Freshly rebuilt engine - tracking down oil leaks

[JonsE30]

I just went through an engine rebuild with much appreciated help from members of these forums but i am noticing some oil leaks in commonly expected places. At rest i dont notice much oil leaks but when i start the car and let it get up to temp, then it becomes more apparent. I removed my a/c compressor to get a better look and it looks like its from the timing case. i am guessing its the gaskets or the seal didnt seat or seal properly before putting on the timing cover. Since i didn’t put back my cooling system yet, I’d like to address this now. Do i need to drain the oil to do this. Is there an external sealer i can use since it’s all buttoned up now?

[roguetoaster]

You should drain the oil, add new once complete, and replace the filter after a short while.

There's probably nothing that would seal from the outside as the leaky area is already contaminated with oil. If you are getting leaks from the sides of the case go ahead and RTV the surfaces after you clean them. Alternately RTV a gasket on both sides before installing. Most importantly, seal the upper to lower T case seal ends, and follow the sealant product application instructions.

If you are getting leaks past a bolt you may need to RTV the integrated washer.

[JonsE30]

So rtv plus new paper gasket ? Sent from my iPhone using Tapatalk

[roguetoaster]

Yes, as it's a bit easier to control coverage that way, or just RTV, depends on what you have on hand and your timetable. Either will work.

[JonsE30]

trying to tackle this soon, since the timing covers come off i am guessing this is the path:

drain oil and coolant, plugs, ignition, valve cover, fan clutch/shroud, rad hoses, thermostat housing, water pump, accessories pulleys and crank pulley have to come off right?

[roguetoaster]

You can leave the plugs in. I suggest cleaning it up and pinpointing the actual source of the leak first, so if it's just at or immediately below the upper T case you won't have to take extra stuff off. If it's only the rubber gasket ends you shouldn't need to take off more than the VC, T stat and upper case, maybe coolant hoses too to allow for work space.

[JonsE30]

so it looks light from the valve cover gasket to the profile gasket, below the profile gasket it gets thicker. then it drips off the oil pan.

[JonsE30]

got the valve and upper timing cover removed. I see the leaks from the profile gasket.

can rtv be used to replace all the timing cover gaskets here, how about the thermostat housing gasket?

is it bad to use rtv below and above the profile gasket for extra sealing?

[roguetoaster]

RTV probably won't be a good substitute for that large rubber gasket or a great fix for the T stat gasket, but would be fine on the side gaskets, You can clean the rubber gasket and possibly RTV where needed to get a seal, T stat gasket might be a good candidate for copper spray a gasket.

[bmwman91]

I think that RTV instead of the OEM gaskets is OK for the timing case covers. Just don't apply it too thick.

I usually apply a film of RTV above and below the profile gaskets in addition to the butt joints.

For the thermostat housing, I'd stick with the OEM gasket though. You will notice a little groove connecting the 2 sides. That is a bypass, and RTV is likely to clog it. While it won't hurt anything to plug it, it makes bleeding the system a pain in the ass. With the bypass clear, 99% of the air will bleed out in less than 30 seconds after starting the engine. If it is plugged, you have to sit there idling/revving until it is warm enough to open the thermostat, and personally I would never run the thing for very long knowing that the head has huge air pockets in it.

[JonsE30]

roguetoaster how would you spray the gasket on, wouldn't there be some overspray into the thermostat housing? or do you just stuff it with paper towel or something? if this can work i can do this asap since i won't have to order and wait for parts.

[roguetoaster]

Was thinking that the fairly new used gasket might have the spray gasket applied if reused. Clearly new is best in every case, as you may end up having to do this again if it's fudged too much. RTV is still a must at the ends of the not profile gasket profile gasket.

[JonsE30]

I swear this engine is teasing me. I snapped a damn bolt from the upper timing cover putting it back on. Noob mistake!!! Uggghhh!!!! Makes me sick to my stomach! Gotta figure out extraction techniques to without causing further damage. I have left handed drill bits that’s worked out wonderfully for my pressure plate bolts but those were just stripped bolt heads. This time it snapped in bolt hole so I’d have to be careful to not damage the threads.

[JonsE30]

How does oil leak to this area?

[roguetoaster]

Likely: oil pressure sensor behind the filter canister, block to oil pan gasket, filter canister to engine interface itself. Unlikely: tranmission or rear main seal getting tossed up, head gasket, valve cover, PCV accumulation leak down, or brake fluid leak.