Ive still got a problem with my boost dropping right off when i go over 5k. Im pretty sure it isnt the actuator as i have a screamer pipe and that goes silent when the boost goes, so it cant be coming out there. So im guessing there must be a leak somewhere. It feels like when you blow a boost hose, but none of the hoses are actually going anywhere, but could it be that when i get to around 5k the turbo is flowing the most air it has enough pressure to leak around one of the hose clips?
Boost dropping off
- Thread starter j4cko
- Start date
Toby@ToyTuning.com
Banned - DO NOT BUY FROM TOYTUNING
It woudn't but if it was split or squigged then it would hamper the air flow. Any whistles or just normal turbo sounds? What actuator are you running? A cracked wastegate can also cause this as when the gate is shut it won't be totally sealed leaking some of the boost away..
T
T
ChrisGT
Member +
Can get bent over and restrict air going into the turbo; hence less boost and general lack of performance ! You have to make sure its seated perfectly and not in any way crinkled etc. Happened to me and a few others, my boost kept dropping off at high revs and I didn't know what it was, drove me mad. It was that 
If thats the problem, bare rep points my way
If thats the problem, bare rep points my way
Toby@ToyTuning.com
Banned - DO NOT BUY FROM TOYTUNING
Yeah I forgot about rep points surely I should start with a million?
ChrisGT
Member +
You scratch my back, I'll scratch yours ?
Also check for puffs of soot around the mani/downpipe...could be the sign of a leak ! Failing that, it must be a boost pipe somewhere, or dump valve sticking open at higher boost levels. Could actually be quite a few things lol.
We should have a checklist for this sorta problem lol
Also check for puffs of soot around the mani/downpipe...could be the sign of a leak ! Failing that, it must be a boost pipe somewhere, or dump valve sticking open at higher boost levels. Could actually be quite a few things lol.
We should have a checklist for this sorta problem lol
Theres just normal turbo noise, so i dont think its leaking all the time. It boosts up to 10psi fine and then as soon as it gets around 5k, the boost drops right off, and feels like a boost hose has blown off. I am running an HKS actuator and as far as im aware the wastegate is ok, i can get it checked though. It all seemed to start when took my fmic off and put the tmic back on, thats why i think it must be leaking around that area, but im buggered if i can find where. I also had the efi pipe off a while ago, so i'll be checking that too!
ChrisGT
Member +
Yup check the EFI pipe. Do you have a gasket between turbo and TMIC pipe ? Might be leaking around there. I just made a gasket out of gasket paper as I didn't have a proper one.
Hole in your intercooler? Bit extreme and probably not the issue; but could leak test it (take it off, cover one hole, fill with water, check for leaks). Just brainstorming really mate !
Hole in your intercooler? Bit extreme and probably not the issue; but could leak test it (take it off, cover one hole, fill with water, check for leaks). Just brainstorming really mate !
Toby@ToyTuning.com
Banned - DO NOT BUY FROM TOYTUNING
As above good lad Mont. If there was even a large part of the cooler that wasn't sealed then it would whistle a lot more than normal, very noticeable and you would get a constant leak not drop off so it won't be the intercooler unless it is a very very small gap. If the intercooler pipes are that loose you get no boost at all and a lot of whistle I doubt it's the cooler. You can check for leaks by spraying Carb Cleaner around the joiners as it stalls the engine but we don't advise it as is dangerous with high heat.
In your circumstance I would check I would say w/gate or actuator issue. With the w/gate, you have to think that is where the boost is held under load, when it pressurizes under initial boost there will be enough volume for it not to leak, once you reach peak pressure the air will be forced to leak at the weakest point which could mean there is a crack somewhere. Either this or the actuator isn't holding the w/gate 100% shut under boost causing some boost to be lost.
The only other thing is the inlet track which you also removed, as Mont and I mentioned if this is at all restricted (rubber connector) then the turbo may struggle to suck enough air at high psi again causing drop off..
Let us know how you get on
T
In your circumstance I would check I would say w/gate or actuator issue. With the w/gate, you have to think that is where the boost is held under load, when it pressurizes under initial boost there will be enough volume for it not to leak, once you reach peak pressure the air will be forced to leak at the weakest point which could mean there is a crack somewhere. Either this or the actuator isn't holding the w/gate 100% shut under boost causing some boost to be lost.
The only other thing is the inlet track which you also removed, as Mont and I mentioned if this is at all restricted (rubber connector) then the turbo may struggle to suck enough air at high psi again causing drop off..
Let us know how you get on
T
Will do, im gnna whip the downpipe off 2nite and have a look at the wastegate. It's going to the garage for new handbrake cables on thursday so i'll get them to have a butchers for me. Im also gnna have a look for any signs of leaks from the manifold, altho it doesnt sound like its leaking. Could a leak from the manifold be like a wastegate crack? As in only leaks at higher revs when flowing most air
Toby@ToyTuning.com
Banned - DO NOT BUY FROM TOYTUNING
In essence yes as the gasses flow through the manifold and power the turbine blades exhaust side, so at peak pressure if it leaked it would simply mean less gasses where getting to the turbine blades but it would be noticeable sound wise, none the less something to check
thats the thing, it goes totally quiet really. If i dont get it sorted soon i might just take the day off and bring it down to you, cos im trying to sell it and need to get this fixed first.
I was going to take the downpipe off 2nite, but its far too much of a ballache, i'll get the mechanics to do it while its in the air lol. And ive just whipped a spark plug out to check too, its a bit black and carbony........ Running rich?
I was going to take the downpipe off 2nite, but its far too much of a ballache, i'll get the mechanics to do it while its in the air lol. And ive just whipped a spark plug out to check too, its a bit black and carbony........ Running rich?
Last edited:
Bullet00th
Member +
The same thing happens to mine now. Put the WEPR manifold on with ex/wastegate. Ran perfectly for about a week, boosting to .7bar and holding spot on.
Then the other day i took the intercooler pipe off the turbo (to spray it), now after refitting it, the boost drops off about 5k. Thought i hadn't tightened a clamp up properly, so i took the pipe off today and theres a load of oil in the pipe work ????
Then the other day i took the intercooler pipe off the turbo (to spray it), now after refitting it, the boost drops off about 5k. Thought i hadn't tightened a clamp up properly, so i took the pipe off today and theres a load of oil in the pipe work ????