Freshly Rebuilt Engine Leaking

[Gumby]

When I bought my 1973 Challenger with a swapped 360CID, it blew a rod on my way home after purchasing. A local reputable classic car shop sent the engine out to get re-machined by a guy they trusted. When it came back, they noticed a crack in the cylinder head so they sent it back to the machinist. They put everything back together a second time and gave it back to me. Immediately, I noticed an oil leak on my garage floor. It was clean engine oil and it seemed like a lot to me. It was leaking a quart every 1,000 miles. I asked the mechanic about it and he said these engines were just known to leak and that It's unreasonable to expect that even a freshly rebuilt engine shouldn't leak. Is this true? It's been 6,500 miles since the rebuild and I'm still leaking all over the garage floor.

 

[Challenger RTA]

They are known to leak if not assembled correctly. start by checking the rear main seal,can you see oil anywhere?

 

[fasjac]

I would say no, shouldn’t leak oil. Like RTA says, if assembled correctly. Things happen though.
JMO, first thing is to find out out where it’s leaking, and why.

 

[Challenger RTA]

When I did my break in I found a quarter size spot coming from back pass side of the valve cover.I kind of expected it because the kit came with the pressed paper gasket. snugged up and ok. I have since then got the rubber type that I wanted. I did have an issue with the oil filter adapter leaking before I stared the motor. just something that had to be dealt with.

 

[Chryco Psycho]

It is not normal to have an engine leak oil , something has been done wrong !

 

[heminut]

It is not normal to have an engine leak oil , something has been done wrong !

I agree! This may have been the case to a certain extent back in the day but with the level of technology available in gaskets and sealants out there today there should be no reason for an oil leak on a new build. The mechanic is feeding you a line of B.S.!

 

[Stockcar axeman]

Get new people to deal with. They have no clue. As a teenager I built multiple engines back in the 80s and they didn't leak and I was just a kid working out of the Mopar book with no garage and a small tool box. There are clueless! How embarrassing!

 

[Mopar Mitch]

Do you know what brand of gasket kit was used?

 

[Ronbo73]

@Gumby Check the oil sending unit location for leaks. I didn't tighten mine enough and it leaked down the back of my engine and was dripping from the bottom of my transmission bellhousing. At first I thought rear main seal was leaking but the oil pan was dry and no oil was seen on the flywheel.

 

[MoparCarGuy]

If you have trouble sourcing the leak, add UV dye and recheck with a black light in a darkened garage.

 

[Gumby]

They are known to leak if not assembled correctly. start by checking the rear main seal,can you see oil anywhere?

I think so. It didn't glow back at me with UV light but here is a picture of what I found after wiping it and driving.

 

[Gumby]

When I did my break in I found a quarter size spot coming from back pass side of the valve cover.I kind of expected it because the kit came with the pressed paper gasket. snugged up and ok. I have since then got the rubber type that I wanted. I did have an issue with the oil filter adapter leaking before I stared the motor. just something that had to be dealt with.

Both of these areas are dry on mine.

 

[Gumby]

Do you know what brand of gasket kit was used?

I'll ask the mechanic.

 

[Gumby]

@Gumby Check the oil sending unit location for leaks. I didn't tighten mine enough and it leaked down the back of my engine and was dripping from the bottom of my transmission bellhousing. At first I thought rear main seal was leaking but the oil pan was dry and no oil was seen on the flywheel.

Thanks, I checked after reading this. The oil pressure sending unit and the surrounding area is dry.

 

[Gumby]

If you have trouble sourcing the leak, add UV dye and recheck with a black light in a darkened garage.

Thanks, I just did.

 

[Gumby]

Thanks everyone. I called the mechanic and told him it's still leaking after 7,000 miles. He told me to have a shop closer to me look at it to find the leak and to make sure they take pictures so he can see if he'll have to warranty the assembly. I'd really like to find the leak myself so I don't pay for a shop's diagnosis.

I washed and wiped the engine cases. Then I tossed in a little bottle of UV dye into the engine fill hole of the driver's side valve cover, washed it down with an ounce of clean engine oil, and I took the car for a 22-mile drive. I brought it back and turned all the lights off in the garage. I looked over the whole engine with a UV light and I couldn't get anything to glow back at me. The top and sides of the engine cases were all dry. I went underneath and found a leak on the front of the engine under the crankshaft pulley. I took two pictures of this area spaced 3 minutes apart and attached them below. Notice the increase in drop size. I then saw something else on the rear of the engine by the bell-housing/flywheel which is shown in the last image attached below. Again, nothing glowed back at me under UV light so either these aren't engine leaks or the UV dye didn't fully mix after 22 miles. Where do I say the leak is coming from?

 

[Steve340]

The one at the front appears to be the sump gasket leaking.
The one at the rear could be either the rear main seal or the sump gasket. It is very difficult to work out which one it is.

 

[Gumby]

The one at the front appears to be the sump gasket leaking.
The one at the rear could be either the rear main seal or the sump gasket. It is very difficult to work out which one it is.

Could it also be the front main seal?

 

[Steve340]

The front seal is in the timing cover - up above the sump seal if you get my meaning. Your leak appears to be between the rubber lip of the sump gasket and the oil pan.

 

[Challenger RTA]

Don't know what you going find. Pictures of net. By chance did you see the assembly of the engine? Missing oil slinger? Rear main bad install? Sneaky Pete for in car install. oil galley plug leaking?Use a usb camera on phone to look.
Not saying it's the problem but not to be over looked