Turbo noises

[Abdullah]

Was cruising highway speed today in my turboed 1hz 76, when the turbo started making a loudish droning noise above it's usual whine, when I would accelerate. Eventually I started loosing boost before I arrived home. Its an AXT kit, only has about 30000km on it. Once home I took off the air filter cap to inspect and could smell a faint burning smell.

Im new to turbos, any advice?

 

[Abdullah]

Low boost turbo usually 7-9 max psi on the highway. And I keep the EGTs under 550 at the manifold. By the time I got home it would boost max 2 psi, and I really had to gun it to even get that.

 

[Mr Cimarron]

Boost leak or time to rebuild turbo. I haven't looked at the ATX kit before but many turbos are pretty easy to rebuild.

 

[IanB]

X2, check your connections between the turbo and the intake manifold as a starting point.

 

[Lumpskie]

I'd check the air connections for a boost leak. The burnt smell has me wondering... is your turbo oil cooled? If so, maybe you blew an oil line off... any leaks?

 

[gerg]

With low boost like that, oil might make its way past your front seal and enter the charge pipe? Possible. Look at the compressor for shaft play. It shouldn't be able to touch the outer edges of the compressor cover even if you push it with some force. I rotate it slightly just to see if it can scrape. This sounds a lot like a boost leak. Some hoses can rupture but only leak under boost and otherwise they look like a normal pipe. Pressurise the intake system and use soapy water or smoke to find the leaks. You will have more leaks than you think.....everybody has leaks.....muhahaha.

 

[Abdullah]

I took off the intake pipe from the turbo and didn't notice any forward/backwards movement in the shaft, (when I pushed or pulled on it), but it sure does move side to side/up and up and down a lot... it looks like I can it move it around in a 1/4 - 1/2 inch diameter circle from center. Is that more play than there should be?

I noticed another thing as I was taking the tubes apart. There is a blue accordion elbow tube connecting the air filter box to the turbo intake tube. I was shocked to find it was dusted! I think a fair amount of air has been leaking in through it. I live in a very dusty place and don't know how long this has been happening for...maybe dust wrecked the bearing? Or is that amount of play in the shaft normal? I hate to think what it's done to the engine...

Sorry, I don't know ow much about turbos, @gerg what is the compressor cover?

 

[Abdullah]

It's oil and water cooled. I don't notice any oil leaks, just a bit of oil in the system from the tube which pipes in oil particles from the head.

 

[IanB]

Turbo shaft play up/down/side to side = turbo is pooched, sorry. Compressor cover is the silver metal housing of the cool side of the turbo.

 

[Abdullah]

Yes, now I think I understand what you mean by compressor cover...the housing? The blades of the propeller do touch the walls when I wiggle it.

 

[Abdullah]

Thanks a lot guys for the info. Sad, as it's only been 30000k on the turbo. What might a rebuild set me back? Or do u recommend a new turbo?

I live a good 120km from the nearest shops and a tow would be a couple hundred bucks, could I hook up the intake tube to the intercooler directly and drive it there?

Or would that just eat up the turbo even more? Or does it even matter at this point? I really just don't want my engine eating the shaft bits.

Like this:

 

[gerg]

Unhook your wastegate and wire it open. Bypass your intake plumbing around your turbo. This way it doesn't get much energy put into it and your not asking it to do any work. That's what I would do personally.
g

 

[mudgudgeon]

Unhook your wastegate and wire it open. Bypass your intake plumbing around your turbo. This way it doesn't get much energy put into it and your not asking it to do any work. That's what I would do personally.
g

To add to this, this is a desperate limp home, limp to a repair shop option only IMO.
you need to replace or rebuild that turbo ASAP.
to continue using it in a compromised condition you risk a catastrophic failure of the turbo. If it fails while connected normally, your engine could run away (rev uncontrollably) by burning it's own oil.
If you bypass the turbo with the intake and wire the waste gate open, if the turbo oil seal fails, you could lose engine oil or oil pressure rapidly and damage the engine.

 

[diby 2000]

I would also say take it easy with the right foot when driving with the turbo bypassed like this as if you put your foot into it, it will be running very rich trying to promote the turbo to spool. That can cause damage.

 

[gerg]

That's why I said to bypass the intake plumbing around the turbo, if it begins to push oil it would only drip out the front cover. I too would only do this as a limp. I'd check the front of the compressor periodically and your oil level. Running a lower rpms will help by keeping your oil pressure down. A runaway is terrible. Id get a plan in mind now rehearsed so that you know exactly where to stuff the coat if the engine takes off and have your supplies right beside you until you bypass the intake plumbing. I'd practice it myself a few times actually drowning the engine. Pretty paranoid I know but I have a parts motor in my garage I got for free because it ran away and the driver wasn't prepared.

 

[IanB]

And replace that blue hose with something proper, that looks like something you'd use for a laundry dryer exhaust.

 

[gerg]

yeah I bet that thing collapses when its under high boost. The heat over there wont help either with its rigidity.

 

[Lumpskie]

Bummer to hear about the turbo... I wonder if that blue pipe let enough air by under boost to overspin the turbo and kill the bearings...

 

[Abdullah]

Yep, you may be correct, along with the loads of dust it ate. Planning to do some comp tests after a bit hopefully the engine didn't 'bite the dust' either. My boost levels were always normal until I heard it go, but is suppose the waste gate would have prevented overboosting.

I ran the car for about two days with the turbo bypassed. It was fine until I revved past 1500...sprayed my engine compartment with a liter of oil...lol. Was a good thing I stopped to check. The rest of the time I plugged along at 60kph without issue. Just got back from the shop now, mounted the factory intake, manifold and downpipe. Runs better than ever! (And louder than ever with a 3in magnaflow)

I changed the oil and filter immediately, should I do anything else to 'clean' it out?

Not sure about a rebuild here in Saudi Arabia...may just have to get a new one. Shame. The blue tube was a big mistake by the previous owner that I'm paying for now...

 

[Abdullah]

Judging by the amount of oil it sprayed all over my engine on my first test drive of the bypass I would say I was literally minutes away from a run away. Good thing I took it apart when I did! Praise to Allah. That's the first time anyone told me about a run away, sounds horrible. I guess I just dodged a bullet. Thanks you guys all so much for the advice.