Give up, BOOST PROBLEMS =(

G

geetee

Active Member
Mate really. Stop wasting time. If it's not overboosting with the actuator line disconnected, as you've been advised countless times in this thread, you have some kind of problem either with the wastegate not sealing or worse still the turbine shaft shearing - the 2nd is bloody unlikely but I have heard of it happening.

The fact that it is a new turbo means nothing at all, in fact they pretty much fail almost immediately due to manufacturing faults or they're ok for ages as long as you keep them lubed and cooled.


Get the exhaust elbow of the turbo and use your eyes! It should be pretty obvious what is wrong.

Cheers
graham
 
R

radiobar

New Member
hi !

got a similar problem on my gt3071r.
max. boost was around 0.5 bar.

it was the internal waste gate.
remove the turbo and check it.

dont know if you can remove the elbow
without removing your turbo.

bye.
 
Kingy69

Kingy69

New Member
Boost problem

I went through this whole crappy situation,spent thousands and got a car back slower than it was before it went to the garage,told me my boost controller was bust!.I went through every single pipe,gasket etc.For starters eliminate your boost controller as im 99% sure it will not be that. Most likely cause is going to be an air leak or wastegate related. The turbo company told me my actuator was correct and tested but after everything it turned out to be that. Its a nightmare looking for an air leak but i removed the intercooler pipe leading to the plenum and made an adapter so i could pressurise it to 1 bar.Best thing for finding leaks is a leak spray.Pop into any plumb center or climate center and they only cost a few quid. Anything dump valve related just remove it and block holes then thats eliminated.Correct me if im wrong but if your exhaust cam is out it is also a cause but if the car feels ok pretty unlikely.Do you have a cat? if its breaking down it will cause high back pressure causing restriction on the turbine.Hope this might help you out in some way as i know how frustrating it can be. In my opinion after my experiance i would go straight for the actuator.Just adjust the rod and then cross your fingers!! If you remove the down pipe and undo the manifold you can carefully pull it forward enough to get your hands in to adjust it. Hope you get it sorted.
 
Fast Guy

Fast Guy

Moderators
Staff member
Have you done a fault code check to make sure the det sensor isn't playing up?

Is the boost reading the same on the AVCR and your boost gauge?

My idle vacuum is about -350mmHg when warmed up. (it was -550 with a standard flywheel)

Another thread I saw on PF yesterday was the penny washer (internal wastegate) not sealing due to the rod bending on a batch of turbo technic turbos.
 
B

BabyGodzillaGTi-R

Member
Hi guys. Old news i know.......
After finding some time available after 7 months and got some other mech to have a look at it..... Still cannot figure out the problem of why it won't boost above 0.5 bar.

-Sumo i don't have a cat on it.
I did remove the down pipe just to see if it boost harder. Still the same
-This time round the mech did the unthinkable. Shut off the waste gate port for good.
Still didn't boost.
-Blocked up the BOV. Still the same.

So now what to eliminate or suggestions b4 i decide to burn it and post it on youtube?
=(
Unless my brand new Apexi AVCR, GT2871R and HKS BOV is a lemon?
Can all the stupid hoses under the inlet manifold be a culprit?
I guess next is to try fabricating a plug for the manifold inlet and pressure test the system?

This sounds dumb but it's like 5 years since i've managed to get the car to run decently. Really true to it's rallying heritage, it spends most of the time offroading or literally off the road than on road.
 
GTIR-LOZ

GTIR-LOZ

New Member
how did he block the wastegate port off, did he physically see the wastegate if not and he just wired it shut then if its cracked or broken then it still could be the problem

also you say your avcr is brand new did you remove the plastic plugs in the avcr's boost solenoid?silly i know but have seen it done before and does limit boost
 
A

ashills

Active Member
so did u pull the hose off the actuator like advised a 1000 times
if so pressure test the boost pipes take pipe off the plenum and off turbo and ull need a way to attach a hose to the pipe work pressurise to 1 bar then 2 bar see what happens
 
neil240z

neil240z

Member
wont be det sensor, i go with gtir loz, i reckon there could be hairline cracks around the wastegate and they expand when the turbo gets hot so a lot of the compressed air from the turbo is just being blown thorugh and straight down the exhaust, had a bit of an argument about this with some one (expert at turbo active called mark) he said it wouldnt make any difference if there were cracks but it bloody does!! happened on my 5 turbo.

chances are you need a cast wastegate housing, you can swap them over in about 30 mins and it will be the same as a standard T28.

Neil
 
B

BabyGodzillaGTi-R

Member
Ashills, as i've said b4 i've pulled out the actuator signal line and checked the port to see if it's not closing at all before posting this message 7 months ago.
Yes i now it's frustrating for everyone and i appreciate the comments.

I have limited internet connection and annoyed with incompetent mechanics from where i am.

The current mech says the turbo is not an issue as he have welded the wastegate port shut. Still boost no higher than 0.5 bar instead of the expected unlimited boost( If only our engines can run on unlimited boost). He did that as he wants to run an external wastegate like a Tial 38mm.

Red through 3 pages all over again of this thread... Someone mentioned about cam timing?

Anyway so that everyone don't get more frustrated we intend to build a pressure tester to get to the bottom of this. Any kind soul have pics of their pressure tester so we've a rough idea how to build one?
 
neil240z

neil240z

Member
have you had the turbo off and checked for hairline cracks around the wastegate?

apart from the boost problem does the car run ok? does it miss? does it hold back, or go better/produce more boost when cold?

Neil
 
neil240z

neil240z

Member
on another note, where is the benefit of welding the wastegate shut? i thought the wastegate has to be open for the turbo to produce boost? isnt that what powers the turbine wheel round? hence a longer rod to open the wastegate further produces more boost!?
 
A

ashills

Active Member
nope the waste gate is a bypass to limit boost at desired level
and u shorten the actuator rod to increase boost as it puts more pre load on the actuator
it isnt gonna be a crack round waste gate as most turbos (t28 internally gated style) will be cracked after a few months and people are none the wiser about it so that wouldnt cause this
 
P

pulsarboby

Guest
ashills said:
it isnt gonna be a crack round waste gate as most turbos (t28 internally gated style) will be cracked after a few months and people are none the wiser about it so that wouldnt cause this
Click to expand...
sorry alan but thats absolute rubbish:roll: :lol: ive changed 3 turbos recently for this very reason, so how can you possibly say that a cracked wastegate will NOT effect turbo boost levels???
it WILL lose pressure if there is a crack around wastegate, where do you think the boost pressure goes when wastegate is not sealing correctly??? (exactly the same applies to a crack in the housing surrounding it)

true that a lot of people are driving around with cracked housings but then they are probably only running standard boost, up the boost and then see what happens!
 
A

ashills

Active Member
ok put it this way they have sealed the penny so they have looked at the housing from where the elbow bolts on if the penny is welded shut and they arent getting any more boost its not gonna be a very small hairline crack it would need to be a pretty visible hole to lose what could be upto 1.5 bar

till he bungs the pipe run and pressure tests it its clutching at straws
 
neil240z

neil240z

Member
i have to go with bob here, i used to have a R5 turbo running at one bar, then one day after flying about the boost dropped off to less than half a bar (and a sad face) so i whipped the little T2 off for inspection and saw around 5 hairline cracks around the wastegate, so i swapped the cast housing for a replacement and it was straight back to one bar again and lots more smiles!!
 
A

ashills

Active Member
yes but im saying that this car is only making .7 bar this turbo without actuator pipe connected would make near 2 bar it would be a pretty large crack that they would have seen when they opened exhaust housing from elbow side
 
You must log in or register to reply here.
Top