Loud "tac tac" sound from the valve area.
#16
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Already remove the cover.. The only problem I can see is the clearance between cam & valve tappet, cylinder no.1 exhaust valve.. way bigger then others..
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little update on my problem.. just to share, maybe could help others..
I have open again the valve cover, we found that the timing chain "jumped" 1 teeth of the gear, so the piston knocking on the valve. job will continue tomorrow, the reset the timing chain & re-tension it. That is the only finding now. Hopefully it is only the problem.. How can the timing chain "jumped"?? that is my question to all gurus out there.. under tension?
And removing the crank pulley without air impact gun is pain is the a**, I have read people wrote, it is almost impossible to do, they're right it is almost impossible, almost.. but it is possible..
I have open again the valve cover, we found that the timing chain "jumped" 1 teeth of the gear, so the piston knocking on the valve. job will continue tomorrow, the reset the timing chain & re-tension it. That is the only finding now. Hopefully it is only the problem.. How can the timing chain "jumped"?? that is my question to all gurus out there.. under tension?
And removing the crank pulley without air impact gun is pain is the a**, I have read people wrote, it is almost impossible to do, they're right it is almost impossible, almost.. but it is possible..
#18
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Maybe you pushed the engine past redline and stretched the timing chain. That's how you could have jumped a gear.
What year is your car I believe Mitsubishi changed to a better timing chain setup starting from 2011 you might want to upgrade to that.
What year is your car I believe Mitsubishi changed to a better timing chain setup starting from 2011 you might want to upgrade to that.
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I never push engine over redline.. it is 2008 mr..
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so now it has become worse.. we have put all back.. reset the timing, start the car and the sound still there, this time it sounds a little bit different, softer "tac".. so my next guess is the con-rod bearing..
we'll start opening oil pan to check for con-rod bearing condition.. hopefully the crankshaft surface is still fine..
we'll start opening oil pan to check for con-rod bearing condition.. hopefully the crankshaft surface is still fine..
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update..
we have open the oil pan today, and it appears that the con-rod bearing is damaged, the bearing is still there, only left 1/3 of it original thickness & both end was grinned sharp. We only open con-rod no.1 & 4.. Con-rod bearing no. 4 is still ok.. that's why the knocking sound came from cylinder no.1..
The crankshaft has a little bit scratch on the surface where the con-rod no.1 sits.. will try to "autosol" or "sandpaper" to smooth-en it again.. luckily it was only a little scratch..
we have open the oil pan today, and it appears that the con-rod bearing is damaged, the bearing is still there, only left 1/3 of it original thickness & both end was grinned sharp. We only open con-rod no.1 & 4.. Con-rod bearing no. 4 is still ok.. that's why the knocking sound came from cylinder no.1..
The crankshaft has a little bit scratch on the surface where the con-rod no.1 sits.. will try to "autosol" or "sandpaper" to smooth-en it again.. luckily it was only a little scratch..
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it start out of no where.. I start the car in the morning and suddenly the sound come.. then I change the lube oil, the sound still there. Yes... I can hear it from inside the car.. make me scare to drive the car..