Vaccuum leak at exhaust manifold
 

I'm sorry if this has been answered somewhere else, but it's getting dark and I have to figure this problem out.

I have an '89 4x4 pickup with 22RE. A few days ago a vaccuum leak started and it was very loud, but it would stop before I could get the hood up to inspect where it was coming from. Well last night it started again and continued throughout the night but I couldn't really stop because it was blizzard conditions and I was afraid I wouldn't get going again. Today when it started, I was able to pinpoint the location of the leak, but I'm confused to why there is a vaccuum leak in this location. Where the exhaust manifold bolts to the head, there is a single hole right in the middle of the of manifold and it is sucking air like crazy and is very loud. If I keep gas to it, the vaccuum leak seems to stop and engine runs fine, but when I let off the gas it starts sucking air again.

Is there some diaphram that is supposed to be there, or just another bolt? I need help soon because I have to get this truck running or I will never make it to work and the roads are too bad to drive the Riviera.

What is wrong with the engine itself? What are the symptoms?

What you're experiencing is extra air being registered at the o2 sensor, making it think your truck is running lean therefore adding more fuel.

I am gonna take a stab that the engine is boggy?

You're right though that it's unusual for it to be sucking air, but maybe the fast moving exhaust is causing that "phenomenon"

When I come to an idle it sputters and dies. It smells like it's running way too rich. If I give it just a smidgen of gas it runs smooth, but if I let off it starts that loud sucking sound and starts running rich again. If I have to drive it tonight like this, I can manage it but my fuel mileage will be pretty bad.

I just stuck my key into the hole and it is threaded. I have no idea why it would be leaking air right there because the are manifold bolts within an inch on each side of this hole.

I wish I could help more, but I am not very familiar with the 22RE so I can't imagine where that hole would be. Pictures would help tremendously.

Either way, the rich diagnosis makes sense.

Well thanks anyway. I phoned the owner of the local garage and he's going to meet me at his shop in 30 minutes. We are just going to try to plug it with a bolt and see if that helps for now. If not, I'm lighting it on fire tonight and getting a new Cruiser.

Mine has a allen plug that threads into that hole. No idea what it does or why its there. Maybe for some air injection or something, but mines blocked off.

Now that you say that, I think I remember an allen head bolt being in there before. Anyway, we are plugging the hole shortly and I'll post whether that helped or not.

It took all of 20 seconds to get the bolt size and thread count correct, then 5 minutes to find a bolt. Slapped it in and no more vaccuum leak and she runs like a top.

I was kinda hoping to get a new Cruiser.


I'd still like to know what the hell this hole is for. It's directly below the two center sparkplugs. If anyone knows what this hole is for please let me know.

my 89 has that too!
 

I just found the same "extra" hole in my 89 22re head and manifold while I was replacing the HG. I would just love to know why it's there. mine was not plugged either. I'll get a bolt for it. I recently did a HG on a 85 22r and it didn't have the extra hole in the head or the manifold. curious.

picture please.

there is a tube like shape for the egr that runs along side the head. i found this out on my 86 when i had the head off and cleaning it. i had it in the parts washer. and put water in a hole at the back where the egr cooler plate is (on the back of the head). and water came out all of the bolt holes where the exhaust manifold bolts to. so im just taking a whild guess and saying its egr related. lol.

That little fella right there. . .
 

I didn't think to get a picture while I had it disassembled. Here it is now, with a brand new stud plugging the "offending" orifice!

i have a 20R header on my 22R...LOL..it doesn't have the hole..nor does it leak..and im using the HEADER gasket off of my 1980 20r...its HORRIBLE but i put some kind of exhaust gasket maker stuff on there..and no leaks :great:

has nothing to do with the topic though..idk why i posted that LOL

plug the hole..poblem solved:drunk: