Boost leak testing with a cold motor

[vbt101]

I was boost leak testing the other day and found air coming out of a small crack in my radiator hose. Does this mean my head gasket is blown?

In the future, is it ill-advised to boost leak test when the motor is cold? Could that have affected this test?

[gtlaw]

was there coolant leaking too?? are you sure it was the rad hose, and not the bpv recirculation hose

[vbt101]

Originally Posted by gtlaw was there coolant leaking too?? are you sure it was the rad hose, and not the bpv recirculation hose

Didn't see any coolant leaking, but then again the leak wasn't large & the car wasn't running, so I think that was expected. yeah, it was def the radiator hose.

[2007speed3]

if your radiator hose is leaking =/= blown head gasket..

[vbt101]

Originally Posted by 2007speed3 if your radiator hose is leaking =/= blown head gasket..

how else would air from my air compressor get into the radiator hose though?

[2007speed3]

your totally right, i just thought about it....

your car is it eating up coolant???

[vbt101]

Nope, not at all actually.

[SSinstaller]

Where were you pressurizing from? Try from the hot pipe, post turbo.. You could also have an issue in the chra--If your still running the K04 I'd say that is more likely than a bad headgasket.. Still running the coolant lines in the TB?

[vbt101]

Chris - I fucking love it when you get in on my threads.

I was testing post turbo. I'm running the stock turbo (PTP reworked). Is it still possible that it's an issue with the CHRA?

[edit] I'm not running coolant lines in the TB. For this to be a factor, would there need to be a crack in the TB?

[SSinstaller]

Originally Posted by vbt101 Chris - I fucking love it when you get in on my threads. I was testing post turbo. I'm running the stock turbo (PTP reworked). Is it still possible that it's an issue with the CHRA? [edit] I'm not running coolant lines in the TB. For this to be a factor, would there need to be a crack in the TB?

Did you have the hot pipe disconnected from the compressor outlet? How do you pressurize the piping?

TB would need to be cracked or have a casting issue to be a factor--your not running coolant through it so it cant be your issue..

I'd do a quick compression test (cold)--don't worry about the numbers, your just looking for one cylinder much worse than the rest.. If you don't see it, you most likely don't have a headgasket issue...

[vbt101]

Yep, I basically took the hot pipe out and replaced it with a Pcv pipe with a pressure gauge on the end. The turbo did not have the hot pipe connected to it. The pressure gauge/PCV pipe fed into the intercooler. Where the hot pipe would have been. I use one of those boostpro gauges with a schraeder valve and pump it with a portable Vaier cig lighter pump.

http://www.boostpro.net/prodtester.html

I'll try compression testing. If the leak is small, is there a chance I won't catch it with compression test? Since the pressure is so sudden onset, I mean..

[edit] fail. Pcv = PVC

[SSinstaller]

Originally Posted by vbt101 Yep, I basically took the hot pipe out and replaced it with a Pcv pipe with a pressure gauge on the end. The turbo did not have the hot pipe connected to it. The pressure gauge/PCV pipe fed into the intercooler. Where the hot pipe would have been. I use one of those boostpro gauges with a schraeder valve and pump it with a portable Vaier cig lighter pump. Boostpro.net : Products - Boost Leak Testers I'll try compression testing. If the leak is small, is there a chance I won't catch it with compression test? Since the pressure is so sudden onset, I mean.. [edit] fail. Pcv = PVC

Ok, if you were post turbo it definitely can't be the chra, so there aren't really too many other options..

Re-try your boost leak test with the motor warm. From the compressor inlet this time. IMO that's the best place to pressurize from if you want to check the whole system.. Make sure you get to 2X your peak boost pressure..

If you still see air, you should do a compression test ASAP... If not, fix all your boost leaks and .

[vbt101]

so, I didn't boost leak test it today (bc I didn't have another car to power the pump), but I did warm it up & do a compression test. I was surprised by the results. I did 2 logs per cylinder (each non-consecutive because I wanted to make sure I got through all 4 before the battery started dying). On each log, we logged the pressure reading of the very first crank (to the best of our ability. someone said that was a useful stat), and the ending pressure reading after 7 cranks.

Cyl 1: 100/195psi and 100/188psi
Cyl 2: 120/177psi and 50/180psi
Cyl 3: 90/184psi and 100/187psi
Cyl 4: 150/180psi and 98/185psi

Not really the results I was expecting. What do you think? I ran the same test a few months ago and got 180 across the board. Not sure how some tested more & some tested less this time :-/. Maybe I let them crank longer? I'm also using a diehard battery now over my previous test with a stocker.

[SSinstaller]

~5% deviation between the cylinders.. I think your fine, but keep an eye on #2.

[vbt101]

So no head gasket issue? Any ideas on how my radiator hose became pressurized during the boost leak test then?

[easy]

ive heard another way to check head gasket is to start car and take off your coolant overflow cap and see if it bubbles. If its steady bubbles then possible bad head gasket. If it has a few bubbles here and there, i believe is not a problem

[vbt101]

Just took the car out. Made some really scary noises once I got into boost. I took a video on my phone. Hopefully it came out well enough to hear what I heard. I'll post it momentarily.

[vbt101]

Ok - here it is...sorry I was a little rushed to take the video & it was on my cell phone, so the sound isn't perfect..you get a much closer idea of the sound it made at :42 seconds in. It's a sudden onset, loud (considerably louder than the video lets on), deep drone sound coming from the passengers side of the engine bay. It probably would have been easier to hear if I left it in boost for longer, but not knowing what it was, I decided to let off quick. I could try to run another video tomorrow if needed, unless there are more conclusive tests that I could run.

YouTube - Noise under boost

Thoughts?

[edit] I should point out that I didn't see any registered knock, or bogging from the engine...*seemed* to run normal even when that noise came on. My fuel trims are way, way negative right now (-12ish LTFTs). didn't take note of what they were during the pull.

[dougefresh_]

I listened to it 10 times, and you can definitely hear it. Never heard that before :/ I had a blown head gasket on a different car a long time ago, but it just sounded like an exhaust leak (like fast farts, lol). The sound increases with rpms.... I hope it's nothing bad.

[vbt101]

Originally Posted by dougefresh_ I listened to it 10 times, and you can definitely hear it. Never heard that before :/ I had a blown head gasket on a different car a long time ago, but it just sounded like an exhaust leak (like fast farts, lol). The sound increases with rpms.... I hope it's nothing bad.

lol -- that's sort of how i wanted to describe it..it sounds what I think a high pressure leak would sound like...though, in my case it doesn't increase with RPMs (maybe it would have if I kept on it once I got into boost). I was up in the high RPMS not in boost & did not have any noise.

I can't help but think that with this, and that I think my coolant lines are getting boost, it's some form of a blown head gasket. I probably owe it to myself to exercise some diligence in diagnosing this before I tear the motor apart.

[dougefresh_]

Hmmm.... maybe it only leaks under boost, or maybe it's something else. Definitely wait for more folks to chime in before tearing shit apart. How close does the video sound to the actual sound?

[vbt101]

The video is pretty close...it's just much louder (iPhone didn't capture all the low freq/bass very well) in the person than in the video...part of that might have come from it just scaring the shit out of me.

[vbt101]

So, I found another sound that is similar, and that I can reproduce more consistently.

If I start from a stop up a steep incline, a noise similar to the one I described earlier occurs It's like a loud dull grinding/deep farting noise. A few other interesting notes:

1. My LTFTs at idle are like -20. Every bolt on you can have, but it's always been around +8 to +12, so this is a def change

2. I cracked open my transmission fill plug to see if there was enough oil, and pressurized air came out! The car has been undriven/not started for about 2 days. That doesn't seem normal..does it?

2a. When I was initially boost leak testing a week or two ago, it held 23psi for a minute or two while I was searching for the leak that was keeping it from building more pressure..then it started losing pressure pretty quick. I chalked it up to my compressor losing steam/overheating...now I'm thinking maybe the continuous pressure blew a leak in some gasket material?

[vbt101]

Not sure if the noise I'm hearing starting up steep inclines, the motor not holding boost pressure with air compressor (gets into boost fine while driving), and the fact that I'm running pig rich are related, but..

Stuff I've tried (no changes):
- Compression test (compression is decent).
- Replaced O2 sensor.
- Replaced Purge Solenoid
- Cleaned MAF
- Cleaned MAP

Now, I want to focus on one prob at a time. First: failed boost leak test. Just re-tested last night and I couldn't get up past 11psi. No coupler leaks or anything. I opened the oil cap and found air escaping from the valve cover. What does this mean?

- Bad PCV valve? (I have Matt Damond's OCC kit with upgraded check valve)
- Bad valve seals?
- Injector seals/injector-rail grommets/injectors
- uhh..?

[Lex]

Where in the intake tract are you applying the pressure when you're doing the boost leak test?

[vbt101]

Originally Posted by Lex Where in the intake tract are you applying the pressure when you're doing the boost leak test?

After the hot pipe into the intercooler.

[Lex]

The "farting" noise and your inability to hold pressure along with ltfts that are off are screaming pressure leak. It doesn't sound like a coupler leak - it sounds more like a gasket leak. Compress the pipes, turn off the compressor and listen to where you hear the hissing coming from.

The compression numbers look good.

Also, take a log of the following as you enter boost and car starts to make that noise:

- Boost
- RPM
- LTFT
- STFT
- Inj duty cycle or PW
- MAF g/s
- WG duty cycle

[vbt101]

Originally Posted by Lex The "farting" noise and your inability to hold pressure along with ltfts that are off are screaming pressure leak. It doesn't sound like a coupler leak - it sounds more like a gasket leak. Compress the pipes, turn off the compressor and listen to where you hear the hissing coming from. The compression numbers look good.

I tried - but I can't hear anything obvious...except at the valve cover., which If I remove the oil cap, I can feel air coming out of. Enough air that I wouldn't be surprised if this is the culprit. Just a little unsure if that is expected or not.

When you say gasket leak -- can I localize it any further based on my symptoms?

[qtrmile beast]

what manifold are you running?

[vbt101]

Originally Posted by qtrmile beast what manifold are you running?

MAP Ported IM. I just installed it, which is why I was boost leak testing in the first place.

At the same time, I installed:

- CPE injector seals
- Upgraded check valve from Matt Damonds OCC kit
- CPE tranny mount (noting, in case the sound im hearing is actually grinding/rubbing)

Originally Posted by Lex Also, take a log of the following as you enter boost and car starts to make that noise: - Boost - RPM - LTFT - STFT - Inj duty cycle or PW - MAF g/s - WG duty cycle

Lex - I'll hook up the standback & log these things. I only have the Dashhawk in the car right now, which I think will only allow me to log 4-5 params.

[qtrmile beast]

Originally Posted by vbt101 MAP Ported IM. I just installed it, which is why I was boost leak testing in the first place. At the same time, I installed: - CPE injector seals - Upgraded check valve from Matt Damonds OCC kit - CPE tranny mount (noting, in case the sound im hearing is actually grinding/rubbing)

exhaust mani!!!

[vbt101]

Originally Posted by qtrmile beast exhaust mani!!!

You think it's a leak at the exhaust mani, Charles? If you're asking which I'm running -- DNP.

[vbt101]

Oh - one more thing, Lex. I am pretty confident the noise I hear when starting from a stop uphill is the same as the one I hear when I'm in boost. It has to be a pretty steep incline. The one in my apartment building garage is about 30*, and causes the noise consistently. Obviously no boost or wastegate action in that instance though..

[Lex]

Ok, so you feel air coming out of your valve cover ... the only way air can get in there is through the crankcase. The most obvious culprit are rings but those seem to check out from your compression test.

You mentioned a new check valve on the PCV. Look there next - could be your source of air going into crankcase. Pinch or block the PCV hose right at the manifold and pressure test the system again. See if there is a drastic reduction.

[vbt101]

I've retested with a new factory PCV valve, as well as by blocking the PCV inlet on the intake mani. that doesn't appear to be the culprit. Boost still holds pretty low (7psi, but my battery is pretty weak at the moment), and dissipates very quickly once I turn the pump off (maybe 10 secs to 0psi). No air is coming out of the PCV valve (off the intake) during the pressure test.

Now, I've put the check valve back on the IM, and disconnected the PCV entirely, by having the hose from the check valve just VTA. In this configuration, I'm still seeing air come out of the valve cover. Does that leave us with bad rings? Also, is it abnormal for some air to leak by the rings? Maybe my pump configuration is just not pressurizing the motor fast enough?

[vbt101]

Okay, update #2. Pump power has nothing to do with it. Same results.

I did decide to manually turned the crank a some and got varying results. After turning it, I was able to get as high as 15-16 psi (from 6-7psi, that's quite a difference). Am I supposed to have the crank and TDC or something when performing a pressure test like this? Or is this indication of a leaky valve seal?

[superskaterxes]

V, come over this week and we can do a super official test at my house

[vbt101]

Originally Posted by superskaterxes V, come over this week and we can do a super official test at my house

fuck, that'd be awesome. when works for you? and, where are you?

[superskaterxes]

uhh any day after monday is good. drag jakey along too.

rockville

[vbt101]

Originally Posted by superskaterxes uhh any day after monday is good. drag jakey along too. rockville

alright cool. I will. he claims to be slammed with his new job, but we all know that's fraudulent.

what kind of tests are we going to run? just wondering if I need to pick up stuff beforehand.