GolfGTIforum.co.uk
Model specific boards => Golf mk4 => Topic started by: dan2252 on 28 October 2012, 23:17
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hello having yet more troubles with lack of boost and its just allover the place basically all im wanting to know is how does the car increase boost and then know when to drop it off? its a agu running a k03s standard atuator. car did run 22psi now its holding more like 8..
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N75 controls the actuator so I think that could be playing up
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Noo it could loads of things mate.
Weak actuator?
Boost leak?
Is it peaking at 22psi still?
If not maf could be goosed?
Are you running standard dv or 007p?
Dont just assume its the N75 buddy in my expeirence the N75's are pretty good iv never had one fail on me. Its nearly always hardware issues.
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Thanks for replays guys no its not peaking at 22psi still peaks at 15 if your lucky then drops off to 8 psi followed all the boost pipe work and I can't see a leak, if you floor it off the line you get a what I can only describe as a high pitch chatter noise, but ive had all the pipes off and there are no leaks, actuator is fairly stiff to move, fitted a new genuine n75 6 month Ago only fault in system is for a coolant temp sensor
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Sort the coolant sensor first mate as the fuelling could well be out. I would look at your DV next
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Got a apr recirc valve on its about 18 month old, and il get a temp sensor today then :) could a faulty lambda cause low boost?
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The noise you are describing sounds like the N75 going nuts to me...
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I don't think it is mate fitted a genuine one 6 months ago but il swap it later with a spare one I have see if it make a difference :) any ideas are welcome sick of it been so flat
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My friends S3 had loads of turbo chatter when his standard DV failed. Swapped it for a 007p and it was fine. Maybe an idea?
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It sounds like you have a boost guage plumbed in.
Have you checked everythings still connected properly with no leaks or any tubes collapsed (strange I know but Iv come across people using window washer tube which are plastic and they collapse easily, makesure you use silicone either 3 or 4mm)
Is it plumbed into the fbr only? or have you plumbed it in the DV (Plumbed into DV is wrong and causes alot of chatter also)
Any other vaccum leaks? AGU have the horrid 90' degree rubber pipe on the on the rocker cover this splits, so do the rest of the PCV system including the plastic 90' tube coming from the oil filter housing check everything around this area.
Without physically checking the car over it could be soo many different things so all we can do is throw potential causes at you :grin:
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Ohh I dunno what the apr recirc valve's are like but id buy a forge 007p. They are proven to be the best money can buy for the 1.8t and can be had pretty cheap in the ad's so defo worth changing for.
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I've got a dump valve so I could try that do you think ? As it ran fine on that agers ago but after joining here I noticed people saying to remove them, it's plunmed into the fbr aswell mate with all new proper vacuum pipe too the rocker pipe the 90 degree pipe you was onabout I've just replaced with a new genuine pipe, i had a idea earlier the noise in getting could that be the waste gate opening? When it shouldn't be, it's strange to be honest I had a new down pipe fitted 2.5 inch same as the old one but a day after that I had boost issues I've looked at the down pipe it looks ok there's nothing I can see around it the exhaust place could have caught
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Try pre loading the actuator a little more.
I advise you to go through a tightish street and on boost listen for a loud hissing noise.
If you hear it its a boost leak. That means split pipe, dodgy dv or something like weak actuator.
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done as you said mate no hissing just get that same werid chatting noise at like 5000rpm with boost holding between 8-10 psi, its so werid. i mean its not slow but its just flat if that makes sense? you get a massive kick at like 3500rpm but seems to take agers to pull its way round it would pull hard right upto near the redline. tommorow i think im going to pull bumper off and go over every little bit of pipe work, also which way is to add preload on the atuator?
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Can you do some logs mate? MAF, engine load, N75 duty, coolant temp would be a good place to start
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As above :cool:
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Id be pushing towards a lazy maf. But logs would confirm.
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Going to do some logs tommorow hopefully new temp sensor coming tommorow a genuine one hopefully that will help :) , just drove home from work once it warmed up I gave it full throttle it hit 20 psi twice then it's not hit it since. Must be a maf like a few of you are saying as a boost leak wouldn't be intermittent would it?
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make sure the n75 is plumbed in the right way round. i got in wrong on my mk2 and it did all sorts of wierd n wonderfulls
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I've had 2 mafs in 9 months which were all Gsf bosh ones anyone else had as much trouble? And il take a pic of the n75 make but I'm pretty sure it's correct thanks for the ideas guys want to get this golf running how it should be. What did people do before forums? Haha