So I have a fuel leak. It seemed to be coming from the exhaust manifold so I replaced that gasket last night but I still get a drip. It drips from the furthest left of the manifold. I recorded a video and set my phone under the exhaust manifold to see where it is dripping from. My Corolla is equipped with a secondary air injection system or a smog pump, they call it. One of the connections was moist so it seems to be coming from there where it connects to the bottom of the exhaust manifold. I tightened all of the threads and I still have the leak. My head gasket seemed to also be moist and wet with fuel. I wondering if my head gasket needs replacing too but the head wouldn't be leaking gas, right? 

 

79' Corolla with 2T-C Automatic

These are the air injection rails that connect to the bottom end of my exhaust manifold. You can also see that gasket really needed some replacing haha!

I hope this is a good picture and explanation of what's going on. I circled where it actually drips from. It's not dripping from inside of the threaded portion but just from the corner of it. That's just an empty thread. Nothing is connected there nor have I seen others with something connected there. Looks like fuel just accumulates there and creates a drip. You can see the arrow pointing at where it connects to the manifold and that's also moist but my head gasket is also moist. 

I'm wondering if I can do without that secondary air injection system. It's just an emissions/smog piece from what I'm reading. Anybody know any info on that and if I could just remove it and maybe throw in some new bolts to seal the space?

Edited October 28, 20205 yr by Misael

Surely there's no fuel on the exhaust side of the engine at all??  The only way I can see that happening is if it drips from the air cleaner down onto the motor. Check that out.

Otherwise, are you sure its fuel and not condensing oil vapour?

Oil those studs and run the nut up and down them, and use a screwdriver on a rag to clean the bolt holes before running a bolt all the way in and out before you re-assemble it.  A tap is even better, or a bolt with a slice down it so it can pick up any dirt in a thread. Lay a steel rule against the manifold and just check it is straight too, that old gasket doesn't look good at all..

I'm sure sealing the air injectors won't hurt it, although the EPA will be upset if they find out. If the pump is still on it make sure its not pumping against the seals though, it would be working hard for nothing.

 

Ah- I see a new gasket in one photo, so its re-assembled already!

That is just a small amount of oil leakage. Nothing that would lead to any real problems. If you just put Permatex  on the air pump threaded fittings, after cleaning off the rust,  that will solve that issue. Then install a new exhaust manifold gasket, you should be in good shape. After replacing the gasket and running the engine for a week, go back and re-check the manifold nuts. Davew7

On 2/19/2020 at 4:46 PM, altezzaclub said:

Surely there's no fuel on the exhaust side of the engine at all??  The only way I can see that happening is if it drips from the air cleaner down onto the motor. Check that out.

Otherwise, are you sure its fuel and not condensing oil vapour?

Oil those studs and run the nut up and down them, and use a screwdriver on a rag to clean the bolt holes before running a bolt all the way in and out before you re-assemble it.  A tap is even better, or a bolt with a slice down it so it can pick up any dirt in a thread. Lay a steel rule against the manifold and just check it is straight too, that old gasket doesn't look good at all..

I'm sure sealing the air injectors won't hurt it, although the EPA will be upset if they find out. If the pump is still on it make sure its not pumping against the seals though, it would be working hard for nothing.

 

Ah- I see a new gasket in one photo, so its re-assembled already!

 

On 2/20/2020 at 5:34 AM, davew7 said:

That is just a small amount of oil leakage. Nothing that would lead to any real problems. If you just put Permatex  on the air pump threaded fittings, after cleaning off the rust,  that will solve that issue. Then install a new exhaust manifold gasket, you should be in good shape. After replacing the gasket and running the engine for a week, go back and re-check the manifold nuts. Davew7

I'm about 99.99% sure it was fuel. I caught a drip and it smelt like gasoline. Changed out the exhaust manifold gasket already. What I did this weekend was, changed the fuel filter and one of the hoses that go down to the fuel line from the filter because the old one cracked when I plugged it into the new fuel filter. Changed the spark plugs and noticed the valve cover gasket was lose so tightened that up as well. Viola! Drip is completely gone and now she's running super smooth and fires up quick and with ease. 

Well done!  Another problem crossed off the list..  Now at least you have it running well before you think about any mods for more grunt.