wastegate dissconnected, hitting 12psi

The Scooby · Post by **The Scooby** » Wed May 03, 2006 1:53 am

what the hell... i went out to try to eliminate the turbo as the problem with my car... unhooked the waste gate actuator from the waste gate are and wired it open, took it for a drive to see if its still acting up and im hitting 12 psi and still running like total crap...

mhrallyteam · Post by **mhrallyteam** » Wed May 03, 2006 8:35 am

The wastegate spring will let the wastegate open at around 12psi, so its normal. If not you would have overboosted, if the wastregate actuator had any harder spring inside.
What are the symptom of your car anyway, it might help in troubleshooting it.

mhrallyteam · Post by **mhrallyteam** » Wed May 03, 2006 8:47 am

Crap, i re-read your post, so the actuator was unhooked and the wastegate open!?! Beats me, if it was physically stuck open you shouldn't read 12psi, euh....

vrg3 · Post by **vrg3** » Wed May 03, 2006 1:43 pm

Wired it open? How? What were you trying to do?

The Scooby · Post by **The Scooby** » Thu May 04, 2006 1:34 am

vrg3, i unhooked the actuator arm and zip tied the wastgate open to not let the turbo build ANY boost to see if the car still is down on power like its been for months.

but its unhooked and hitting 12/13psi and is now running goot here and there and crappy the rest of the time.

i talked with a shop the other day and they said that it sounds like the seals in the turbo are bad and letting it build boost then it leaks out then builds again, i see the needle stay stable on my boost gauge. i am totally lost on this car and thinking of buying this 04 IS300 lexus at my work.

vrg3 · Post by **vrg3** » Thu May 04, 2006 1:50 am

What did you ziptie the arm to though?

The ziptie didn't come apart at those temperatures? Neat.

If the wastegate really is fully open and you're making boost, something very weird is happening, and it has nothing to do with the turbo's seals. Maybe somehow the gasket between the turbo and downpipe is covering the wastegate opening? Or crud has built up on the downpipe flange to the point that it's blocking the wastegate?

If I were in your shoes the first thing I'd do is pull the downpipe off and take a look at the downpipe flange, the gasket, the turbine, and the wastegate.

The Scooby · Post by **The Scooby** » Thu May 04, 2006 3:12 am

vrg3 wrote:What did you ziptie the arm to though?

The ziptie didn't come apart at those temperatures? Neat.

If the wastegate really is fully open and you're making boost, something very weird is happening, and it has nothing to do with the turbo's seals. Maybe somehow the gasket between the turbo and downpipe is covering the wastegate opening? Or crud has built up on the downpipe flange to the point that it's blocking the wastegate?

If I were in your shoes the first thing I'd do is pull the downpipe off and take a look at the downpipe flange, the gasket, the turbine, and the wastegate.

done and done, ive already had the down pipe off, and checked it all out along with checking for shaft play on the turbo which it doesn't have any.

and i ziptied the wastegate arm to the a/c line.

vrg3 · Post by **vrg3** » Thu May 04, 2006 3:17 am

Bizarre. I'm stumped!

When you had the downpipe off, did you open the wastegate flapper and look inside? Maybe it's clogged.

I don't know, man... I guess in your shoes I'd be looking for a cheap used TD04 or something.

The Scooby · Post by **The Scooby** » Thu May 04, 2006 5:12 am

well what is a turbo that bolts on with minimal moding to get to work that is also on the cheaper side, i can get a JDM TD04 off a 93 EJ20 for $200 which will work great with the TMIC i have that came off the same engine.

mikec · Post by **mikec** » Thu May 04, 2006 5:25 am

Do you have an aftermarket downpipe that might be keeping the wastegate partially shut? I dunno... Trying to figure this out as well.

The Scooby · Post by **The Scooby** » Thu May 04, 2006 6:31 am

no, stock downpipe, to a 3inch cat-back w/magnaflow muffler
stock intake assembley, stock bypass valve, turboXS MBC/stock boost controller/looped vacume hose from compressor to wastegate.

nothing else done.

BAC5.2 · Post by **BAC5.2** » Thu May 04, 2006 4:11 pm

With the wastegate bolted in place, you only hit 10psi?

I'd bet you haven't secured it nearly as well as you think, and while driving, it's actually partially closing.

When you build boost, what happens? Does it spool as quickly as it did before?

The Scooby · Post by **The Scooby** » Thu May 04, 2006 7:54 pm

no its open all the way i made sure by seeing how far it opens on my broken spare VF11, its open all the way.

but it wont build boost till like 4,000rpms but when it hits it hits HARD and pulls like never before, if it runs right.

vrg3 · Post by **vrg3** » Mon May 08, 2006 6:07 pm

I guess there's some debris in the exhaust housing that's restricting flow through the wastegate. That's all I can think of.

If you're willing to spend $200 on that TD04, it would be a pretty good choice... Like you say, it'll fit right up to your intercooler. I believe you could actually use your stock upper coolant line, too. It would also fit right up to the inlet stuff, although I think you might need to cut two tiny notches in the rubber elbow that connects to it. Aside from that, you'd just have to replumb the PCV stuff to make room.

The Scooby · Post by **The Scooby** » Mon May 08, 2006 6:35 pm

well when i change out turbo's wether its to another VF11 for now or i just give up and buy my td04 im changing out my valve covers to n/a ones so i done have so darn many PCV lines to deal with and then it would be easier with my oil catch can.

vrg3 · Post by **vrg3** » Mon May 08, 2006 6:41 pm

You don't think there's a reason turbo models have those two ("so darn many") additional PCV fittings?

The Scooby · Post by **The Scooby** » Mon May 08, 2006 6:59 pm

why do they? i figured that it was just for getting all the fumes out of the crankcase, but if we need so many then why are people elnimating them from their engines?

vrg3 · Post by **vrg3** » Mon May 08, 2006 7:02 pm

I don't know exactly why, but it might have something to do with the head and deck designs.

People are eliminating them? But they don't even have anything to do with catch cans!

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wastegate dissconnected, hitting 12psi

wastegate dissconnected, hitting 12psi