharing options...
disepyon Posted May 20, 2012 Author Share Posted May 20, 2012 (edited) Thanks for the reply fellows. I drove my car for about 5 to 6 miles, some what got on the gas to go fast to get the engine super hot. Right after that I checked the valve clearance and made the adjustments needed. Everything looks fine under the cover. Again the car runs strong and smooth. According to the stock oil pressure gauge it reads good. The noise is a solid one loud click. As i raise the rpms the noise gets faster. How would I go about checking the gasket without pulling the carbs and exhaust manifold off? I tried to feel for leaks and didnt feel any air blow out. Not sure if this helps but I tapped on the exhaust number 1 runner and it sounds exactly like the noise i hear. I just dont under stand these cars, you fix something and a new problem arises, its a never ending battle. If i can get this noise figured out then im solid, I can then finally enjoy driving the car. Edited May 20, 2012 by disepyon Quote Link to comment Share on other sites More sharing options...
disepyon Posted May 20, 2012 Author Share Posted May 20, 2012 Alright folks, I stopped being a lazy azz and took the 20 minutes or so taking the intake/carb assembly off to check for exhaust leaks. Its kind of strange, the leak is on the opposite side of the exhaust runner from the missing stud and nut. You would think it would be on that side but it occurred on the side with the stud and nut. However i did notice this nut was a bit loose. So I think over time it slowly backed out and thus led to the leak. Looks like next time ill double on the nuts. I cant believe it sealed on the side with the missing stud and nut. By the way this is for exhaust runner 1. Gasket on the head. Gasket off the head. Gasket by itself, front side. Gasket by itself, back side. Well i will be ordering a new gasket and double up on the nuts on that one stud. Hopefully this will fix the noise ive been getting. I would like to extract that snapped stud but i had no luck in the past and pretty sure I wont be getting it out now unless I bring the head into the machine shop. Quote Link to comment Share on other sites More sharing options...
disepyon Posted June 2, 2012 Author Share Posted June 2, 2012 (edited) Well i thought i should update this. Ive taken the exhaust manifold to the machine shop to get resurfaced and put a new gasket on. I still get that loud ticking noise. Its seems to get louder when the car is warmed up. I rechecked the valve clearance again according to the link I posted up in one of my posts. I just dont understand what it could be. Edit: Forgot to mention that the snapped stud I talked about, I managed to get it out, so now I am able to use a bolt. Edited June 2, 2012 by disepyon Quote Link to comment Share on other sites More sharing options...
disepyon Posted June 2, 2012 Author Share Posted June 2, 2012 (edited) I believe I found the Cause of the symptom. The rocker arm for exhaust valve to cylinder one is very loose. Keep in mind that this is after ive adjusted and checked like 6 times and its still loose. Any ideas on why its so loose? Ive checked all the other arms for the other valves and they are not this loose and does not make a clicking sound like this. Could it be a worn shim or something? My terminology may not be right so correct me if i am using wrong terms to describe. Here is a video i made: For some reason i cant get the video to embed, so here is the link. Edited June 2, 2012 by disepyon Quote Link to comment Share on other sites More sharing options...
Lazeum Posted June 2, 2012 Share Posted June 2, 2012 Your lash pad seems to be broken... I see the seating face moving while the top isn't. What is the valve clearance on this particular valve? Don't you have a contact between the rocker and the spring seat? Quote Link to comment Share on other sites More sharing options...
disepyon Posted June 2, 2012 Author Share Posted June 2, 2012 The largest size gauge that fits right now with the engine completely cold is .008inch instead of the .010 inch gauge. .010 fits in between the other exhaust rocker arm and cam lobs. Quote Link to comment Share on other sites More sharing options...
disepyon Posted June 2, 2012 Author Share Posted June 2, 2012 Took the exhaust and intake rocker arms off for piston 1. I do not know how to tell the difference between a good and bad rocker arm or lash pad. Hoping someone here could enlighten me. Do the springs and keys look correctly seated? The red arrow points to the rocker arm for the exhaust that is causing the clicking noise (what i believe, wont know for certain unless i make the clearance smaller, run the engine and hear if the noise is gone). So my plan is to readjust all valve clearances on cold. put everything back on and run the motor. If noise still persist the i will make the clearance between the rocker arm and cam lob for the exhaust valve for piston 1 smaller. Put everything back together and run the motor just to see if the noise is gone. If so, then i may just buy a new rocker arm and lash pad from the z store for $42.13. Is it ok to just replace one rocker arm? Quote Link to comment Share on other sites More sharing options...
disepyon Posted June 8, 2012 Author Share Posted June 8, 2012 Update!! I am proud to say that the new rocker arm and guide replacement is a success! No ticking/knocking anymore. Engine runs and sounds smooth and sexy. Pictures of the new rocker arm and guide: Sorry i do not have any pictures of it installed. I actually brought my camera out to the garage but was so excited and anxious that i completely forgot about pictures. It was tough getting the new rocker arm on. Had to really depress the spring just to barely slide the arm in. Quote Link to comment Share on other sites More sharing options...
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