EpyonFD

iTrader: (4)

I replaced the factory turbos that were on my car when I bought it cause the oil seals in them went bad i think. They shaft play was also bad on them. Keep in mind this a twin turbo conversion. was converted before i bought the car. I bought replacement used turbos and they did have some cracks on them around the iron flanged area but the shaft play felt good. I have no way of knowing if the previous owner that sold them to me complained about them, they were bought on this site. So because my car was smoking before when I bought them, i figured they were the seals in the turbo went bad as there were leaks all over the place around the turbos. I now got the replacement turbos on and it still smokes some. I dont see any visible leaks anywhere around the turbos or engine. It just seems to smoke constantly. im having a hard time telling if its coolant or oil smoke since the car is running a bit rich. I did a compression check with the rotary compression tester and both the front and rear rotors read from 107 to 118 in that general range, this is psi correction readings from what the tester showed at around 270's rpms on a warm engine. Also would like to note, I did port the waste gate a little and completely removed the precontrol flap, instead of just rigging the flap to stay open all the time. The turbos make a low humming noise, which Ive never heard ever before on any turbo car or turbos. The intake filter pipes when touch them have a strong vibration to them, not visible by eye just when you hold the pipes you can feel it. The engine idles great and revs great too. I havent driven the car yet though.

Im just curious if the turbos are bad and what is causing the smoking and if my coolant seals in the housings are bad? even though my compression is good, can you still have bad coolant seals? it doesnt smoke a lot but it is enough to grab someones attention.

Edit: forgot to mention when I pulled the trailing plugs to the compression test, both plugs were not wet.

DaleClark

iTrader: (55)

First off, turbos can only leak oil into the exhaust or intake. They will never leak coolant into the exhaust or intake, it's a sealed passage through the center housing of the turbo and it's impossible to get into the intake or exhaust.

That said you say you haven't driven the car - any reason why not? It's best to drive it around and get it warmed up to get a good idea of what's going on. It's common to see some smoke on first start up (or sometimes just condensation) - if you are still smoking at idle, driving around, full throttle then you know something is up.

Testing for bad coolant seals is well documented, search around on that. You would probably notice the coolant level going down and the buzzer eventually going off it it was burning coolant.

Dale

EpyonFD

iTrader: (4)

Thanks Dale, i borrowed my friends coolant leak down tester and the coolant system holds its pressure on a cold test. I had the engine pulled to fix a bunch of leaks and worked on suspesion replacing bushings is why it sat for a long time. Even though i drained the fuel and refueled my friend suggested that if the previous owner mix oil with fuel, what ever left may still be burning off since we dont know how much oil was mixed in. He said could be maybe a bad oil rotor seal might be leaking into the housing. Or perhaps turbos i bought the oil seals may be going out.

DaleClark

iTrader: (55)

Yeah if you are burning oil it can be hard to track down where it's coming from, turbos or engine. I'd get the car running and driving and see if it clears up. An engine that has sat a while will often smoke a bit until things are all burned off.

Dale

EpyonFD

iTrader: (4)

Thanks Dale, will give an update when i get it driven, hoping i can get it ready by tomorrow.

djseven

iTrader: (56)

It can take over an hour of run time at idle for the turbos to quit externally smoking after swapping them out. Usually if you drive the car for 20 minutes it will clear up. Are they smoking out of the exhaust or just seeing smoke out of the engine bay?

EpyonFD

iTrader: (4)

Djseven it is shooting out the exhaust. Yeah my friend said the same thing you and Dale said. That i need to drive it around for a little bit then i can start worrying about it. This is obviously my forst rotary engine and im not really sure how these engines react. Thanks for the reply.

Also please note it is on a 3inch exhaust from downpioe and back, no cat, and did come with powerfc, i have the datalogit. My commnder oled screen is unreadable, from the searches on here seems only the nonoled screen can easily be replaced. I have a friend that works on cell phone repairs so i my ask him what he thinks. From what i can tell in dataogit looks to be on stock tune, i unchecked seq turbo setting, o2 feed back as im running a wide band, since im running apexi boost control kit i have the scale set to option 1, stock map plugged into side of ecu. My wideband at warm up idle reads around 12 afr. I saw a old thread on here (very detailed) on changing your stock settings to be safer for driving untill a tune can be performed. Ill have to spend some time looking through it.

DaleClark

iTrader: (55)

Turn off O2 feedback, you probably don't have an air pump and the O2 feedback won't work right without the stock air pump. This is for the stock narrow band O2 sensor and has no relationship to a Wideband. That will probably get the car idling better.

Dale

EpyonFD

iTrader: (4)

Thanks Dale, the 02 was already disabled. So after driving around for a bit it still smokes. It does have a blueish tint to it. I looked inside the y pipe and it is dry and clean. The only thing i see is the rear turbo, on the exhaust side, the outside looks a little wet. So could it be that the oil seal on the exhaust side of the turbo is leaking oil into the exhaust stream? The whole exhaust system is new and when i rub my finger across the muffler tip inside, there is like a think oily residue.

DaleClark

iTrader: (55)

Yep, probably the turbos or one of them leaking oil into the exhaust. There's a certain smell to it, I had a car once that had an oil burning turbo and you never forget that smell.

Unfortunately there's no good way I've found to bench test used turbos to see if they are good or not. Used turbos are always the cheapest way to go but you never know what you get. If you can find some clean low mileage JDM turbos that may be a better place to start.

Dale

EpyonFD

iTrader: (4)

Thanks Dale, i do have all parts to switch over to single setup. I have a efr 7 something series one. Since i weld, only thing i need to do is weld my own manifold, intercooler setup and another downpipe. Also have a hose crimper to make my own lines. Just wanted to drive around on the twins for little bit, but may just make the switch.

Thanks again for the help and input.

TwinCharged RX7

iTrader: (14)

What did you mean in your first post that it is a twin turbo conversion? They all have twins until you convert to single.

EpyonFD

iTrader: (4)

I was meaning that it went from sequential to non sequential.