chevy 250 leaking oil - The 1947 - Present Chevrolet & GMC Truck Message Board Network

big10ratrod77 · 09-07-2011, 08:42 PM

Hey guys my chevy 250 smog motor has devloped an oil leak since ive had it. I replaced the side cover gaskits and they leaked worse. So i replaced the gaskits with RTV silicone and that cleared up alot of the leaking. But now it is almost what I would call "spraying" oil all over the passengers side of the engine bay. the motor is wetist down by the fuel pump. Ive also replaced the valve cover gaskit, the pcv valve is good becouse cant that cause an engine to push oil out. It is very puzzling leak have eny of yall seen enything like this? I would realy like to clear this up becouse its not very economical to add a quart once a week.
thanks guys
josh

bradford · 09-07-2011, 10:10 PM

hmmm...I dont remember what side the dip stick is in but maybe its loose?
Maybe the distributor gasket is bad?
I just dont know. I'm not that familiar with the 250.

D13 · 09-08-2011, 06:17 AM

All L6's leak (at least in my experience).

If it is getting oil on the passenger side inner fender, best bet is that the fan or balancer is throwing it there, which means your leak is up front. I would be looking at the timing cover, front seal in the timing cover (the most likely culprit), the valve cover seal at the very front (notorious for getting bent on reinstall), or the oil pan to timing cover joint. It is possible for the fuel pump gasket to leak, particularly if it's had a new pump and the gasket was not sealed properly. But if you have oil on the inner fenders it's most lilely the fan putting it there.

Best way to find an oil leak, clean everything up then spray it with foot powder, let it dry, then run the engine. Oil shows up real nice against the white powder, and the powder washes off easily.

big10ratrod77 · 09-08-2011, 07:28 AM

thanks guys im gonna try the using the foot powder to find the leak this weekend couse i need to get it fixed.

**old Rusty C10** · 09-08-2011, 08:18 AM

if you have the time just pull the motor and give it fresh seals all around

njlimbaugh · 09-08-2011, 09:47 AM

If it's wettest by the fuel pump, maybe the fuel pump gasket is leaking.

Axle · 09-08-2011, 06:26 PM

Check your oil pressure sensor with the engine running. I've had more than one that developed a spraying leak out the end and it'll coat the passenger side quite well.

Alex.

big10ratrod77 · 09-08-2011, 08:32 PM

Quote:

Originally Posted by old Rusty C10

if you have the time just pull the motor and give it fresh seals all around

i wish i could man if i had another truck to drive rite now i would but every thing else i own is either A in a state of dissassembly, B has no tags, C wont run or, D up on blocks... lol if i could i would rebuild just rebuild the old 250 with a bigger cam, 4bbl, headers and some pistins with a bump on the top just for charictor if ya know what i mean.

im gonna look into the oil pressure sending unit maby put a copper washer on it or somthing

83highsierra · 09-08-2011, 09:05 PM

my 250 was the same way i didnt have time to do the work so i got a bottle of "white shepherd" follow the directions and it will help alot trust me. it swells the and conditions the gaskets im not saying it will fix it but i used the treatment drove it for a couple days then put engine degreaser (aka 99 cent oven cleaner from dollar tree ) sprayed with pressure washe and my normal puddle turned into a few drips

it will also help you locate the problem

09-07-2011, 08:42 PM	#1
big10ratrod77 Registered User Join Date: Aug 2009 Location: hillborough nc Posts: 410	chevy 250 leaking oil Hey guys my chevy 250 smog motor has devloped an oil leak since ive had it. I replaced the side cover gaskits and they leaked worse. So i replaced the gaskits with RTV silicone and that cleared up alot of the leaking. But now it is almost what I would call "spraying" oil all over the passengers side of the engine bay. the motor is wetist down by the fuel pump. Ive also replaced the valve cover gaskit, the pcv valve is good becouse cant that cause an engine to push oil out. It is very puzzling leak have eny of yall seen enything like this? I would realy like to clear this up becouse its not very economical to add a quart once a week. thanks guys josh __________________ 77 chevy BIG 10 350/sm465/12bolt w 3.73 bout 240 horse power NO power steerin 79 chevy 1/2 ton 250/three on the tree/3.08s soon to get built 250/floor shift conversion/3.08s 81 mercedes 300d 25 MPG 77 chevy BIG DOOLEY 454/sm-465/14 bolt 4.10s "fully loaded" 73 plymouth duster 225 slant six/230 3 speed/8 1/4 trying to acheve 300 horse six http://www.cardomain.com/ride/3135091 '77 chevy trucks. built to stay tough. life is short build a hot rod Last edited by big10ratrod77; 09-07-2011 at 08:48 PM.

09-07-2011, 10:10 PM	#2
bradford Registered User Join Date: Oct 2009 Location: North Carolina Posts: 151	Re: chevy 250 leaking oil hmmm...I dont remember what side the dip stick is in but maybe its loose? Maybe the distributor gasket is bad? I just dont know. I'm not that familiar with the 250.

09-08-2011, 06:17 AM	#3
D13 Registered User Join Date: Feb 2007 Location: Memphis MI Posts: 1,851	Re: chevy 250 leaking oil All L6's leak (at least in my experience). If it is getting oil on the passenger side inner fender, best bet is that the fan or balancer is throwing it there, which means your leak is up front. I would be looking at the timing cover, front seal in the timing cover (the most likely culprit), the valve cover seal at the very front (notorious for getting bent on reinstall), or the oil pan to timing cover joint. It is possible for the fuel pump gasket to leak, particularly if it's had a new pump and the gasket was not sealed properly. But if you have oil on the inner fenders it's most lilely the fan putting it there. Best way to find an oil leak, clean everything up then spray it with foot powder, let it dry, then run the engine. Oil shows up real nice against the white powder, and the powder washes off easily. __________________ 1987 2 ton 1982 250/TH350 beater in progress Dad's 1981 3/4 L6 3 on tree posi and no options, awaiting restoration or scrapping Plus a mess o' tractors

09-08-2011, 07:28 AM	#4
big10ratrod77 Registered User Join Date: Aug 2009 Location: hillborough nc Posts: 410	Re: chevy 250 leaking oil thanks guys im gonna try the using the foot powder to find the leak this weekend couse i need to get it fixed. __________________ 77 chevy BIG 10 350/sm465/12bolt w 3.73 bout 240 horse power NO power steerin 79 chevy 1/2 ton 250/three on the tree/3.08s soon to get built 250/floor shift conversion/3.08s 81 mercedes 300d 25 MPG 77 chevy BIG DOOLEY 454/sm-465/14 bolt 4.10s "fully loaded" 73 plymouth duster 225 slant six/230 3 speed/8 1/4 trying to acheve 300 horse six http://www.cardomain.com/ride/3135091 '77 chevy trucks. built to stay tough. life is short build a hot rod

09-08-2011, 08:18 AM	#5
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,313	Re: chevy 250 leaking oil if you have the time just pull the motor and give it fresh seals all around __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

09-08-2011, 09:47 AM	#6
njlimbaugh Registered User Join Date: Jun 2011 Location: LaFayette GA Posts: 111	Re: chevy 250 leaking oil If it's wettest by the fuel pump, maybe the fuel pump gasket is leaking.

09-08-2011, 06:26 PM	#7
Axle Registered User Join Date: Jul 2011 Location: SW Ontario Posts: 1,212	Re: chevy 250 leaking oil Check your oil pressure sensor with the engine running. I've had more than one that developed a spraying leak out the end and it'll coat the passenger side quite well. Alex.

09-08-2011, 09:05 PM	#9
83highsierra Registered User Join Date: Jun 2011 Location: georgetown kentucky Posts: 193	Re: chevy 250 leaking oil my 250 was the same way i didnt have time to do the work so i got a bottle of "white shepherd" follow the directions and it will help alot trust me. it swells the and conditions the gaskets im not saying it will fix it but i used the treatment drove it for a couple days then put engine degreaser (aka 99 cent oven cleaner from dollar tree ) sprayed with pressure washe and my normal puddle turned into a few drips it will also help you locate the problem



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