Exhaust Manifold Stud Oil Leak

[1991ZR1]

I'm trying to fix the oil leak from the driver side exhaust manifold stud. I have all the bolts loose to remove the manifold but if I remove it, I'm not sure how to get the front bolt back in because of working space. The manual simply says to install the bolts. Are there any tricks to doing this? Maybe removing the power steering hoses will allow you to get your hand in from the front?

The manual also says to use Loctite 620 when you reinstall the stud. Is this the best thing to use? If you can't find Loctite 620, what's the next best thing to use?

Any advice will be appreciated.

[1991ZR1]

Thanks for the link. It seems that RTV is a popular substitute.

I don't think I will be able to work between the tubes and get the stud off and reinstall it but I'll give it a try. I didn't mention earlier but i have the stock manifolds. I still need to know how to reinstall the front bolt on the manifold in case I can't reinstall the stud without removing the manifold.

[secondchance]

Originally Posted by 1991ZR1

Thanks for the link. It seems that RTV is a popular substitute.

I don't think I will be able to work between the tubes and get the stud off and reinstall it but I'll give it a try. I didn't mention earlier but i have the stock manifolds. I still need to know how to reinstall the front bolt on the manifold in case I can't reinstall the stud without removing the manifold.

It has been awhile since I installed my header w/ the WAZOO gang and can't remember how diffiult the particular bolt was. Actually on later cars first and last bolt holes are substituted with stubs on the block eliminating bolts.
I presume you removed the plastic liner?

[1991ZR1]

I'm not sure what plastic liner you're talking about. If you're talking about the wheelhouse panels, yes I removed them.

Now that you mention studs, I could replace the bolts with studs.

I'm also thinking the manifold flange could be slotted to allow the stud or bolt to be in place before installing the manifold.

Thanks for the ideas.

[Blue Flame Restorations]

Originally Posted by 1991ZR1

I'm not sure what plastic liner you're talking about. If you're talking about the wheelhouse panels, yes I removed them.

Now that you mention studs, I could replace the bolts with studs.

I'm also thinking the manifold flange could be slotted to allow the stud or bolt to be in place before installing the manifold.

Thanks for the ideas.

This is exactly why I like this group of great guys!!!

[1991ZR1]

Looks like I have a bigger problem. The problem is that I don't know where the oil is coming from. I removed the exhaust manifold and took out the center stud. When I removed the stud, the threads were dry. No oil. Everything is a mess so I can't tell where the oil is coming from. The only thing above the exhaust Manifold is the cam cover but that does not appear to be leaking. I cleaned things up a little and I'm going to have to reinstall the manifold and see if there is still a leak. If it still leaks, I have to remove the manifold again and look for fresh oil.

[Z51JEFF]

A leaky dipstick tube seal will cause a leak.

[scottfab]

Originally Posted by 1991ZR1

Looks like I have a bigger problem. The problem is that I don't know where the oil is coming from. I removed the exhaust manifold and took out the center stud. When I removed the stud, the threads were dry. No oil. Everything is a mess so I can't tell where the oil is coming from. The only thing above the exhaust Manifold is the cam cover but that does not appear to be leaking. I cleaned things up a little and I'm going to have to reinstall the manifold and see if there is still a leak. If it still leaks, I have to remove the manifold again and look for fresh oil.

If not the stud then the usual suspects are the Oil Pressure Sender and the Oil Level sensor if your MY has one. The leak can run along the side of the engine and gets to the bottom.

Best detection is a complete cleaning of all oil.
Then allow to dry and then a drive.
If it's still there it's then easier to detect.
Good luck.

[Pete]

Guys he said "driver side"

Check cam sensor.
Also one of the 3 power steering mounting screws goes thru needs RTV,it's the one furthest left just take it off RTV it and reinstall.

Also it might give you some more working room if you take motor mount nut off and jack up/raise motor a bit.

Pete

[1991ZR1]

I never thought about removing the motor mount nut and raising the engine. Or checking the cam sensor. Is that the thing just below the cam cover? Funny that it is the thing that was in my way when working on the manifold.

I ended up getting the front bolt on by using a shorter bolt without the spacer. Because of the tight space I still couldn't get a regular socket and ratchet on the bolt. I got a 12mm 1/4" drive socket that has a hex on the back end from Lowes and used a gear wrench with that socket. That setup is shorter than a regular socket and ratchet.

Anyone working on the manifold bolts needs to be careful not to drop the bolt into the manifold or the area next to the steering coupler. I spent quite a bit of time trying to fish them out with a magnet before I figured out that they are not magnetic.