Is this a boost leak or ???

Howdy all

1st post here. I am not new to diesel or VW but i am new to Diesel VW's.

I recently bought a 2000 Golf with an ALH. It runs great but has had some modifications. I dont have many miles to know what " the norm" is.

It has forged rods a garrett VNT17 and an aftermarket intercooler and 3" exhaust. I was told it runs ~24 psi but the boost gauge broke just before i bought it. It had tunes from Kerma and all aftermarket parts are from there. 1t has 179k right now. At 150k it had a 5 speed conversion done from DubWerks in Cincinnati Ohio. They also put an 11mm pump on it and removed the tunes for a factory 5 speed computer.

So when i got it it makes noises im not accustomed too. Not bad noises just ALH noises. It ran great and strong. After a few days it started to have issues with higher rpms. It used to go to 5k rpms so fast. Like i wasnt used to how fast it would do that. It started to begin to spool and when i get to 4k it was sputter and smoke and buck just a bit. It did it once. Then a day later it did it again and now its more often then not. Yesterday it did it at 2k. It doesnt do anything if i just rev the engine. It starts right up and drives fine. Its just as it starts to spool and pull it starts to act up.

Im wondering if its a boost leak. I dont see a hose off any piping. On my truck with a 7.3 it had no spool when that happened and was borderline undrivable. Ive looked here and dont see anything that really " spudders at 4k and smokes"

One other thing. I am 90% sure when i 1st got it. There was a very noticeable release from the waste gate. Quick " psshh" and gone that now im not hearing??? But like i said i never had it long enough to really know the sounds

Thanks ... Sry for the book

Also no engine codes have been thrown

1st off, any gauge you get as a replacement you should consider Auber gauges, they are the Best there is and never fail.

When your issue happened, was the engine 100% to temperature? or was it warming up?
I have an issue and its just a fueling issue (TOO MUCH) and when its cold it stops the combustion. its really bad and smokes crazy bad until it burns off.

1st off, replace the gauge and you will know if its boost. both need to happen anyways.
make sure the engine is fully warm before going WOT, Thats my solution to my problem

It has happened hot and cold both. Getting u to temp hasnt remedied it by any means. Thx for the gauge advice the new one is on my agenda for sure

if it was a boost leak, the issue would be liniar, not random like this. Might be a leak that only happens when high enough boost?
What colour is the smoke?

Black smoke when it sputters

Air restriction/boost leak.

Sounds like you had a marginal leak and now it's more pronounced.

One is more likely to notice leaks in a higher gear because you're pushing boost longer: lower gears run the RPMs very quickly, as you have noticed. When I got my car it would rev pretty good in lower gears, but then in higher gears it would turn into an utter dog: different issue -clogged intake, not a boost leak, though an air restriction nonetheless.

"They also put an 11mm pump on it and removed the tunes for a factory 5 speed computer."

You said it had a Kerma tune when you got it and then DubWerks removed the tune?

I haven't noticed issues as much in high gears but in the high gears I'm not running 4000 RPMs either. It doesn't give me any issues just maintaining a speed it's only when you're accelerating


As for the tunes they were on there when it had automatic when it was switched over to a 5-speed they put a 5-speed computer in it that didn't have any tunes I don't know if they could have reprogram the other one or if it was easier or the guy did not want to pay for it but that was before I had it so I don't know all the ifs ands and buts about that I just know what it did have

Since a VNT doesn't have a waste gate maybe the "psshh" was a hose blowing?

Hmmmm it sounded like a def mechsnical release from what i recall. Is it possible it was added during mods?

cesspool said:

I haven't noticed issues as much in high gears but in the high gears I'm not running 4000 RPMs either. It doesn't give me any issues just maintaining a speed it's only when you're accelerating


As for the tunes they were on there when it had automatic when it was switched over to a 5-speed they put a 5-speed computer in it that didn't have any tunes I don't know if they could have reprogram the other one or if it was easier or the guy did not want to pay for it but that was before I had it so I don't know all the ifs ands and buts about that I just know what it did have

Click to expand...

RPMs and gears are two independent things. My references were, in essence, about accelerating. I should have just used that word. But...

Acceleration is when the ECU will signal a demand for boost. Boost and demand come and go very quickly in lower gears (you've already stated noting this), so quickly that boost problems often aren't noticed in lower gears.

Go find a long hill, one that you can run in at least 3rd gear. Start running up it and hit the accelerator to the floor and hold it. You'll likely encounter your problem with this. Now try it in 1st or 2nd gear and you'll likely max out RPMs before you notice any boost issues.

There is ZERO reasons to swap ECUs when changing transmissions. The ECU only needs a simple bit fiddled: there's a programmable field that only requires a simple change. IF a different ECU was put in and it has not been programmed with a tune to support the modifications you have currently (or a tune was removed and you're only running a stock tune) then THAT is likely going to cause all sort of problems similar to what you're encountering.

Il try The hill thing. I do know tho that the car has had this ECU for 30k miles now tho and it wasnt like that previously. I bought the car off a guy i know. Ive been in the car avfew times and it wasnt like that. Unfortunately he didnt do any of the mods so he knows as much as i do

Running your car that very likely has larger then stock nozzles but no tune may
have carbon-ed up the turbo's vanes. Check how hard it is to move the actuator.