Had my engine rebuilt by a bad shop. Got it back and it's still leaking a oil a ton. 93 3vze. Just looking for advice/tips/techniques for finding the source of the leak. I'm so close to getting her road worthy again and this is a frustrating problem. Thanks in advance.

 

Get spray-on degreaser; use that and a garden hose to get the engine so clean you can eat off it. Then start it, and look closely. Remember that gravity is not your friend; something as simple as a valve cover gasket leak will work its way to the bottom and look like a leak at the main seal.

 

this is the third post in a row you've helped me with scope. Thank you, I really appreciate it.

 

Like scope mentioned that is the best way to find the leaks. On several occasions I take a socket and gently check them. Several easy leaks to find are going to be a oil pan or valve cover bolts. Sometimes a quarter to half a turn will fix some of them.

 

Check the valve cover very common place or oil filter

 

Since you can't see it easily the back of the valve cover is a common leak.

On COLD aluminum parts I like to use S100 cleaner and a couple different sized brushes. It is more expensive than your typical foamy engine cleaner but I've found it doesn't discolor the aluminum or mess with the paint like some cleaners. Just don't use it on a hot surface and be sure to rinse it off good. http://www.s100.com/s100_tcc.htm




I cleaned mine up good when I replaced my valve cover gasket (Toyota part) and 1/2 moons (FelPro part) but there's still a leak back there somewhere. I'm about to look around back there with a dental mirror I got from the dollar store to see where it's coming from.

Done:
I had to shine a flashlight in the mirror to see anything and at 7/8 inch the mirror proved to be on the small side. A 1 1/4 inspection mirror would be better. I'm not sure if a 2 inch one would work or not, might be a little big for the space and angle.

I was still able to see that despite me using FIPG on the the 1/2 moons there's still traces of oil on the bottom of it.
I only turned the valve cover nuts 1/2 turn after seating, maybe it wasn't enough. I'll try 3/4 and see if that stops it.
If not I guess torquing to specifications is in order,... then perhaps a new set of 1/2 moons with torquing to spec.

 

I've heard you can also get UV dye for your oil to test leaks. Clean engine really well, run dye in engine and then lol for the glowing spots with UV light. Never used it personally though but have thought about it since I have a leak somewhere on my truck.

Best advice I once got for cleaning dirty engine with less elbow grease: spray down engine with simple green, drive vehicle to warm it up and spread the cleaner everywhere. Park it and spray down engine again with simple green. Let it cool off, then finally a rinse down with some scrubbing if needed. Repeat if it needs a 2nd cleaning once first layers of goop are gone.

Good luck!

 

Works, with the right light and glasses. Clean engine and you can also use powder to locate the leak once totally dry.