hairline crack in turbo manifold

as some of you may know i have been having some issues with no boost coming in from my second turbo through 1st to 3rd gear its intermittant, so some times it works and some times it doesnt, which is really starting to annoy me.

I have checked pressuer drop accross the FMIC and everything is fine,

I have checked that all vsv are operational and they are.

Checked all pipes related to the turbos and no cracks, splits, or kinks.

so the only other thing i can think of is a hairline crack in the manifold its self, as i have seen this mentioned a few times on here.

Would this crack reduce boost levels or even stop the boost from coming on line from turbo 2. Or does the crack more commonly happen on the first turbo.

Gav

No one any ideas

crack in the exhaust housing at the turbo near wastegate flap or ?

ive seen pictures of a hairline cracks in the turbo housings itself.

just i dont know if this would create such a boost problem or not.

Today i managed to get both turbos to work from first gear all the way through to 4th and had to back off.

But it wasnt boosting until around 5500rpm and later towards 6000rpm and by that point your getting ready to change gear any way .

then it can be the crack , depending how much it leaks it will affect the spool. is it the shorter or longer housing? i dont rember 1 or second wich is what i have many housings at home and all of them looks better than that:) you can have it for free if you pay post or pick up

im pretty sure that mine has a crack in it. the picture above is a generic picture that i found.

Which turbo is it that most commonly cracks. Im thinking its number one as this gets used alot more than number two if this was so why would it effect when turbo 2 comes online im not sure.

It won't be that.

any other ideas im completley out

My guess is the EGBV VSV.

Which one is that ive checked all 4 vsv's and they open and close as they should and i have just changed the actuator that opens the exhaust valve.

have you got a diagram of which one the EGBV VSV is. Because then i can go and double check it.

The only other thing i can think of is the fact that there is some aftermarket silicone hoses to some of the vsv's but not all would a difference in the internal diamater of the pipes make a diference.

Could one of the actuators on the turbos themselves be faulty

If it leaks pressure it will cause problems. Mine opens and closes ok but it starts to leak after a few PSI.

Could be the actuator itself but that is a PITA.

Have you tried TTC?

Could one of the actuators on the turbos themselves be faulty

Could be, I had to change mine for similar reasons. Toyota don't sell the actuators separately though. I used an HKS one which was adapted to fit.

Ive got the ones from my old turbos that blew they used to work fine on them beforre they went. i seem to have been having trouble with these since i put them on.

Changing the turbos was such a pain in the arse is it the same changing the actuators too, or is it just a case of removing all the pipes above the turbos, im not going to have to remove the lot am i

Ive got the ones from my old turbos that blew they used to work fine on them beforre they went. i seem to have been having trouble with these since i put them on.

 

Changing the turbos was such a pain in the arse is it the same changing the actuators too, or is it just a case of removing all the pipes above the turbos, im not going to have to remove the lot am i

Depends on what actuator you are having the issues with. Most of them are attached to the assembly, it would be difficult to remove one in situ.

It is most likely to be the VSV though, TTC mode will check the actuators in question for you

cant find the link for ttc mode in the search link have you got it to hand as i cant remember how to do it off the top of my head

http://mkiv.com/techarticles/ttc/ttc.htm

Something like that. It is actually very easy. You just swap over 2 of the vac lines and the job is done

Ive done it before i just couldnt remember which pipes it was to swap

Cheers for the link

That link seems to make it look really confusing

That link seems to make it look really confusing

Yip, hence my comment lol.

Done, just been out in ttc mode and .

So it must be a VSV even though i have tried them and they are working fine.

Confused now as i hope its not an electrical problem in the wires somewhere

As I said, the VSV's may work electronically but they might not be holding pressure. This is the problem I have at the moment. Sometimes they boost perfectly, other times I don't get full boost till 4500rpm.

I put an ad in the wanted section but didn't get any responses. I have been happy with the TTC mode for now so I have just left it.

ive got 2 spares in the garage one of each type so i may change them, if its turbo 2 which one is it likley to be.

As you look at the car from the front which is the turbo 1 and turbo 2 i cant remember

The VSV's don't work that way bud, to answer your question the one closest to the radiator is tubby 1.

are the vsv specific to the car.

Can a bust one not be replaced by on that works. ie changing the two related to turbo 2