Overboost protection is destroying my life!!!!

[s2avant]

I've just spent another drive home having to stop and restart the engine just to keep up with the rep mobiles. I was even blown away by an old A4 1.8T as I kangaroo'd down the road

Now I know everyone is going to shout fit your samcos, change your vac lines, it must be a boost leak, etc, etc. but please hear me out.

I'll be pulling the front end off in the next few weeks to fit the samcos, change the vac lines, fit catch tank and remove the PCV system, fit the IC mister, etc, etc so will hopefully remove any leaks but I want to make sure this problem is gone (at least for the forseeable future). I don't want to have to pull it apart again because of something I could of changed the first time.

It only happens when the ambient temp. is above 15 degrees and the engine is hot. To me this would appear to be something is expanding with the heat which is causing a leak. Any ideas?

Fingers are crossed that it isn't the intercooler. Is there a cheap and cheerful way to pressure test the IC on it's own? I already know there is a leak so there isn't much point testing the whole system.

Also can the IAT sensor or any other electrical components cause the overboost protection to kick in? Those that know me are aware that if needs be I will order anything and everything to fix my avant (it's not my money ) but I'd rather have an idea where to look instead of changing everything.

It's getting to the point where I'd consider removing the S2 badges and becoming one of the hum-drum sunday driving set until the cold weather comes round again.

Ben

[GlynRS2]

It's getting to the point where I'd consider removing the S2 badges and becoming one of the hum-drum sunday driving set until the cold weather comes round again.

You could fit a 1.9 TDI badge like Lee

Sorry, can't help on your query though. If it is just a "normal leak" it will be corrected by your planned future works. However, it would be very annoying to do all that & still have the problem - so I see where you are coming from

[s2avant]

It's the temperature thing that gets to me. I can thrash it to within an inch of its life all day long in the winter and it never cuts out. One blip of the throttle in this weather and bang goes the overboost protection.

Ben

[90quattrocoupe]

Fingers are crossed that it isn't the intercooler. Is there a cheap and cheerful way to pressure test the IC on it's own? I already know there is a leak so there isn't much point testing the whole system.
Ben

Use pvc. Get the approiate size pvc couplings, with one end threaded, and two threaded caps. Drill in the center of one cap, and thread it for a T fitting. Insert pvc couplings in the inlet and outlet hoses on the IC, thread in a cap on each end, put T fitting on one cap, put presssure gauge on one end of T fitting, put air line fitting on other. Pump up the pressure slowly. Spray a combination of liquid soap and water on the hoses and the IC. Watch bubbles for leaks.

[newsh]

Sounds like the problem that plagued me for a year or so, didn't go till I changed the ECU. Do you have anyone you can swap ECUs with?

[Berra_200]

Hi!

Not a nice way of overtaking ?? One thing that you can try is a thing called "reseting the MAF" I don´t know what is actually goes on ECU wise, but it works for some people, well when the engine is ideling disconnect the connector to the MAF then shut off the ignition and connect the cable again, try the car is it working? This has worked for me but I have also had to clean the MAF at the same time, only "reseting" MAF or cleaning didn´t help. But I belive the cutoff occured soner after only cleaning??

Maybe the adaption mode in ECU learns something when the MAF wire gets dirtier and dirtier and then one day it did not see the amounts of air coming in to engine but boy to much boost according to the airflow I cut power to injectors... and the driver kisses his steering wheel :-)

Try it and check your MAF the wire should be shiny not brown.

I used to have a oiled sport filter but I have changed it now for a OEM paper filter´, the car has not kangarouing since but it was only a few days ago since I swap.

[Sidspud]

Ben
Is it only on full throttle when this happens? If so then the easy answer is don't floor it. You'll still have plenty of power on 80% throotle. I managed to lose a Clio 172 when my car was in overboost protection mode. Just change up early and let the torque do the work. You can still get deep into triple figures as well.

[s2avant]

It's primarily on WOT that the overboost protection kicks in. Hence why I steer clear of WOT when it's a hot day. Your right, 80% throttle is more than enough for dusting most cars out there.

The thing is I want to have it acutally running right. Prevention is better than cure as they say.

Ben

[audiman]

The MAF is what brings on the cut out. Its simply a boost leak. The only way you will find this is by fitting those spanking Samcos and then pressure testing the system. Do you have access to one of the pressure testers that are around??

Good luck Ben, these boost leaks are a right pain in the ****. I have no overboost protection on mine either so it makes it harder to know when I have one.

[horvathg]

The MAF is what brings on the cut out. Its simply a boost leak. The only way you will find this is by fitting those spanking Samcos and then pressure testing the system. Do you have access to one of the pressure testers that are around??

Good luck Ben, these boost leaks are a right pain in the ****. I have no overboost protection on mine either so it makes it harder to know when I have one.

Ben?

Is your VGF ok? And the lambda probe? Try whether the fault is there after you've disconnected the single black wire connector that goes from the lambda to the ecu. Its on the right side in front of the windscreen-behind the rod that connects the two suspension towers. I have the same problem as you and I could drive home from Germany only after having this plug disconnected. Still waiting for the feckin lambda. Good luck.

[dkw_dude]

Fingers are crossed that it isn't the intercooler. Is there a cheap and cheerful way to pressure test the IC on it's own? I already know there is a leak so there isn't much point testing the whole system.

Ben

IMO it's easier to pressure test the whole system if you have a adapter for the MAF to turbo hose (80mm outside diameter).

Pressure test with the engine warm! Pressure tested my system first cold, had a small leak, didn't do anything about it.
Pressure tested again after a few days with warm engine, the leak was much more apparent, the pressure gauge wasn't moving at all before a whooshing sound came from the "michelin man" hose (which I changed about 1,5 years ago). Used soap water on it and there the leak was. Local dealer had to to order it from Germany, will get here next week.

Don't give up! Hopefully with some help from the forum you'll get it running right, then get on the road and set the record straight!

good luck!

[Josh-stateside]

Hi

" have run across a couple of 20V Turbo cars which had a 2224 code stored inside the ECU and were getting the overboost fuel pump cutout, even though the boost was only going up to 1.0-1.2 bar. In the first case this would occur only when the throttle was quickly floored, and would not happen if the throttle was gradually opened all the way. In the first case, it ended up being a defective MAF sensor. In the other case it was only a poor connection at the MAF sensor. Try using some contact cleaner on the MAF connector and terminals, and see if the overboost problem is eliminated."

Cheers
Josh

[Josh-stateside]

oh yah if you have an aftermarket air filter it could be screwing up your maf. The oils in K&n air filters etc are sapposely bad for our applications.

Cheers
Josh

[newsh]

Yes, definately check the connection to the MAF, clean the contacts very carefully and thoroughly.

[s2avant]

It did it when I blipped the throttle on Sunday

I've cleaned the MAF and it's connections but will add it to the to do the list. The PCV system is all new as are the lambda probe and ISV. Two of the intake hoses are brand new too.

I've ordered a new plastic boost tube today to replace my metal one and the two high temp. silicone hoses for the WGFV (one of them is £40+ ) I'll be uprating all the hose clamps and replacing all the vacuum hose (again) as well when I tear it apart.

The RS2 intercooler and cross member are only a year old so this will mean that every part of the intake pipework has been replaced (except the turbo). The PCV system is going in the bin as well so fingers crossed the problem should be resolved. If not then it's a new MAF and onto the sensors etc.

One last thing, would dead cats (as in catalysts) cause this problem?

I'll have the b!tch do WOT in all gears whatever the weather if it takes me forever or my name's not Baron von Watkins

They'll be a lovely pile of bits (boost hoses and pipe, PCV system pipework, etc) left over when I'm done if any one needs any spares.

Ben