Please Help Engine Noise Low oil Pressure????

[sirmike]

I recently aquired a 98 tahoe ,,it had the intake manifold replaced due to a water/coolant leak into oil...after replacement and several oil changes with additives ...i have a knock sound coming from engine ...and low oil pressure..5.7 l engine .any ideas????

you can hear this noise i made small video below thanks for the input


http://www.youtube.com/watch?v=ZO_fWgGOyVE

 

[Trippers99hoe]

Sounds like a collapsed hydraulic lifter(just a guess ) I would do an oil change and put 1 quart of Marvell Mystery oil in place of 1 quart oil....

How low is the oil pressure?? My truck idles @ 20psi and goes to about 50-60 psi while driving.

 

[SunlitComet]

yup lifter trouble.

 

[BattelWagun]

Ok, sorry to hijack, but I have the same issue! I know which lifter it is too, it's the lifter closest to the radiator on the #3 cylinder. I heard about the marvel mystery oil and was a little leary about a whole quart. I have heard it does wonders though. I mean Iv'e been driving on mine for moths and its been fine, just noisy... I'm thinking i may just take off the intake and 'un-collapse' it. (I'm prepared to be yelled at for not being a good tahoe owner and taking care of it)

 

[gregsb]

Marvell is some great stuff. My first vehicle was a '56 Willy Jeep CJ5 that had sat is a field for over 5 years. First thing I did when I got it home was dump some in each cyl. After a month of working on it and doing fluid changes along with new plugs it fired right up after some serious cranking. A lot of smoke and crap but it ran.

Smells kind of nice too, we used to call it bubblegum oil.

 

[SunlitComet]

Ok, sorry to hijack, but I have the same issue! I know which lifter it is too, it's the lifter closest to the radiator on the #3 cylinder.

Intake valve lifter.

 

[BattelWagun]

Intake valve lifter.

You seriously know just wayyy to much about these things!
Thanks sunlit

I just bought a quart of marvel mystery oil. I was about a half a quart low so I put about half a quart of marvel in there. I also put about 6oz of it in the tank. Time shall tell what happens

 

[SunlitComet]

Sure thing.







Duckie!

 

[BattelWagun]

Sure thing.







Duckie!

You're just jealous!

 

[SunlitComet]

Just cause mine does not work and I have no job. After those problems are fixed it will be the other way round.