LSChevelle

Hey everyone,

I posted this in my build thread (link in sig) but I figured it would have a better chance of being answered here.

I am having a problem with this turbo burning oil. It's a regular cheap GT45 you get with the Denmah kit. At first I thought it was possibly a feed/drain problem. Maybe it still is. What do you guys think?

Feed: 4AN coming from directly above the oil filter. Has a .060 restrictor in the line.

Drain: 1/2" falling directly down (maybe 2') to the timing cover. I originally had a 90 degree fitting in there which I have heard can cause problems. However, I removed it and it still does it.

The car does have high oil pressure ~55psi at idle. Goes to 80 at higher RPMs.

Driving the car around without getting into boost there are no problems. As soon as I step on the gas a little (not even getting into boost, but so you can hear the turbo start to spool) it blows a small amount of blue smoke. If I really get on it, it smokes. Then if I let off it blows a huge cloud.

I haven't tested to see if it could be valve seals or something. I am fairly certain it is the turbo because I took off the intake tube and there was a pool of oil in it. I also removed the center section from the exhaust housing and there was baked on oil.

It just seems weird, I thought for sure it was my drain. But, it flows fine and we even put an adjustable valve in the feed to further limit the oil the turbo is getting. We cut it down to half (approx. 150ml/20secs, was 275ml/20secs before - at idle) and it made no difference.

Did I get a bad turbo? Or could I possibly be still getting too much oil to the turbo/not enough away?

Any help is appreciated!

denmah

iTrader: (2)

oil feed at the top and oil drain at the bottom of the turbo?

sorry i had to ask, we have seen people with turbo feed and drain horizontal haha
see if your drain is clogged

i have seen it happen many times

LSChevelle

Thanks for the response Denmah!

Haha no worries. Yes, I have the turbo clocked so that the oil drain is perpendicular to the ground. Draining straight down. Has a fall of probably 16 inches and an overall run of maybe 28 inches. I have had the hose off and it flows tonnes of oil. I also stuck my finger into the hole on the timing cover. I couldn't feel any obstruction there. The .060 restrictor that they send with the kit is what I am using. Plus the adjustable valve now. Doesn't seem to make a difference.

I am going to run the car with the intake off and see if it smokes as badly. If it does the next step I guess is to remove the turbo completely and see if it still smokes.

I read a couple things online about rebuilding these turbos with better seals and such, have you ever had to do that? Any luck with it?

LSChevelle

I took a couple of pics.

Let me know if anyone sees anything wrong!







I had AN line and a 90 degree fitting at the timing cover before but I removed that to see if the 90 was causing the problem. Right now It's sloppy-style with a ID 1/2" fuel hose. Looks pretty direct to me, I'm no expert though.

My only other thought is that maybe the motor has too much oil pressure? Obviously 55psi is quite a bit, my old small block had ~30psi at idle.

LSChevelle

Okay, sorry for all of the posts. I took the intake side completely off the turbo compressor and went for a drive. The car is no longer smoking at all. I opened the hood and the turbo had blown oil all over my engine and there was an actual pool of oil in the coupler that was hanging off the turbo outlet. Needless to say, it is definitely the compressor side of the turbo that is leaking oil. I am running it without an air filter at the moment (haven't mocked one up yet) and I don't have a blow off valve. Would either of these cause it to leak oil like crazy??

I guess the next step is to take the turbo apart and inspect the seals.

SM105K

iTrader: (3)

I know not having a blow off valve can hurt the turbo seals by means of surging......

tonypaul

iTrader: (2)

are you running a oil restrictor in the feed line?

LSChevelle

Yea, I thought of that. Correct me if I'm wrong, compressor surge is pretty loud and noticeable isn't it? I have had compressor surge on imports before and you clearly know that is happening, I haven't heard this one make any noises like that.

Yes I am!

I'm thinking about ordering an S475 with the T4 flange. How are the external dimensions of that compared to the GT45? I'm hoping to not have to change the piping too much.

I am going to take this GT45 apart and have it looked at by my turbo guy. I'm thinking I might have just got a bad one.

LSChevelle

Alright guys,

Sadly I think I got a bad turbo. I played around with it all afternoon, I have an adjustable valve on the feed line so I was able to vary the amount of oil the turbo sees. I am getting oil in the compressor no matter how much oil the turbo is getting. I turned it down to about 1/5th the amount it was getting with just the .060 restrictor, it still burns oil. Albeit, less.

After we couldn't get it to work I took it to my turbo guy and he says that the design of the seals on the compressor side is something he normally sees in diesel turbos. Not sure if this is a bad thing or not, apparently he thinks it should have a spring loaded ceramic seal instead of just the piston ring type seal.

I gambled and lost apparently! Although I had a lot of fun doing it, the turbo made 10psi no problem, just burned oil. I'm going to order an S475 with the T4 housing and see how that goes!

Thanks for your help everyone.

ls1_chevelle

iTrader: (9)

What is your catch can setup for crank case pressure? I pulled my catch can off while doing some fab work and put AN caps on my valve covers, started the car it it pushed lots of oil past the rings as the crank case couldn't breathe.

LSChevelle

I don't really have one at the moment. I thought the same thing as you so I just stuck a rubber hose on the valve cover and "vented" it under the car. I think I am probably going to buy the mightymouse one. This should work okay for the time being though. I was able to confirm that the engine doesn't smoke at all (yay) it was just the turbo.

I called Forced Inductions up today and ordered the S475 with a 1.25AR T4 housing. Hopefully it isn't much bigger than the GT45, I would rather not change my hotside piping.

denmah

iTrader: (2)

i never run a blow off valve and have built a ton of turbo kits with these turbos, without an issue.

not sure what the deal is here, maybe talk to VS and see if he has some suggestions or will swap it out?

AJGls1

is the fitting in the timing cover flush in the inside?

Tanus

hose kinda looks kinked ?
add make your drain better before deciding turbo is bad. you can add like 4 inch of vertical drop by moving fitting to pan, up size to 10an, also seen where people add a little reservoir below turbo when they have long horizontal stretches

LSChevelle

I could give that a try, I figured since it was an eBay thing they probably wouldn't help out (and I wouldn't expect them to for the price.) Worth a shot though!

It threads into there approx. 1/8th of an inch. I stuck my finger in there and couldn't feel anything, which makes me think it should have enough flow. I never thought, I should have used the calipers to see how far away the block actually is, I'll check that today.

I had an adjustable valve on the feed line and restricted it down a lot and it still leaked oil past the seals, it is 100% possible that I over-oiled the turbo at the beginning. But, most guys say that over-oiling it usually doesn't wreck the seals.

Yea, good eye. It was kinked a bit, that is why we put the hose clamp on to keep it round. I would have tried moving it to the pan. I have an aluminum pan (and no TIG) and can't take the pan off with the engine in the car though. So it would have been a lot of work to get it out and then I would have to pay someone to TIG a fitting on there. It may come to that still. If it wasn't for the fact that limiting the oil supply down (which in theory should have also limited down the amount going into the drain) didn't affect the turbo burning oil, I would have tried this.

LSChevelle

Hey all,

I thought I would update this. I have been working with the guys from VS Racing to try and figure out what is up with this thing! They requested that I do a leak-down test on the engine because they were convinced I must have huge crank case pressure as a result of excessive blow by. Fortunately for me, the test came back amazing, less than 8% leakdown on all the cylinders (1-2% on 6 of them.) VS Racing has agreed to take the turbo back and send me a replacement. I can't say enough good things about the service and prompt email replies I have received. I will update once I get the new turbo back and hopefully it doesn't burn oil!!

Sleeperls

awesome.

SM105K

iTrader: (3)

Very cool.

LSChevelle

Hey guys,

I just thought I would update this with the results! I received the replacement turbo on Friday and got it bolted up. I didnt change anything. This one doesn't burn any oil!! It also feels like it spools a lot faster and isn't as noisy. Glad I got this figured out, it was driving me nuts!

Thanks again to VR Speed for going the extra length to make the customer happy!

krwyellowZ28

iTrader: (10)

Good to hear you got it figured out and got such good service on a cheap unit. Do you plan to keep running the GT45 or move up to the S400 you ordered?