White smoke and a random backfire?

[JMDigital]

Not very often I get a backfire after I takeoff from a stop or when I slow down to turn, its only 2 or 3 times a month. Also I have some white smoke out the muffler under heavy acceleration. I am in the planning stage of what I should upgrade next and before I do that I want to make sure everything that is in there is working 100% , Currently this is the list of mods installed by prev owner.

JDM 7MGTE Engine
ARP Head Bolts
Rebuilt turbo with the 60-1 wheel (Majestic Turbo)
Felpro head gasket
K&N FIPK
Fidanza flywheel
Exedy clutch and pressure plate
HardPipes (ceramic coated)
Greddy Type S BOV
Chrome plated valve covers
SupraSport Upper Intercooler
BIC divorced downpipe
Test Pipe Megan Racing
3 inch catback exhaust
Joe P Manual Boost Controller
Eibach lowering srings
935 Motorsports front strut tower bar

I think the next upgrade has to be a Lexus AFM , Safc , 550cc Injectors. Electronic Boost Controller.

 

[Snotcycle]

Not very often I get a backfire after I takeoff from a stop or when I slow down to turn, its only 2 or 3 times a month. Also I have some white smoke out the muffler under heavy acceleration. I am in the planning stage of what I should upgrade next and before I do that I want to make sure everything that is in there is working 100% , Currently this is the list of mods installed by prev owner.

JDM 7MGTE Engine
ARP Head Bolts
Rebuilt turbo with the 60-1 wheel (Majestic Turbo)
Felpro head gasket
K&N FIPK
Fidanza flywheel
Exedy clutch and pressure plate
HardPipes (ceramic coated)
Greddy Type S BOV
Chrome plated valve covers
SupraSport Upper Intercooler
BIC divorced downpipe
Test Pipe Megan Racing
3 inch catback exhaust
Joe P Manual Boost Controller
Eibach lowering srings
935 Motorsports front strut tower bar

I think the next upgrade has to be a Lexus AFM , Safc , 550cc Injectors. Electronic Boost Controller.

::bhg::

 

[JMDigital]

I had that checked its not a BHG.. any other ideas..

 

[jdub]

I swear...sometimes it seems everytime "white smoke" or "high temp gauge" is mentioned, the first suggestion is a BHG. Eliminate the simple things first.

Anyway...on to your problem.

Is there a common time when the motor does this? (i.e. motor cold, after highway speed run, etc.) Do you have any ECU codes? How did you eliminate a BHG as the cause? Are you losing coolant?

Backfire is most commonly caused by a rich condition...check for codes first and then make sure your timing is at 10 deg BDTC...read the TRSM on setting the timing, you have to jumper the diag block for an accurate setting.

Smoke is caused:
White - coolant
Black - fuel (rich)
Blue - oil

You sure the smoke is white?

 

[Shytheed Dumas]

According to the TSRM, white smoke can be an indication of turbo seals going south, and it would seem likely to show up under heavy load/acceleration. It's easy enough to check for excessive shaft play...

 

[JMDigital]

I have the mechanic checking for BHG one more time right now. I am shure its what people have told me. How can I check for the Turbo seals?

jdub - Last time it backfired it was about 6:20am before the sun came up, it was cool outside but it was after I was driveing for about an hour so the car was heated up. I have been feeding the "birdcage" a little (it seems to be empty every 2 weeks?) I dont think it has a hole in it.

Thnaks for the advice. I will check codes today..

 

[JustAnotherVictim]

Coolant leak or BHG are the causes for coolant disappearing.
Check the easy one first and pressure test your cooling system.

 

[jdub]

Rick beat me to the pressure test

On a CT26 center section, there is two housings...the inside is for the oil..the shaft is bathed in it via a small hole. The oil seal is really not a seal like in the motor...rubber could not stand the heat. It's a series of restrictions to minimize oil escaping to the turbine/compressor sections. The coolant is outside the oil housing...it encases it. Coolant bathes it to assist in cooling, especially when it is shut down. There is no way (unless the housing is cracked) for coolant to get to the oil channel or turbine section...the center section is cast metal. The cooling channel and oil channel are completely separate.

The coolant pressure test will tell you if there is a leak in the system....for peace of mind, you may want to get the NAPA block tester. It will tell you if there is exhaust gas in the cooling system.

 

[JustAnotherVictim]

That's always my first answer, everybody likes to jump on the bhg train. Keep it simple and cheap first, then go broke.

 

[JMDigital]

The mechanic I droped it off to is checking for exaust gas in the coolant. I will also call him about the turbo and see of he has time to check it. and presure test the cooling sytem...

Thanks for all the info guys... ! I will post what the mechanic finds out..

 

[JMDigital]

UPDATE--

Mechanic results. No head gasket problems. Ran car with radiator cap off , after 15 min almost all the water came out of the radiator, He found that there was no thermostat and installed one.

Question- Would not having a thermostat make that happen? or do I need to look for another problem? The car does not run hot at all, the temp gauge is always below the 1/2 way mark even after a long drive.
I am going to still check the codes when I get home tonight.

 

[JustAnotherVictim]

With the thermostat out the car is constantly flowing coolant which doesn't allow the engine to fully warm up.
Running the car with the rad cap off is not pressure testing the system.

 

[jdub]

Not knocking your mechanic, but how did he determine there was no HG problem?

Your coolant is going somewhere A pressure test is the only way to figure that out. Most mechanics do not realize how finicky the MKIII's coolant system is...a small leak will induce air into the system and push coolant out. It is a good sign though that the car is not overheating.

 

[JustAnotherVictim]

^True. Back when I used to take my car to mechanics my car would overheat but then they said they couldn't find anything. Turned out it was air in the heater core making the gauge rise. That place was the only place I would even consider taking my car but they couldn't find anything. Actual pressure testing is the absolute best way to check your cooling system.
I would just go out and buy one myself. You'll probably need an adapter to fit the radiator though.

 

[JMDigital]

He was going to pressure it but I had to get going, I will say that he is not a "supra" mechanic however I have known him forever and he did not even charge me today, He does not try to work on anything he is not familar with and he has worked on my fathers supras (2 others same year turbo auto but all stock) I think installing the thermostat did fix a problem, I could not sit at an idle for more then 10 min without the car getting hotter then 1/2 , I think without the thermostat switching on and off the water did not have a chance to cool off at an idle. Soon as I drive it cools down right away. Now on my way home I did test that and was able to sit at idle for 20 min without getting hotter then the normal less then 1/2 . I think the smoke is from oil leaking into the turbo. How fast shoud I get that fixed if that is the case? I assume it will only get worse. He is going to check that another day. He did have the test for the head gasket leak, I was shure it was not that, The engine only has about 60k miles on it with a new head gasket, the prev. owner had it installed. Wish he would have done the metal but he did the Felpro

Thanks for all the great help and information!

 

[JustAnotherVictim]

IIRC not having a thermostat should make your car run colder not hotter.

 

[JMDigital]

IIRC not having a thermostat should make your car run colder not hotter.

Thats exactly what I said when I got there but he did explain it this way.

with no thermostat the water allways flows and when the engine gets up to temp. the water returning to the radiator does not have time to cool before it goes back to the engine, So now we are flowing hot water. I thought it sounded right, and its the only thing that was done to the car and now it does not get hot sitting at an idle for 20 min, when before it would not last 10 or 15. Im not saying it got too hot after 20 min, its how long I waited to see what would happen.

weird eh? I thought so to....

 

[kylefoto]

It's hard to tell sometimes between the white and blue smoke, I get some blue smoke that looks VERY white unless you look at it in the correct light. You can also tell from the smell. Coolant is sweet and oil is a more burning smell. I also get backfires, not sure the cause of it, but the cause of my smoke and coolant loss is my turbo seals on my turbo. and my turbo is just going down the shitter. This is all according to my mechcanic, and he's been around yotas for yeaarssssssssss.