Coolant (?) leaking onto outflow manifold

[Minlest]

Hi everyone. ‘83 FI Spider. I did an engine rebuild and it ran well for a bit. I installed new exhaust, including a resonator, which was too large so created too much exhaust pressure, making my engine whine and snub. Only ran it maybe 10 minutes with the new exhaust, but pretty quickly something started leaking onto my outflow manifold, creating white smoke.

I removed the exhaust, and am now running it without anything past the down pipe (removed the catalytic converter as well), but still getting something leaking onto the manifold and smoking, after maybe 30 seconds with the engine on. Smells sweet, so I’m assuming it’s coolant.

Any thoughts on how I can steal it back up? Should I just try adding some sealant to the studs, or am I likely to need a new manifold gasket. Or something else? Any thoughts appreciated!

[18Fiatsandcounting]

Without knowing where the leak is, it's hard to suggest a solution. Is it coming from the front of the engine or the rear? Do you see any leakage with the engine not running (perhaps the exhaust manifold is getting moist), or does it leak only when running? Any chance coolant is "spritzing" out of a leak in the hose that goes to the water pump?

I agree that white smoke with a sweetish smell sounds like a coolant leak. Could be a leak in the head gasket (not so good), or a leak in the hoses that go to the heater (not so bad). One thing to do is to check the torque on the cylinder head bolts. Crack each one in turn just slightly, then retorque to the specification. Follow the suggested diagonal tightening pattern.

If you can't see / find the leak, you could buy some of that UV-active dye that you add to your coolant and then shine a UV light around the affected area with the car in relative darkness. I suggest cleaning off the area with engine degreaser or at least water before you do this (on a cold engine).

-Bryan