isn't there a spray for detecting an intake leak?

[dickster]

i am sure there is something you can spray around the manifold to check for leaks. when the substance gets sucked in it affects the rpm and is audible.

but what is the spray?!

richard

[rstoll]

WD-40 should work.

[T Bird]

I believe the substance is propane gas.

[Adam]

If you're talking about finding vaccuum leaks, then I think something like Brake Cleaner should work really well. It's basically dry-cleaner's fluid (alcohol and water) and less likely to go up in flames than propane.

It comes cheap too. But be very careful!

[dickster]

thanks i'll give wd40 a try

richard

[bjola]

Hey guys,

In Sweden you can buy starter-gas for helping out during cold (winter) starts when the battery is low. The can is filled with ether that you spray through your air intake to help with the ignition. This spray is also perfect for finding leaks in your system as i vaporizes quickly and is drawn through the leak into the engine. Your engine will tell you if it inhales ether! I don't think WD-40 will work.
I'm sure that you can buy this product in the colder states over there.

Hope this helps, Bjorn

[dickster]

Bjorn

nice one i'll try it.


richard

[PanAmeriCan]

I'd always thought (spray) carb cleaner worked best.

[dickster]

thanks guys, plenty of things to try.

has anyone tried one of the methods?

richard

[RarlyL8]

I've always used starting fluid.

The can comes with a small red "straw" type tube. Use it to pinpoint vacuum leaks with small bursts of spray.
I always check for leaks when the engine is cold. Fortunately with the 911 the exhaust system is under the engine so much less to worry about.

[T Bird]

Actually, propane will reveal a vacuum leak by causing the engine to speed up. The way to do the test with propane is to use a torch (unlit of course). Turn on the propane flow and place the nozzle near the suspected areas.

As far as safety goes, I believe that it would take quite an open spark to light the propane. Unless your distributor wires are arcing visibly, I would think that the chances of encountering an open spark are relatively remote. Besides, with an open engine lid and the engine running, the small trickle of propane from the torch is not likely to collect in sufficient quantities to cause a hazard. Personally, I would be more concerned with pouring flammable liquids over a hot engine than using propane. While liquids may work too (?), I have doubts about how effective those liquids would be compared to propane which, as a gas, would probably be drawn into the vacuum more readily.

[john walker's workshop]

i've always used oxygen from my torch. the idle speeds up if it's sucked in. bad around open flame, but there probably isn't any around your engine. also good for cluster headaches which my ex-partner suffered from.

[dickster]

great stuff!

i'll see what i've got in my cupboards.....in give it a go (carefully!)

richard

[jlex]

Careful, T Bird... last time this topic came up and I passed along the propane suggestion, lots of posters went absolutely spastic... they thought you'd blow up the car. Can't overdue it of course.
There's a radio show thru NPR called Click and Clack, the tappet brothers who use the propane trick in their garage. It's supposed to work well.
regards,
jlex.

[radcon]

I think carb cleaner is definitely one of the safer options. Propane and starting fluid seem like they could definitely present some safety hazards in the right(wrong?) conditions. I've used carb cleaner on several different types of engines and it works really well.

[john walker's workshop]

brake cleaner becomes something evil, like phosgene gas, when it goes thru a running engine. do it outside. propane might be fun. do that outside too. check for arching plug wires first.

[jkeyzer]

I use starting fluid after brake cleaner got on some rubber parts and caused a headache by trying to dissolve them. I haven't tried propane.

Starting fluid is also great for determining if you have a lean cylinder in an MFI system... Just spray a little down each stack.

[pjv911]

Definetely carb cleaner. I use berkable 2+2 for finding vaccum leaks. Propane is even better but sometimes hard to pinpoint its direction. Been doing it for years.

[RoninLB]

I have friends that own repair shops. I sometimes buy tools they would not buy. I bought a Snap-On Vacuum Leak Detector, model AC-6500. I get calls to borrow this thing. Finds leaks that shops can't find.

[Roland Kunz]

Hello

Many ways to go a very good one for finetuning is to use gasoline and brush it onto the suspicious parts or get a little injector with a fine needle and spray it onto the area.

Well do i need the Kindergardendisclaimer ?
Playing with fire needs big boys, big brains or big balls.
If you are either then leave it to others with such attributes.

Grüsse