What did you do to your MKIV today?

[gmenounos]

Found the source of the clunk coming from the back of the Golf:


Anyway, old muffler removed thanks to a Sawzall and Dremel with cutting wheel. New muffler ordered.

 

[northern diesel]

https://flic.kr/p/2pW5Jum Deleted my Vac ball, asv and egr vac lines today on my quest to solve my control range not reached issue.
The bay looks good uncluttered, And vac leaks should be really easy to locate now with only 3 vac lines in there.
https://flic.kr/p/2pWbwc4 I ran new vac lines, from the brake booster junction and to the turbo.
Vcds n75 test shows i have 23 hg of pressure when the n75 is on.
I took it for a test rip and still got limp mode plus a code for the egr control.
All workable once the Tune Man gets to it Im told.
Beautiful day for some tinkering up here.

 

[northern diesel]

Found the source of the clunk coming from the back of the Golf:

View attachment 138215
Anyway, old muffler removed thanks to a Sawzall and Dremel with cutting wheel. New muffler ordered.

Muffler delete! Its probably sounding pretty mean until that new muffler arrives!

 

[Fix_Until_Broke]

northern diesel - I'd recommend putting the vacuum ball back in the circuit, particularly for transients in tuning.

 

[Zak99b5]

Welp, I got the $37 axles from Rock Auto the other day. Not happy to see that they are solid shafts, not tubular (like OE) as shown in their picture. I could return them, but we (son & I) will put them in our cars and at our leisure reboot the originals, and replace any joints that look suspicious. Then when these Chaxles sh!t the bed, we will swap them out.

 

[JDSwan87]

Welp, I got the $37 axles from Rock Auto the other day. Not happy to see that they are solid shafts, not tubular (like OE) as shown in their picture. I could return them, but we (son & I) will put them in our cars and at our leisure reboot the originals, and replace any joints that look suspicious. Then when these Chaxles sh!t the bed, we will swap them out.

Hopefully the Chinese axles don't pulse in/out and slowly wipe out your wheel bearings in the process

 

[P2B]

Found the source of the clunk coming from the back of the Golf:

View attachment 138215
Anyway, old muffler removed thanks to a Sawzall and Dremel with cutting wheel. New muffler ordered.

Fixed mine with a length of baling wire years ago The bracket on the body has rotted off too now so there's nothing to attach a new muffler to anyway.

 

[P2B]

I took it for a test rip and still got limp mode plus a code for the egr control.
All workable once the Tune Man gets to it Im told.

Limp mode means the control system is not working correctly or you have a boost leak. Can't tune that out.

 

[KrashDH]

Limp mode means the control system is not working correctly or you have a boost leak. Can't tune that out.

Overboost can result in limp mode as well. Ie stuck vanes

 

[P2B]

Overboost can result in limp mode as well. Ie stuck vanes

If the vanes are stuck the control system can't work properly

 

[KrashDH]

If the vanes are stuck the control system can't work properly

Yes it's an infinite loop of reasoning

 

[northern diesel]

northern diesel - I'd recommend putting the vacuum ball back in the circuit, particularly for transients in tuning.

Thanks for this, can you expand a little on why.. I am on a steep learning curve since joining the community.

 

[burpod]

Thanks for this, can you expand a little on why.. I am on a steep learning curve since joining the community.

no, no need for the vacuum ball has no affect (and have taken logs to prove it). haven't had a vac ball on any of my tdi's in years, and delete them all the time. same with the little checkvalve to the n75. either something else is amiss in the hardware and/or most likely, the tune just needs adjustments - namely the n75 map... that's all. that little checkvalve can cause problems - just had this occur the other day. very strange crazy overboost problems - then i suggested delete that rats nest of vac lines including the checkvalve to the barebones - after that, problem solved and near perfect boost

 

[northern diesel]

Limp mode means the control system is not working correctly or you have a boost leak. Can't tune that out.

Overboost can result in limp mode as well. Ie stuck vanes

Yeah, I can rule out vanes and vac now.
New turbo, new vac lines and new N75...
I will scour the interweb for more diagnosing, because I do have ALH style piping from the turbo to IC to PD150 intake manifold.. no clip or notch connectors, just t-bolt clamps and silicone piping.
The thing is , I got turbo, until I don't... then shut down the car and it's back...
So the ECU doesn't like requested vs actual boost I'm assuming.

 

[Fix_Until_Broke]

northern diesel - I'd recommend putting the vacuum ball back in the circuit, particularly for transients in tuning.

Thanks for this, can you expand a little on why.. I am on a steep learning curve since joining the community.

no, no need for the vacuum ball has no affect (and have taken logs to prove it). haven't had a vac ball on any of my tdi's in years, and delete them all the time. same with the little checkvalve to the n75. either something else is amiss in the hardware and/or most likely, the tune just needs adjustments - namely the n75 map... that's all. that little checkvalve can cause problems - just had this occur the other day. very strange crazy overboost problems - then i suggested delete that rats nest of vac lines including the checkvalve to the barebones - after that, problem solved and near perfect boost

I agree with burpod that simplifying the vacuum circuit is the right thing to do: Vacuum pump, Brake Booster, N75 Valve is all you need for boost control. My opinion is that the vacuum ball adds reserve capacity for both boost control transients (higher speed changes in boost, which VNT's excel at) and if necessary, brake assist. It's the least complex part of the whole vacuum system, so low risk of any issues with it.

Continuing on this tangent - I recall someone about 15 years ago messing around with different diameter vacuum lines to/from the N75 and actuator documenting the "best" size. Too small of a line and it becomes a restriction that slows the actuator movement. Too large of a line and it adds more volume of air that has to pressurize/depressurize before the actuator begins moving. "Best" is a compromise between the smallest line that doesn't provide a significant drop as the actuator strokes and the largest line that doesn't significantly effect the volume of air so as to make it take longer to change pressure.

 

[Fix_Until_Broke]

Yeah, I can rule out vanes and vac now.
New turbo, new vac lines and new N75...
I will scour the interweb for more diagnosing, because I do have ALH style piping from the turbo to IC to PD150 intake manifold.. no clip or notch connectors, just t-bolt clamps and silicone piping.
The thing is , I got turbo, until I don't... then shut down the car and it's back...
So the ECU doesn't like requested vs actual boost I'm assuming.

What does your boost gauge say, or VCDS logs of requested vs actual?

 

[dieseldonato]

no, no need for the vacuum ball has no affect (and have taken logs to prove it). haven't had a vac ball on any of my tdi's in years, and delete them all the time. same with the little checkvalve to the n75. either something else is amiss in the hardware and/or most likely, the tune just needs adjustments - namely the n75 map... that's all. that little checkvalve can cause problems - just had this occur the other day. very strange crazy overboost problems - then i suggested delete that rats nest of vac lines including the checkvalve to the barebones - after that, problem solved and near perfect boost

I agree, you talked me into ditching everything almost a year ago now. Haven't had any issues with the turbo, brakes or anything else since the vac ball has been removed. May be more important if the egr system was still there.

 

[northern diesel]

What does your boost gauge say, or VCDS logs of requested vs actual?

I'd love to get a boost guage installed eventually, right now the specified to actual seems within range, up until I floor it. The ECU triggers limp mode, and then the numbers are obviously way below specified until I shut it down and try again. Burpod thinks it has to do specifically with N75 mapping, considering the size of the 1856v.
I am hoping for a near mint ALH IC... probably will have to order a new one eventually.
The one I'm running was a wrecker pick that I spent an evening bending tin fins back to relative straightness.
The dirt that I blew out of my old one, and the ALH one made me realize that could be part of the routine maintenance.

 

[braddies]

Pulled the intake manifold and one bolt took some threads with it

In an attempt to retorque the fastener, added a few strands of aluminum wire into the hole before inserting the manifold bolt. Was able to get it fairly snug (5ft-lbs-ish) and the other bolts held tight so hopefully no leaks.

Thinking of tapping the head for a 3/8 bolt with coarser threads and cranking it in

 

[The Cream Dolphin]

I regularly go 60-70 km after the light comes on, furthest I've gone is 105. If you only went 15 something else is going on.

I have also gone 10̷5km after the light, I wanted a 1450̷km (90̷0̷mi) tank. I was starting to sweat at the end, and not just because I was not using AC or opening windows in the beating sun... I have not done anything to my car in a while, been away for a month and a half, but I did find this mobil1 shirt at a thrift store today.

IMG_0584.jpeg

• The Cream Dolphin
• Jun 10, 2024

Thrift store find

 

[Judson]

Hey Burpod - you mentioned a check valve for the n75. Is that the little hockey puck thing? And that can be safely removed?
Thanks!
Jud

 

[burpod]

Hey Burpod - you mentioned a check valve for the n75. Is that the little hockey puck thing? And that can be safely removed?
Thanks!
Jud

the little black/white (or maybe blue/black) checkvalve to the n75 can be deleted, yes, as can the vac ball, if you have egr/asv delete the only vac lines you need are:
1) n75 ATM to air filter (or a 3" vac hose + $2 little gas mower inline filter)
2) n75 VAC to brake booster
3) n75 OUT to turbo

i delete that big honky firewall bracket and use 1 10mm nut and put the n75 right on one of those studs. clears up even more space

i also get rid of the silly bracketry around the vac pump (and use a braided stainless feed line), which gets rid of more BS and lets you get the vac pump off in 2 min

thats it

 

[wonneber]

no, no need for the vacuum ball has no affect (and have taken logs to prove it). haven't had a vac ball on any of my tdi's in years, and delete them all the time. same with the little checkvalve to the n75. either something else is amiss in the hardware and/or most likely, the tune just needs adjustments - namely the n75 map... that's all. that little checkvalve can cause problems - just had this occur the other day. very strange crazy overboost problems - then i suggested delete that rats nest of vac lines including the checkvalve to the barebones - after that, problem solved and near perfect boost

Isn't the vacuum ball used to hold the ASV closed when you shut the car off and help stop a run away if you shut it off soon enough?

 

[burpod]

Isn't the vacuum ball used to hold the ASV closed when you shut the car off and help stop a run away if you shut it off soon enough?

i don't think it really matters, as the engine is still turning so it's still making vacuum. and the ASV only shuts off for a couple seconds anyway...

 

[oilhammer]

He's comparing a modified engine setup vs. a stock one. The stock setup has the reservoir there for the anti-shudder valve.

 

[06TDIBEETLETDI]

Greetings…
So my shifter would bind from left to right,not freely move back to center position, making it sort of difficult to shift correctly. But this would only happen once it warmed up.
After research I removed the relay lever on top of trans shift tower. Sticky to remove but pulled it out. Bushings stayed in. Sanded the shaft alot till it moved freely in place. Clean,lube with Mobil1 snthetic grease. Reassemble. and it feels like new. Took me a little over an hour.
Just thought I would pass the info along in case anybody has the same problem.
checked the bushings in the shifter in the car itself and everything looks good.

 

[Nuje]

i also get rid of the silly bracketry around the vac pump (and use a braided stainless feed line), which gets rid of more BS and lets you get the vac pump off in 2 min

Oh - that is a GOOD idea; definitely doing that next time I'm futzing around there.

 

[GlowBugTDI]

Pulled the intake manifold and one bolt took some threads with it

In an attempt to retorque the fastener, added a few strands of aluminum wire into the hole before inserting the manifold bolt. Was able to get it fairly snug (5ft-lbs-ish) and the other bolts held tight so hopefully no leaks.

Thinking of tapping the head for a 3/8 bolt with coarser threads and cranking it in

You'll be good to go. Mine has been missing a bolt for 60k.

 

[CanadianALH]

Today marks a year and a day with my mk4 ALH. 24k km in a year. It has been my favourite car I have owned by far. I said I would keep it stock and well that hasn’t worked out well… the bigger turbo is going in sometime in the fall. I would like to thank this forum for all the help, information and for the awesome people I have had the pleasure of getting to know a little. Huge thanks to @burpod for taking the car from barely able to pass to barely able to stop passing! Here is to another year in (arguably) the best car ever built.

 

[braddies]

You'll be good to go. Mine has been missing a bolt for 60k.

Maybe it's just the bv39 doing it's thing but sure sounds like a whistling boost leak when spooling, especially noticable when next to a wall or in a tunnel.