oil pres drop and tapping sound

[marks1972]

i posted this in the engine forum also but trying to get as much feedback as posible before droping alot of money and wasting alot of time that i dont need to. I have a new 350 Crate Engine from Car Quest. I have a taping sound when the engine gets to temp. I have tried adjusting the rockers twice. replaced the locker nuts on the rockers. but it still starts taping again when it gets to temp. it sounds more internal then it does when i loosen the nuts up on the rockers. also when it starts tapping my oil press goes down from around 40 to around 10-20.

[cdowns]

was the oil pickup tack welded to the pump whrn installed?

[marks1972]

couldnt tell ya it was a complete engine only thing i had to do was put on intake carb dist fuel pump water pump headers etc... oil pan was already on. i have never heard of welding anything dealing with the engine

[71tahoe]

I think Car Quest has a new 350 crate and you need to go pick yours up when they get it in. (meaning it should be under warranty)

Either oil isn't getting picked up or as it heats up and gets thinner there is too much clearance in the bearings.

I have never welded an oil pickup and never had one drop. My cousin has had one drop though. There was no oil whatsoever to the top of the motor and it made the worst screeching noise I've ever heard.

[marks1972]

the engine was built by ATK not Car Quest so i have to do all warinty through the ATK warantie. havent started that rout yet i am sure it will ba a pain in the but though if it is something small i will probably just take care of it myself. like replace lifters cam etc.. i want to put a bigger cam in it anyway but if it is something big like crank piston or rod barrings then yea i will put up with frustraition and have them do it.

[BADPURPLE70CHEVY]

My father in law bought a 350 from autozone 5 years ago and from day one it had a knock. Took it back no trouble. Found out that those reman motors are usually thrown together. I would not start it or anything anymore. Contact them and get the ball rolling quick. The more that you mess with it just gives them a way to blame you. Just my 2 cents.

[junkyardjohn]

THERES A REASON THOSE REMAN. MOTORS FROM AUTOZONE (OR PEP BOYS, CAR QUEST, ECT. ECT.) ARE QUITE A BIT CHEAPER THAN THE G.M. CRATE MOTORS. BELIEVE ME... I'VE HAD MORE THAN A COUPLE APART. EVERYONE THAT I'VE TAKEN APART LOOKED LIKE IT WAS ASSEMBLED BY A 15 YEAR OLD WITH A DRINKING PROBLEM. WITH G.M. CRATE MOTORS RUNNING ABOUT $1500 FOR A BARE BONES BOTTOM OF THE LINE 230 HORSE CRATE MOTOR, DO YOU REALLY THINK A $699 AUTO-ZONE MOTOR IS GOING TO BE JUST AS GOOD??. IF THEY WERE G.M. WOULD NEVER BE ABLE TO SELL ONE. OIL PRESSURE DROPPING & TAPPING OR KNOCKING SOUNDS TEND TO GO HAND IN HAND & ARE SELDOM GOOD. JOHN

[QKENUF4U]

heres an idea..... im a mechanic for a guy here in town.. he has rhinos, limos, bikes, and a boat... well the boats got a 502 bb in it.... the PO put a drain line from the drain plug so you could drain the oil thru the water drain hole on the back of the hull...well he had it plugged with a bolt and hose clamps.. the hose clamp didnt hold and my boss spit 6+qts oil out into the hull over the weekend... he was rescued .. so today i had to go suck the oil out and put in good oil..
so anyways got the new oil in etc.. started it up to make sure it wasnt leaking anymore.... looked good.. boss came down and started it a few times... bout the 6th time he started it there was a huge FLAME BALL and and then CLACK CLACK CLACK.... i thought the worst.. sounded like broken rod,piston,bent push rod etc...
so we messed around a bit then he called his guru in cali... described it to him and first thing outta his mouth is the LIFTERS have bled down and they need pumped up again...
go run it for a ten minutes at 1500 and see if it gets better...
so down we go, boss gets it running at 1500 clack clack clackin away.. sounded horrible and i thought it was gonna come apart... longer it sat there the better it sounded...
so anyways, the reason this happened was the boss man idling it back to dock with low oil.. i have never heard/seen this in my entire life and ive been around race cars,street cars etc. for 15+ yrs.. have built motors etc.. was cool to learn something new and glad it was actually a simple problem...
so what im saying is maybe you have some bad lifters or they need to pump up since you have low oil pressure... replace your oil pump first before going crazy and replacing the engine...

[travis.vaughan]

loosen the mounts jack the engine up by the harmonic balancer get the oil pan off put a new oil pump on replace gasket and front and rear seal. its easier than taking the engine out for warranty.

[69heavychevy]

im surprised nobody has asked this yet...what oil weight/brand did you use?

[Coreyterry]

im no well trained mechanic but it sounds to me as it does to most of the posters in here its more then likely the oil pump. as for warrenty if it has to be replaced talk to the manufacture before doing anything, even replacing the gaskets could void the warrenty. iv'e had pleantly of places tell me i could return or exchange because it was mishandled or abused just so they didnt have to replace whatever it was. but yes try the oil pump first, if that doesnt work then take it back and let them replace the hole motor.

[Blazer1970]

10 - 20 psi should be plenty to keep the lifters pumped up. If that is as low as it is getting, the oil pressure is not causing your sound.

[marks1972]

Originally Posted by 69heavychevy

im surprised nobody has asked this yet...what oil weight/brand did you use?

10w40 Castroil GTX

[marks1972]

if it is the oil pump why does it wait for it to get to temp before doing this. it does just fine till then, between 30-40psi

[cdowns]

i'd think there might b a drainback problem ,that the oil is restricted from draining back to the sump fast enough causing starvation// can also b a poorly adjusted pickup from the pump that is too high above the oilpan bottom or not enough oil in the engine or partially clogged oilfilter could also cause similar problem

[marks1972]

i have changed the oil and filter twice. 1st to get rid of brake in oil. 2nd to put in heavyer oil to see if that would help. i always change filter when i drain oil even if it only had 20miles on it.

[cdowns]

wwell i'd suggest takin the pan off and checking your pump pickup// if you dont think its wirth it run asis