Is This A Crack Or Moulding Mark?

[eXc]

Hey Guys,

I am chasing a boost leak on my car, I came accross this while checking the turbo bolts. I never noticed it when I installed it (it's an RB25 Turbo on a Rb20). That doesn't mean it wasn't there, I just didn't notice it.

Can anyone tell me if this is just from when it was made, or if it is a crack? Anyone have it on theres? (someone please take 4 mins to remove the heat sheild and tell me?

Pic attached.

Cheers

Chris

[GeeTR]

The way it smoothen's out to almost nothing on the right hand side, i would say a casting mark.

If it is a crack, it happened a while ago as the edge is quiet smooth too.

[WogsRus]

definatly not suppose to be there. I have 2 lying arround.

It looks like your gasket is shaged though. The one between the turbo and the manifold.

[SECURITY]

looks like a crack to me.

you can see how the distance between the flange and the gasket gets bigger as it goes along.

if you tighten that nut it and the gap gets smaller then you'll know its a crack.

[MANWHORE]

I put my money on el cracko

[teazn_r33]

while its running spray a lil amount of aerostart on the crack should pick up the revs for a sec or two if its a crack

[Adriano]

The mark right at the end of the arrow is a casting mark, the heatshield has a crack(or 2), but dont worry about them. The manifold gasket between the turbo and the manifold seems fine, as there is no discolouration or evidence of carbon buildup.

[eXc]

The mark right at the end of the arrow is a casting mark, the heatshield has a crack(or 2), but dont worry about them. The manifold gasket between the turbo and the manifold seems fine, as there is no discolouration or evidence of carbon buildup.

That's what I thought....One of the bolts (the hardest one to get too, is loose, so I am hoping that is all it is....

BTW, Yes, at the very end of the arrow is where i meant, I was not worried about the heatsheild

Let ya's know tommorow how it goes after I get this bolt done up (gotta take a heap of stuff off to get to it. grrr

I'll try the aero start/carbi cleaner too

Cheers

Chris

[MANWHORE]

while its running spray a lil amount of aerostart on the crack should pick up the revs for a sec or two if its a crack

Why would it? It's the exhaust housing. You should be able to spray anything down there without it affecting revs

That is 100% a crack. See how the gasket in the middle is black? exhaust gas is leaking out there. IT's because the turbo's cracked, so the gasket can't seal. Just change the turbo. they're cheap.

did you buy that turbo off a car that was in an accident or something? Was it there when you bought it?

[MANWHORE]

Tightening the bolt won't fix it.

[tridentt150v]

With the engine cold, use a leak detector like 'Snoop', if you don't have this, some really soapy water. Start the car up and then apply to the crack. It should froth up straight away. The window of opportunity will close when the manifold heats up.

[deant1]

bad picture quality but from what i can see it looks nothing like a crack... like said above, a casting mark. As far as the gasket goes, if it's the origional one then id change it. or at least take it off and re apply with gasket sealant. small leaks normally mean gasket problems.

But again like above you can play with snoop (which pretty much is soapy water) if you want but if the bolt was loose id put money that the seal was broken and can easily be fixed!

[Adriano]

Are you chasing a boost leak, or an exhaust leak?If there is an exhaust leak there(which must be underneath, as there definately isnt one in the photo)Then it has to be very bad to affect boost, bad enough that it would be quite loud, and it usually occur at the head-manifold flange, as the rb20/25's tend to break the end studs due to thermal expansion of the manifold

[turboedsloth]

you wana spray aerostart onto an exhaust manifold? i like flame throwers to but i wouldnt do it anywhere near my car.

[eXc]

Tightening the bolt won't fix it.

I don't usually like telling people they are wrong, but this is one time I am glad to say you were! (atleast initial testing says so) Just got it all tight again, went for a drive and it seems fine now.

Of course time will tell...

Are you chasing a boost leak, or an exhaust leak?If there is an exhaust leak there(which must be underneath, as there definately isnt one in the photo)Then it has to be very bad to affect boost, bad enough that it would be quite loud, and it usually occur at the head-manifold flange, as the rb20/25's tend to break the end studs due to thermal expansion of the manifold

Well, all I know is it was a squeel, and it was sugested to me that it sounded like a boost leak. I took it to my tuner and he was confident in saying "it's the exhuast-turbo gasket"

you wana spray aerostart onto an exhaust manifold? i like flame throwers to but i wouldnt do it anywhere near my car.

Yeah, I thought of that, I was like...yeah not such a good idea!

The 'crack' to me looks more like a cast to me, because it is so straight, and I couldn't move it, and it's a wierd direction, I would have thought it would split the other way.

Either way it seems fine now...Time will tell.

Thanks all

[MANWHORE]

When I said tightening the bolt won't fix it, I should have elaborated better. Tightening it (if it is a crack) won't make it perfect. If the turbo to man bolt is very loose and leaking a lot, of course tightening it will help. But if there is a crack, just the stock nissan gasket isn't 'spongy' enough to be able to seal perfectly, but of course reducing the gap will help quite a bit if it's loose.

I still think it's a crack. I've got a few of those housings here, and I have never seen that before. Now, whetehr that crack actually goes 'all the way through' or not, that is another story, but I still think it's a craack.

[eXc]

well if I get the chance, I'll get a closer look, maybe take it off and see.

thanks for the help guys.