I just took my turbos off and found a crack between the waste-gate and I believe the exhaust outlet. I was getting a boost leak and tons of smoke on initial startup. Would this be the only cause? What would a crack like this one do to a car? Please let me know ASAP if anyone has any info on this subject.

 

I don't think that can be a good thing...

I would look into getting it machined. But that is just my personal inexperienced opinion.

I can't wait to take my engine apart and take pictures and ask "WTF is this???" type questions.

 

Normal problem.

 

"Normal problem."

Actually I don't even think I'd call that a problem unless it got so bad that two cracks grew together & broke free a chunk of iron...

 

they all crack...cant see any detail on your pic

 

That won't cause a boost leak or tons of smoke on startup. The boost leak will have to do with the intake hoses, and the smoke will have to do with the turbo's seals going out, or your engine going out, or something else that's not too big of a deal. That crack is very common and won't hurt anything.

 

it will eventually cause pre control problems, if its really big

mike

 

That is a pic of a turbo kit I got online. I just got my motor rebuilt and when I originally took the motor apart there was no sign of any kind of problem or failure. I don't want to put this motor in and still have the smoke and half boost. This looks like it would be the most logical explanation. I have now been told by many that it is common and that is should not be 10mm or over. I just dont like the fact that there is a crack in my manifold and that it is normal and alright. What would cause these problems considering that the engine is freshly rebuilt? I am so fed up with this because I have been trying for 8 months to figure it out! I have searched all over for a cause and can't find a solution, let alone what the problem is! @$#^@$#%@!!!!!!!!!

 

That is the turbo control valve not the waste gate - a crack at that location is very common (im guessing 95% of all used fd turbo manifolds) and would NOT be the cause of your boost or smoke problems MAZDA says that cracks up to 10mm are ok at that location

the wastegate is located under the cover plate on the other side of the manifold. Cracks in the wasgate seat area can cause boost probems if they prevent the wastgate from sealing. You have to take the turbos apart to inspect the wastegate seat.

 

Recently while getting my friends 16g turbo rebuilt at Majestic Turbo, I found the tubines housing sitting on a pile of turbo housing on the bottom of a table. After inspecting if for a few moments, I ask the guy working there what cause all the cracks going across it. This housing had about 6 cracks so deep you could stick a small screw driver in it. the guy whos been rebuilding turbos for 25 years and drives a Porsche modified by him said that what caused those cracks was an engine not running rich enough. I guess hairline cracks are not too much to worry about. I seen lots of them. My brother-in-law says that he could reweld then together even stronger than the metal itself. He builds SS machines for a living and makes good money without risking his life. But the problem is that if the metal is fatiged enough the metal around the new weld will brake. Ev7

 

10mm long or wideor deep? I just inspected my turbos tonight. I have a crak there too it is very small but spans that bidge between TC and WC. Also, there is another questiosn for the experts, in the passge to the furthest right in the pic. I have cracks that have little chunks out coming out of corners, etc. they aren't that long and don't even reach the gasket. doesn't look serious, just thought I would check.

Engien install is going well so far, yanked turbos tonight off the block along with water pump, etc. engine is going to be in tomorrow, if the freight co. keeps its promiss lol.

thanks guys, amazing how threads like this come up just as I was starting to worry about it.

ciao
Philip

 

I'm having boost issues as well .. I'm boosting 8.5 psi according to my power FC in first gear till 7k rpms , my car is still being built ( not hte motor ) but the body . so I cant really take it on a high way or anything yet . justa back road I know of ..

Now I ported my waste gate and my waste gate had a crack .. I took a picture but I accidentally deleted it the other day .

unfortunately .. the crack isn't a hair line crack but it isn't a canyon either .. it goes from under the flapper's bracket till the seat of the waste gate flapper it traverses the seat , BUT it does not traverse all the way down its prretty shallow I thought it wouldn't be much of a problem , plus with the car running no cat I didn't think there would be much of an issue . now its only boosting 8.5 psi (.61 power FC reading) .. I've been searching up and down looking and re tightening every clamp bolt , hose . short of going and making one of those home made boost testing things from home depot I've done about everything .

and I just cant seem to find the issue , if it were hte boost pills it would open at 7 psi not 8.5

so the only thing I can think of is the crack on the waste gate . could this be the cause.

 

Start with a thread that isn't a decade old.

 

the thread is relevant , and I rather not start a new thread when one has good info and has been started already