Boost leak, diverter valve, something else....?

I have experienced over the last few months, what in my mind would be like a clutch slipping. It doesn't happen often, maybe once every three weeks, and it is just a slight hesitation that I can see in the rpm's. Problem is, I have a DSG transmission, so I don't think that would be slipping... though I could be wrong. Car is a 2013, with 19,000 miles on it. Is not driven hard 90% of the time, as I am hauling around a wife or kids, or both. Tuned for maybe 6,000 or 7,000 miles of the 19,000 miles.

I am curious if this is a diverter valve issue that is starting to show itself? Do I have a slight boost leak? Is it something else? If I catch it, it is right around 2,500 rpm's while I am trying to accelerate. Not WOT, but maybe 50%. I have experienced it while in a lower gear (2nd or 3rd), as well as one time being in 6th gear, and not downshifting, to accelerate back up to speed while on the highway.

I am not overly concerned, right now, as it is very infrequent. But I would rather try and fix a potentially larger issue that could develop, than deal with the consequences or issues when it is too late.

Can you describe the problem in a little more detail?

All I can read there is you think your clutch is slipping at 19k with a tune.

Sorry... hopefully this clears it up a little better.

Typically when accelerating, the rpm's climb at a somewhat constant rate. When I have the issue, I will be accelerating, and around the 2,500 rpm mark, I will see the rpm's fluctuate just a little bit. When this happens, the rpm's will spike a couple hundred rpm's, drop down, and then back to what appears to be the normal rate of accelerating. To me, it appears similar to what they would do with a slipping clutch, but on a smaller scale.

In my case, I don't have a manual transmission. I have the DSG transmission. I can't replicate it which makes it more difficult to diagnose or give specifics as to when or why it is happening.

The car has not thrown any visible codes, and no warning lights come on when it does happen. Its sort of like the engine has a hiccup, and then carries on.

Never having had a FI car, this is all new to me, hence the question of could this be indicate of a boost leak, the diverter valve going, or something else.

The Canuck said:

Sorry... hopefully this clears it up a little better.

Typically when accelerating, the rpm's climb at a somewhat constant rate. When I have the issue, I will be accelerating, and around the 2,500 rpm mark, I will see the rpm's fluctuate just a little bit. When this happens, the rpm's will spike a couple hundred rpm's, drop down, and then back to what appears to be the normal rate of accelerating. To me, it appears similar to what they would do with a slipping clutch, but on a smaller scale.

In my case, I don't have a manual transmission. I have the DSG transmission. I can't replicate it which makes it more difficult to diagnose or give specifics as to when or why it is happening.

The car has not thrown any visible codes, and no warning lights come on when it does happen. Its sort of like the engine has a hiccup, and then carries on.

Never having had a FI car, this is all new to me, hence the question of could this be indicate of a boost leak, the diverter valve going, or something else.

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Clutch slip on the DSG(At least everything ive read and seen) is the rpms go up but speed doesn't. Is that's whats happening? Also are you really on the gas (hard acceleration) or just normal put put around city gas acceleration? Most times slipping is only shown on hard acceleration.


What quality of gas are you using? You're close to a service interval bring it up to your service advisor.

Have you visually checked everything? Do you have access to vagcom or someone with it to scan and see if there are any soft codes?

lilonespaz said:

Clutch slip on the DSG(At least everything ive read and seen) is the rpms go up but speed doesn't. Is that's whats happening? Also are you really on the gas (hard acceleration) or just normal put put around city gas acceleration? Most times slipping is only shown on hard acceleration.


What quality of gas are you using? You're close to a service interval bring it up to your service advisor.

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Correct on the rpm's go up but the speed doesn't. Not hard on the gas at the time. Most of the times that I can remember, it is more half-throttle. I think there have been one or two times that were full throttle, but mostly half-throttle around the city. Gas is 93 octane from Shell.

Did a VCDS scan, and the only code that is being thrown is for the navigation and the Sirius being deactivated.

The Canuck said:

Correct on the rpm's go up but the speed doesn't. Not hard on the gas at the time. Most of the times that I can remember, it is more half-throttle. I think there have been one or two times that were full throttle, but mostly half-throttle around the city. Gas is 93 octane from Shell.

Did a VCDS scan, and the only code that is being thrown is for the navigation and the Sirius being deactivated.

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Hmmm that's weird. Id bring it up to your service advisor you should be going in shortly correct? for the 20k service?

Is it the weird fluctuation between 2.5-3k rpms in 4th and 5th gear? Makes your car go "womp womp womp" Yup I have it. I have a GFB DV+ in the mail. Hoping that will fix it.

Does OP have a boost gauge?

@Ketchupfreak - it has happened as you described. Not sure it went "womp womp womp", more like it just lost some power, and then found it a split second or two later.

@FriggenT - no boost gauge, though I am sure that would help a lot in explaining whether there is a boost leak or something to do with the diverter valve.

The biggest problem in my mind is not being able to replicate it. I have tried recreating the same sequence of events that I can remember when it does happen, but can't get it to replicate itself. If I could, I think we would have this narrowed down in no time.

Honestly man, a tranny is unlikely, people put these cars through all kinds of hell and don't break them.

We might be having the same issue. My Dyno is in the APR tune page that shows there is a drop around 2500rpm..

The suggestion currently for me is to check boost leak on the inlet and outlet discharge pipes.. no idea how to do that.. and will wait for my service internal in 5000km more. My car is at 62000km.

bernardryan said:

We might be having the same issue. My Dyno is in the APR tune page that shows there is a drop around 2500rpm..

The suggestion currently for me is to check boost leak on the inlet and outlet discharge pipes.. no idea how to do that.. and will wait for my service internal in 5000km more. My car is at 62000km.

Click to expand...

You don't know how to check for leaks?

http://turboboostleaktesters.com

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