Lost Boost

creechy

creechy

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Hi everybody
I seem to have lost boost, scanned it this evening and there,s no fault codes. Car,s running fine apart from the lack of boost. Ive got a new DV and silicone hoses to replace the old braided ones.
Any advice welcome.
 
Unbolt the cat off the turbo and try have a wee look inside , as byzan said.. Check the flapper. You have a boost gauge?
 
Thanks Guys, will have a look at the weekend. Anybody got a good used K03 if it is the flapper, im still a long way off fitting my K04 064.
 
If I sort out the exhaust and intake etc could the K04 be run on the standard map,injectors, maf and intercooler.
I,d like to rebuild the engine with rods before upping the power.
 
Actuator pressure only will probably be fine, yes.

You'll need to do some logging to ensure the airflow is within sensible bounds, as the much bigger turbo will flow a lot more air at 5psi than the weedy K03.

Personally, i'd just get it mapped, but get the mapper to keep the torque sensible, say 280lbft max. Once you've built the engine you can always go back and get it turned up a bit more.
 
Just a thought, has the battery run very low at all. Mine dropped all the boost off and a simple throttle body adaption had full boost returned
 
Had a look at the turbo today, wastegate flapper ok and no play in the shaft. Replaced faulty DV and some pipework.
Still not getting any boost or fault codes Feels the same with N75 unplugged, could this be the culprit.
 
Do you need VCDS to do the throttle body adaption correctly, only got one of the Gendan hand held scanners.
Im going to treat myself to vcds as my son has just brought a mk5 golf so im sure it'll pay for itself time and time again.
As to one of your earlier posts about the Quaife diff in a fwd, "i say go for it" it's alot of beer tokens but it can only make a great car better.
 
Turn ignition lights on and touch nothing. After about 20 seconds you'll hear the TB whir, and finally click an go quiet. Once this cycle has done it should be adapted.
 
If it's not the TB, then just cover the basics, check the wastegate with a vac pump and triple check your vac lines, switch out the n75 for a known good one and check the one way valves in the PCV system too.
Do you have a boost guage fitted ? You can see wether there is any boost at all or if it's all just atmospheric...
 
creechy said:
Had a look at the turbo today, wastegate flapper ok and no play in the shaft. Replaced faulty DV and some pipework.
Still not getting any boost or fault codes Feels the same with N75 unplugged, could this be the culprit.
Click to expand...

When you say replaced faulty DV and some pipework, what was wrong with DV and which exact pipework have you replaced ? Just thinking N75 valve pipes may not be positioned correctly. As above a boost gauge will help you see whats exactly going on you should see 4 psi actuator pressure as thats the set cracking pressure of the wastegate actuator. How was the wastegate on inspection was the flapper closed and could you move the rod to open with little force and could you feel it trying to return to the closed position.
 
Oranoco said:
Turn ignition lights on and touch nothing. After about 20 seconds you'll hear the TB whir, and finally click an go quiet. Once this cycle has done it should be adapted.
Click to expand...
You've just answered a question that been bugging me since I got the car. So that's what the noise is when I start the car.
 
Hi all
thanks for the replies. I replaced the DV due to lost boost, the diaphragm had gone. Replaced the braided fabric covered pipes as they where old and the covering was falling off. Tried it with the N75 unplugged and feels the same, it registered a code so can assume the wiring is ok. Getting 30 ohms across it terminals which I think is ok but ordered a genuine new one. The wastegate penny is loose on the arm but still there and returns to its closed position after moving the arm manually. Done a visual check on all the hoses and seem ok, got a pressure tester on its way so hope that'll be here soon.
163k and 13 years of ownership and apart from a maf and normal service parts its never let me down.
 
Replaced the N75 valve and I'm pleased to say i now have my boost back. A big thankyou for all the advice and i will be putting a boost gauge on in the near future.
 
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