Very weird noise

[lynx]

hi.

I have one question.
I just readed many threads about wierds sounds and I couln' t find the answer to my problem.

Anyway, problem is: when enigne is cold and I starting to drive . . . there' s coming very stange noise, just before turbo whistle. Hard to describe, but like humming . . . it' s starts about 1500-2000 rpm and goest off approx. 3400rpm or something like that. First it was a quiet one, but now it' s going more noisy, when engine is cold (outside temp. max. 20C*).

First it went away when engine is hot, like 90C* and so one, but today it didn' t.

I know that the steering pump is noisy, but I don' t think it is doing that noise. It does do the noise with steering.

Anyway, that noise has got my attention, and I' d like to fix it.

What do You think, what could cause that noise?

with best regards,

[PeteRR]

Not sure myself as this sounds similar to a noise my car makes when cold. But mines almost like when someone blows over the top of a bottle, only happens on the overrun when the engine's cold for a couple of minutes. Is that similar?

I'm more likely to suspect the Diverter Valve on yours though, is it the original?.

I've got a new Forge DV so I dont think its that on mine. Also replaced the crank breather valve (PCV), but the noise is still there. Strange one.

[lynx]

Not sure myself as this sounds similar to a noise my car makes when cold. But mines almost like when someone blows over the top of a bottle, only happens on the overrun when the engine's cold for a couple of minutes. Is that similar?

I'm more likely to suspect the Diverter Valve on yours though, is it the original?.

I've got a new Forge DV so I dont think its that on mine. Also replaced the crank breather valve (PCV), but the noise is still there. Strange one.

thanks

I have two of DV' s, one of TT and other isn' t (metal). But I don' t think there' s a problem.

But that breather valve. Good point . . . mine is broken I just found out this a coupe a month ago . . . I mean, it let pass both way. I know, I have to change it, but could this be a reason? If so, then why that scary noise?

[lynx]

I just get back and noise is even worse than before.
It get more noisy.

The noise is coming only then when turbo starts to push air, I mean, when turbo gauge going to show numbers 0 and so, with vacuum, there' s no problems. But maybe some other devide is going to be "noisy," when power is coming. On place, even with 6000rpm there isn' t that noise.

I suspected oil hoses witch goes to turbo and out. I just checked, they were just fine, not any complication. Turbo were all-so in perfect condition.

When engine is normal temp. approx 90C* and so, the noise is very quiet, sometimes even hardly to heard.

I'm out of ideas, anyone else?

with best regards,

[WabTheKing]

check end float on your turbo turbine, bearing might be going should have about 0.5 - 1mm float on the bearing, if there is more than this probably should look at getting your turbo recond, this can make a weirring noise on boost

[lynx]

check end float on your turbo turbine, bearing might be going should have about 0.5 - 1mm float on the bearing, if there is more than this probably should look at getting your turbo recond, this can make a weirring noise on boost

Hmm, I don' t get You corretly (sry, but my home language isn' t english), but if You think turbine "cluck" - there isn't anything like that. Turbo is like new. It' s rotating with no any problems and no any "cluck."

thanks