I heard a light knocking noise inside the engine earlier this week and was told it might have been that the motor oil I was using is too thin. I change it again with high mileage oil and an additive, but the sound is still there. The noise, although you can barely hear it, is there from start to drive to off. Any ideas of what it could be?

I have a 2000 Dodge Durango SLT Magnum, 4.7 V8. It has 174,000+ miles. Thanks for the help!

Photo of my dodge:

 

limited knowledge here, but i have a few questions that may be helpful for diagnostics
#1. is the oil level full?
2. does the sound go away when you press the throtle?
3. have you been under the durango to see if anything is loose?

the answers to these questions might help us help you!

 

Thanks for your reply. The noise seems to be coming from the top of the engine, not the bottom. To give you a more audible idea of the noise I uploaded a video audio file on YouTube. You can view the video .

 

i would have to say it sounds like something to do with your valves. either a bad valve seat or whats called valve float. thats when your valve spring looses its strength and isnt able to keep up with the reving of your engine which causes it to hit the cam causing a tapping or knocking noise. it could have been caused to low oil for a while or bad old oil creating build up or gunk in your cylinder head which weakend your valve springs due to heat.

 

Thanks for your reply, Krupaeric. That's what I'm thinking too. Any idea of how much the parts and labor might cost? Average/estimate? What can happen if I keep using the vehicle as it is for another two weeks?

 

sorry im at work and got caught up. but, if the sound gets worse i wouldnt use it because that means that the valve spring is getting worse and you could possibly end up damaging your piston. and bending your valve, possibly causing catastrophic damage to the engine.this job isnt for the every day backyard mechanic. you have timing chains and cam positioning to worry about as well as completely dissasembaling the whole front of your engine. like everything that your serpintine belt touches.
head work costly. especially on your vehicle. the 4.7 has overhead cams, unlike the 5.2 and 5.9 which has a single cam and uses pushrods and lifters. you would be better of taking it to a mechanic.
and your looking at around $700-$1000. for the job total including parts and labor. they will have to completely remove all your valves on that side of the engine test them for straightness, they will have to test every spring for strength, retention. clean and possibly shave your head. then reassemble the head to spec.
this kind of situation sucks!!!
it happened to my 83 blazer and i ended up selling it cuz i damaged a piston and eventuially cracked the block. i needed a new motor. and didnt have the money.
if i were you i would take it to a few different shops. not just one. and get quotes from them then weigh your options. you may end up finding that buying a rebuilt head will end up costing less than getting yours rebuilt.
most mechanics are theafs and lie about the hours it took to rebuild. or they just didnt have the right tools to do the job and it ended up taking them alot longer than nessarry to do it.
so in the long run.
get a professional diagnosis from a reputible engine shop. and not a regular mechanic.
sorry i couldnt help much more.