GTI 1.8T 180Bhp

[Carl.as]

I have a 2002 golf Gti..the engine is a 1.8T 180 bhp...I had some problems with my dumpvalve so i got it changed ..i have put a FORGE dumpvalve and its getting better...But does anyone kno how much the boost should be at max coz in my car its 0.7bar...

[dubcruiser]

I can't answer your boost question, but I have the same car. What problems were you getting from your dumpvalve as I think mine is playing up. I know they are a weak point.

[Carl.as]

If u have the Bosch dumpvalve it should be changed every 40000Km because it is made of plastic and other weak materials..the Forge one is made of aluminum and metals and never breaks up...The problems that I had were that the boost was lost between one gear and another and at each gear u feel that u were starting from 0 wiz ur boost

[Crasher]

The standard “cut off valve” (it is not a dump valve as it re-circulates) is more reliable than any aftermarket valve and does not need changing at an interval, I have more problem on customers cars with aftermarket valves than with the original. The way to test the cut off valve is to remove the 3-mm bore pipe from it’s top connection and attach another piece of pipe. Suck on this pipe and you should not be able to draw air through it, if you can, it is faulty.

[dubcruiser]

Thanks crasher, I will try that little test. Sometimes my Golf on light throttle seems to boost up and then let the boost go sort of lurching you forward. Just wondered if this was diverter valve related...

[Crasher]

That can be caused by the solenoid (under the tray on the front of the inlet manifold) that controls the cut off solenoid, it is called the N249 valve.
My Octavia VRS has the same 180PS AUQ engine as yours and mine failed, causing a sudden loss of boost on lite throttle and an annoying pulse under light boost.

[dubcruiser]

You have just described exactly what mine does so looks like mine is failing too. Is it something that can be fitted by me or does it need coding? Any idea of cost of the part? Thanks in advance Crasher

[Carl.as]

Such problems can be caused by many things..u have the TPR which regulates the Boost by the ECU...I had also a very fine whole in one of the boost tubes and it took me days to know where the problem is from!

[Crasher]

The part is about £58 and takes about a hour to fit. At the same time you can inspect and preferably replace the crankcase “T” piece to inlet manifold breather hose which splits regularly (probably what Carl means) and the solenoid doesn't need coding.

[dubcruiser]

Thanks Crasher. Will bear this in mind. This morning I removed the engine cover (both bits) and checked the hose lines to make sure they were all tight and secure. I found one of the pipes from the N75 a bit sloppy so resecured this. Driven it since and the car seems a lot smoother so I am hoping I have cured the problem.

Thanks again

[Carl.as]

yea i was talkin abt the "T"

[dubcruiser]

carl / crasher,

I checked the T pipe you spoke about and it had a massive split in it. Replaced this (£27!) and the car drives a whole lot better. A lot smoother. Thanks for pointing me in that direction guys!!

[Carl.as]

anytime dude