vaccum leak?

[rb77413]

I found the problem with the high idle on my wofe's 66 barracuda. like you guys said a vaccum leak. Kinda. I did the carb cleaner around the intake and carb base but nothing. It has a old Weiand high rise 4 bbl dual plane. On the driver side there is a vertical flat surface (looks machined) with 4 holes in it. I sprayed carb cleaner in one hole and the idle dropped. I put my finger over the hole but didnt feel any vaccum. The weiand web site doesn't have anything for this manifold. Anyone have one like it? Is it the spot for the egr? the holes look threaded but....the idle only changed when I sprayed cleaner it it, not when I covered it with my finger.


Bob

[Devilbrad]

Are you sure the carb cleaner didnt run down to the intake manifold gasket at the cylinder head?

Brad

[cuda66273]

I had one of those manifolds at one time......I think that is for the EGR, but the holes should be blind. I think you've got something going on with the intake gaskets.

You can get good leak test results with water in a spray bottle, safer, cheaper and cleaner.

I watched an Old Mechanic (that's anyone older than me) add some sort of dye into the water bottle, sprayed water down one side and killed the motor, pulled the plugs and found the bad hole by the color on the plug porcelin. I guess I should have payed more attention...

[freak007]

another way to check for leaks is to take a small UNLIT propane torch,and run it along the gasket surfaces,the idle speed will increase when you are near a leak...if you find one 90% of thr time you can fix it simply by retorqueing the intake,just crack all the bolts loose,and retorrue the back to specs,but DO NOT loosen the intake itself from the gasket....

[rb77413]

No i sprayed the intake/head area first, did the passenger side then the carb, sat back then I saw the holes on the intake. Stuck the straw in there then there was the idle change. After that happened I did retry the intake area around that area and still no change except when I sprayed it directly in those holes. I might have to try the propane and colored water trick after I get done moving. Thanks guys



Bob

[Devilbrad]

Well, if its the holes and they are threaded, just run some short bolts in there with loctite, that should seal it up.

Brad

[Devilbrad]

I just reread the post. That is definetly an EGR manifold. Two holes should be threaded, two not, I assume one of the unthreaded holes is the one that is the problem one. Two things you can do, find an EGR valve and bolt it on but non functioning, or make a block off plate with an EGR gasket underneath. I'm not familiar with EGR manifolds, but I would suspect that they ARE drilled all the way through as they are designed to be smog legal, they would have to be drilled through. One should go to the heat crossover, the other to the intake plenum. Only fix is to block it off.

Brad

[rb77413]

I went back out and let it warm up, resprayed the holes same thing, This time when I went to put my finger over the hole, the metal seemed to be hotter than the rest of the intake. Which does go along with everyone here about it being for the EGR. Maybe I will make a plate out of some thin sheet metal and some gasket material/jb weld. I'll keep you all posted. Thanks


Bob