[ma61turbo]

Posted this yesterday on the national forums, but haven't had much feedback, figured might as well post it here in case anyone has had similar experience:

My JZA80 has just developed a whine when the first turbo starts generating positive boost(according to Greddy boost gauge). Searching through old threads it seems that this may be a boost leak issue rather than a turbo death whine issue. Anyone able to help confirm this?

I can't feel any difference in how the engine is running, and it doesn't feel any different when boost pressure is starting to build, ie doesn't feel like there is a lack of power. Everything sounds normal up until positive boost pressure is seen, I can hear normal turbo sounds prior to that. At around 4-5ish psi, the whine starts and is fairly loud, doesn't really seem to die away. I haven't pushed the car to find out how it sounds once the 2nd turbo is online, just in case it is something potentially terminal.

Here is a fairly crappy recording from my mobile phone. Should give a reasonable idea of what it sounds like.

Whine

FWIW it's a 98 VVTi manual. Minimal mods; 3" cat-back with 2" dump/front pipe and TRD panel filter.

[RZ TT 94]

definitely sounds like a boost leak of some sort, either that or you have taken chunks out of the blades like my stock turbo's had...

checked vac hoses I assume?

[ma61turbo]

Yeah, checked everything over as much as I could. I couldn't see any obvious leaks. Thinking I might start taking stuff apart and have a look at compressor of the first turbo, check for shaft play etc. Pity this thing isn't as simple as my old 7m-gte, I could check the turbo on that in under 5 mins. Looks like it could take an hour or so to take everything off that I need to to get to turbo no. 1.

[ma61turbo]

Ok, it seems as though my stock BOV may be leaking, I can blow through either side of it when it is off the car without any issues. According to the following, which I found on the UK MKIV forums, I shouldn't be able to do that:

Quote

Take the BOV off and if you block the small vacuum nozzle with your finger and can blow through the large pipes, then its busted.

Anyone got a known working BOV that I could borrow today or this weekend for some testing?

[RZ TT 94]

blank off the hoses and run without one ;)

[Darren]

That is a viable option. There are a few big horsepower guys on the National Forum that run without one.

[ma61turbo]

Yeah, that has already been suggested to me by a guy on PF. What'd be the easiest and cheapest way to go about this? Just checked out a spare BOV that Stika had and it wouldn't fit, so it could be easier to test by blocking off the stock one.

[ma61turbo]

Big thanks to Dragosani for letting me borrow the BOV off his car for 10 mins, unfortunately nothing changed. Looks like I'll be spending today pulling the intake side of things to find the problem, definately sounds more like an air leak than anything else. Fingers crossed it isn't something expensive to fix...

[IcE]

yeah, i thought that test you did was a bit bleh.

If you cover to escape hole, your still always going to be ableto blow out a BOV as thats what itsdesigned to do, well, at least that was my assumption.

Have fun hunting for the boost leak!

[ma61turbo]

Just going by something I found on the UK MKIV forum...

Anyway, I've taken the under-covers off the car and inspected all the IC piping. Can't see or feel any obvious signs of a leak. Couldn't get the fucking intake piping off to inspect the front turbo so I give up trying to work it out myself.

Obviously Fours N More would be a reasonable place to take it but a) it is too far away from me and b) they are pretty busy still i think. Anybody know of somewhere on the southern side of town that knows Supras, would be able to diagnose and perhaps fix the problem and most importantly not cost a bomb?

[IcE]

Hmm, try maybe turbo tune although ive heard way too many mixed results fromthem.

Graham west?
Boost worx?

Either of those two should be able to sort you out. As for cost, NFI matey

[ma61turbo]

Heard mixed things about Turbo Tune as well. Boostworx I'm not a fan of. Graham West I have NFI about *shrug*. Thanks for the suggestions.

[Hardy]

if you find a good tuna keep with them :P

[Yiros]

Hardy, on Sep 14 2008, 06:49 AM, said:

if you find a good tuna keep with them :P

John West isn't too bad.

[Darren]

Prefer Seakist myself :lol:

[ma61turbo]

buncha comedians :P

[IcE]

*shakes head*

[Stika]

hmmm id maybe go to adelaide turbo services on marion rd

[ma61turbo]

Yeah, actually heading there shortly!

[ma61turbo]

Bill at ATS confirmed my first turbo is fucked :(

Anyone selling a set of good condition stockies? Stupidly expensive to get it rebuilt, and I don't have the funds to go to big single...