BEW Squealing under boost

[05MK4TDI]

(2005 Vw Jetta mk4 BEW)
i was cleaning out my intake manifold, and on reinstallation of the manifold and egr cooler, i accidentally broke the arm of the “intake manifold vacuum actuator.” it’s located on the passenger side of the engine, shaped like a little circular plunger with an arm (pointing towards the front of the car) going to a pivoting bracket on the intake manifold. it’s just below the Anti Shudder valve, and is made of plastic. when i reinstalled the intake system, i took it for a drive and under high boost, high load, up until VGT actuation i get a very loud squeal and a “flat spot” in my power curve. i have no clue what creates this, and i’m not sure if that broken arm on that actuator could create that noise. i have a new one that is shipping right now but it’s not gonna be here for a week or so, and i’m kind of scared to drive my Jetta because this noise did not happen before and i don’t want to damage anything further. any thoughts? i saw a video online and a guy said that he had lost braking power and boost pressure because his vacuum pump main supply nipple cracked, causing a vacuum leak. (nipple located on vacuum pump directly below the intake pipe. to the right of the engine, left of the air cleaner, and on the back side of the vacuum pump.) i thought it could be that intake manifold vacuum actuator arm being broken but i don’t know what to do anymore. thanks in advance!
-Jaxon
(for pictures of the part i broke, search up “1.9tdi bew intake manifold vacuum actuator”)

 

[Tdijarhead]

Those little plastic actuators can get brittle.

As for the squeal, you need to tighten up the egr pipes. Those pipes have metal gaskets and one of them is just loose enough that air rushing over them at boost causes it to vibrate.

Crawl back under you car again and retighten the bolts about a quarter turn or so.

 

[05MK4TDI]

(2005 Vw Jetta mk4 BEW)
i was cleaning out my intake manifold, and on reinstallation of the manifold and egr cooler, i accidentally broke the arm of the “intake manifold vacuum actuator.” it’s located on the passenger side of the engine, shaped like a little circular plunger with an arm (pointing towards the front of the car) going to a pivoting bracket on the intake manifold. it’s just below the Anti Shudder valve, and is made of plastic. when i reinstalled the intake system, i took it for a drive and under high boost, high load, up until VGT actuation i get a very loud squeal and a “flat spot” in my power curve. i have no clue what creates this, and i’m not sure if that broken arm on that actuator could create that noise. i have a new one that is shipping right now but it’s not gonna be here for a week or so, and i’m kind of scared to drive my Jetta because this noise did not happen before and i don’t want to damage anything further. any thoughts? i saw a video online and a guy said that he had lost braking power and boost pressure because his vacuum pump main supply nipple cracked, causing a vacuum leak. (nipple located on vacuum pump directly below the intake pipe. to the right of the engine, left of the air cleaner, and on the back side of the vacuum pump.) i thought it could be that intake manifold vacuum actuator arm being broken but i don’t know what to do anymore. thanks in advance!
-Jaxon
(for pictures of the part i broke, search up “1.9tdi bew intake manifold vacuum actuator”)

P.S. before the intake cleaning i had an average boost pressure of 15.8 and after the cleaning on that little test drive

(2005 Vw Jetta mk4 BEW)
i was cleaning out my intake manifold, and on reinstallation of the manifold and egr cooler, i accidentally broke the arm of the “intake manifold vacuum actuator.” it’s located on the passenger side of the engine, shaped like a little circular plunger with an arm (pointing towards the front of the car) going to a pivoting bracket on the intake manifold. it’s just below the Anti Shudder valve, and is made of plastic. when i reinstalled the intake system, i took it for a drive and under high boost, high load, up until VGT actuation i get a very loud squeal and a “flat spot” in my power curve. i have no clue what creates this, and i’m not sure if that broken arm on that actuator could create that noise. i have a new one that is shipping right now but it’s not gonna be here for a week or so, and i’m kind of scared to drive my Jetta because this noise did not happen before and i don’t want to damage anything further. any thoughts? i saw a video online and a guy said that he had lost braking power and boost pressure because his vacuum pump main supply nipple cracked, causing a vacuum leak. (nipple located on vacuum pump directly below the intake pipe. to the right of the engine, left of the air cleaner, and on the back side of the vacuum pump.) i thought it could be that intake manifold vacuum actuator arm being broken but i don’t know what to do anymore. thanks in advance!
-Jaxon
(for pictures of the part i broke, search up “1.9tdi bew intake manifold vacuum actuator”)

https://youtube.com/shorts/eEOoE7E-f7o?feature=share quick little video i made of the noise

 

[05MK4TDI]

Those little plastic actuators can get brittle.

As for the squeal, you need to tighten up the egr pipes. Those pipes have metal gaskets and one of them is just loose enough that air rushing over them at boost causes it to vibrate.

Crawl back under you car again and retighten the bolts about a quarter turn or so.

shoot dude that makes sense. there’s 2 EGR pipes. exhaust to cooler, and cooler to intake. when i tightened them on the bottom side (exhaust to cooler, i got them pretty freakin tight, and one of the bolts on the Cooler side got tighter, tighter, then loose, so i left it alone. the ones on the top side (cooler to intake) are as tight as i could get them but with caution as i didn’t want to strip it out again. you think it could be losing a seal on the stripped out side? i have a lot of bills coming up and i can’t really afford to buy a new cooler and spend time under there again trying to replace it. what’s an easy way out of this? i have a VNT17 turbo on it, with the EGR still hooked up obviously lol.

 

[05MK4TDI]

Those little plastic actuators can get brittle.

As for the squeal, you need to tighten up the egr pipes. Those pipes have metal gaskets and one of them is just loose enough that air rushing over them at boost causes it to vibrate.

Crawl back under you car again and retighten the bolts about a quarter turn or so.

should i get an EGR Delete block off plate? take my cooler out, and put a block off plate on the turbo manifold side and a block off plate on the intake manifold side and call it good? if i do that i’ll keep the actual valve itself still in and connected so the ecu doesn’t know it’s deleted lmao. what’s your input on this? i have Arizona emissions coming up in january and i have an appointment to get it tuned on the 21st of december so i gotta get it running 100% before then…

 

[Tdijarhead]

I think it very likely that is your problem. Can you put a longer bolt with a nut on the end in there to get it tight? Can you do a helicoil?

I have never done a delete so you’ll have to let someone else comment on that.

 

[flan]

Exhaust to cooler has a decent amount of meat on it for a helicoil, also it isn’t a blind hole so a through bolt is possible. Access may be tough with it installed though.

 

[05MK4TDI]

I think it very likely that is your problem. Can you put a longer bolt with a nut on the end in there to get it tight? Can you do a helicoil?

I have never done a delete so you’ll have to let someone else comment on that.

i can try and put a nut on the backside, yea. i feel that a helicoil might be too big, but that nut and bolt idea is a pretty good idea. is it okay to drive it with that egr leak and squeal noise? obviously i run the risk of dumping exhaust onto wires and hoses… thanks for all of your help

 

[05MK4TDI]

Exhaust to cooler has a decent amount of meat on it for a helicoil, also it isn’t a blind hole so a through bolt is possible. Access may be tough with it installed though.

thank you man! i might try and do that bolt idea with a nut on the back first then if that doesn’t work i’ll go back in again and install a helicoil. thanks!

 

[flan]

i can try and put a nut on the backside, yea. i feel that a helicoil might be too big, but that nut and bolt idea is a pretty good idea. is it okay to drive it with that egr leak and squeal noise? obviously i run the risk of dumping exhaust onto wires and hoses… thanks for all of your help

I’d not do it for the long term, diesel exhaust is sooty (abrasive) and over time can wear away the machined surface and make getting a good seal in the future difficult. For the time until you are able to make the repair? I’d do it if I were in Your shoes.

 

[05MK4TDI]

I’d not do it for the long term, diesel exhaust is sooty (abrasive) and over time can wear away the machined surface and make getting a good seal in the future difficult. For the time until you are able to make the repair? I’d do it if I were in Your shoes.

never thought of the abrasive soot leaking past my mating surface, creating gouging in the material, thank you for the heads up.

i did some research last night and today, and i’m stuck in between two options.

making that repair means i have to disassemble everything behind again for the 3rd time. half of me wants to repair it, and the other half of me wants to get rid of the problem in total. while i’m in there i might as well delete the cooler, and the egr pipes, and block it off. i need to take my manifold off to clean it, and to remove those flimsy vortex fins in my head anyways, and my cooler will be completely off. i’ll mate the coolant lines together and i won’t worry about carbon buildup or anything anymore. i’m getting it tuned on the 21st so i need to make up a decision. i asked around the forums and i’m being told that besides extra long warmup times, there’s no side effects (i live in Arizona lol). if i did this i’d keep the egr actuator valve itself installed to prevent a Check engine light. on the other hand, vw installed it for a reason, so why would i delete it. sorry for rambling, and thank you for your help

 

[flan]

It’s there strictly for emissions. It’s ultimately a hassle as you are discovering. If you’re getting it tuned and they can make it so there isn’t a CEL on at all times go for it. Save on expensive parts and future maintenance like cleaning out the intake, etc...

 

[05MK4TDI]

yea

I drove with that squeal for years in my BEW, only happened when cold and disappeared when warm. Cracked EGR flex pipe to intake.

dude that’s exactly how mine used to be, but since i took the pipe out and put it back in i must’ve accidentally cracked it more, or messed up the seal/mating points on it. i just cant justify spending $125 or however much it is to get a new one. deleting it for $5 sounds more logical

 

[05MK4TDI]

tha

It’s there strictly for emissions. It’s ultimately a hassle as you are discovering. If you’re getting it tuned and they can make it so there isn’t a CEL on at all times go for it. Save on expensive parts and future maintenance like cleaning out the intake, etc...

that might just be what i’m going to do. thanks for the input man, you’ve helped me out a ton. having an outside point of view really helps me understand what’s going on. thanks again