Jump to content
SAU Community

Recommended Posts

well when im on boost i get some blue smoke. on idle and low rev driving its fine.

oil pressure is fine too.

im not sure if its my rings or my valve stem seals.

ive completely ruled out the new turbo as ive checked the cooler pipes etc.

ill be doing a compression test tomorrow to see if its my rings (mind you ive rebuilt the motor with NEW rings).

what should i be looking out for if its my valve stem seals?

Link to comment
https://www.sau.com.au/forums/topic/150005-blue-smoke-out-of-exhaust/
Share on other sites

sorry to ask this question, i am curious how you guys find out that smoke is blowing out of the exhaust while you are driving? especially on boost.

revision mirror dude.

your turbo can still be burning oil without traces in your cooler pipes...the rear seal in your turbo could be gone. say movement in your turbo shaft can be pulling forward under boost so that allows oil to slip out the seal on the exhaust side. hence only on boost. idle the motor and take the oil cap off and feel for excessive blow by.

you cant really 'check' valve stem seals. you only know it was them when you change them and the smoke stops. spent hours on a 4g63 changing the valve stem seals only to find out that it was the turbo seals.

Edited by Ryanrb25
orh ok. thanks. i am wondering how to spot the problem if i happen to encounter one.

cheers

do you have a catch can???

also is it plumbed back into the inlet and or turbo ducting?

take off your rockers and check if the breathers are clogged in the rocker cover baffles,

i had similar problem after i built my engine, new turbo everthing, was blowing shit loads of smoke(blue)

found to be cause the breathers were blocked due to old engine having so much blo by..

hope this helps

Jeremy

thanks for the replies guys.

im going to compression test it today, ill take it for a drive and see if its doing it today, its a bit on and off sometimes.

ill check my breather pipe after the drive too.

any other symptoms??? misfiring... check out your spark plugs too (stupid to say i guess coz you take em out when you comp test anyway) if theyre fouled or very clean

how long since the rebuild

After my engine was built, it was doing similar things and it came down to 2 of the rings were leaking. They said it was something to do with the type of rings that were used, they either seat properley and you never have a problem or they don't and they leak. They replaced all the rings with new ones and haven't had a problem since.....

i have heard the same thing about the valve stem seals

your having the exact same symptoms as i did,

check your breathers in the rocker covers,

take them out and soak them in kero,then let them dry then put it all back in

Edited by DVS32R
the rings i used were brand new from nissan. they were placed on the right angles too (i.e. not on the thrust side of the piston).

ah fair enough, I dun have factory ring there something else. Can't think of what there made of off the top of my head....

Yeah valve stem seals going is usually evident by what I would call back off blow by.

I'd be thinking of rear turbo seal possibly. This happened to me recently.

Are you sure it's blue and not black from running rich? (Have to ask. :dry:)

Is it definitely coming OUT of the exhaust? I mean, some oil could be dripping ONTO it from somewhere possibly, although you would probably smell it when idling.

Blue under hard acceleration sounds like rings to me, of course turbo seal will do the same thing, stemseals will smoke downhill of throtle.

Don't forget slightly worn or not bedded in rings won't always show on a compression test because the oil blocks the gap and you could have perfect comp. Actualy a slightly worn engine ( bottom end, not worn valves) could have higher comp due to the fact that you may have carbon on the top of the pistons.

Do a leakdown test , then you will know for sure if you are loosing comp.

Blue under hard acceleration sounds like rings to me, of course turbo seal will do the same thing, stemseals will smoke downhill of throtle.

Don't forget slightly worn or not bedded in rings won't always show on a compression test because the oil blocks the gap and you could have perfect comp. Actualy a slightly worn engine ( bottom end, not worn valves) could have higher comp due to the fact that you may have carbon on the top of the pistons.

Do a leakdown test , then you will know for sure if you are loosing comp.

thanks mate, ill get a leakdown test done.

is there any way to check if its the turbo?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Must have been an absolute nightmare to drive when the power steer was out, the rack ratio/wheel size/caster is all set up for power assistance
    • Welcome to SAU, what are you looking at buying?
    • I checked the injectors again (1 and 2, since they’re easiest to access) to make sure they weren’t clogged. Even though the entire fuel system had been cleaned, I wanted to be certain. Everything looked clean, so I reinstalled and connected everything. When I started the car to confirm everything was okay, it immediately revved up high, so I shut it off straight away. I checked to see if I’d missed a vacuum hose or something, but everything was connected. On the second attempt, the car ran without the high idle, but I noticed a distinct “compressed air” sound coming from the engine bay. Tracing the sound, I pushed injector #6 forward slightly and the noise stopped — it turned out it wasn’t seated properly, despite the fuel rail being bolted down. While holding it in place, the car idled steadily without stalling and ran for over 5 minutes. At this point, I pulled all six injectors out just in case I hadn’t seated them correctly or dirt had gotten onto the O-rings. Unfortunately, I discovered that I had damaged 3 out of 6 injectors (the OEM 270cc ones) during installation. So yes, this was my fault. Since only the pintle caps were damaged, I’ve ordered a Fuel Injector Service Kit from NZEFI to refurbish them. In the meantime, I reinstalled my new injectors – the car now idles fine for over 15 minutes without stalling. I have not attempted to drive it so far. It’s not perfect yet, as it hesitates when the throttle is pressed, but it’s a big improvement. Unplugging the IACV with the new injectors idles at around 800rpm, even with the IACV screw tightened fully. But this is probably due to tune.
    • I wanted to try and preserve the front bumper as long as possible, they're not cheap and are made to order in Japan. Taking inspiration from my previous K11 Micra build where I made an undertray for the Impul bumper, I did the same for this BN Sports bumper but a little slimmed down.  This time round I only made a 'skid plate' (if that's the correct wording/term) for just the bumper surface area, the Micra version covered the gap like an undertray. Starting off with a sheet of mild steel approx. 0.9mm thick 4ft x 2ft in size. I traced around the bumper, cut it out and cleaned the edges. Luckily I was able to get two halves from one piece of metal In the video I installed it as is, but I've since then I've removed it to spray and add a rubber edging trim. The rubber trim is suitable for 1-2mm and it's a really nice tight fit. The bolts had to be loosened due to the plates being too tight against the bumper, the trim wouldn't push on I used some stainless M6 flat headed bolts for a flusher finish (rather than hex heads poking down), I believe this style fastener is used for furniture too incase you struggle to source some. The corner's are a little wider, but this may be an advantage incase I get close to bumping it  The front grill got some attention, finally getting round to repairing it. Upon removal one fixing pulled itself out of the plastic frame, one side is M8 that fixes inside of the frame, where as the other side is M5. Not knowing I could get replacements, I cut down an M8 bolt, threaded it inside the frame along with a decent amount of JB Weld.  The mesh was replaced to match the bumper. One hole on the bonnet/hood had to be drilled out to 8mm to accommodate the new stud, once the glue had set it could be refitted. I think the reason the grill was double meshed was to hide the horn/bonnet latch (which makes sense) but I much prefer it matching the bumper Bumper refitted and it's looking much better IMO The Youtube video can be seen here: https://www.youtube.com/watch?v=bVZP35io9MA
    • The video for the servicing and fuel filter change can be seen here: https://www.youtube.com/watch?v=uLJ65pmQt44 One of the main jobs I wanted to do before the car officially went on the road, was to remove the awful looking blue silicone hoses. There's nothing wrong with having coloured silicone hoses, but I realise as I'm getting older I prefer monotone engine bays with a splash of colour on the engine cover(s). I cover this in a lot more detail in the Youtube video, so unfortunately there's limited photos of the process. The intercooler, upper radiator, boost vacuum and upper breather hoses were all changed to black silicone with mikalor clamps. The only blue left is a blanking cap at the back of the inlet manifold and the GReddy pulleys (which will be replaced for stock when the cambelt gets replaced) While the intercooler pipes were off I gave them a quick clean/polish too A before photo I do have a replacement air filter on its way. Fuse box covers were painted blue, they're now satin black Another job on the list while the bumper was off, is to add some mesh https://live.staticflickr.com/65535/54737966256_99b28bfa30_c.jpg[/img] I was hoping to use some thin wire to secure it, but it seems I've misplaced it and the wire I had was too thick to twist easily. I ended up using cable ties for the time being https://live.staticflickr.com/65535/54737131882_c2b7989dcc_c.jpg[/img] Was pleasant to see this https://live.staticflickr.com/65535/54737131627_8b2aab13b3_c.jpg[/img] The last thing to do was to fix the front grill and re-mesh that to match but I ran out of time The Youtube video can be seen here: https://www.youtube.com/watch?v=R4FsF6tgizE&t=23s
×
×
  • Create New...