Rebuilt Detroit 12.7

funny how most of them drip from that area. i would stay clear from it. chity work rebuilding the engine. i built several small engines before. never had one leak from a seal or gasket from the start

 

Ask what kind of parts were used for rebuild. Maybe it has crappy aftermarket gaskets installed

 

How much of a leak is it? Probably leak more running under pressure. Depending on where the leak is coming from, may or may not be a big deal. Valve cover gaskets are easy to get crimped installing them, or didn’t seal corners with silicone properly. Temp sending unit, no big deal. Head gasket, big deal!! Lol. Often they leak between the rear structure, or bell housing, at the block, where they mate. If that’s the case, an inframe wouldn’t have anything to do with that. Transmission needs to come out, clutch, flywheel, then replace rear main seal while it’s apart, take structure off and reseal it to the block. Find out the source of the leak, before making a decision.

 

@Rideandrepair He is correct. Without knowing whats leaking, very hard to answer. But he pointed out all good areas.

Watch for fuel slobber out of exhaust ports and clamps to. Fresh engine at a idle will drip alot sometimes. Need to be put to work under a hard load. Not strange for rings and liners to take 75k miles to seat. It will use oil in that time. Mpg normally sucks to.

 

rear main seal or flywheel housing nether will seal with running

 

My last Truck slobbered oil through the stacks, it dripped out of the flex tube, near the turbo. I took it back, they explained it would stop within 1000 miles, once the rings match up with the cylinders a bit. I’ve got 70k on my current Trucks inframe. It didn’t blow any oil that I saw. Still the rings haven’t fully sealed up. Still burning oil, and terrible fuel mileage. Any day now, mpg should jump up almost 1 mpg. The burning oil you smell may be inside the exhaust. It will blow past the rings when freshly rebuilt. Till the rings cut into the cylinders enough to start sealing up. That’s probably what the Mechanic was referring to.

 

No. Any mechanic who spews that crap, you don't want an engine they built. Oil leaks don't get better.

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