Turbo Oil Drains (1 Viewer)

Joined
Dec 7, 2019
Messages
478
Location
North Carolina, USA
I turbocharged the 3B II in my 89' BJ73. I had problems with oil leaking past the seals. I thought it was a cheap turbo and rebuilt it. It helped a little but still the same deal. I bought another turbo blaming it on the cheap made in China turbo. My oil drain line is 1/2" straight down to the oil pan and into the side of the pan above the oil. I checked the oil line for obstruction prior to installing the new turbo. With the new turbo there is less leakage, but I still have oil blowing around the seals into the intake and exhaust.
I do have blowby, but I had no problem with oil consumption/burning oil prior to turbo install. I am really not wanting to rebuild/re-ring my engine right now.
My understanding of what is happening is that blowby gasses are blowing up the drain line tube puffing in/foaming up the oil inside the turbo and causing it to blow out the seals. I have no doubt that the oil pressure going in the turbo is greater than crank vapor pressure puffing in . I'm just guessing that the presence of crank vapor pressure inside the turbo housing is pushing out the oil.
I've considered a few different solutions. 1- is to put a elbow inside the pan from my oil dran and run the drain line to the bottom of the pan. In this way blowby gasses will not enter the drain line as it is routed below the oil level. I assume gravity and weight of the oil in the line would still let it drain down. 2-buy a electric oil scavenging gear pump to route the oil return to. This a expensive option to do with 100% duty cycle. 3-increase the size of my crank case vent to 3/4" and run the hose directly to the air filter vent to help take pressure out of the crankcase. My current vent is 3/8" and it will develop a few PSI with the restriction.
4-Final option is to do a "in frame rebuild" with new rings, rod bearings, and pistons if need be......(2 of my pistons are suspect now and I will be doing a compression test soon).
My turbo is a TD04l-13T-6 current fuel setting produce 10PSI max and it is difficult to get it higher than 550C on EGT's.
Any advice/solutions are appreciated.
 
Joined
Dec 7, 2019
Messages
478
Location
North Carolina, USA
My problem was very simple and If I had done a bit more investigation I could have saved myself some money and time. The Catch Can fittings were too small. AFter I got my wastegate fixed and had good boost I drove about 10-20 miles checking it out and all was well. I didn't like the oil spray I was getting in my air filter housing from my valve cover vent line so I bought a catch can which ended up being a little smaller than I expected, but I installed it anyway. I did this just prior to my road trip in the 70, but did not test drive it with the catch can, only idling in the driveway...........I had forgotten that I installed the catch can just prior to the trip(at night). It was smoking a little within a 4 miles of the house and heavily within 20 miles.
The catch can fittings are 3/8" OD, but inside they are only about 1/4". The vent on the valve cover is approximately 5/8". The catch can fittings and lines were constricting the crankcase gases at RPM and causing pressure buildup at the same time as my turbo was recieving maximum pressure. I removed the catch can today and no more smoke, no more oil leakage. I'm making a new larger catch can and plumbing 3/4" hose from valve cover to catch can to bottom center air filter housing. 3/4" fittings the whole way for no restriction.
I was sure my $99 ebay turbo had bit the dust since it had a small bit of weeping oil at the start and it was after all a "cheap Chinese Ebay turbo". I felt a very small wobble on the shaft as well.....I probably could have stayed with it, not rebuilt it, given up on it, and not bought another turbo..
If anyone wants a really cheap rebuilt TD04l-13T-6 let me know.

I went ahead and water cooled the new turbo. Shaft on the new turbo is a bit tighter feeling than the old one. I do not get quite as much boost as I did with the old turbo without water cooling. The cooler running CHRA/cooler thicker oil is probably giving more resistance to the turbo shaft bearing. Currently the boost guage vibrates between 12-13PSI max boost. Accelerating to 60mph up the on ramp onto the highway I can hit 600-650C. If I increase fuel to hit 15PSI I can hit 700C or hotter. I have good power where I am and not much smoke, so I'm going to leave it alone for now. Finish the new catch can and 3/4" plumbing tomorrow. Got to get it ready to go beach camping before too much of the summer is gone.
 

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