Turbocharger longevity/durability (1 Viewer)

[robmobile73]

I recently turbocharged the 3b in my BJ73. The turbo failed prematurely which I mostly attribute it to being a poor quality/faulty turbo. I am posting this thread to both gain knowledge and perhaps prevent future failure.
First the Turbo was a TD04L-13T-6 unbranded made in China bought off Ebay. I know that cheap from China is a gamble, but China makes good products as well sometimes from the same factory it's just hard to tell what's what. This is the 3rd cheap turbo I've bought and the first to go bad. Some people have suggested "Buy a better turbo". I have ordered another turbo that was a little more expensive with a decent warranty that will hopefully take care of that. Still a cheap turbo, but the warranty is long enough for them to take it back if it is deffective on install.
My install was weeping oil into the intake from the start and not making full boost due to improperly shut wastegate. I was only getting 4-5psi so the turbo wasn't spooling up full speed. I read on the forum about people installing a 1/16" restrictor hole to prevent too much oil from going into the turbo. It did not help with the oil seepage.
My install did not utilize water cooling. I read a number of posts and other information that turbos do not really need water cooling if you shut down the engine properly by letting it idle long enough for the turbo to spool down before shut down. There is some serious debate on this, but there are engines out there that do not have water cooling on the turbos. I wanted a simple install so I chose not to water cool and just paid attention to shut down. I am curious if this may have exacerbated my oil seepage/failure: high heat thinning the oil so it seeps out, heat changing tolerances between CHRA and bearing surfaces increasing wear and tolerances?
I did not utilize the wastegate activator. I had read that the 3B wouldn't be able to make too much boost with the stock IP. At first the wastegate was held shut but not in the full shut position. Only getting about 4-6PSI and EGT's approaching 700C maintaining highway speed full throttle uphill. I drove it like that for about 3 weeks still with oil seepage. Once I figured out the problem and got the wastgate to shut properly my boost went up 5-6PSI driving around and 12-15psi under load. I experimented with the fuel screw a few times and was able to get 20PSI under load, but my EGT's would go over 650C when pushing it. So I set the fuel screw for 12-15 PSI max and less than 600C on a full throttle 0-60 run through the gears. 350-400C normal driving. The turbo started heavily leaking oil into the exhaust and intake in less than 100 miles of driving once the wastegate was shut properly..

At 12-15PSI it is possible I was spooling the turbo faster than it would have been with the wastegate actuator causing it to fail prematurely.

Having the 1/16" restrictor hole in the oil line to prevent seepage may not have provided enough oil to the bearings causing failure soon after I got it spooling up properly with full boost.

Excess heat through lack of water cooling lowering my oil viscosity and changing tolerances may have exacerbated issues and caused failure.

I was seeping a bit of oil from the start so I really believe it was simply a junk turbo from the beginning. I bought a rebuild kit for the turbo and put it in with all the parts, but with the kit in there was still a slight amount of wobble in the turboshaft(less than before, but it was there). After rebuild it was seeping on the exhaust and on intake within a few minutes almost as bad as before......I've never had a turbo seep/leak oil like this one.

New turbo will have a warranty and water cooling, but I am not sure if I should keep or remove the 1/16" oil restrictor or not?

Does anyone see anything horribly wrong with my setup that likely killed the turbo before it's time, or do people just agree "it was a junk turbo from the beginning"?

 

[ERNRAM]

@gerg
@Diesel42

 

[KiwiDingo]

What's the exact turbo you're taking about, is it journal bearing? If it is they don't need an oil restrictor. If it is journal bearing you are also correct about the water cooling, they don't need any to function correctly as the oil does all the cooling but can be used if that's what you want. It's not needed in diesel applications and is more a petrol engine thing as they always run near stoich, even at idle which means they always have much hotter EGT than diesels and causes oil coking after shutdown which eventually damages the turbine shaft seal and the bearing at the turbine end.

Also just check your turbo oil drain hose, any blockages or restrictions in this hose going back to the engine sump can cause oil to be pushed through the shaft seals.

 

[robmobile73]

What's the exact turbo you're taking about, is it journal bearing? If it is they don't need an oil restrictor. If it is journal bearing you are also correct about the water cooling, they don't need any to function correctly as the oil does all the cooling but can be used if that's what you want. It's not needed in diesel applications and is more a petrol engine thing as they always run near stoich, even at idle which means they always have much hotter EGT than diesels and causes oil coking after shutdown which eventually damages the turbine shaft seal and the bearing at the turbine end.

Also just check your turbo oil drain hose, any blockages or restrictions in this hose going back to the engine sump can cause oil to be pushed through the shaft seals.

The turbo was a TD04L 13t-6. 2X brass journal bearings inside. My oil drain line is 5/8 or 3/4" and goes straight down to the pan where there is a 1/2 or 3/4" iron elbo fitting going into the pan. There is no reason for any blockage but I will check.

I will remove the oil restrictor from the oil line.

In the first install I didn't use water cooling because I wanted a super simple install and didn't want added complexity/points of failure that were not really necessary. I already ordered the fittings to water cool the next turbo which I may decide to do just for good measure. It may lower my EGT's a bit.
There are plenty of good products out of China, it's just that some are not and it's kind of luck of the draw. The new turbo has a 60 day warranty and ebay offered a 1 year warranty protection add on for $17 so I went for it. There is a wild variation in the price of turbochargers.

 

[KiwiDingo]

It may lower my EGT's a bit.

Water cooling on turbos has no effect on EGT. All it really does is stop the oil from coking up after hot shutdowns and also used for quicker engine warm up to aid with emissions for certain applications. I always recommend people with IDI engine to just leave the water cooling off as they are more susceptible than DI engines with keeping water temps under control once boost and increased fueling is added. But it really doesn't hurt either way, completely up to you.

 

[Dougal]

Turbos bleeding oil into the intake and/or exhaust can mean your engine has too much blowby and is pressurising the crank-case.

Turbos chewing out their bearings is almost always an insufficient oil supply issue.

 

[gerg]

3Bs aren't known for making tons of oil pressure ever. Certainly not high milage ones. Should never run a restrictor unless your running a ball bearing turbo and even then I'd do hot oil flow tests to check for adequate flow before I ran it.

 

[robmobile73]

Turbos bleeding oil into the intake and/or exhaust can mean your engine has too much blowby and is pressurising the crank-case.

Turbos chewing out their bearings is almost always an insufficient oil supply issue.

If the new turbo doesn't fix the issue I may do a compression test. I know I have blowby, just not sure how much it is. Crankcase is vented back into the air filter housing for "re-burn" by the engine so the crankcase isn't "sealed" and should not be building significant pressure. It would definately be less than my oil pressure.

I believe the oil restrictor caused me problems when the turbo began spooling properly and exacerbated wear on bearings/shaft/housing that already had too loose tolerances. It was fine for maybe 50 miles before it started leaking excessively. It was "weeping oil" from the beginning, but not enough to create oil smoke. I know it was weeping oil because my intake plumbing had some leaks and there would be some oil film around the leaking area, but not enough to pool/spray on the hood or wet the engine down. My intake pipe is made from exhaust tubing and has a weld done with a flux core spool gun so there are a couple of very small pinholes that will show oil seeping out into the intake.

 

[robmobile73]

3Bs aren't known for making tons of oil pressure ever. Certainly not high milage ones. Should never run a restrictor unless your running a ball bearing turbo and even then I'd do hot oil flow tests to check for adequate flow before I ran it.

Thankyou for the reply. I am beginning to believe that I had a turbo with loose tolerances that wept oil, but acceptably whose bearings were worn out quickly by thin insufficient oil at very high temperature due to no water cooling added to insufficient oil cooling and high boost pressure 12-20PSI intermittently.

 

[gerg]

Lack of oil pressure will definately not cause "weeping" oil seals. Only thing I've ever seen to cause an oil seal to fail was on the turbine side due to excessive coking. If freezes the ring. Just so you understand the oil seal does not stop leakage, it's literally just a piston ring. It's not like an o ring. Not air tight. Oil feeds directly to the bearings and drips down in the housing much like the inside of an engine. It's just a big open space in most of the housing. It never fills with oil. It's suppose to drip down inside unempeded. If pressure in the bearing housing is higher than the boost pressure it will easily push oil past the seal. Now excessive crank case pressure will back up the oil drain increasing bearing housing pressure and push crank gasses through the seal carrying oil with it. Increasing boost can decrease your oil leaks as this pushes back against the extra bearing housing pressure.
In my experience you get oil in the intake for two main reasons:
If your oil drain is not draining properly
Excessive crank case pressure due to blowby.

As far as water cooling goes.....it's only a bennifit at shut down. That is when the turbos not even running. Coking only occurs when a very small amount of oil remains in the turbo housing and turbine housing heat soaks into the bearing section that literally burns the oil left there. This is a somewhat slow and insidious process. It creates carbon.....much like nicely cooked bacon. Water in the housing keeps the bearing temps below coking for the short time it's at risk after shut down. During operation the bearing temps are very stable as they are constantly fed new cool oil and even if they weren't cool enough the oil only is exposed to the high temps for as long as it takes to drip out of the housing. Couple this with the normally low egts diesels run its doing just fine when running.

Your boost pressure has nothing to do with anything unless you burned up your thrust collar.
I've made td04 turbos running very near the same design as your turbo, with better bearings mind you, that ran no water cooling and 30+lbs of boost with a larger compressor than you for a year that showed no wear or coking when I took it apart to try a different turbine. Ask Kowalski. It was his turbo during his North America walk about.

 

[robmobile73]

I have blowby just not sure how much or if it's too much. Before I put the new turbo in I'll check the oil drain line for obstruction. If the new turbo does the same thing I may do a couple temporary experimentations to see if it is in fact blow by causing the problem.
Currently my oil drain is near the top of the oil pan above the level of the oil. So theoretically pressurised gases will enter the oil drain along with some oil vapor...perhaps oil slung into the drain which goes into the pan sideways and then burped or pushed upward by blow-by vapor. I could try running the drain down into the oil to the bottom of the pan. in this way there would be no blow by gases entering the drain tube, not sure if the pressure in the crankcase will be enough to push the oil up the drain tube into the turbo..............I could also make a larger breather line and catch can currently it is about 3/8 inch and my catch can is only about 1 pint........lot of speculation here need to just get that new turbo and put it in see what happens.
I do really appreciate everyone's information.