Installing new Exhaust manifold questions

[jrod 74]

Good Morning. New member here. I recently bought a 74 CJ5 with a AMC 258 i6 / 4.2l . I bought a new exhaust manifold to replace my quite tired old one and I have a few questions. Once I removed the intake and exhust manifold, I saw that it looked like a small ammount of oil was in the ports. there was no standing oil just looks like some may have leaked by over the years. is it ok to have some oil stain here, or is this showing a bigger problem? Maybe leaky head gasket? leaking valves?

Just wanted to ask while I have it apart so I dont just put back together to take it apart again.

Thank you

 

[Lumpy Grits]

:ww:

Most times that 'oil' you see in the intake ports is old gasoline that has leaked from the carb.
Start it up when you have the new manifold on, and you'll know if all is 'rite'.
LG

 

[Torxhead]

Welcome to the forum. You might want to pull the spark plugs and inspect the deposits on them. A repair manual or internet research will show you a spark plug analysis chart.

 

[jrod 74]

Thank you both very much. I'll take a look at the spark plugs.

 

[jrod 74]

spark plugs are clear, and I had some pics and took it to my one boss who was a mechanic for years, he also agreed, I'm not actively leaking oil out of there so a little oil stain was ok.

The new manifold is amazing by the way. very quiet now that everything is sealed. amazing how that works huh? lol

I don't know why I didn't do it while it was on the ground, but I didn't tighten the plugs in the new exhaust manifold and one backed out on he maiden voyage. luckily it was around the block. I couldn't find the plug, so i had to buy a $17 kit from advance auto to get the right size. Well I didnt HAVE to, but I had to because I wanted it fixed now. Ace hardware, home depot, and fastenal didn't have any. well now I know lol.

Does anyone know why those are manufactured into the new exhaust manifolds? is it for sound? emissions? I'm just curious as for why the change.

Thanks again for the help.

 

[gert]

spark plugs are clear, and I had some pics and took it to my one boss who was a mechanic for years, he also agreed, I'm not actively leaking oil out of there so a little oil stain was ok.

The new manifold is amazing by the way. very quiet now that everything is sealed. amazing how that works huh? lol

I don't know why I didn't do it while it was on the ground, but I didn't tighten the plugs in the new exhaust manifold and one backed out on he maiden voyage. luckily it was around the block. I couldn't find the plug, so i had to buy a $17 kit from advance auto to get the right size. Well I didnt HAVE to, but I had to because I wanted it fixed now. Ace hardware, home depot, and fastenal didn't have any. well now I know lol.

Does anyone know why those are manufactured into the new exhaust manifolds? is it for sound? emissions? I'm just curious as for why the change.

Thanks again for the help.

emissions, depending on plug location and year there were air injection ports and O2 sensor ports so you probably have all of the holes in yours to cover a broader range of years and motors

 

[Lilredwagon]

Welcome to the forum! We are looking forward to your pictures.