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The mkiv Supra Owners Club

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Jake

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That's your BOV - looks awfully similar to my recent problems - I'd be pretty sure the inside of the BOV will be clean like mine was, the grime seems to come from the area underneath - possible turbo oil seal failure, when I removed mine there was a lot of play in the shafts too :(

 

More photos here - are you getting any smoke?

 

(fingers crossed that I'm way off the mark here!)

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Originally posted by mcanny

That's your BOV - looks awfully similar to my recent problems - I'd be pretty sure the inside of the BOV will be clean like mine was, the grime seems to come from the area underneath - possible turbo oil seal failure, when I removed mine there was a lot of play in the shafts too :(

 

More photos here - are you getting any smoke?

I've just been and had another look. There doesn't seem to be any other muck like that on any other parts. Nothing like this pic of yours.

The car does make white smoke when it's cold, it always has done in the year that I've owned it. I had put this down to worn Valve Stem Seals.

 

I don't understand what you mean about "the grime seems to come from the area underneath" I can't see how that could happen, there's a big heatshield between the BOV and the turbos.

What am I looking for if I take the BOV off?

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The white smoke you mention shouldn't be an issue, sounds more like condensation - if it smokes once warm them maybe it's the valve stem seals but otherwise I reckon you are OK there - mine smoked when I came to a stop, basically a small amount of oil getting through the turbo oil seals when there was no backpressure and then getting burnt off when the AC kicked in and upped the idle.

 

I couldn't suss where the oil was coming from at all - the BOV was clean, the pipes around it has a light film of oil on them but nothing out of the ordinary IMO.

 

The only thing I could think was that it was coming up from below the heatshield and being drawn out in the air flow or something... maybe unlikely, I'm just guessing :) I presumed that area of the engine bay was some kind of air vortex and oil was being drawn up from around the turbos and then setting on the bov before dripping down when the car stopped - all flawed theory ;)

 

If you take the BOV off the first thing to look for is if it's full of oil, obviously if it's clean it's unlikely the oil is coming from within. People were kind enough to post some diagnostics tips in this thread - that might help you a bit.

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Originally posted by Jake

Thanks Michael. I'll read that thread in a mo.

I've been preparing the GF all afternoon for another impending big spend : )

 

Jake what was the result of the compression test i did for you , do you still have the numbers ????

 

dude:flame Dev

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Originally posted by dude

Jake what was the result of the compression test i did for you , do you still have the numbers ????

It's here somewhere, IIRC they were all in the 165 to - 190 range.

 

What would poor compression have to do with this leak though mate?

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(In another thread) eyefi said:

to test the stock bov:-

take it off the car and take off big hoses, leave the thin one on.

blow through it, if u can its fucked. this wont b the case with u, cos u r seeing good boost.

 

apply vacuum (a syringe is useful for this, i have one that will apply 0.5 bar vac) to the little hose and u should b able to blow through the big hole.

Is this correct? I've taken my std BOV off the car and I can blow through it easily. I find this odd because car makes good boost (1.25 bar then it hits fuel cut)

I tried sucking on the small pipe and I can feel and hear what sounds like a diaphram moving up and closing very quickly when I release the vacuum.

 

Any thoughts?

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Originally posted by Jake

It's here somewhere, IIRC they were all in the 165 to - 190 range.

 

What would poor compression have to do with this leak though mate?

 

Just trying to rule out oil in the BOV and pipes due to excess worn rings !!!:thumbs:

 

Dude:flame Dev

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Originally posted by Jake

Is this correct? I've taken my std BOV off the car and I can blow through it easily. I find this odd because car makes good boost (1.25 bar then it hits fuel cut)

Any thoughts?

 

Yep the BOV has gone, happened on my MKIII Turbo when I upped the boost. It won't effect your boost, that's why you are still hitting 1.25 bar.

I very much doubt a stock BOV could take 1.25 bar for long.

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Originally posted by Andrew

Yep the BOV has gone,

I very much doubt a stock BOV could take 1.25 bar for long.

OK thanks. So does this mean I need to replace it? Like I said the car is still boosting OK.

 

--

Jake

(Doesn't really know what a BOV is for)

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Originally posted by dude

Just trying to rule out oil in the BOV and pipes due to excess worn rings !

I see. Well there wasn't any oil inside the BOV at all when I took it off. It's spotless inside.

 

I'm still wondering where that oil grime came from though.

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Originally posted by Jake

OK thanks. So does this mean I need to replace it? Like I said the car is still boosting OK.

 

--

Jake

(Doesn't really know what a BOV is for)

 

Good chance for more MODS dude !!!!:thumbs:

 

Dude:flame Dev

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Originally posted by Jake

Like what?

I don't want one of those wanky BOVs that make your car sound like a bus when it's braking.

 

LOL, come on Jake you know you want one :)

 

To be honest mate, I think you may need to upgrade to an aftermarket bov.

I think another stock bov will break again at 1.25 bar.

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But do I need one? My car is suffering no loss of boost with the BOV like it is.

According to what Eyefi said (in that other thread) it shouldn't do. I just don't understand.

 

Can any of the Techy guys explain to me if and why I need a new BOV?

 

Thanks

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I'm not techie but as I understand it: The BOV just lets turbo pressure out between gear change, so the turbo doen't stall. also supposed to give quicker responce.

 

So as you let off the go faster pedal, the BOV opens and still lets the turbo spin. Joining the compressor out side of the turbo, to the exhaust out let. So turbo spins freely instead of it being restricted of even reversed by the engine.

 

Waiting to be shot down in flames.........:stupid:

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Exactly what Tim said :)

 

You can fit a SAAB Bosch BOV which is better than the stock supra BOV, lots of MKIII owners did this. Can be bought from a SAAB dealer, I paid about £35 for mine about 4 years ago.

This was on a MKIII turbo so not sure how it would fair on a MKIV.

 

Personally I'd fit an aftermarket, I have an HKS SQV.

 

If you are going to run high boost like 1.25 bar, you have to take other things into consideration.

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Jake, my stock BOV has been dealing with 1.3 to 1.4 (and sometimes a bit higher) bar of boost all it's life and it's peachy. Get another stock one. Check with Brian Duff and Hisupe et al for spares.

 

Then see if the new one gets grimed up and where.

 

-Ian

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Originally posted by Andrew

You can fit a SAAB Bosch BOV which is better than the stock supra BOV, lots of MKIII owners did this. Can be bought from a SAAB dealer, I paid about £35 for mine about 4 years ago.

This was on a MKIII turbo so not sure how it would fair on a MKIV.

Like this one :

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=2470869813&category=10416

 

I wonder if it'd work OK on a MKiv

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