'97 3800 engine squeal issue

[randy78]

hello,
we are really stumped on this `97 3800 buick we are working on

we swapped the dead original 3800 engine out for a real low miles junkyard 3800 and its been bad luck ever since, we have had great luck with all the past 3800 engine replacements until this one now..

it has 40 psi oil pressure when cold
runs great
but when it gets all warmed up the front of the engine will start to make wierd squealing noises
if you rev it up it will go away for a second then return by the time the engine returns to idle speed again
we removed the belt and ran it and it still does it
its something in the front of the engine
we also tried another balancer, that changed nothing either
we cannot figure it out

the oil pressure sits under 40psi when warm, but i still suspect possible oil pressure/filter problem ?
it seems ot be starting to develop some bottom end ticking also, and a little bit of a knock almost when you are listening under the hood and rev the throttle by hand

is there any kind of issue with the oil pumps on the later `90's 3800 engines i need to know about


we dont know what to do now short of pulling oil pan and/or pump cover and replace the pump and inspect the pan

[maxwedge]

Remove front cover and check the cam thrust button and spring.

[randy78]

Originally Posted by maxwedge

Remove front cover and check the cam thrust button and spring.

ok, neat thanks for the reply!

so i take it that you maybe have seen this happen on one of these in the past ? or ?

very curious to know/learn more, if possible

thanks!

[HotZ28]

QUOTE;
"we dont know what to do now short of pulling oil pan and/or pump cover and replace the pump and inspect the pan"
You have a gearator oil pump driven by the front of the crankshaft. They are almost bullet proof on the 3.8. Normally they idle at about 40-45 psi and go to 55-60 psi above 1500 rpm with good 10W30 (warm). You seem to be low @ 40 cold and less than 40 warm! Could it be that the pump was dry when you started it? Did you turn it over with the ignition disabled first, to prime the pump and engine?
If not, it could also be the pump gears are squealing!

[randy78]

Originally Posted by HotZ28

QUOTE;
"we dont know what to do now short of pulling oil pan and/or pump cover and replace the pump and inspect the pan"
You have a gearator oil pump driven by the front of the crankshaft. They are almost bullet proof on the 3.8. Normally they idle at about 40-45 psi and go to 55-60 psi above 1500 rpm with good 10W30 (warm). You seem to be low @ 40 cold and less than 40 warm! Could it be that the pump was dry when you started it? Did you turn it over with the ignition disabled first, to prime the pump and engine?
If not, it could also be the pump gears are squealing!

hi well no we had no reason to prime or anything, as this engine was a pull from a wrecked car and was simply a replacement, nothing more

although we did replace the intake manifolds- upper and lower because the intake that was on the engine was burnt due to the donor car being wrecked and it had caught fire

but is low miles engine

the squaeling is jut wird and is definitely in front of engine somewhere and is worst at idle only, and will go away with rev-up, only to return by the time its idled back down again

its just wierd as heck
and not until its plenty warm
will start to squawk as it starts getting to full operating temp until its just squawking continuously at full temp
it only gets up to around 180 and thats it



thanks for any further !

[HotZ28]

I was just concerned that if the engine had been sitting for an extended time in the donor car, that it was dry on the inside and that cylinder walls could even be rusted.
Have you pulled the valve cover to check the rockers for oil? It sounds like something is not getting oil!

[randy78]

no we have not done that, yet

but if there was no oil getting to the top end or one head or something then wouldnt that still lead back to an issue with the oil pump or somwhere in the bottom end ?

no ?

this is why i am thinking we need to get into the front/bottom of the engine

but i dont really know what we should check for or how, with not knowing exactly what is going on here

this is the whole problem here, see

stumped

this engine was never sitting or anything like that, it was always in a car and wasnt dry or anything like that

theres definitely an oil problme of some kind here though

i wonder about filter maybe

i dont know,

thanks for anything further

[txcowpug]

I know this is an old post, but here is the solution to the original issue: When the plastic upper intake plenum was replaced, it did not come with a PCV installed. The vacum is so great without the PCValve installed that the vacum starts to suck through the front main seal, causing what sounsd like a belt squeal. An easy way to check if this is your trouble would be to remove the engine oil cap. When you do you will feel suction against the cap and with the cap removed, the noise will go away. So remove the MAP sensor and twist open the PCV retaining clip and replace or install a new PCV. Remember to install the proper "O" rings and all should be great agian. Thanks. Good Luck.