idle problem after over rev
#1
idle problem after over rev
hello,
i had a miss shift and over revved my b16. ran out of oil then i changed the oil and motor seems to be somehow fine. the problem is that after the engine warms the idle begins to go down (~600rpm, lower than usual)with drops bellow ~300. i have no cel/error. what could it be?
thanks
i had a miss shift and over revved my b16. ran out of oil then i changed the oil and motor seems to be somehow fine. the problem is that after the engine warms the idle begins to go down (~600rpm, lower than usual)with drops bellow ~300. i have no cel/error. what could it be?
thanks
#3
Re: idle problem after over rev
after the miss shift, oil light turned on and engine sounded really bad. i checked the oil level and it was very low (before over rev oil level was fine).
there is a small knocking noise, but it sounds more it from the exhaust. i feel small vibrations inside the car like shakings but don't know if it's because the low idle.
the engine pulls ok, vtec feels normal, just the issue with the idle behavior
there is a small knocking noise, but it sounds more it from the exhaust. i feel small vibrations inside the car like shakings but don't know if it's because the low idle.
the engine pulls ok, vtec feels normal, just the issue with the idle behavior
#4
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Re: idle problem after over rev
after the miss shift, oil light turned on and engine sounded really bad. i checked the oil level and it was very low (before over rev oil level was fine).
there is a small knocking noise, but it sounds more it from the exhaust. i feel small vibrations inside the car like shakings but don't know if it's because the low idle.
the engine pulls ok, vtec feels normal, just the issue with the idle behavior
there is a small knocking noise, but it sounds more it from the exhaust. i feel small vibrations inside the car like shakings but don't know if it's because the low idle.
the engine pulls ok, vtec feels normal, just the issue with the idle behavior
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Re: idle problem after over rev
loss of oil pressure right after the over rev indicates a spun bearing, the bearing surface would have been destroyed increasing oil clearance and causing the oil pressure drop. I don't see bent valves causing the oil pressure drop, pull the pan and you will probably find metal.
#11
Re: idle problem after over rev
when i let the oil out didn't see any metal in it. i'll do a commpression test.
thanks guys. in case of spun bearing, just replace the bearings or could it be the crankshaft too?
thanks guys. in case of spun bearing, just replace the bearings or could it be the crankshaft too?
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Re: idle problem after over rev
if you spun a bearing, the engine needs to come apart, it needs to go in an engine stand and be turned upside down so the crankshaft can be removed, then all the journals on the crank need to be checked, you don't replace a bearing, you replace them in a set, I've heard of people replacing one, but thats a really half *** way to fix things.
#13
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Re: idle problem after over rev
usually once u spin a rod bearing its hard to just throw bearings in and think everything is ok. ive seen many people do this and then about 3k later the rod is knocking again. you wil need a new bottom end or new crank and bearings to fix it correctly. or have a shop look at your current crank and see if its within spec.
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#15
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Re: idle problem after over rev
usually once u spin a rod bearing its hard to just throw bearings in and think everything is ok. ive seen many people do this and then about 3k later the rod is knocking again. you wil need a new bottom end or new crank and bearings to fix it correctly. or have a shop look at your current crank and see if its within spec.
#16
Re: idle problem after over rev
as a said the engine is running quite well, only at idle i hear a small knock which seems to come more from the exhaust (if i cover the muffler with my hand the engine sounds better, smoother, no knocking like). i hoped i don't have to take the engine apart, but i guess i'll have to do it. is there any risk driving the car as it is now?
#17
Re: idle problem after over rev
If the noise gets quieter when you cover the exhaust it might be a bent exhaust valve. Either way something went wrong and your gonna need to rebuild. If your gonna put new bearing in your going to have to pull them all and take the crank in to get turned. And your gonna want to make sure you didnt burn up your rings. So you might as well just rebuild the whole thing. So your gonna have to take the head off regardless. Long story short, you had a stroke of bad luck thats started with that missed shift.
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