SR runs strong but backfires with lots of white smoke [Archive] - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Munki

10-07-2009, 10:11 PM

I have a redtop with FMIC and full 3in exhaust with no cats at stock boost. Not too long ago my car started backfiring after shifting at high RPMs. Even back fires when I down shift. Doesn't backfire much but when it does it also shoots out some white smoke. And when it backfires, its LOUD!! lol

Also, it has a smoking problem... When I first start it up in the morning it doesn’t smoke at all, even if I let it idle for about 5 min. But after driving around its starts to smoke a lot at idle. I noticed that once I give it gas in neutral if shoots out even more white smoke. When I start driving it no longer shoots out white smoke.

The car doesn't overheat or anything. Runs really strong and idles perfect. So far I changed out the plugs because they needed to be changed... I also changed the oil using 10W30 royal purple. First time using this oil and it started to smoke shortly after the oil change. Today I tried to check the oil level and I couldn’t tell where it was at unless I started up the car… I’m also going to try to do a compression test, so ill post up the numbers in the morning.

Anyone know whats causing this problem?? I thought It might be a blown head gasket but the car doesn’t over heat at all. Also don’t think it’s the turbo because the smoke is white and it boost perfectly…

landins13

10-07-2009, 10:18 PM

does the smoke have a blueish tint to it if so then it could be a seal going bad on the turbo, turbos will boost perfect even with a blown rear main seal, but you will burn a lot of oil off.

Munki

10-07-2009, 10:24 PM

nope, its grey/white smoke.

The person who owned this car before me had a s15 turbo on the car but for some reason his turbo blew, then he replaced it with a stock t25... even when he had the s15 turbo it never saw past 7psi. He also drives like a granny, i know because hes a friend of mine. lol

ill check again tomarrow to make sure theres no blue smoke.

rebornS14

10-07-2009, 11:01 PM

sounds like BAD TURBO and running RICH. cant be valve seals cause your not getting smoke at start up.

jhageman

10-08-2009, 05:29 AM

mine does the same thing...seals are going bad on turbo and it runs a tad bit rich. in my case the turbo is 20 yrs old on the CA18. i have an SR T25 getting rebuilt now...should clear up the problems.

fliprayzin240sx

10-08-2009, 05:59 AM

Do a compression check, could be a headgasket issue...but white smoke is water. Could be a busted headgasket or a blown turbo.

jhageman

10-08-2009, 06:30 AM

no blown head gasket for me...mine only smokes upon downshifting. i always check my oil and radiator fluid every week and its good...just as a precaution.

Munki

10-08-2009, 10:23 AM

wow, i just did about 10 compression test and each one was exactly at 150 on all four... I guess my turbo is going bad?

Munki

10-10-2009, 11:08 PM

Also forgot to mention that my boost gauge reads 0 vacuum at idle... Could a leak on my boost gauge lines cause my car to smoke??

RBSilvia1406

10-10-2009, 11:39 PM

im still learning about 240sx but on my eclipse that same problem happened with me on the boost gauge reading '0' at idle. you should be in vacuum. i think i was at 8 psi vacuum. did you 't' your boost gauge off anything? i know if you 't' it off something with a big vacuum demand it'll mess ur gauge reading up across the board. you could be running to much boost and destroying your turbo. and yes im pertty sure a leaking gauge could give you that reading. like i said im still learning dont take my exact knowledge to heart. sharing my experience.

RBSilvia1406

10-10-2009, 11:41 PM

back fire when shifting at high rpm-- running rich.

RBSilvia1406

10-10-2009, 11:44 PM

what type of oil did you use before? i know when you use synthetic oil on an older car it tends to leak by seals. maybe you got a seal issue somewhere if your head gasket and comp test is fine

Munki

10-11-2009, 12:41 AM

what type of oil did you use before? i know when you use synthetic oil on an older car it tends to leak by seals. maybe you got a seal issue somewhere if your head gasket and comp test is fine

The car has always had synthetic oil, but I used royal purple for the first time not too long ago... I think im going to follow my vac line for my gauge and remove and cap it. i'll see what happens from there.

Another thing I forgot to mention was that the turbo was rebuilt not too long ago..

RBSilvia1406

10-11-2009, 02:31 AM

something ive learned is to check someone elses work. i say start inspecting the turbo. maybe on rebuild a bad seal was put in. ive seen some stupid stuff. i would start inspecitn the turbo.

Munki

10-12-2009, 06:07 PM

Ok, I really don't think my turbo is gone. My oil level is about the same as when I changed my oil... Could a damaged fmic cause my car to smoke and have 0 vaccum?

Munki

10-13-2009, 03:43 PM

I just checked my turbo and there is no shaft plat at all. No oil either. I also found a tear in my intake tube, that might be why my boost gauge was reading 0 vacuum..

Munki

10-13-2009, 08:57 PM

damn, shit just got even worse!! lol

Today I changed my oil and I only had 1 quart of oil in the pan... So, I put in new oil and added some lucas oil stabilizer. Now my car smokes even more, and it idles really low. Before my car would start to smoke after about 45 sec at idle but now it starts smoking as soon as I idle.

What do you guys suggest me do/check? I dont know what else to do now...

warauto

10-13-2009, 09:36 PM

Got a similar problem, Not much white smoke though. fix your vaccum problem, you should be about 20 vacuum.

Munki

10-14-2009, 04:45 PM

Got a similar problem, Not much white smoke though. fix your vaccum problem, you should be about 20 vacuum.

I checked for more leaks,can't Find anymore though...

lazysk8er2

10-14-2009, 04:54 PM

jr_ss

10-14-2009, 07:12 PM

Your vac/boost gauge is hooked up to a boost only source, which would be located before the throttle body. Find a location after the TB to tap for vac/boost source.

Because you're turbo has no shaft play does not mean that your seals are no bad. The seals wear out over time regardless of huge amounts of play or not in your turbo shaft. I bet if you pulled off the downpipe/turbo outlet you'd find some serious oil caking in there.

As far as your idle getting worse, you have a vac leak somewhere or your MAF is going bad. Unplug your MAF with the car idling and see if it gets better. If you idle does get better with the MAF unplugged, you need to replace it.

Hope any of this helps.

Munki

10-14-2009, 07:16 PM

i dont think shaft play will effect the fact that you have blown seals inside. your burning coolant you just gotta find out where and im betting its coming out of that beat ass t25.

what other uprades are in the car bigger injectors? etc.

Well, the smoke is blue now... Before it looked white/grey.:-/

And this 240 hasn't seen any fun since 2005, so the turbo never really got beat on. I have a stock red top with FMIC, HKS bov, walbro, full exhaust. no other mods to it right now.

Its burning oil somewhere. The other day I changed the 1 quart of oil that I had left and added some lucas oil stabilizer. Now it smokes even when im driving... I even ran another compression test and I got the same results.

Munki

10-14-2009, 07:19 PM

cobras89

10-14-2009, 07:24 PM

just my opinion but i would use mobil 1 10w-30 ive been running it for a while in my sr and it runs great with it

Ceepo

10-14-2009, 07:35 PM

bad maf could cause your car to run rich, change it out and see what happens...

Munki

10-15-2009, 05:29 PM

bad maf could cause your car to run rich, change it out and see what happens...

Just changed out my maf. Now the car idles perfect again. At idle it still smokes alittle, but once I give it gas it smokes ALOT.

jr_ss

10-15-2009, 08:34 PM

Why don't you drive it... and see what it does once it's warmed up

Munki

10-15-2009, 09:07 PM

Why don't you drive it... and see what it does once it's warmed up
i did, nothing changed.

Munki

10-15-2009, 11:12 PM

Got another question, whould not having a pcv valve cause any problems?? The guy who owned my car before me took it off a few weeks before I got the car and just put a tube in its place.

jr_ss

10-16-2009, 07:22 AM

Yes, the PCV prevents boost from entering your valve cover engine. You could be pushing oil past your rings and burning it. Buy one, put it in and see if there is a difference.

Munki

10-16-2009, 12:11 PM

Yes, the PCV prevents boost from entering your valve cover engine. You could be pushing oil past your rings and burning it. Buy one, put it in and see if there is a difference.

I had the pcv valve in my trunk since I bought this car. put it on today and drove around for about an hour... still see lots of smoke, just not as much at idle...

After I drove around i went back home and had someone give it gas while im behind the car. At idle the car blows a decent amount of smoke, once they give it gas you see a big ass thick cloud of smoke.

Munki

10-16-2009, 04:05 PM

found a new problem. lmao!!!!!!!!

I havn't really drove the car hard since the smoke problems but today I did and at high rpms the car sputters like every second. The car pulls really hard but just makes a pop noise once every 1/2 sec. Someone told me that a stuck open injector could cause that and smoke. Should I be looking at the injectors now?

Munki

10-16-2009, 06:55 PM

also forgot to mention that sometimes its hard to start my car up. Itll just keep turning over like its not getting any fuel. gotta keep taking the key out and try to restart it.

Iron_Zenki

10-16-2009, 07:36 PM

Does it run like this?:rolleyes:
YouTube - Stock 240sx smokes Subaru STi (http://www.youtube.com/watch?v=BB_zgx1cuOA)

Munki

10-16-2009, 07:53 PM

Does it run like this?:rolleyes:
YouTube - Stock 240sx smokes Subaru STi (http://www.youtube.com/watch?v=BB_zgx1cuOA)

lol, it doesnt sound like that and my car smokes ALOT more than that.

At :45, thats how my car starts up every once in awhile.

I just checked my oil and I noticed there where some really small bubbles on the dip stick. could gas mixing with my oil be causing my oil to become thin and bubbly?

Munki

10-19-2009, 08:44 PM

UPDATE:

I've been driving my car alot in the past 3 days and on sat night i did lots of drifting and hard driving. The car never overheated and my oil levels are the same. It still smokes but sometimes its STOPS!! About 30 min after drifting and on the way home my car stoped smoking, but came back later. I was checking my wiring and everytime I moved the harness the car would idle low or die. I think i fixed the problem, it was the maf wiring...

So now im thinking its a bad ECU, wiring problem, or even exhaust valve seals. What do you guys think it is now?? How do I check for the exhaust valve seals? And could loose wires on my harness cause my car to run alittle rich and smoke?

rebornS14

10-19-2009, 10:52 PM

take off your manifold after the car sits for a day and check to see if theres oil.

Munki

10-20-2009, 05:11 PM

I took off my intake tube and found some oil dripping out of the elbow...

s13silvia123

10-20-2009, 06:08 PM

I took off my intake tube and found some oil dripping out of the elbow...

blown oil seals for the turbo or either really bad blow-by

jr_ss

10-20-2009, 07:50 PM

It's your turbo, like everyone has been saying. Replace it.

jdm213

10-26-2009, 12:15 PM

it has to be your turbo and its smoking and burning in their and thats how you have smoke its as easy as that man cant you listen to theese nice people? go get another turbo or go get a turbo rebuild kit and clean dat shit up also if you car is not turning on change your dizzy, rotor, and plug wires

jr_ss

10-26-2009, 06:55 PM

Munki

10-29-2009, 11:27 AM

It's your turbo, like everyone has been saying. Replace it.

it has to be your turbo and its smoking and burning in their and thats how you have smoke its as easy as that man cant you listen to theese nice people? go get another turbo or go get a turbo rebuild kit and clean dat shit up also if you car is not turning on change your dizzy, rotor, and plug wires

Well, after everyone telling me it was the turbo I went ahead and took it out. When it was out, there was no oil or shaft play on both sides. Even though i drove with this turbo for over a month with it smoking like crazy there seemed to be nothing wrong with it. I was even stupid enough to take it to get rebuilt. still having the same problem, no changes at all.

I guess its not the turbo..

Munki

10-29-2009, 08:53 PM

would this cause my car to smoke bad??

http://www.hi-upload.com/upload/uploaded12/DSC05753.JPG
http://www.hi-upload.com/upload/uploaded12/DSC05752.JPG
http://www.hi-upload.com/upload/uploaded12/DSC05751.JPG

warauto

01-23-2010, 03:00 PM

Are you still having issues with white smoke ?

Munki

01-26-2010, 03:23 PM

nope, i went ahead and swapped in a s15 t28.

TallPaul5950

12-07-2010, 12:13 PM

so it was the turbo? my car is doing the same shit

s14freak93901

12-08-2010, 04:17 PM

even if you didn't beat on it. it's a 20 year old turbo. neither your seal is blown on the turbo or you have really bad blow by. your bad maf is causing you to run rich. replace it.

Munki

12-08-2010, 08:08 PM

so it was the turbo? my car is doing the same shit

No, its wasn't the turbo. This thread is pretty old and i kinda forgot what i did to fix the problem. I do know that the turbo was fine, I gave it to a friend of mine and he is still running to this day with no problems at all.

StReeTz

12-08-2010, 08:58 PM

No, its wasn't the turbo. This thread is pretty old and i kinda forgot what i did to fix the problem. I do know that the turbo was fine, I gave it to a friend of mine and he is still running to this day with no problems at all.

After having all that trouble how could you forget what fixed it? I hate when I read a thread where someone has a problem and when they finally fix it they neglect to tell the rest of those who helped or had similar issues what the problem was and how they fixed it. :squint:

punn303

12-08-2010, 11:39 PM

After having all that trouble how could you forget what fixed it? I hate when I read a thread where someone has a problem and when they finally fix it they neglect to tell the rest of those who helped or had similar issues what the problem was and how they fixed it. :squint:
yeah, really....