Smoke machine to locate vacuum leaks?

[GNRick]

My BLM is pegged at 160 at idle. I replaced the EGR valve and PCV, to no avail. I checked all hoses and they look good. My mechanic says he uses a smoke machine to locate leaks, but they cost over $1,000 (his was $2,000). So I checked Ebay and the kind used for parties go for $40. Here is a link Professional Fog Fogger Smoke Machine Party DJ Disco - eBay (item 260225787123 end time Apr-07-08 06:02:01 PDT)

Would the party version work on our cars?

 

[matswtt]

a 3.5in rubber plug with a air fitting on it.
in the maf. and a spray bottle of soap.
less than 20.00

 

[GNVYUS 1]

A $2000 machine to find vacuum leaks, Jesus.

Boost Leak Detector

A water bottle with some soap in it will help find the leaks while under pressure.

 

[GNRick]

A $2000 machine to find vacuum leaks, Jesus.

Boost Leak Detector

A water bottle with some soap in it will help find the leaks while under pressure.

Has anybody used that detector? Does it work? So if I understand it right, it sends pressurized air through the turbo, into the intercooler, and up through the throttlebody to check for leaks in the intake?

 

[turbo nasty]

I made one similar to that and yes they work.

 

[GNRick]

A $2000 machine to find vacuum leaks, Jesus.

Boost Leak Detector

A water bottle with some soap in it will help find the leaks while under pressure.

I was thinking...when under boost, BLM goes to 128, which is where it should be. So does that mean I don't want to check for leaks under pressure?

 

[PaCemkr86]

i just use the smoke from my marlboro to find em

 

[GNVYUS 1]

No, you need to check for the leaks while the system is being pressurized, otherwise how are you going to hear/see them when you spray either bubbly water or WD40?

There are some who make the boost leak detectors, but I had a bitch of a time trying to find caps that would fit in 3" couplers, so Mark's boost leak detector is the easiest way to find them all instantly.

Pressure up to 10-20psi, start spraying around places you hear hissing and fix them up.

Most likely you have a leak based around the vacuum block but I had a few that were not near it.

 

[GNRick]

A couple people have suggested using propane. They said just give it a little spritz in different places and see if the idle changes. Does anybody recommend this method?

 

[87NAT]

First thing to do is remove your vacuum block and seal up the TB. Your BLMs should go to 119-120. Then put the vacuum block back on and just plug all the ports on it. See what the blms do again. (Keep resetting ECM as you check each thing.) If vacuum block checks out get a handheld vac pump from a parts store and start checking all 5 of your vacuum lines coming off the vacuum block one at a time. Each one should hold vacuum.

If all 5 lines check out its intake leak most likely.

 

[Black Power]

Hell dude, buy the smoke machine and if it doesn't work out for you finding the leaks, at least you will have a sweet smoke machine for making "adult" movies.

Un ss un ss un ss un ss

 

[8AV8]

i just use the smoke from my marlboro to find em

Thats like a Clint Eastwood one liner....lol...thats cool.

The guys at the dealership use a type of pressure test apparatus to check for leaks on the Cummins. It doesn't use plug, it uses a cap with a clamp. Same principal though.

 

[GNVYUS 1]

Rick it's a $50 boost leak detector and will find them much faster than Propane and is much cheaper than a smoke machine.

Not every leak is going to affect the idle when sprayed on which is why using WD40 doesn't always find every leak. I went through a whole bottle and found 0 leaks, did the boost leak detector and found 4 - 6 leaks.

 

[GNRick]

Wow! 4 - 6 leaks! Do you happen to remember where they were located? I just ordered the vacuum block gasket on top of the throttle body, as that seems to be a logical place to start. Plus GM might discontinue it some day. Looks like I'll be buying that leak detector. Thanks for everybody's input.

 

[GNRick]

Here is an ultrasonic tester on ebay...seller said he found a leak in vacuum line in 4 minutes of use. There is also one sold by Snap-On on ebay.


eBay Motors: Omitec-OmiSonic - Ultrasound Diagnostic System (item 370038754412 end time Apr-08-08 20:02:08 PDT)

 

[Pronto]

Dr Booster, did you pull the rocker arm shafts to close off the valves or did you just keep pumping air though the intake?

 

[bmackinnon]

Dr Booster, did you pull the rocker arm shafts to close off the valves or did you just keep pumping air though the intake?

THAT'S what I want to know.....

 

[BlackMetal]

First thing to do is remove your vacuum block and seal up the TB. Your BLMs should go to 119-120. Then put the vacuum block back on and just plug all the ports on it. See what the blms do again. (Keep resetting ECM as you check each thing.) If vacuum block checks out get a handheld vac pump from a parts store and start checking all 5 of your vacuum lines coming off the vacuum block one at a time. Each one should hold vacuum.

If all 5 lines check out its intake leak most likely.

I like this idea better. See if you have better vacuum with the block removed. If you do, reconnect the block, and seal off one port at a time, then you'll know where the leak is at.

 

[GNVYUS 1]

The inlet system will hold psi due to the throttle body being closed almost 100%, it will bleed down but it does very slowly so

No, I didn't do anything to the intake valves.

GNRICK, at this point in time I think you are just looking for ways to spend way more $$ than you have to. So send me $100 and I will send you a boost leak tester which will find all of your leaks, it's very similar to the one BuickGN sells for $50, hell it might even be that very same one. :biggrin:

Two of my leaks were the coupler nearest the turbo and the TA49 turbo inlet bell itself. I didn't have a gasket and those both wouldn't have been found by blocking off the vacuum block.

But I do agree that an effective way to hunt the majority of leaks would be to start at the vacuum block.

 

[GNRick]

The inlet system will hold psi due to the throttle body being closed almost 100%, it will bleed down but it does very slowly so

No, I didn't do anything to the intake valves.

GNRICK, at this point in time I think you are just looking for ways to spend way more $$ than you have to. So send me $100 and I will send you a boost leak tester which will find all of your leaks, it's very similar to the one BuickGN sells for $50, hell it might even be that very same one. :biggrin:

LOL. Actually, I am trying to spend as little money as possible. I plan on replacing the vacuum block gasket first, before I buy any leak detector. I ordered 10 gaskets (only $2/each). Can't hurt to replace the gasket as it is 21 years old. If that doesn't work, then I'll buy the leak detector. I was just curious if anybody used the ultrasonic detector or if it is a waste of money. Thanks for your help.