3.1 oil leak on back side

[midwestmech]

Motor oil dribbles off the center of the front of the transmission oil pan as the car idles. I thought it was coming from a faulty rear valve cover gasket but looking back there, the spark plug area is dry. Is the engine oil pressure sensor below that on the crankcase? Are these known to fail and leak? Engine has 123,000 miles but runs well otherwise. Gets over 30 mpg on trips!

[geoffinbc]

Oil pump drive seal. Top middle back of the block. When it leaks it will send oil down over the transmission

[pepsi_coke]

Oil pump drive seal. Top middle back of the block. When it leaks it will send oil down over the transmission

X2

[RednBlack]

Oil pump drive seal. Top middle back of the block. When it leaks it will send oil down over the transmission

X2

X3... This is a very popular subject. There are dozens of threads posted on it. Someone needs to do the job and photograph and document the whole thing. Put it in the general maintenance section.

[bszopi]

I thought someone already did. Maybe not. Perhaps I'll do some searching tonight through the forums and see if I can put together something...

[midwestmech]

Thanks for info

Thanks for the answers. I've got a digital camera, maybe I can put something together, and an expert can add more captions if need be. Clearly this won't be easy to photograph, though- I can hardly see it! The article would be more easily done with an engine removed from the car. And my buddy, that put this newer motor in, has the other sitting in his garage. (50 miles from here.) I should take a look at that to see how the unit is removed. 'Cuse me for thinking out loud!

[bszopi]

RE: Thanks for info

I don't want to copy this directly, but it would be nice to get a write-up similar to this one, along with the corresponding pics to go with it.

http://www.v6z24.com/howto/oring

[midwestmech]

I have taken a good look at the back with a light and mirror and I can't identify positively what device you may be talking about. What size and shape is it, please?

[geoffinbc]

Think of where a distributor would go on the back of a motor. Well that is the location you are looking in. The thing is a metal cap silver in colour about 1.5" in diameter. It also has a hold down clamp holding it in place.

When you remove the clamp you pull it out and it is about 6" long or so and has a gear tooth on it. This is what connects the cam to the oil pump.

[midwestmech]

Thanks. I found the thread with photos:
HELP!!! Changing Headgaskets in 93 Lumina *PICS ADDED*
We'll try it!

[midwestmech]

What's the best way to post a message here with photos in it?

[geoffinbc]

Use the IMG tags

Like this
[img]image link goes here, no spaces[/img]

Dont forget the forward slash on the closing tag or it wont work. There is also a handy button that says "Img" you can highlight you link and the click the button and it does all the work.

[midwestmech]

The oil pump O-ring certainly was the problem with this Lumina?s oil leak. (The parts store calls it the distributor seal- the salesperson helping me couldn?t find anything under oil pump seal.) In the first photo can be seen the wet, oily area around the hole. It?s not easy to get down to this pump! Two coolant hoses must be removed, the upper half of the intake manifold raised, and two fuel lines loosened and repositioned. I drained down the coolant level about a gallon and that proved sufficient. The plug is in the lower, rear of the radiator on the driver side.

[img]IMG_2293-s.JPG[/img]

This photo shows the oil pump shaft. It came easily out of the hole. The leaking O-ring is near the top. I just cut it off with a sharp knife and rolled up the new one over the gears and ridges. Getting the shaft back into the hole was more difficult- I don?t know if it was the hex drive connection below or the gear that didn?t want to fit into place, but after working it around some it suddenly went down! Radiator cap is there for a size comparison.

[img]IMG_2294-s.JPG[/img]

The next photo shows how much I had to raise the intake manifold to make room to work in the oil pump area. There were still some parts connected to the manifold that held it down some but I didn?t bother to check what they were, I was just concerned with getting the job done.

[img]IMG_2295-s.JPG[/img]

The EGR valve also had to be loosened and repositioned slightly. This seemed easier to do than attempt to loosen the pipe that goes to it from the exhaust manifold. I feared that nut would be securely stuck! To the left you see the grommet that holds three vacuum lines. In two cars I have seen where these rubber blocks have to be wired onto the throttle body because they seem to shrink in the cold and can work loose.

[img]IMG_2297-s.JPG[/img]

Last, here?s a photo of a poor man?s (semi) universal joint. It got the job done! The bolt holding down the oil pump head is a 15 mm. The fuel lines just above the pump have a 10 mm bolt.

[img]IMG_2299-s.JPG[/img]

[geoffinbc]

Look like the problem. Dont forget to pick up a small block chevy distributor gasket to go on there.

Looks like you still need some help with the IMG tags. You need to have the images hosted on a server somewhere in order for it to work.

[midwestmech]

Looks like the photos can be hosted here.