[69GPModJ]

Anyone know what to use to create smoke so a vacuum leak can be traced?

I'm thinking of getting some dry ice to see if that works.

[69GPModJ]

Anyone know what to use to create smoke so a vacuum leak can be traced?

I'm thinking of getting some dry ice to see if that works.

[Robby D]

I have heard that one can use a butane torch.. turn it on low (UNLIT!!) and put it near suspected leak areas. The engine will supposedly increase rpm when the butane gets sucked into any leaking areas. I personally have never tried this or know anyone who has, but it is part of the lore I have heard.

[69GPModJ]

Someone has also told me you can spray brake clean where you're testing and the engine will speed up. However, I don't want to try that because it'll peel the clear paint I have sprayed on the manifold.

[george kujanski]

WD-40 works, too.

George

[BVR421]

unless you have a way to stop the radiator fan from blowing the smoke or any vapor that light will just blow up on the windscreen. Not many vacuum leaks there.

[69GPModJ]

I've got electric fans so no worries there.

[Jim Hand]

Kerry,
Get several feet of small rubber hose/tubing. Hold one end to your ear and pass the other over every possible source of vacuum leak with the engine running. You will hear it if there is one. And a small hose will reach under the intake to check there also. To calibrate the leak detecting "system", pass the end over the carb and listen to the air moving into it.

Jim Hand

[69GPModJ]

Hi Jim:

Thanks for the tip! I've got a mechanic's stethoscope. I'll take the end off and simply listen with the tube instead of the end.

[Jaggs79transam]

Hey kerry,

For a couple of bucks you can go to your local hardware store and get some leak detector for an air conditioning unit.

Glows green ( flourescent) has a dip stick and swab for application and will not damage or harm anything under the hood (its kinda like water with dish detergent in it.

We use it at work daily (maintenance) we use it on the roof top in high wind and all other kinds of conditions its good stuff.

[69GPModJ]

Jagg:

I'll look into that as well.

[connman]

to use the butane torch it take a fitting that ya'll can put a hose on it so it will get close to the leak. What kind of vac leak do ya'll suspect? hard to find one "under" the intake sometimes.

DRIVE IT LIKE YA'LL STOLE IT!

[69GPModJ]

I suspect something hard to get at because I haven't been able to find it in the usual places--hoses, threaded connections, carb, et cetera. I'm going to have a go tonight and see if I can find it.

[Brian Baker]

Don't forget to check the vacuum advance on the distributor, vacuum modulator on tranny (if equipped), etc.

[69GPModJ]

Hey Brian:

The problem developed with the vacuum advance blocked off. I've checked idle with the vacuum modulator blocked off too and that doesn't seem to be the problem.

A friend of mine brought one of those mini foggers you see in indoor fountains. I'll see if that's any use while checking for leaks.

[69GPModJ]

I think someone here--probably George Kujanski--advised me to use a piece of hose to find the vacuum leak. In any event, Jim Hand suggested it today, which reminded me again of my stethoscope.

It did the trick! I've got a major vacuum leak at the rear of my Torker II on the driver's side. Actually, it almost sucked my eardrums outside my head when I put the tip of the stethoscope hose over the leak.

So, off comes the manifold--probably this weekend.

Question: Is it likely my manifold warped? I don't have that many miles on it and the engine has never overheated.

If the manifold is warped, does that mean I have to buy a new one or can it be repaired?

[Big Mike]

I don't believe it could be warped unless you dropped it or torqued it down incorrectly nad had something keeping it from seating. Remove the manifold, clean all gasket surfaces well, use a good gasket like Fel-Pro brand and be sure the bolts are not bottoming out before they exert pressure on the intake. I always slightly snug the bolts to the head, then torque to bolt that pulls the manifold forward and seals that "O" ring to the timing cover. Then I torque the other bolts starting from the center bolts outward.

[69GPModJ]

I was pretty careful to torque the manifold down properly. However, I did loosen and tighten a couple of the bolts in installing and removing a couple of things. I don't think something like that could warp the manifold--could it?

Regarding snugging the bolts then tightening the bolt to the waterpump, I'm planning on cutting the water crossover away from the rest of the manifold anyway. I've already removed the webbing between the plenum and crossover when I polished it.

[grandville455]

Congrats Kerry...these guys are the best here!!!!!!!!

[69GPModJ]

Yep, this is a great place for Pontiac support!