17705: Pressure Drop

[POLOZ]

Guys I cleaned my throttle body just last week and while doing the TB alignment, I found a error as shown below:

Control Module Part Number: 06A 906 032 TL
Component and/or Version: 1.8l R4/5VT 0040
Software Coding: 11500
Work Shop Code: WSC 00788
VCID: 7B8974EF7AEB
Additional Info:
1 Fault Found:
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
P1297 - 35-00 - -

While carrying out the clean I changed the throttle body gasket aswell.

Now, I got the following gasket from TPS which is basically VW:



And this is the one which was originally on the TB



I am pretty confident the leak could be from the gasket?!? But also
I didnt use a gasket sealent while putting the new. Is it recommended?

[POLOZ]

Anybody?

[9N3 Turbo]

You don't need sealant just the gasket.

Make sure bolts are done tight and Jublie clip to hold on the hose I tight too.

[whitegtipolo]

Could be dv valve or turbo on it's way out

[NMavs]

Is the car running rough on idle mate? Mate of mine had the exact same problem, we tried changing DV valve but made no difference. I ended up finding that it was the 'pancake valve' as people call it. The pressure check valve, Connected to the turbo intake pipe. The diaphragm inside the valve had bust, and was causing an air leak. Changed it and all was fine. There around £30 from VW/audi. Well worth a try.

[POLOZ]

Is the car running rough on idle mate? Mate of mine had the exact same problem, we tried changing DV valve but made no difference. I ended up finding that it was the 'pancake valve' as people call it. The pressure check valve, Connected to the turbo intake pipe. The diaphragm inside the valve had bust, and was causing an air leak. Changed it and all was fine. There around £30 from VW/audi. Well worth a try.

The idle issue something similar to this video:



If you watch closely the idle drops a wee bit and climbs up. Exactly what is happening to my car.

I ended up finding that it was the 'pancake valve' as people call it. The pressure check valve, Connected to the turbo intake pipe. The diaphragm inside the valve had bust, and was causing an air leak. Changed it and all was fine. There around £30 from VW/audi. Well worth a try.

Can you describe this a little more please. Will it be possible for you to take a picture please?

[NMavs]

I no longer have my gti so cant really take any pics mate, but if you start working your way down from your airfilter, you then have your maf, then your DV, then n75 valve, then the PCV valve. Its bought similar size valve as your DV, round and flat top on it. Theres like a small hole on the back of the valve, put ur finger over the hole and see if its sucking air in. If it is, then thats possibly your problem. It shouldnt be sucking air in. The ecu tries to compensate for the air leak, but youll proberbly find its all ready adjusted itself to the max limits. If you know anybody else with a 1.8t 20v u cud try theres on and see if it solves the problem first

[POLOZ]

I no longer have my gti so cant really take any pics mate, but if you start working your way down from your airfilter, you then have your maf, then your DV, then n75 valve, then the PCV valve. Its bought similar size valve as your DV, round and flat top on it. Theres like a small hole on the back of the valve, put ur finger over the hole and see if its sucking air in. If it is, then thats possibly your problem. It shouldnt be sucking air in. The ecu tries to compensate for the air leak, but youll proberbly find its all ready adjusted itself to the max limits. If you know anybody else with a 1.8t 20v u cud try theres on and see if it solves the problem first

NMavs the valve you are mentioning is it the N249 valve? Is it placed inside the black box that sits on top of the head?

[POLOZ]

Right NMavs I cant located the n249 valve. Heres a picture of my engine bay please direct me accordingly.

[POLOZ]

I think this the n249 valve

I dont see any holes?

[NMavs]

Yeah its the first valve youve drawn a red arrow to mate. Theres a minute square hole on the back of it.

[POLOZ]

Yeah its the first valve youve drawn a red arrow to mate. Theres a minute square hole on the back of it.

Hi thanks for the reply mate! I dont mean to be rude but there is no hole what so ever on the side, back and around

[POLOZ]

Well i have been checking almost everyday for the fault code and it hasnt come back.

But bouncing idle is making me mad It is exactly like the one showed in the above video.

What can it be? Vaccum leak, spark plugs, coil packs etc??????