Boost leaking out of fuel injector

[RDA990]

Before I even started with a boost leak test I noticed my intake manifold being darker near the fuel injectors than the rest of the manifold. I took a closer look and realized that the area around my 4th fuel injector (towards rear of engine) was darker than the others:



1st Injector:

2nd Injector:

3rd Injector:

4th Injector



I said great, another problem that I'll have to start looking into, so I continued with the boost leak test and thought they weren't related at all, until I pressured the intake. It took me a bit to figure out where exactly it was coming from since the sound of it was a very high pitched noise, sort of like an electrical coil noise. For a second I thought it was something electrical making the high pitch sound...that's how unsure I was on where it coming from. I thought it was in the back of the engine somewhere, until I got some soapy water and started spraying at everything. I was actually surprised that the leak was coming from that location. Here is a video:



That must explain why the regulator gauge shows that the car is holding 0 PSI, meaning that it's not holding up boost at all. At the same time, according to my Bluetooth ELM327 OBDII I'm spiking 12 PSI, which quickly (less than 2 seconds) drops down to a "steady" 6 PSI. But I'm not sure how accurate OBD measurements are, I'm not even sure if it OBD shows the "requested" boost, or "actual" boost, anyone know??

Could that explain:

1. The 6 PSI boost that I am holding instead of the stock 10 PSI? (I'm sure I read stock PSI was 10 around here)
2. The "crappy" 15-17MPG CITY only driving I am getting? Then again, I'm starting to think this is normal after reading a few threads. Surprisingly, I easily get 31MPG Highway @ ~60mph. Damn stop signs & traffic lights.

Will I be needing a new injector? Or is it just the O-Ring around it? I should also mention that I changed my fuel filter around 2-3 months ago, I guess it been getting a bit more fuel pressure that the old O-Ring can't handle?? I'm not sure when the last time the injectors/O-Rings were changed, is it was at the same time the fuel filter was changed then it was never, the fuel filter that it had was from 2003. Hopefully the fix is an easy fast one & since it's around the same area of my leaking rear coolant flange, I'll hopefully get both issues out the way at the same time.

[A4Maine-iac]

It happens, the inserts and o rings get crusty and brittle. Pull that intake manifold and get new inserts and o rings. Be a good time to paint it as well to pretty it up.

[gmudan]

You can double check if its the seats or the o rings on the injectors. Just apply pressue like your doing a boost leak test and pour a tiny amount of water on the injector seat. If it bubbles from the cone part, replace the seals. If It bubbles from the outside part, it's leaking from the threads. Now this does not always work, after I replaced my o rings they were still leaking so I had to replace my seats. You can either pull the manifold and take them out or use the method I did. I loosened the bolts and the bracket, and pulled the IM up slightly. Then placed a thin strong piece of cardboard paper underneath and placed the IM back down. No need to drain the coolant. I have a picture if you need it, just ask. Make sure you get a 20mm Allen key, as anything other then that can damage the seats and they won't come out nicely in one piece, if not you have to grab a pick tool and take every bit of plastic out of the threads. It helps if your IM is warm.
Make sure you use thread sealant on the new ones.

[RDA990]

It happens, the inserts and o rings get crusty and brittle. Pull that intake manifold and get new inserts and o rings. Be a good time to paint it as well to pretty it up.

I didn't think you had to take the actual manifold out. Painting it would be a good idea, but not sure if I could finish the rear coolant flange, injector seals/o rings in less than a day. Are OEM inserts and o rings a better route than aftermarket ones?

You can double check if its the seats or the o rings on the injectors. Just apply pressue like your doing a boost leak test and pour a tiny amount of water on the injector seat. If it bubbles from the cone part, replace the seals. If It bubbles from the outside part, it's leaking from the threads. Now this does not always work, after I replaced my o rings they were still leaking so I had to replace my seats. You can either pull the manifold and take them out or use the method I did. I loosened the bolts and the bracket, and pulled the IM up slightly. Then placed a thin strong piece of cardboard paper underneath and placed the IM back down. No need to drain the coolant. I have a picture if you need it, just ask. Make sure you get a 20mm Allen key, as anything other then that can damage the seats and they won't come out nicely in one piece, if not you have to grab a pick tool and take every bit of plastic out of the threads. It helps if your IM is warm.
Make sure you use thread sealant on the new ones.

Thanks for the mini-DIY. A picture would be very helpful.

[old guy]

Here's some excellent (as usual) research by Thomas for your "O" ring options: Clicky click

My recommendation would be to just clean the area up and replace the "O" rings before you mess with replacing the seats. The "O" rings may take care of your problem.

[jubei4769]

I didn't think you had to take the actual manifold out. Painting it would be a good idea, but not sure if I could finish the rear coolant flange, injector seals/o rings in less than a day. Are OEM inserts and o rings a better route than aftermarket ones?



Thanks for the mini-DIY. A picture would be very helpful.

taking the manifold helps if you're gonna do the injector seats. they tend to break into pieces when you remove them so having the manifold off, nothing will fall into the head.

[RDA990]

Here's some excellent (as usual) research by Thomas for your "O" ring options: Clicky click

My recommendation would be to just clean the area up and replace the "O" rings before you mess with replacing the seats. The "O" rings may take care of your problem.

Thank you, that's perfect. Personally would you go with some OEM ones from GAP, or say aftermarket ones from advance auto parts?

Based on the video would you say its a big or small leak?

taking the manifold helps if you're gonna do the injector seats. they tend to break into pieces when you remove them so having the manifold off, nothing will fall into the head.

Ah I see, I'll do the O rings first and see how that goes. Thanks guys, now figure out how to release the pressure off the fuel rail.


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[old guy]

To release the fuel rail pressure all you need to do is depress the schrader valve on the end of the fuel rail. Have a rag ready to soak up the fuel spray. I replaced my "O" rings with the inexpensive Sorensen kit 130k miles ago and they are still leak free.

[CoreyRS]

Replacing O rings helped on my car as well.

[gmudan]

Heres how i did it without removing the IM. Once the crap falls in, the cards catch it. Then just vacuum it out.

[old guy]

That's a really neat tip with the cardboard! I'll keep it in mind if I ever have to replace the injector seats.

[customa4]

I believe I'll be using that method when I replace the seats on mine as well. I've had the new seats since Waldo was active and have been discouraged to install due to removing the intake manifold. This seems like a good solution to not have to remove the IM and risk breaking the dipstick tube. (probably still at risk)

[gmudan]

Thanks, i believe some playing cars will be perfect for this. Make sure you vacuum and try using compressed air to get all the crap out, it gets messy. Also i wrapped them in 3-4 coats in teflon tape but they still leaked, so i got liquid teflon and that worked perfectly.

[RDA990]

Rhanks for all the help guys. While pulling the injectors/rail up I "broke" the link between the first injector and the rail. Got gas all over the the engine around where the alternator is so not sure how safe it would be to turn the car on anytime soon. Got the injector back inside the fuel rail with the little clip it has so everything is fine now.

The actual injectors are spotless clean, just the area around the o ring is dirty with old burnt oil/sand/dirt:





I'm also afraid of cleaning the seats fearing some of the dirt will fall inside:



Now that I have them out, how do I even get the O rings out? I've tried twisting and pulling the little brown piece at the end and it won't come out

[gmudan]

The O rings just pull off, you can cut them off very carefully, or roll them off very carefully. Make sure not to break that brown piece, if you do, your injector is useless. They make a tool to put the new injector orings on, it looks like this

Or just roll them on. If you dont want to go get the tool, maybe a pen cap can help.

[RDA990]

Thanks, it's pain in the ass taking them out being careful the brown piece doesn't break.

Got replacements at Pepboys, I thought the kit came with 8 including the tool, but gave me this instead:



At least it's the same exact size. Any lube needed on them before I put them in the manifold?

[RDA990]

Ha.......it actual might be the injector seats...look at the hairline crack on it, which is exactly where the leak was coming from. Other ones have nothing like that. I tried cleaning it to see if its just oil and it's definetly a small crack.



I won't be able to tell if the o rings I just put on fixed the leak or not. I'll see how my boost holds up and do another boost leak test tomorrow to find out.

[Charles.waite]

Ha.......it actual might be the injector seats...look at the hairline crack on it, which is exactly where the leak was coming from. Other ones have nothing like that. I tried cleaning it to see if its just oil and it's definetly a small crack.



I won't be able to tell if the o rings I just put on fixed the leak or not. I'll see how my boost holds up and do another boost leak test tomorrow to find out.

Honestly? It's probably both. In my case the injector seats themselves were leaking badly. Look up my thread (google "injector seats disaster").

[RDA990]

Honestly? It's probably both. In my case the injector seats themselves were leaking badly. Look up my thread (google "injector seats disaster").

Yup. Did a boost leak test again and it's clearly leaking from there. Amazing how a little hairline crack makes it leak so much. I really hope this is the reason I'm hearing the "wooooosh" under boost, the same noise I heard when my 3-way check valve was broken but I've already checked it out and it's good.

While I'm going to be removing the Intake Manifold, I'm going to go ahead and paint it + do injector seats + draining coolant (even though I already did 4 months ago >.< should I just use the same one??) + rear coolant flange + check valves under the IM and behind it as well, just in case. Anyone know the P/N to the intake manifold gasket + throttle body gasket + any coolant O-rings I'll be needed? I already have the injector seats P/N + rear coolant flange + check valves.

[Charles.waite]

I would just re-use the coolant. Just drain it into a clean bucket and re-use. I did that on my old b7. It wasn't perfectly pink, so I strained it though a paper towel to catch any large particles and poured it back in. Worked just fine for over a year.

[RDA990]

I would just re-use the coolant. Just drain it into a clean bucket and re-use. I did that on my old b7. It wasn't perfectly pink, so I strained it though a paper towel to catch any large particles and poured it back in. Worked just fine for over a year.

Perfect, it'll save me ~$30 for the coolant.

[rowdyaudijeffy]

this leak caused misfire code?

[texasboy21]

Who makes the billet injector seats?

[Charles.waite]

Who makes the billet injector seats?

http://www.verdictmotorsports.com/Pr...uctCode=VMS107

Meow.

[agentsmith988]

http://www.verdictmotorsports.com/Pr...uctCode=VMS107

Meow.

I've got a set of these coming in the mail to tackle my leaks. I bought their install kit too so I don't have to bother with hunting down a 22mm hex (or whatever size it is).

I'm really glad this thread got bumped back up. Gmudan's card trick looks like a good way to skip the IM removal.

[texasboy21]

http://www.verdictmotorsports.com/Pr...uctCode=VMS107

Meow.

Thanks Chuck! I used some compressed air to clean up the area around my fuel injectors after all this talk of busted O-rings causing boost leaks, and I was able to blow air into the injector cup and a lot of crap blew out. I figure if I can blow air in, boosted car can escape so I may as well get my hands dirty.

Although I dont have any symptoms of a leak..

[gmx]

^ Was thinking about those too. Just noticed they only do what seems like small port manifolds (didn't even know there was a difference..)

[Charles.waite]

^ Was thinking about those too. Just noticed they only do what seems like small port manifolds (didn't even know there was a difference..)

If you look at their products page, they have early and late 1.8t. The early ones include AEB.

They just have different injector cup -> fuel rail spacing and thus are a bit different.

[gmx]

I see, thanks

[homegrowna4]

I definitely recommend the verdict motorsports injector cups. They are bulletproof and only $30 more than the oem plastic. Just got finished installing a set and I am leak free. Used the head of a 1/2" bolt to install them.

[RDA990]

this leak caused misfire code?

Absolutely. No CEL, but scanning with Vag-Com I find misfire in cylinder 4. I can even feel the missfire a little bit while driving which has worried me all week so I've been baby-ing the car trying not to hit boost.

http://www.verdictmotorsports.com/Pr...uctCode=VMS107

Meow.

I definitely recommend the verdict motorsports injector cups. They are bulletproof and only $30 more than the oem plastic. .

Saw those, price tag surprised me. They are $50 more than OEM, got 5 from GAP for $20. If it was only $30 more I would of probably gotten them.

Speaking of GAP, my order just came in. I don't have the car right now so I can't verify this but I think I recieved the wrong seats. :banghead::banghead::banghead:





I'm really hoping these are the correct ones since & my eyes are just playing games with me, I want to get this done this weekend. All of them are the same size, but oddly have different ending part #s.

"06B 133 555 H6"
"06B 133 555 H8"
"06B 133 555 H3"

Everything else looks exactly the same and can't tell a difference between them.

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[diagnosticator]

Before I even started with a boost leak test I noticed my intake manifold being darker near the fuel injectors than the rest of the manifold. I took a closer look and realized that the area around my 4th fuel injector (towards rear of engine) was darker than the others:



1st Injector:

2nd Injector:

3rd Injector:

4th Injector



I said great, another problem that I'll have to start looking into, so I continued with the boost leak test and thought they weren't related at all, until I pressured the intake. It took me a bit to figure out where exactly it was coming from since the sound of it was a very high pitched noise, sort of like an electrical coil noise. For a second I thought it was something electrical making the high pitch sound...that's how unsure I was on where it coming from. I thought it was in the back of the engine somewhere, until I got some soapy water and started spraying at everything. I was actually surprised that the leak was coming from that location. Here is a video:



That must explain why the regulator gauge shows that the car is holding 0 PSI, meaning that it's not holding up boost at all. At the same time, according to my Bluetooth ELM327 OBDII I'm spiking 12 PSI, which quickly (less than 2 seconds) drops down to a "steady" 6 PSI. But I'm not sure how accurate OBD measurements are, I'm not even sure if it OBD shows the "requested" boost, or "actual" boost, anyone know??

Could that explain:

1. The 6 PSI boost that I am holding instead of the stock 10 PSI? (I'm sure I read stock PSI was 10 around here)
2. The "crappy" 15-17MPG CITY only driving I am getting? Then again, I'm starting to think this is normal after reading a few threads. Surprisingly, I easily get 31MPG Highway @ ~60mph. Damn stop signs & traffic lights.

Will I be needing a new injector? Or is it just the O-Ring around it? I should also mention that I changed my fuel filter around 2-3 months ago, I guess it been getting a bit more fuel pressure that the old O-Ring can't handle?? I'm not sure when the last time the injectors/O-Rings were changed, is it was at the same time the fuel filter was changed then it was never, the fuel filter that it had was from 2003. Hopefully the fix is an easy fast one & since it's around the same area of my leaking rear coolant flange, I'll hopefully get both issues out the way at the same time.

That is normal seepage. There is no way those seeps on cylinders 1>3 or the miniscule air leak on #4, are causing any loss of boost pressure. Compared to the mass air flow the turbo flows, about 20 pounds per min at peak boost, the tiny amount of air leaking from the injector seal you posted the video of, does not make any difference in boost pressure. The amount of air leaking at #4, is less than any pressure gauge can measure. At lower boost pressure, the injector seal leak on #4 is even less. It's not even an issue when the manifold is under vacuum pressure. The boost pressure control problems you described are caused by something else.

[Charles.waite]

That is normal seepage. There is no way those seeps on cylinders 1>3 or the miniscule air leak on #4, are causing any loss of boost pressure. Compared to the mass air flow the turbo flows, about 20 pounds per min at peak boost, the tiny amount of air leaking from the injector seal you posted the video of, does not make any difference in boost pressure. The amount of air leaking at #4, is less than any pressure gauge can measure. At lower boost pressure, the injector seal leak on #4 is even less. It's not even an issue when the manifold is under vacuum pressure. The boost pressure control problems you described are caused by something else.

Normal? or within spec? Those are two different things.

After replacing my injector seats and sealing them with teflon tape, they were squeaky clean until a few weeks ago when I noticed cylinder 4 starting to seep around the edges. Those leaks shouldn't cause much of a boost leak, but if you're trying to address everything, fixing those leaks isn't a bad place to start.

[RDA990]

That is normal seepage. There is no way those seeps on cylinders 1>3 or the miniscule air leak on #4, are causing any loss of boost pressure. Compared to the mass air flow the turbo flows, about 20 pounds per min at peak boost, the tiny amount of air leaking from the injector seal you posted the video of, does not make any difference in boost pressure. The amount of air leaking at #4, is less than any pressure gauge can measure. At lower boost pressure, the injector seal leak on #4 is even less. It's not even an issue when the manifold is under vacuum pressure. The boost pressure control problems you described are caused by something else.

Yea I'm fine with the seepage and agree that it won't be causing an actual boost leak, but the seat on #4 has a crack on it which shows leaking air with a boost leak (Video shows this) 1-3 don't leak while doing the leak test.

I peak up to 12psi but only hold 6psi. Boost leak shows the seat the only place leaking (other than the air escaping through the engine oil cap). If what you're saying is true, then I have no idea why I'm not holding boost. I'll probably take a look at the DV first, I'm sure it's never been looked at or changed.

EDIT: Just recalled the misfire I'm getting on #4. If the air leak on 4 isn't much, that wouldn't explain the misfire it's having?

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[Charles.waite]

Yea I'm fine with the seepage and agree that it won't be causing an actual boost leak, but the seat on #4 has a crack on it which shows leaking air with a boost leak (Video shows this) 1-3 don't leak while doing the leak test.

I peak up to 12psi but only hold 6psi. Boost leak shows the seat the only place leaking (other than the air escaping through the engine oil cap). If what you're saying is true, then I have no idea why I'm not holding boost. I'll probably take a look at the DV first, I'm sure it's never been looked at or changed.

EDIT: Just recalled the misfire I'm getting on #4. If the air leak on 4 isn't much, that wouldn't explain the misfire it's having?

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Are you tuned? And only boosting 12psi? yikes. I hold around 16 psi (peaks at 18-19) dropping to 12 or so by redline. On APR Stage 1. You definitely have a large leak somewhere. The misfires are likely a clue.

I agree with Diagnosticator though, that the injector seat wouldn't necessarily be the root cause of this leak, but it is a contributing factor in the misfire as more air leaks out of that runner than the others. Have you checked the sparkplugs? Try swapping the coilpack between cylinder 3 and 4. if the misfire follows the coilpack you've got a bad coilpack.

[diagnosticator]

Normal? or within spec? Those are two different things.

After replacing my injector seats and sealing them with teflon tape, they were squeaky clean until a few weeks ago when I noticed cylinder 4 starting to seep around the edges. Those leaks shouldn't cause much of a boost leak, but if you're trying to address everything, fixing those leaks isn't a bad place to start.

Normal as in practically all injectors on 1.8Ts seep a little fuel residue eventually. The design does not allow for seepage by intent though.

[diagnosticator]

Yea I'm fine with the seepage and agree that it won't be causing an actual boost leak, but the seat on #4 has a crack on it which shows leaking air with a boost leak (Video shows this) 1-3 don't leak while doing the leak test.

I peak up to 12psi but only hold 6psi. Boost leak shows the seat the only place leaking (other than the air escaping through the engine oil cap). If what you're saying is true, then I have no idea why I'm not holding boost. I'll probably take a look at the DV first, I'm sure it's never been looked at or changed.

EDIT: Just recalled the misfire I'm getting on #4. If the air leak on 4 isn't much, that wouldn't explain the misfire it's having?



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It needs to be fixed certainly, and on second thought it's possible the air leak into the manifold runner when the intake mani is under vacuum pressure on #4 is causing a lean condition, but I am skeptical it's lean enough to result in misfire (remember that the ECU can easily add extra fuel to compensate for that small air leak,) . Being located where it is, the air leak into the mani will be the worst when the engine is at idle, at wider throttle open angles, the amount of air leaking into the manifold decreases to zero, then at the vacuum/boost transition, the leak direction reverses and gets worse as boost increases. But regardless, compared to the mass air flow from the turbo, the relatively tiny amount of air leaking through the injector seat crack/O ring, is not likely to cause any running defects.

The stock K-03 turbo is sized and the boost pressure controlled specifically so that the turbo produces max boost at the engine's torque peak RPM, and then decrease as RPM increases above that speed.

[RDA990]

Well. Both of you were right.

The bad: The injector seats isn't the cause of the boost leak. Under boost I still here a lot of air escaping from somewhere. Like I said boost leak test doesn't show air leaking from anywhere.

The good: After replacing injector seats my dash shows ~20MPG on the same exact trips it used to show ~17MPG. I did change coolant flange, injector seats, and IM gasket. Really surprised that the cracked injector seat was making me lose ~3MPG? Also no more misfire! (I hope)

Well now that I know it's not the injector seats, I'm going to move on to the DV. I think the DV is getting stuck opened or something, because at certain times when I go under boost I hear the air leaking, and other times I don't hear it and the car actually goes faster than when I do hear it.

Are you tuned? And only boosting 12psi? yikes. I hold around 16 psi (peaks at 18-19) dropping to 12 or so by redline. On APR Stage 1. You definitely have a large leak somewhere. The misfires are likely a clue.

I agree with Diagnosticator though, that the injector seat wouldn't necessarily be the root cause of this leak, but it is a contributing factor in the misfire as more air leaks out of that runner than the others. Have you checked the sparkplugs? Try swapping the coilpack between cylinder 3 and 4. if the misfire follows the coilpack you've got a bad coilpack.

Nope, not tuned at all. Trying to get all the maintenance stuff done and get rid of any boost leaks I currently have before getting a tune. Stock right now it peaks at 12psi for less than a second and drops to ~6psi until 5k or so.

Spark plugs are less than 1k miles/4 months old & coil packs got replaced by Audi because of the recall earlier this year.

It needs to be fixed certainly, and on second thought it's possible the air leak into the manifold runner when the intake mani is under vacuum pressure on #4 is causing a lean condition, but I am skeptical it's lean enough to result in misfire (remember that the ECU can easily add extra fuel to compensate for that small air leak,) . Being located where it is, the air leak into the mani will be the worst when the engine is at idle, at wider throttle open angles, the amount of air leaking into the manifold decreases to zero, then at the vacuum/boost transition, the leak direction reverses and gets worse as boost increases. But regardless, compared to the mass air flow from the turbo, the relatively tiny amount of air leaking through the injector seat crack/O ring, is not likely to cause any running defects.

The stock K-03 turbo is sized and the boost pressure controlled specifically so that the turbo produces max boost at the engine's torque peak RPM, and then decrease as RPM increases above that speed.

Yup, I think it was adding a bit TOO much fuel to compensate for the leak. My idle hasn't changed at all though it's still at ~760-780 as before. Really hoping it's the DV.