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At a loss, testing boost leak...

Charlie22911

Charlie22911

Ready to race!
So I've been searching the forums and reading threads to make sure I don't ask any dumb questions.
I've been running logs, and actual boost never meets requested boost.
I tried testing for leaks by sealing off my intake and removing my oil cap while pressurizing from my boost tap. However I can't hold any amount of pressure, it's all coming out of the oil cap. I've read that if the PCV valve is functioning properly it will run rough when you remove the oil cap (mine does).
I'm at a loss, I removed the PCV hose from the intake manifold and blocked that off and still lose pressure through the oil cap...
What gives?

I've attached an APR mobile screencap, I'm away from home for the holidays so I don't have a way to get the CSVs to a PC right now.
 

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Charlie22911

Charlie22911

Ready to race!
I disconnected the hose that leads from the PCV to intake manifold, I've been doing more reading and it seems there is another hose from the PCV I need to disconnect and block as well...?

I'll be going back into it tomorrow to look over some more things.
 
T

TheCastle

Ready to race!
You have a boost leak, if actual never meets requested and you see your n75 duty cycle near or at 100%.

The most common areas for boost leaks on this car are the o ring in the top to intercooler coupler, diverter valve blown, or pcv.

Get a boost leak tester and connect it to the turbo inlet, with you oil cap off. If you can't build pressure you have a big leak. Check the oring, diver and pcv.

P.s. The pcv often semi fails on this car. I've replaced mine. When new if you pull the dipstick the engine will bog and die. When old it will just run a bit rough. They don't outright totally fail, they just start to leak on this car.

Oring and diverter are more common issues. I've replaced all 3 at one time or another.
 
Velociraptor Thrust

Velociraptor Thrust

Go Kart Champion
TheCastle said:
You have a boost leak, if actual never meets requested and you see your n75 duty cycle near or at 100%.

The most common areas for boost leaks on this car are the o ring in the top to intercooler coupler, diverter valve blown, or pcv.

Get a boost leak tester and connect it to the turbo inlet, with you oil cap off. If you can't build pressure you have a big leak. Check the oring, diver and pcv.

P.s. The pcv often semi fails on this car. I've replaced mine. When new if you pull the dipstick the engine will bog and die. When old it will just run a bit rough. They don't outright totally fail, they just start to leak on this car.

Oring and diverter are more common issues. I've replaced all 3 at one time or another.
Click to expand...


Is the car supposed to actually stall? Then damn I do need to replace my PCV, because mine just runs rough when oil cap and dip stick are removed.


Did you replace with another PCV or did you go with a catch can?
 
R

RGTI13

Go Kart Champion
Velociraptor Thrust said:
Is the car supposed to actually stall? Then damn I do need to replace my PCV, because mine just runs rough when oil cap and dip stick are removed.


Did you replace with another PCV or did you go with a catch can?
Click to expand...

I'm curious about this too. I pull my dipstick and nothing happens. I remove the oil cap and it runs a little rough.
 
T

TheCastle

Ready to race!
The pcv valves on these cars don't fail catastrophically like the ones on the fsi cars. But they do begin to leak with time.

So on my car while chasing boost leaks and having replaced my torn dv with a dv+, I noticed I had still had negative long term fuel trims aroun -7.8 or higher. WIth the engine idling I'd pull the dip stick out or oil cap off, and the engine would run slightly rougher for a moment. Good indicators the pcv was bad.

So I replaced it and my long term fuel trims at steady cruise are 0 and the engine dies or runs extremely rough when I remove the dipstick. It was a night and day differnce. I had 43k miles when i replaced mine and it's very easy diy job. 10 screws and about 15 minutes tops if you have the hand tools. Just a hex screw driver is all that's required.

I'd GTI13 your pretty likely to have a bad pcv. According to apr they fail fairly often on these cars by leaking and can be a source of boost leaks. But if you suspect a boost leak I wouldn't start with the pcv.
 
G

GIACUser

Master Wallet Mechanic
Charlie22911 said:
So I've been searching the forums and reading threads to make sure I don't ask any dumb questions.
I've been running logs, and actual boost never meets requested boost.
I tried testing for leaks by sealing off my intake and removing my oil cap while pressurizing from my boost tap. However I can't hold any amount of pressure, it's all coming out of the oil cap. I've read that if the PCV valve is functioning properly it will run rough when you remove the oil cap (mine does).
I'm at a loss, I removed the PCV hose from the intake manifold and blocked that off and still lose pressure through the oil cap...
What gives?

I've attached an APR mobile screencap, I'm away from home for the holidays so I don't have a way to get the CSVs to a PC right now.
Click to expand...

Is this Apr screencap a look at peak values during WOT through a particular gear? Based on the screen shot, why do you think you have a boost leak? According to the cap you are actually going into slight overboost, which is the opposite of what you would expect to see if there was a leak. Looks like you are flowing well, boost looks good, the ignition angle of 6.0 sounds off if this is supposed to be max angle I would expect to see something around 16-22 depending on which tune you are running. Maybe I am just not getting what you have posted but that is what I am seeing.
 
Charlie22911

Charlie22911

Ready to race!
Logs were run using 93oct shell in 93 mode with APR v3.1 ko4 software, I feel like I have a leak because actual never meets requested apart from that blip.
Peak ignition angle during that run was 15.75 in 3rd gear, I don't have the roads to do a 4th gear pull comfortably.

I literally just got back home today and have my DV+ sitting on the table, if I've got the longer bolt included then il throw it in this week and re log.

Anything in particular you guys want me to log for some before and after data?
 
G

GIACUser

Master Wallet Mechanic
Charlie22911 said:
Logs were run using 93oct shell in 93 mode with APR v3.1 ko4 software, I feel like I have a leak because actual never meets requested apart from that blip.
Peak ignition angle during that run was 15.75 in 3rd gear, I don't have the roads to do a 4th gear pull comfortably.

I literally just got back home today and have my DV+ sitting on the table, if I've got the longer bolt included then il throw it in this week and re log.

Anything in particular you guys want me to log for some before and after data?
Click to expand...

I think what you are seeing with specified vs actual is probably fairly normal. Early in the graph what you see is the ECU calling for a particular boost level and the K04 in the process of spooling up which is why you eventually see specified and actual catch up. After peak boost the curves match and the actual is a little lower than specified but you should log it in 4th gear or 3rd gear going uphill (as much load as possible) to see if that difference is significant, my bet is that it is fairly normal.

I would log all of 115 and 118-2 and do a nice smooth run from 2000 rpm to about 6200 rpm, again 4th gear or 3rd gear with an incline if possible.
 
S

sean@apr

Ready to race!
Charlie22911 said:
Logs were run using 93oct shell in 93 mode with APR v3.1 ko4 software, I feel like I have a leak because actual never meets requested apart from that blip.
Peak ignition angle during that run was 15.75 in 3rd gear, I don't have the roads to do a 4th gear pull comfortably.

I literally just got back home today and have my DV+ sitting on the table, if I've got the longer bolt included then il throw it in this week and re log.

Anything in particular you guys want me to log for some before and after data?
Click to expand...

Instead of just posting a screeny, post an entire section of the log. (To do that, slide the previous log to the right and tap email to email it to yourself)

From that picture, it looks like it's slightly exceeding boost request and not leaking. But, that doesn't give enough information to make any actual judgements.

The group you logged is perfectly fine for this. Just give more data!
 
Charlie22911

Charlie22911

Ready to race!
Thanks for the replies! Modded Euros didn't include the longer bolt so I have to wait until I get that bolt in to install the DV+.

Sean, my Excel skills aren't the best but I've attached trimmed logs (zipped, forums can't upload CSV) that just have the run data without the extra stuff. I've also attached the original logs just in case I broke something.
 

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Charlie22911

Charlie22911

Ready to race!
Quick update, I got my DV+ installed.
First impressions are that the car seems mostly the same, I still peaked about 26psi boost on the on ramp to work this morning.
I've not had a chance to run more logs yet, any opinions on the ones I uploaded in my previous post?
 
G

GIACUser

Master Wallet Mechanic
Charlie22911 said:
Quick update, I got my DV+ installed.
First impressions are that the car seems mostly the same, I still peaked about 26psi boost on the on ramp to work this morning.
I've not had a chance to run more logs yet, any opinions on the ones I uploaded in my previous post?
Click to expand...

Since APR has already chimed in probably best just to wait for their comment since they wrote the tune.
 
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