WTBorrow Boost Leak Tester
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Car Info: 03 Sonic Yellow WRX Sport Wagon
WTBorrow Boost Leak Tester
My tuner thinks I must have a boost leak.
This all started recently when all of a sudden, my max boost would only reach ~13psi. I talked to my tuner and he said to look for a boost leak. I took off the stock TMIC and poked around, looking at all the hoses I could, but didn't see anything obvious. I also cleaned out the MBC with brake cleaner and found when I went to take it apart, that the barbs barely finger tight, and hoped that was the problem.
I cranked up the boost with the MBC back to 17 PSI and took a log of a 3rd gear pull and sent it to my tuner. His reply was, "The log doesn't look too good. The injectors are beyond maxed out and the engine is knocking up top. I still suspect a decent size boost leak here."
Does anyone have an air compressor and one of those boost leak tester adapters for it so I can pressurize the system and look for leaks? I've got a garage, just neither of these. Any other advice?
I saw this video and am going to try it tomorrow. I hope it's not a leak under the TMIC where it would be impossible to find it unless it makes a sound or you put smoke in the system somehow.
The car is stage 2 with a custom tune and feels/sounds fine to me, but obviously isn't based on the log (attached).
This all started recently when all of a sudden, my max boost would only reach ~13psi. I talked to my tuner and he said to look for a boost leak. I took off the stock TMIC and poked around, looking at all the hoses I could, but didn't see anything obvious. I also cleaned out the MBC with brake cleaner and found when I went to take it apart, that the barbs barely finger tight, and hoped that was the problem.
I cranked up the boost with the MBC back to 17 PSI and took a log of a 3rd gear pull and sent it to my tuner. His reply was, "The log doesn't look too good. The injectors are beyond maxed out and the engine is knocking up top. I still suspect a decent size boost leak here."
Does anyone have an air compressor and one of those boost leak tester adapters for it so I can pressurize the system and look for leaks? I've got a garage, just neither of these. Any other advice?
I saw this video and am going to try it tomorrow. I hope it's not a leak under the TMIC where it would be impossible to find it unless it makes a sound or you put smoke in the system somehow.
The car is stage 2 with a custom tune and feels/sounds fine to me, but obviously isn't based on the log (attached).
Last edited by Cody8675309; May 16, 2013 at 10:46 PM.
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Car Info: EQ Tuned * Corn Juiced '05 WRX
Before I even saw the video you included, I was thinking this exact method. The crew over at EQ showed me this technique a while back when I had them work on my mystery car. This definitely helps!
Goodluck
Goodluck
You can go to home depot and get a PVC cap that fits in the after-MAF hose.
Buy one of these from amazon: Or get a tire valve at an auto parts store for about the same price.
Drill and tap (for the NPT one) or just drill a hole (for the press fit auto parts store tire valve) and you have your tester. There you go, your ~$5 boost leak tester.
A football pump or bike pump works fine too, you don't need a compressor. When you pressurize, cap off the three inlet hoses that aren't your boost solenoid return (closest to airbox) or your bypass valve return.
Buy one of these from amazon: Or get a tire valve at an auto parts store for about the same price.
Drill and tap (for the NPT one) or just drill a hole (for the press fit auto parts store tire valve) and you have your tester. There you go, your ~$5 boost leak tester.
A football pump or bike pump works fine too, you don't need a compressor. When you pressurize, cap off the three inlet hoses that aren't your boost solenoid return (closest to airbox) or your bypass valve return.
Last edited by Concillian; May 17, 2013 at 08:31 AM.
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Car Info: 03 Sonic Yellow WRX Sport Wagon
Well, no luck with the motor running and the soapy water. Gonna take off the TMIC and look really hard for any bad hoses or cracks in the IC one more time before I go get raped by a mechanic.
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Haha, thanks. My buddy had one but we couldn't find any leak. We also tested the IC/y pipe/recirculation valve combo off the car and no leaks there.
The recirc valve opens when you send vacuum to the small nipple.
The wastegate opens when you send pressure to the nipple.
I'm stumped. My thought is to make another log to make sure the issue still exists (which I'm sure it does) but I'm not sure how I should set the boost and how dangerous it is for the motor.
The recirc valve opens when you send vacuum to the small nipple.
The wastegate opens when you send pressure to the nipple.
I'm stumped. My thought is to make another log to make sure the issue still exists (which I'm sure it does) but I'm not sure how I should set the boost and how dangerous it is for the motor.
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If you can't find a "leak", are you just basing the "existing leak" off what your tuner told you?
How does it feel when you drive? Normal? I saw you cranked the MBC up the 17psi. What's it showing on your gauge when you step on it?
How does it feel when you drive? Normal? I saw you cranked the MBC up the 17psi. What's it showing on your gauge when you step on it?
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Car Info: 03 Sonic Yellow WRX Sport Wagon
He's one of the top NorCal tuners. If he says it's knocking up top, it is. I can see the IDCs are over 100%. But the real tell is the 4psi lower boost. It is nuts that it build boost quickly and feels fine though. Wish I could borrow someone's stock recirc valve.
i believe your tuner, when logging should already be able to tell if you have a boost leak just off the logs shown on the dyno or runs.
Last edited by mistaanime; May 19, 2013 at 04:34 PM.
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Also, I've been talking to FLI and Miles thinks it's the turbo since I told him that a few months ago I drilled out a hole in the ex. manifold to thread a plug into it as a temporary fix, and even though we used a magnet, it's possible a metal flake entered the turbo. Also, the turbo does sound like it makes a high pitch whistle lately. My tuner still thinks it's a boost leak though. I'm going to try to pressure test it again with my buddy or have FLI do it. I started a WTB thread for another stock turbo, but I really hope I don't need one.
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Here's what my tuner says:
From the log he sent me I still suspect a boost leak as his MAF V is high and IDC's are way past 100%. From the log I saw, the ECU was also pulling quite a bit of timing up top. I believe this tune has been on his car for over 5 years now and has never had issues before.
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Okay, I was at a track day today and the problem returned. Here's the rundown I just sent my tuner but I'm doubtful he'll know what's wrong again. Any suggestions are appreciated.
By the way, no problem was found when I brought my car to EQ Tuning, they confirmed I had no boost leak. That was months ago and the car has been running fine up until recently when it wasn't hitting more than 11PSI again. Help.
Thanks for replying to my text today. So here's what happened. Please let me know if I need to bring my car in again or what you suggest. I'm thinking of trying a new MBC and maybe a replacement stock recirc valve.
1. The car has only been boosting to around 11 PSI lately so I hooked up the AccessPort and put it "read live boost" mode to make sure it wasn't my boost gauge reading incorrectly.
2. The AP agreed with my boost gauge 100% of the time through this entire deal (within 1PSI)
3. I raised the boost back to 16PSI this morning by craning the MBC about a full turn or so.
4. During session 1 at the track and on the way to the track, max boost was 16PSI, no problem.
5. During session 2, I only had 11PSI again.
6. I hooked up the AP again to confirm and it agreed, 11PSI.
7. I reset the ECU, still only 11PSI
8. I cranked the MBC another turn or so and then I was back to 16PSI.
9. During session 3, the problem returned for the last half of the session. I'm definitely down on power when I'm only hitting 11PSI.
10. Even though I didn't touch the MBC, sometimes I'd only hit 10-14 PSI and other times I'd hit full 16.5. At one point, I started getting a flashing CEL for about half a lap, but I kept driving hard anyway. I think it was hitting 16PSI during the flashing CEL.
11. full boost ranged between 11psi and 16psi intermittently, no rhyme or reason why.
12. I'm still stuck at 11PSI. I just checked with the AP and it doesn't detect any CEL codes. Isn't that weird since I had a flashing CEL on the course?
13. Other than being at 11PSI max boost, the car still runs great, just down on power at full throttle. Boost seems to build fast and normally up to 11PSI.
Thanks for any advice.
Cody
1. The car has only been boosting to around 11 PSI lately so I hooked up the AccessPort and put it "read live boost" mode to make sure it wasn't my boost gauge reading incorrectly.
2. The AP agreed with my boost gauge 100% of the time through this entire deal (within 1PSI)
3. I raised the boost back to 16PSI this morning by craning the MBC about a full turn or so.
4. During session 1 at the track and on the way to the track, max boost was 16PSI, no problem.
5. During session 2, I only had 11PSI again.
6. I hooked up the AP again to confirm and it agreed, 11PSI.
7. I reset the ECU, still only 11PSI
8. I cranked the MBC another turn or so and then I was back to 16PSI.
9. During session 3, the problem returned for the last half of the session. I'm definitely down on power when I'm only hitting 11PSI.
10. Even though I didn't touch the MBC, sometimes I'd only hit 10-14 PSI and other times I'd hit full 16.5. At one point, I started getting a flashing CEL for about half a lap, but I kept driving hard anyway. I think it was hitting 16PSI during the flashing CEL.
11. full boost ranged between 11psi and 16psi intermittently, no rhyme or reason why.
12. I'm still stuck at 11PSI. I just checked with the AP and it doesn't detect any CEL codes. Isn't that weird since I had a flashing CEL on the course?
13. Other than being at 11PSI max boost, the car still runs great, just down on power at full throttle. Boost seems to build fast and normally up to 11PSI.
Thanks for any advice.
Cody