no boost until 2.5k rpm!

hi
first of all im new to the tdi forum and already im posting for help,i have a golf tdi anniversary edition and friday night the turbo let go,anyway fitted new/remanufactured turbo yesterday and now the car will not come on boost until 2.5 rpm,theres no fault codes wot so ever so im puzzled as to what could be the problem,ive unplugged the maf and i get no boost at all so that seems fine,all pipes are on correctly and the problem was not there with the old turbo unit.So guess i could do with a little help guys if you would be so kind,all suggestions welcome.thanks in advance scott.

This sounds as if your turbo is staying at the minimum boost position.
What year car is this? What engine?
If it is a VNT turbo, does the turbo actuator move to the stop set screw when vacuum is applied?

It would really help to know what year and engine code you have.

Were did you get the new turbo? If it is a re-man than you may have wasted your money.

Could you explain how the old turbo failed? If it came apart, parts of the compressor may have been ingested by your engine causing damage to pistons and valves.

If the seal in the old turbo failed and you had a run away from the engine burning it's own oil you could have had a hydro-lock which will bend connecting rods.

If the VNT actuator is not adjusted properly, it could cause boost problems. Also, vacuum leaks could cause the problem you describe.

sorry assumed when i registered and had to put what type of car ect it would show,the car is a 2002 golf tdi 150 (arl) anniversary edition,the bearings failed in the turbo and i stopped straight away as to prevent further damage,certain nothing has gone into engine and cams ect are all fine,the turbo was from turbo solutions and ive fitted remanufactured turbos to a few other cars and they have been fine,wouldnt have thought they would be able to sell them if they are unfit for the purpose they are being sold for but if it isn't then it can go back,gunna try adjusting actuator which turbo solutions has advised and see if it cures anything,had to do same on vxr i had before so shall update when ive tried this,thanks

Right ive adjusted the actuator 3/4 of a turn like the turbo supplier told me to and it doesnt seem any better,2nd comes on boost at 2500 rpm,3rd about 2100 rpm and 4th at 1800 rpm,5th and 6th seem fine,had a lot more poke low down in low gears before and still no codes.now im puzzled!

are there any tdi wizards out there?

When you put 20" hg or more vacuum on the actuator, does it move to the stop set screw?

Did you adjust the actuator rod length 3/4 turn? Hopefully not the stop set screw.

You need to ensure your turbo actuator is set to start moving at about 4" hg and then it should be at full boost before 20" hg.

There are plenty of people willing to help you. Maybe even your next door neighbor. Are you in Chesterfield Australia? Ohio, USA? England?

Also the more explicit and exact you can be in presenting your facts and communications, the better we can help you.

scottyboy553 said:

....2nd comes on boost at 2500 rpm, 3rd about 2100 rpm and 4th at 1800 rpm, 5th and 6th seem fine,...

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That description makes me believe there is a time component involved. The amount of time needed to build pressure may be consistent in each gear, but the amount of time from accelerator pedal application to some rpm will vary depending on the gear ratio.
If boost builds slowly enough it's even possible that in first gear you'd be at red-line and fuel reduction before boost ever builds. In 5th and 6th the acceleration and RPM increase is slow enough that the same number of seconds needed to get to 4000 rpm in first might only bring you to 1400 or so and as a result the boost might 'seem fine'.
I'd check for things like leaking pressure or vacuum in the control hoses, and for slow reacting movement of the actuator. It's probably moving far enough, just not quickly enough to be effective in the lower gears.

Are you seeing on Vagcom your actually not getting measured boost, or is just a seat of the pants deal?

Might be good to actually log whats going on to help troubleshoot.

First of all thanks for the replys,gettin frustrated with the car now,im good with spanners and sockets but not really any good with the technical side of things.
I am located in chesterfield derbyshire which is indeed england.I have no idea what 20hg is but phoned turbo solutions who advised me to move the actuator rod and he just asked me to see if the actuator rod moved upto the grub screw stopper when you start the engine and it does,he says "it cant be the turbo as when it comes on boost it pulls hard(which it does) and doesnt die straight off plus in the higher gears its fine" which he is gunna say but i think its something else aswell.I dont have vag com but do have access to a couple of good diagnostic scanners from my mates garage where i do all my own work,think one's called launch and cant remember the other but only know how to read codes and stuff on them.
Thinking of trying a new boost control valve just to eliminate this but it was fine before turbo went,other than this i really have not got a clue,dont know of anyone near me that has vag com apart from probably jbs autodesigns and they have ripped me off before so i wont use them ever again so ive hit a dead end,all pipes look fine and no signs of leaks.

Hi,Ive had the same problem on a 140 gt tdi,run very well before the turbo blew,fitted re-con turbo and the car feels like its lost loads of power and boosts now at 2400rpm but before around 1400rpm, everything has been tested so in my eyes its the turbo, will post again when fixed!!!!!! this coming week

We expect a response if you succeed to solve the problem .... I have the same problem on my car,Seat Leon ARL.my old turbo was broke on half,and i put remanufactured turbo.

adjust your actuator would be my guess

The problem is in the turbo, we tried 3 garret turbo and the problem is still present.In the end we put KK Turbo and the car works perfectly

ive got this same problem on my mk 4 golf gt tdi 150 arl. still has stock turbo.been to awsome gti on vagcom and shows no error codes atall,he checked vnt on turbo n75 all ok and g31 air temp sensor all perfect its a 2002 model.new mas air sensor fitted .bosch.im at a loss now as io dont know what to do.any help would be great guys thanks.ill check this every day and post the cure if i find one b4 getting rid lol.garage told me to keep driving it until it throws up a fault code but *** they had it 3 hrs and didnt find anything even with the vagcom.i ordered a new boost control solenoid just to see if it helps but well see.

Check the Black/White check-valve.
If this little POS is defective your performance will be flat...weak...lame...limp.

want to add one more thing ive noticed.the turbo seems to come in later after leaving my car over night by about 500 rpm but after couple of miles it settles at about between 2000 rpm and 2100 rpm? any suggestions guys??

fixed my problem and it was my boost control solenoid but thanks for the help anyway NOT.not a single reply to help me out guys.ive put the fix on for anyone else who reads this anyway but bit dissappointed in the lack of help.seems google was the best help lol.

my m8 had similair probs with his seat and was just the maf.check in this order.vagcom first if available then maf sensor then boost control sensor then the vains in tyhe turbo and actuator.to find vagcom in uk just put in vagcom users uk and it will give you a list m8.

to check maf just unplug it and see if it makes any difference if not your mafs goosed lol

this sounds a lot like what happened to mine a few months back scott.i asked for help on here tried different things,took it to awsome gti for diagnostics which showed no error codes and no boost leaks also checked the vnt which was fine so i went on a gut feeling and changed maf sensor even though it said it was ok on diagnostic which still didnt fix it and then i changed the boost control sensor off just behind the maf it is m8.pull off the pipes and put a new one in and screw back to body work .pipes back on and hey presto my car has been perfect since.car ran perfect except the boost lag so very similair to whats happening with yours m8. mines a gt tdi 150 golf. hope this helps m8 as it cost me a bloody fortune lol.

You want real help? Get that trash turbo off your car and install a new one.

shotgungaz said:

this sounds a lot like what happened to mine a few months back scott.i asked for help on here tried different things,took it to awsome gti for diagnostics which showed no error codes and no boost leaks also checked the vnt which was fine so i went on a gut feeling and changed maf sensor even though it said it was ok on diagnostic which still didnt fix it and then i changed the boost control sensor off just behind the maf it is m8.pull off the pipes and put a new one in and screw back to body work .pipes back on and hey presto my car has been perfect since.car ran perfect except the boost lag so very similair to whats happening with yours m8. mines a gt tdi 150 golf. hope this helps m8 as it cost me a bloody fortune lol.

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I have got the same problem as you had. I have no power. It's Never missed a beat for the 2 years I've owned it. Then after being stood for the weekend, It's slow as a snail. Thanks for posting this. I've been searching for 2 weeks now to cure my problem. And I was going to go down the route of booking it in for diagnostic, but at least now I have some starting point of a possible cure.
I have a Bora pd150. Is this possible faulty part on the bulkhead held in place with 2 10mm nuts, and in front of the part is the flexible air duct pipe? Thanks again. From ant

02 Jetta TDI with 311,000 miles, I am having the same issue with no boost in first until it hits 2500rpm after replacing turbo with an after market. Any more ideas? Just bought it today and it is our first VX and TDI.

rkarski said:

02 Jetta TDI with 311,000 miles, I am having the same issue with no boost in first until it hits 2500rpm after replacing turbo with an after market. Any more ideas? Just bought it today and it is our first VX and TDI.

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Why did you replace the turbo? If the old one puked I hope that you cleaned out the intercooler piping/bits. And I hope that you didn't have a runaway (and there's engine damage that wasn't dealt with).

What turbo (manufacturer) did you install? A cheap turbo is going to cause you nothing but headaches.

Did the turbo come with an actuator attached? (if not, then it's likely a cheap one) Good turbos will come with actuators that are adjusted. Regardless, it may come down to needing to adjust the actuator rod.

shotgungaz said:

fixed my problem and it was my boost control solenoid but thanks for the help anyway NOT.not a single reply to help me out guys.ive put the fix on for anyone else who reads this anyway but bit dissappointed in the lack of help.seems google was the best help lol.

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Hope you respond been having same issue myself, when you say boost control solenoid, do you mean the n75 valve that has the vacuum lines or the map sensor the goes into the inter cooler? Tia