Howling Noise at high RPMs

[Abraham39]

When i am accelerating I've been having problems w/ fuel cut, so i did a boost leak test, and saw that my BOV is leaking from the gasket.

I did a search, and i think it answered my question, but when I'm accelerating my turbo will spool up like normal (14B) and I've been getting boost creep pretty badly, but when i get up to like 5500rpms my turbo starts to make a howling noise, right before i hit fuel cut at a bout 6000-6200 rpms.

So, I'm thinking this howling is the leak at my bov? when i did the boostleak test, i tried to move the turbo shaft w/ my hand and it won't budge either way, so i don't think the turbo is going out.

If anyone has any suggestions, or ideas it'd be greatly appreciated.
Thanks,
-Marty

 

[ChvyKc]

When i am accelerating I've been having problems w/ fuel cut, so i did a boost leak test, and saw that my BOV is leaking from the gasket.

I did a search, and i think it answered my question, but when I'm accelerating my turbo will spool up like normal (14B) and I've been getting boost creep pretty badly, but when i get up to like 5500rpms my turbo starts to make a howling noise, right before i hit fuel cut at a bout 6000-6200 rpms.

So, I'm thinking this howling is the leak at my bov? when i did the boostleak test, i tried to move the turbo shaft w/ my hand and it won't budge either way, so i don't think the turbo is going out.

If anyone has any suggestions, or ideas it'd be greatly appreciated.
Thanks,
-Marty

That could be a lot of things. I had the same problem, but my 14B was shot. Put the 16G on there and it took care of it. Exhaust pressure would build up in the turbine housing and make the wheel hit the housing, but when I pulled the turbo off it had significant shaft play in it. I wouldn't say that it was your turbo if you weren't able to feel any at all.

I also had a howling noise coming from the exhaust manifold. I had a really bad exhaust leak right there and the gasket was making a whisling noise.

Have you tried to do another boost leak test?

 

[oldman]

My suggestion, boost leaks causing fuel cut and over spinning the turbo possible making contact with the housings especially at higher rpms. Just because you found a leak at the BOV doesn't mean it's the only leak. Your priority should be finishing the boost leak test, final desired result should be 20 psi for 30 secs.

 

[Abraham39]

I should have some ample time this weekend, so i'll start working on getting all the bugs out of the boost leak, and then worry about the turbo and other stuff... for now i'll just take it easy on the car, the last thing i want to do is break somthing
Thanks guys,
-Marty

 

[Abraham39]

So i did a boost leak test again this weekend, and found a HUGE leak at my thermostat housing?Is it okay to plug all those holes? I'm hearing a very slow bubble under the front of the engine, by the turbo is this normal to hear while testing from the compressor?

I'm running 20PSI through it, and so far it'll only hold about 5psi .. working on that magic 20 for 30

Thanks in advance,
-Marty

EDIT: Is it ok to spray soapy water every where? or is there somthing else you guys use that is more engine friendly?

 

[oldman]

So i did a boost leak test again this weekend, and found a HUGE leak at my thermostat housing?Is it okay to plug all those holes?

You shouldn't have boost leaks at the thermostat housing, please elaborate.

I'm hearing a very slow bubble under the front of the engine, by the turbo is this normal to hear while testing from the compressor?

You're probably hearing the sound of pressure leaking through the turbo seal which is normal during a static pressure test as long as it's not leaking oil during operation.

EDIT: Is it ok to spray soapy water every where? or is there somthing else you guys use that is more engine friendly?

The only place you need to worry about are the sensors around the throttle body and the injector harness, just make sure they're dry before you start the car.

Just some boost leak tips.

1. Pressure test from the TB elbow first and focus on smaller areas at a time then work your way back to the compressor inlet.

2. Disable or turn the mbc all the way up to prevent pressure leaking through the wastegate pressure relief hole.

3. Open the oil cap and listen for leaks.

4. Listen for leaks out of the tailpipe.

Good luck.

 

[Abraham39]

At the thermostat there are 4 vaccuume lines running into it, two of them leak, so i pulled them off and plugged them, I'll post a pic asap so you can see.

I'll try the boost leak asap again, and spray soapy water around the injectors, and TB area. and also perform it from the LICP.

As for the nosies from the oil cap i hear nothng, i'll check the tailpipe too tomorrow.

If i think the car runs well now, once i get a GOOD boost test and get my system holding proper boost, will i notice that the car runs much better?

Thanks,
-Marty