Boost Leak Test
09-09-2009, 06:54 PM
#1
Senior Member
SL Member
Thread Starter
Join Date: Apr 2009
Location: Buffalo, NY
Posts: 782
Boost Leak Test
There are many reasons to check for a boost leak.
1. If let go they have potential to damage turbos.
2. Boost leaks make turbos spin faster thus making hotter air.
3. Severe boost leaks cause oil leaks in turbos from over spinning. The vacuum created in the compressor can suck oil past seals and destroy parts in short order
4. Boost leaks cause lag and thus lower performance
5. Boost leaks can cause improper fueling on MAF based cars
6. Boost leaks are bad mmmmkay.
Things you will need:
1. Compressor
2. Some form of air regulator to supply a constant flow of air
3. transition coupler
4. clamps
5. squirt bottle and soapy water
6. pvc cap
7. a tap (depends on how you decide to introduce shop air)
8. a screwdriver
So how do we go about checking if we have a boost leak. There are many methods but I will post my favorite because I feel it is the fastest and most efficient way to check. It involves you ordering a part from harbor freight or home depot.
1. I start with a leak down tester from Harbor Freight. Why? Because using this I can regulate how much air pressure is run through the system and add a constant stream of pressure.
2. I get a transition coupler that fits the inlet of my turbo and one end that fits a nice pvc cap from home depot.
3. Drill into the cap and tap it for a 14mm x 1.5 hole. This is the standard thread of spark plugs and since we are using a leak down tester to regulate air supply to the charge system we need to match that of the spark plugs.
4. Remove the intake to your turbo, secure your coupler on the inlet and clamp it down. Thread your leak down tester hose into the pvc cap you have prepared and then install that into the end of the transition coupler that is now on your turbo.
5. Hook your leak down tester up to the hose that is now hanging off of your pvc cap and then hook the leak down tester up to shop air. Always make sure the leak down tester is turned to the lowest setting before connecting air. Raise the air pressure to about where you want to test your system at. If you are testing at 15psi, raise it to 15psi if you are testing for 20 raise it to 20. You get the idea.
6. You will hear hissing and leaks. This is air rushing out of places you will never see with your naked eyes. So go get a squirt bottle and fill it with water and your favorite dish detergent. Spray all intercooler pipe connections, intercooler, vacuum lines, BOV and mating flange or gaskets, compressor cover, throttle body seal area and shaft (if not DBW), injector seals and intake manifold gasket area.
You will be shocked at how many boost leaks you actually find. Common places for leaks are the ones listed above. A lot of compressor covers leak and so do the bolts. Throttle shaft seals are very big culprits as well. Clamped sections of couplers can leak very bad as well if not clamped just right. You use the soapy water so that you can see the bubbles and pinpoint leaks. This is better than just listening for the leaks as you will be chasing your tail all day. Some home made boost leak testers tell you to get a tire valve stem and pressurize the system. Trust me that sucks. If you haven't done it this way you haven't found all of your leaks. The driveability differences and response differences of a car with boost leaks and one that has had them fixed is very noticeable.
Here is the tool I use and suggest, however any form of air regulator will work so long as you can hook up to supply constant air. If you have a compressor you could even thread the cap for the thread on the end of a quick disconnect nipple and regulate your compressor down to the desired pressure. Either way so long as you are supplying constant air pressure you will be able to find the boost leaks. Also one more thing to note anywhere you find air escaping after the throttle body is not just a boost leak but a potential vacuum leak as well. Having all of these mechanical bugs worked out makes for a truly complete car that is now ready for tuning. If you ever go to a tuner without performing a boost leak test and fixing them first you are just wasting your time and money and his time. You will see much better results always with no boost leaks or vacuum leaks.
I hope this helps SL.
http://www.harborfreight.com/cpi/cta...emnumber=94190
1. If let go they have potential to damage turbos.
2. Boost leaks make turbos spin faster thus making hotter air.
3. Severe boost leaks cause oil leaks in turbos from over spinning. The vacuum created in the compressor can suck oil past seals and destroy parts in short order
4. Boost leaks cause lag and thus lower performance
5. Boost leaks can cause improper fueling on MAF based cars
6. Boost leaks are bad mmmmkay.
Things you will need:
1. Compressor
2. Some form of air regulator to supply a constant flow of air
3. transition coupler
4. clamps
5. squirt bottle and soapy water
6. pvc cap
7. a tap (depends on how you decide to introduce shop air)
8. a screwdriver
So how do we go about checking if we have a boost leak. There are many methods but I will post my favorite because I feel it is the fastest and most efficient way to check. It involves you ordering a part from harbor freight or home depot.
1. I start with a leak down tester from Harbor Freight. Why? Because using this I can regulate how much air pressure is run through the system and add a constant stream of pressure.
2. I get a transition coupler that fits the inlet of my turbo and one end that fits a nice pvc cap from home depot.
3. Drill into the cap and tap it for a 14mm x 1.5 hole. This is the standard thread of spark plugs and since we are using a leak down tester to regulate air supply to the charge system we need to match that of the spark plugs.
4. Remove the intake to your turbo, secure your coupler on the inlet and clamp it down. Thread your leak down tester hose into the pvc cap you have prepared and then install that into the end of the transition coupler that is now on your turbo.
5. Hook your leak down tester up to the hose that is now hanging off of your pvc cap and then hook the leak down tester up to shop air. Always make sure the leak down tester is turned to the lowest setting before connecting air. Raise the air pressure to about where you want to test your system at. If you are testing at 15psi, raise it to 15psi if you are testing for 20 raise it to 20. You get the idea.
6. You will hear hissing and leaks. This is air rushing out of places you will never see with your naked eyes. So go get a squirt bottle and fill it with water and your favorite dish detergent. Spray all intercooler pipe connections, intercooler, vacuum lines, BOV and mating flange or gaskets, compressor cover, throttle body seal area and shaft (if not DBW), injector seals and intake manifold gasket area.
You will be shocked at how many boost leaks you actually find. Common places for leaks are the ones listed above. A lot of compressor covers leak and so do the bolts. Throttle shaft seals are very big culprits as well. Clamped sections of couplers can leak very bad as well if not clamped just right. You use the soapy water so that you can see the bubbles and pinpoint leaks. This is better than just listening for the leaks as you will be chasing your tail all day. Some home made boost leak testers tell you to get a tire valve stem and pressurize the system. Trust me that sucks. If you haven't done it this way you haven't found all of your leaks. The driveability differences and response differences of a car with boost leaks and one that has had them fixed is very noticeable.
Here is the tool I use and suggest, however any form of air regulator will work so long as you can hook up to supply constant air. If you have a compressor you could even thread the cap for the thread on the end of a quick disconnect nipple and regulate your compressor down to the desired pressure. Either way so long as you are supplying constant air pressure you will be able to find the boost leaks. Also one more thing to note anywhere you find air escaping after the throttle body is not just a boost leak but a potential vacuum leak as well. Having all of these mechanical bugs worked out makes for a truly complete car that is now ready for tuning. If you ever go to a tuner without performing a boost leak test and fixing them first you are just wasting your time and money and his time. You will see much better results always with no boost leaks or vacuum leaks.
I hope this helps SL.
http://www.harborfreight.com/cpi/cta...emnumber=94190
Last edited by DezodDon; 09-09-2009 at 07:02 PM.
10-20-2009, 04:32 PM
#8
Senior Member
SL Member
Join Date: Aug 2005
Posts: 879
My tuner did this for me when he tuned my Turbonetics kit. He found that the brand new Garrett turbo I had just bought was leaking massively. Once he put a gasket in the compressor cover, the car ran much better. Felt faster too!
10-20-2009, 04:35 PM
#9
A lot of turbo manufacturers do not seal their compressor housings. When you clock your housing, I would urge you all to take time and see if there is an o-ring at minimum inside of the compressor housing to the backing plate.
10-20-2009, 07:01 PM
#10
Great info actually i think this should be a sticky. Alot of shops would most likely do half job but charge you for the whole thing and some...
so now we know how to do this stuff.
Thanks Don.
so now we know how to do this stuff.
Thanks Don.
10-20-2009, 11:03 PM
#11
Banned
SL Member
Join Date: Nov 2007
Location: Germantown, MD
Posts: 2,893
dezod don, i did a boost leak test from the intake of the compressor and when i did it i noticed smoke coming from the crankcase breather, not like pressurised air just smoke,
before u go and say oh well looks like rings or valve seals are shot...
im thinking that maybe i have boost leaking past the turbo seals since they arent filled with oil and then the air is going down through the return hose and into the oil pan thus causing crankcase smoke...
please verify....
before u go and say oh well looks like rings or valve seals are shot...
im thinking that maybe i have boost leaking past the turbo seals since they arent filled with oil and then the air is going down through the return hose and into the oil pan thus causing crankcase smoke...
please verify....
10-23-2009, 03:37 PM
#12
Senior Member
SL Member
Thread Starter
Join Date: Apr 2009
Location: Buffalo, NY
Posts: 782
dezod don, i did a boost leak test from the intake of the compressor and when i did it i noticed smoke coming from the crankcase breather, not like pressurised air just smoke,
before u go and say oh well looks like rings or valve seals are shot...
im thinking that maybe i have boost leaking past the turbo seals since they arent filled with oil and then the air is going down through the return hose and into the oil pan thus causing crankcase smoke...
please verify....
before u go and say oh well looks like rings or valve seals are shot...
im thinking that maybe i have boost leaking past the turbo seals since they arent filled with oil and then the air is going down through the return hose and into the oil pan thus causing crankcase smoke...
please verify....
Are you currently running with a PCV?
10-24-2009, 01:41 AM
#13
Banned
SL Member
Join Date: Nov 2007
Location: Germantown, MD
Posts: 2,893
hey sorry after visiting ptuning and hearing that a bit of smoke was normal (it was just a poof of smoke at the initila pressurizing, after getting to like 15 psi is was fine no smoke) i did a compression test numbers were even and pretty high i cant remember numbers
11-17-2009, 12:43 PM
#15
Video HOW TO: Compression Test
Found a decent how to video on Youtube on how to do a compression test. This is not my video and disregard the tool in the sideways cap
http://www.youtube.com/watch?v=ujVhVt_rhOk
http://www.youtube.com/watch?v=ujVhVt_rhOk
11-17-2009, 01:04 PM
#17
You guys out there with some spare time, hows about creating some videos so we can stickie this!
11-17-2009, 01:17 PM
#18
Senior Member
SL Member
Join Date: Jun 2009
Location: Hagerstown, MD
Posts: 238
Off topic, but I just got back from Pyeongtaek, South Korea. I was there for two years. I loved it there. South Korea is such a wonderful country. I don't think it gets the attention it deserves.
11-17-2009, 09:49 PM
#19
That's Camp Humprhies and Osan AB territory. Been there many many times. I'm down in area IV in Deagu around Camp Walker, Henry, and George. Was originally only doing a 1 year tour but after bringing the wife over it's been extended to 2. This is a nice country, but i soooo badly miss the states. Nothing like driving around in a $500 93' hyundai and ordering McDonalds by pointing at pictures.
11-17-2009, 10:07 PM
#20
Senior Member
SL Member
Join Date: Jun 2009
Location: Hagerstown, MD
Posts: 238
ha ha, You have to try the Bulgolgi Burger. I lived off those things for the longest.
Yea, I was at the Hump... 25P. The company was trash, but the country was nice.
If you have any leave time saved, JeJu island is beautiful. Me and my fiance took a week long trip there.
Yea, I was at the Hump... 25P. The company was trash, but the country was nice.
If you have any leave time saved, JeJu island is beautiful. Me and my fiance took a week long trip there.