Just bought a mk1 1.8t and was driving fine, bit after a few days starting to have issues with the turbo. 

Has a boost gauge fitted and the gauge is either not passing 2psi or shooting up to around 12psi and then dropping. Sometimes running ok sometimes seems a complete lack of power and some times it's engaging and rising high at low revs with now actual noticeable boost. 

Waste gate seems to be moving fine. Issue is somewhere along the line a previous owner has fitted a dump valve and seems he has pierced an inlet hose and ran another off it going....somewhere. Can get pics if needed.

I am assuming it's been remapped to as when it is working ok it certainly seems to be pushing beyond 180bhp.

 

Have searched around for an answer but no luck. Any help would be appreciated. Or I'll have to just take it to a garage

Thanks 

Pics of your pipes that have been modded and the dump valve setup please, not easy to say much without seeing how ther car has been changed.

On further reading I'm guessing this is an external waste gate.

But you can see this job looks pretty special...

I'm completely ignorant with a lot of this stuff and just reading up on it now but the car was 400 quid so i went for it 

I see the problem, that special stabbed hole in the pipe will be a creating a massive boost leak. Where does the pipe that's pushed into the hole go to?

 

Also, the recirc valve is running the the wrong way round.  The bottom of the valve should go into the intake pipe and the pipe that comes out the side of the valve should then go across to where the bottom of the valve is currently connected to.

6 hours ago, Fireisborn said:

On further reading I'm guessing this is an external waste gate.

But you can see this job looks pretty special...

I'm completely ignorant with a lot of this stuff and just reading up on it now but the car was 400 quid so i went for it 

 

It definitely looks very "special".

 

Have you got a trusty local mechanic you can take it to who can give the whole car a good look over? If it's going to need other significant work doing soon then you might be better off punting it on and buying another car. Used cars sub £2k really are a minefield though.

Edited 31 March, 20188 yr by vrsTom

I Will check as soon as I can. From what I remember it's going down to where the turbo is but will get some pics as best I can.

Yeah pretty good workmanship as you can see

 

 

2 minutes ago, vrsTom said:

 

It definitely looks very "special".

 

Have you got a trusty local mechanic you can take it to who can give the whole car a good look over? If it's going up need other significant work doing soon then you might be better off punting it on and buying another car. Used cars sub £2k really are a minefield though.

I was thinking about just taking it to someone. Guys made such a botch job and I'm not really read up on turbos either so maybe best to put it in someone else's hands.

Although car is running and driving fine other than this turbo issue. And it was running normally for the first 2 days even like this .

Edited 31 March, 20188 yr by Fireisborn

The hose from what I see is running down under the engine possibly back to the turbo and has suction. 

 

I see what you're saying aboit the recirc valve 

Edited 31 March, 20188 yr by Fireisborn

Omg who plumbed that together. That set up is hiddeous!

 

I would first start from the left. The red pipe thats set left of your throttle body typically runs to your charcoal canister. Remove the tee piece that the dump valve is running from (aka yellow line) and the clear line (boost gauge). As this line is reading vacuum before throttle body. Replace or use a straight connector for your charcoal canister.

 

Typically you should alway source an "absolute pressure" source from the inlet mani. This could be the reason your boost gauge is erratic  (along with the huge noob boost leak you have).

 

Locate the vacuum piping under the inlet mani at front of car. Remove black plastic panel surrounding dip stick. Here youll find the N249 and other associated vacuum valving. Tee into a 4mm vac pipe directly plumbed into manifold. I.e not after a valve but before it. This will give you absolute pressure and instant response from dump valve and boost gauge.

 

The upper hose located into the "stabbed split" could be from the wastegate??? Have a check of the N75 valve located in the turbo intake pipe. Its the 3 pronged valve residing by the hockey puck looling valve. All 3 prongs should have a line attached. 1 to boost source, 1 to wastegate actuator and the last to the tubo intake pipe.

 

You need to replace the hose runnong from your dv to the turbo intake pipe asap. That is just the best piece of diy on a turbo'd car ive seen in ages hahah. If you cant source a replacement, temporarily remove pipe from dv and bung the hole on the tip. This will make car run better until you have sourced your new recirc pipe. 

 

I hope this helps

 

I think we're all curious as to what that "new" stabbed pipe leads too lol

Haha I'll do my best to find out tomorrow where the hose goes exactly and update you. I can only assume an orc did this 

Did you not open the bonnet before purchase and wonder what was going on

7

8 hours ago, Liverpool-Lad said:

Did you not open the bonnet before purchase and wonder what was going on

I don't really know much about turbo, and it was driving and boosting fine for a couple days, it was 500 quid, and can prob sort this without to much trouble and the car seems fine otherwise 

Edited 2 April, 20188 yr by Fireisborn

@Fireisborn - Well, since no-one has said it, the 1.8T was designed to run with a re-circulating dump valve, not an external wastegate, so that would cause problems even if the job was done well and not "special".

From what I can figure out that hose pierced it the inlet is running to a connector for these hoses. Hard to follow it as it goes under part of the engine and hard to keep track

Hi mate.

 

Probs best you remove the engine cover and take some more detailed pictures. 

 

I carried out the vacuum simplification on my car some years ago now. So cant quite remember the orientation of all piping however Rob Cully (correct me if im wrong) posted a brilliant diagram for all the vacuum routing. Ill try finding it and copy you in.

 

 

Edited 3 April, 20188 yr by Adz_VRS

http://www.pimpmyskoda.co.uk/Engine.htm

 

There you go, have a good read up. Will help you understand your car and how the turbo system should be routed. 

Edited 3 April, 20188 yr by Adz_VRS
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