Help find oil leak - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Mitzki5 · 07-10-2002, 11:45 PM

I just built the motor and put it in. After break in and everything I took it for a drive. When I got back there was oil all over the passenger side of motor below the heads. I cleaned everything and started motor back up to see where leak was. Couldn't find a leak, so I took it for a short drive and sure enough, oil all over side of motor again. So I decided to replace the oil pan gaskets because I thought it was leaking at the joint between timing cover and oil pan. After I did all that I started it up and no leak while parked. Took for drive and sure enough oil all over side of motor again. Where in the hell is it coming from. It only leaks while I am driving it and it leaks bad. It's hard to tell anything because it is so bad. I think the fan is blowing the oil all over the place. Please help. Thanks.

frost89434 · 07-10-2002, 11:50 PM

Did you put a bolt in where the fuel pump shaft is. There should be a 3/8" x 1/2"L bolt there. If it's not there you will get a leak. It's located on the front passenger side of the engine.

Longhorn Man · 07-10-2002, 11:58 PM

Yup, I'll bet tehats what it is too. The hole you probably stuck a long bolt in to hold the fuel pump pushrod up.

Mitzki5 · 07-11-2002, 12:04 AM

Not sure where you are talking about. I bolted the fuel pump on of course but is there another bolt hole somewhere?

Mitzki5 · 07-11-2002, 12:15 AM

Where does this long bolt go that you are talking about. I don't understand. Here is a crappy pic. Can you describe where bolt goes. Does it go in block or pump. Why does oil only leak when I drive and not when parked?

Mitzki5 · 07-11-2002, 12:23 AM

I found two holes to the left of the timing cover. They look to be for a 3/8" bolt. What is the purpose of the bolt and do I just need to put a bolt in the hole. Neither of the two holes have a bolt in them. Which do I put a bolt in. Thanks a million fellas. I was ready to sell everything earlier. It is much appreciated.

Longhorn Man · 07-11-2002, 12:37 AM

When replacing your fuel pump. you need some way to hold that pushrod up. You remove the short bolt out, install a longer one in. This holds the push rod in the up position...or what ever position it is in when you put the bolt in.
The oil pump area is the last place to get oil, it commonly runs dry.

frost89434 · 07-11-2002, 12:38 AM

I think it is the lower left. Don't put too long of a bolt in it though. If you do it will hit the fuel pump rod. It is a 3/8" x 1/2"Long bolt. I would just put bolts in both holes just too make sure you get the right one. Hope this helps

**chevy71super** · 07-11-2002, 12:48 AM

When I first built my motor (350) I had a similar problem. In my garage no leak, took it out on the road and came back with oil everywhere. So this is what I did. I block the wheels REAL good and had my wife powerbrake the truck (not hard) while I laid underneath it. (Legs pointing forwrd just in case the truck got away from her.) I discovered the engine was developing enough torque to twist the pan away from the block even though I thought I had the bolts tight enough. I tightened th bolts further and that took care of it for the most part. To completely solve the problem I ended up buying a new oil pan.

I do not necessarily recommend laying under your truck while your wife (or anyone else for that matter) torques the engine.
Doug

Mitzki5 · 07-11-2002, 12:51 AM

Thank you so much. I just read in a book that it is the top hole. You can imagine what a pain in the a@@ this has been. I was so pi$$ed earlier I couldn't think straight. I appreciate you taking the time to help me out!

I'll plug that first thing in the morning. Later Thanks Mitzki5

Blue68 · 07-11-2002, 07:26 PM

Be sure and let us all know how it turns out.

I don't know what bolt these guys are talking about. I don't see one in my shop manual. Never dealt with such an animal when I changed my pumps.

Of course, now I have a fuel injection block so no manual pump. Still not magic bolt either.

My bet would have been the lifter cover. You get the rpms up for a while you can pump a lot of oil and depending on your heads and covers, it's easy for the corners to not have a gasket seal.

Still like to know about the bolt though.

68 Suburban · 07-14-2002, 05:56 AM

Mitzki5, did plugging that hole take care of your problem?

07-10-2002, 11:45 PM	#1
Mitzki5 "TRUCKLESS" Join Date: Jan 2002 Location: Tuscola IL Posts: 457	Help find oil leak I just built the motor and put it in. After break in and everything I took it for a drive. When I got back there was oil all over the passenger side of motor below the heads. I cleaned everything and started motor back up to see where leak was. Couldn't find a leak, so I took it for a short drive and sure enough, oil all over side of motor again. So I decided to replace the oil pan gaskets because I thought it was leaking at the joint between timing cover and oil pan. After I did all that I started it up and no leak while parked. Took for drive and sure enough oil all over side of motor again. Where in the hell is it coming from. It only leaks while I am driving it and it leaks bad. It's hard to tell anything because it is so bad. I think the fan is blowing the oil all over the place. Please help. Thanks. __________________ Mitzki5 No longer have an old truck! But always looking for another one!

07-10-2002, 11:50 PM	#2
frost89434 Registered User Join Date: Nov 2001 Location: sparks, NV Posts: 1,141	Did you put a bolt in where the fuel pump shaft is. There should be a 3/8" x 1/2"L bolt there. If it's not there you will get a leak. It's located on the front passenger side of the engine. __________________ 68 short fleet with 71 front clip 2wd jaguar blue 99 chevy ext cab shrtbed z71 loaded 99 chevy swb fleetside(daily driver) Sparks, Nevada

07-11-2002, 12:04 AM	#4
Mitzki5 "TRUCKLESS" Join Date: Jan 2002 Location: Tuscola IL Posts: 457	Not sure where you are talking about. I bolted the fuel pump on of course but is there another bolt hole somewhere? __________________ Mitzki5 No longer have an old truck! But always looking for another one!

07-11-2002, 12:15 AM	#5
Mitzki5 "TRUCKLESS" Join Date: Jan 2002 Location: Tuscola IL Posts: 457	Where does this long bolt go that you are talking about. I don't understand. Here is a crappy pic. Can you describe where bolt goes. Does it go in block or pump. Why does oil only leak when I drive and not when parked? Attached Images __________________ Mitzki5 No longer have an old truck! But always looking for another one!

07-11-2002, 12:23 AM	#6
Mitzki5 "TRUCKLESS" Join Date: Jan 2002 Location: Tuscola IL Posts: 457	I found two holes to the left of the timing cover. They look to be for a 3/8" bolt. What is the purpose of the bolt and do I just need to put a bolt in the hole. Neither of the two holes have a bolt in them. Which do I put a bolt in. Thanks a million fellas. I was ready to sell everything earlier. It is much appreciated. __________________ Mitzki5 No longer have an old truck! But always looking for another one!

07-10-2002, 11:58 PM	#3
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Yup, I'll bet tehats what it is too. The hole you probably stuck a long bolt in to hold the fuel pump pushrod up.

07-11-2002, 12:37 AM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	When replacing your fuel pump. you need some way to hold that pushrod up. You remove the short bolt out, install a longer one in. This holds the push rod in the up position...or what ever position it is in when you put the bolt in. The oil pump area is the last place to get oil, it commonly runs dry.

07-11-2002, 12:38 AM	#8
frost89434 Registered User Join Date: Nov 2001 Location: sparks, NV Posts: 1,141	I think it is the lower left. Don't put too long of a bolt in it though. If you do it will hit the fuel pump rod. It is a 3/8" x 1/2"Long bolt. I would just put bolts in both holes just too make sure you get the right one. Hope this helps __________________ 68 short fleet with 71 front clip 2wd jaguar blue 99 chevy ext cab shrtbed z71 loaded 99 chevy swb fleetside(daily driver) Sparks, Nevada

07-11-2002, 12:48 AM	#9
chevy71super Registered User Join Date: Jan 2002 Location: So Cal Posts: 658	When I first built my motor (350) I had a similar problem. In my garage no leak, took it out on the road and came back with oil everywhere. So this is what I did. I block the wheels REAL good and had my wife powerbrake the truck (not hard) while I laid underneath it. (Legs pointing forwrd just in case the truck got away from her.) I discovered the engine was developing enough torque to twist the pan away from the block even though I thought I had the bolts tight enough. I tightened th bolts further and that took care of it for the most part. To completely solve the problem I ended up buying a new oil pan. I do not necessarily recommend laying under your truck while your wife (or anyone else for that matter) torques the engine. Doug

07-11-2002, 12:51 AM	#10
Mitzki5 "TRUCKLESS" Join Date: Jan 2002 Location: Tuscola IL Posts: 457	Thank you so much. I just read in a book that it is the top hole. You can imagine what a pain in the a@@ this has been. I was so pi$$ed earlier I couldn't think straight. I appreciate you taking the time to help me out! I'll plug that first thing in the morning. Later Thanks Mitzki5 __________________ Mitzki5 No longer have an old truck! But always looking for another one!

07-11-2002, 07:26 PM	#11
Blue68 Registered User Join Date: Apr 2000 Location: Frisco, Tx, USA Posts: 606	Be sure and let us all know how it turns out. I don't know what bolt these guys are talking about. I don't see one in my shop manual. Never dealt with such an animal when I changed my pumps. Of course, now I have a fuel injection block so no manual pump. Still not magic bolt either. My bet would have been the lifter cover. You get the rpms up for a while you can pump a lot of oil and depending on your heads and covers, it's easy for the corners to not have a gasket seal. Still like to know about the bolt though. __________________ http://home.comcast.net/~r.landrum/w...tos.html-.html '68 C-10 LWB, '98 Z-71 350 w/accessories (Serpentine), Edelbrock Performer, Edelbrock 1405 (600cfm) carb, GM HEI, CompCam Extreme 4x4 roller cam, Thorley Headers, Carter Electric Fuel Pump, Vintage Air, 700r4, 3.73, disc brakes and power steering upgrades.

07-14-2002, 05:56 AM	#12
68 Suburban Registered User Join Date: Oct 2000 Location: From Chicago, Live in Phoenix, AZ Posts: 6,802	Mitzki5, did plugging that hole take care of your problem? __________________ Just sitting here contemplating contemplation.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.