Help!!! Blasted boost

[Drummer87]

Right guys.

As some will know I'm experiencing some issues with the running of my car.... Again

So to the start.

Cars been running perfectly since getting it back on the road. Had a problem before with a coil had played up causing similar issues.

So driving along having some fun on full wot then a bang (not sound wise but like hitting a wall)

The car just started limping, boost fluttering up to 1.2 then instantly dropping to 1 bar steady then 0.5 etc...

Parked up, tried the maf connector a few times and turning the ignition on and off a couple, as this seemed to cure my problem before temporally. But no luck this time.

So laid her up for the winter, and Martin (as2q) kindly pulled my fault codes.



So the hunt begins. To date the following I have done.

Removed coil cover and checked all sparks for tightness. Seeing since fitting new ones hasn't been back in to check the torquing. But all good. Removed a few to check condition but all good.

Removed wastegate cap, checked diaphragm, no splits on inspection. And the spring Wasn't broken. But further reading if wastegate was at fault I would be over boosting before the protection kicks in. (Maybe wrong on this one)

Removed air filter, cleaned it up nothing wrong in there. Checked maf and was nice and clean. Nothing covering the grate.

Checked over hoses for anything obvious pop'd off or massive splits. Reading up alot on urs4boy pages followed all the hoses and advice. Found one hose at the back of my inlet to be looking worst for ware. Doesn't feel to be leaking.

Removed passenger scuttle for the ecu. On first inspection I say the hose dropping down and thought maybe someone has stamped on it. But nothing wrong with all the vacuum lines.

Still needing to look at the moisture trap.

Needing to get a boost leak kit.

As I know everyone is going to say boost leak lol

I started testing the coils. As I'm convinced its coil related if not pos.

Idled the car and started pulling the injector plugs off one by one noting change in the idle. But everyone one I pulled just went rough.

Needing to remove the cover again and test the firing of sparks. If a plug has failed in a very short lifespan of a thousand miles. Or the coil!!

The DV is forge, and I read issues arising with them. Looks oily around the cap...

Drove the car tonight, and decided to eliminate this problem! so disconnected the N75 and was driving faultless at 0.4 mech boost. But when cruising say in fifth or sixth low revs felt what I believe was a misfire ever so often.

The car drives like this.. Haven't explained the symptoms fully.

So most of the time car is hitting 0.5 bar, if low down I can make the car reach 1.2 1.1 then holds like 1.0 but feels slow. When boosting it judders, it's shaking its just plain 5HIT. All this on Wot sometimes a quick judder on half when boost is expected.

I can hear with my exhaust there no over boost. This to me feels like the protection I have read.

I'm going round the bend now. Whom up in Aberdeen has a boost leak test and knows how to use it?? Beer as a reward

What to do now????

Check spark firing..
Defo boost leak test
Hit the car
N75
Change out coils for 1.8T loom
Buy all new hoses
Buy a new turbo
Buy some nice upgrades

But all joking aside needing some Divine intervention now.


here's one on me

Chris

[merlin's S4]

Yep sounds like a boost leak. You can probably forget everything else until you've ruled this out. So have you checked the hoses to and from the moisture trap at the back of the engine? They've a habit of blowing off completely. Most common boost leak is the short ribbed hose down by the intercooler. It usually splits near one of the ridges so isn't always obvious to see by eye.

[Drummer87]

After reading about the moisture trap. I went out took panel off under the glovebox and searched the ages.

Went back in re read and read. Seemed that the write up on the urs4 was in different position. Then found it might be behind the piece on the side in the footwell. Is this correct?? Or has someone deleted my trap. Which I doubt very much.

The intercooler hose you speak about is the one turned into the mark h mod??

[prj]

Clear faults, re-produce the problem and post up faults again. Pressure test the intake.
The MAP sensor code will cause boost control to be switched off.

You can either diagnose the problem and fix it, or try running around like a headless chicken, swap tons of stuff that has nothing to do with the issue, get nowhere, get pissed off and sell the car.

Sorry for the sarcasm, but the latter happens pretty often on this forum.

[merlin's S4]

Just read it properly. Ignore me about the hoses, thought you were talking about an S4 or S6 for some reason!

It could be a coil or POS if it's misfiring but if its idling ok then it's firing ok so removing the spark plugs won't help at this stage. If there is a misfire then is it worse when the engine is hot (POSs fail under heat) or is it only under load (more likely a coil).

[as2q]

Not so good dude, I have a boost leak test kit at home can get it to you when I get back onshore, looking to be home next week sometime.

[Drummer87]

Clear faults, re-produce the problem and post up faults again. Pressure test the intake.
The MAP sensor code will cause boost control to be switched off.

You can either diagnose the problem and fix it, or try running around like a headless chicken, swap tons of stuff that has nothing to do with the issue, get nowhere, get pissed off and sell the car.

Sorry for the sarcasm, but the latter happens pretty often on this forum.

Codes were cleared and driven it a few times since.

Martins offer to boost test will be taken up and check the codes again.

Hey we all need a laugh and I was just taking the Pi$$ about what to change after reading some many threads.

[Drummer87]

Just read it properly. Ignore me about the hoses, thought you were talking about an S4 or S6 for some reason!

It could be a coil or POS if it's misfiring but if its idling ok then it's firing ok so removing the spark plugs won't help at this stage. If there is a misfire then is it worse when the engine is hot (POSs fail under heat) or is it only under load (more likely a coil).

Abit of both

When hot it did tonight twice.

[Drummer87]

Not so good dude, I have a boost leak test kit at home can get it to you when I get back onshore, looking to be home next week sometime.

Awesome cheers Martin got a crate with your name on it. If your cool to come over a night or during the weekend that be spot on.

Good thing we cleared the codes and now see what comes up.

How's work going

[as2q]

Awesome cheers Martin got a crate with your name on it. If your cool to come over a night or during the weekend that be spot on.

Good thing we cleared the codes and now see what comes up.

How's work going

No problem will take the vagcom up aswell and see what it says this time, a week in and not did anything yet will give you a shout when I get home.

[twoqu]

You need to concentrate on that 00519 code. According to the documentation it could be:
Vac line from intake to ecu interrupted, blocked, kinked or crimped.
Moisture trap full of liquid.
Blow off valve faulty.
Solenoid valve faulty.
Map sensor faulty.
Turbocharger faulty.
It would be helpful if we knew what the signal too high indicates, a leak or a restriction in the ecu line. That should give you an idea on where to look!

[Drummer87]

You need to concentrate on that 00519 code. According to the documentation it could be:
Vac line from intake to ecu interrupted, blocked, kinked or crimped.
Moisture trap full of liquid.
Blow off valve faulty.
Solenoid valve faulty.
Map sensor faulty.
Turbocharger faulty.
It would be helpful if we knew what the signal too high indicates, a leak or a restriction in the ecu line. That should give you an idea on where to look!

For sure I agree with you

Maybe dmitri could clear this up.

I made the point saying my blow off value is changed to forge after reading some issues with them.

Also the moisture trap has been noted that on the S2 the clips are solid compared to the urs4 which failed.

But if someone can indicate what the high pressure would point towards

[Rocco]

how old is your wastegate?
most of them are tired and worn and they are not able to hold boost properly

[Drummer87]

how old is your wastegate?

Would need to check service records.

Spring looked near new. The diaphragm split free. Ok they all leak slightly.

But if it was failing, be overboosting to silly figures. Never seen my car above what is chipped to.

[twoqu]

You can visually check somethings. Look at the moiture trap, if its clear- move on. If you can get a mityvac or something similiar you could check the integrity of the vac pipe to the ecu etc.
You could substitute the dump valve for the original.
It appears to make boost initially so that seems to rule out a lot of components especially if that code switches off the boost control which it appears to be doing.
The chip is another variable!