No Boost Hi-Flowed CT26 ???

[1200det]

Freshly rebuilt CT26 built to 62-1 Specs on 7MGTE

Turbo has been working fine for say 50kms of spirited driving since rebuilt and fitted , Today whilst driving hard under boost i hear a noise for a few seconds like a grinding noise and then no boost at all.

Car runs perfectly although no boost at all

Turbo spins freely and i all blades seem intake looking at the inlet and also intact on the exhaust side.

I have checked all the intake for hose leaks / splits and nothing obvious although being AFM the vehicle would run like shit all the time anyway.

So could it be the baldes that you cant see that have been chewed out or maybe under harder spinning the bearing/bush is seizing up and no boost ??

[slide86]

is the wastegate jammed open? can you manually move the rod to open and close it?
maybe the wastegate flap has come off and gone down the exhaust!
so you can see the rear wheel then, its still there?

If the bearing had siezed then it would probably still be siezed and you wouldnt be able to turn it with your fingers.

the wastegate controls boost, so maybe start there.

[1200det]

Wastegate flap is closed so that hasnt been stuck open.

Front and Rear blades are there!!

Turbo spins freely !!



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[1200det]

Here are the pics of the exhaust and compressor wheels , Can they be broken where you cant see the Balde inside the housing ?






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[BlackSupra]

Looks pretty good to me, that should still make boost.

Have you checked for leaks in the intercooler piping, or a hole in the intercooler for that matter?

[1200det]

I checked the wastegate was closed when i got home and had the car idling with the exhaust dropped and revved the car and no + boost , although could the wastegate be something that is sticking opening off idle and not staying stuck open hence it looked fine when idling in the garage.

The wastegate was shimmed also

Done visual checks of the pipeing and also tighetened all the hose clamps , I figured it would had to of been a large split / leak to cause no boost at all and the car was still starting and running fine which i didnt think it would being AFM

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[Hibba]

It might be spining freely by hand, but might be shifting underload and contacting the housing and stoping the blades.

This happend to a person i know on a 2J supra.

Check to see if there is any side to side movement in the blades or if you can contacting points inside the intake or exaust housing.

[1200det]

Hibba

Well that was my thoughts that when revving the vehicle and no load on it , Spins freely and when under load and boosting it locks up and doesnt spin , I might just send it off to GCG and get them to check it out whilst its off the car and if it checks out ok ill start looking at wastegate issues and other things.

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[EldarO]

taking a guess, but are you sure the wastegate actually has resistance against it?

it could just be flapping open as soon as boost starts pushing against it...

complete guess, dont cruicify me!

Eldar.O.

[oldcorollas]

the compressor and turbine are still firmly attached to each other?? (ie the nut hasn't come loose?)

["Z" UTE]

Damo, do the shaft freeplay test, then remove the front cover off the compressor. If there is any gouging in the housing, take it back to the people who hi flowed it.

cheers Chuck.

[1200det]

Chuck

Do you know how to remove the front cover ? To inspect


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["Z" UTE]

Damo, at the rear of the compressor housing, there should be 6 bolts, each pair holding a180 deg segment retainer. Undo the bolts, slide the segments out, and the front cover should drop off . Or it could just be a hugeantic circlip. Maybe slightly different on your turbo, but the principle is the same. The rear cover for the compressor wheel is actually part of the core. Once the rotating assembly has been put together, the front cover has to be attached to the rear cover/core. The front cover usually slips over the rear cover, and is retained by some mechanical means.

If you run into probs, give me a ring, cheers Chuck.

[whatthe?]

Big assed circlip if i remember right on a CT26

[CLG]

the compressor and turbine are still firmly attached to each other?? (ie the nut hasn't come loose?)

Yep, is the comp wheel nut tight?