smoke on deceleration???

si_c1978

as above, i went for a bit of a tune yesterday and may have gotten a bit carried away,
i was holding 15psi of boost while going up a hill in nearly every gear, then on the way home if a accelerated hard then decelerated i was getting a puff of smoke on changing gear so this is obviously when the wastegate opens,
what are the chances ive fucked something???? :oops: it was running rich before tuning and has leaned off quite a bit, im hoping the smoking will die off/or is fueling related but it was too dark this morning to tell.

Gary14

White, blue or black smoke?

White / steam = normal on cold morings and warm up but not so when engine at operating temperature.
Blue = Oil burning past valve stem seals, or piston rings. Burning all on overun indicates worn valve stem seals
Black = fuel mixture rich, sooty tail pipe

si_c1978

ive always got a sooty pipe!
yeah i think its grey blue the weathers been too shitty to tell today as it wont do it on the spot, only if i run the boost right up/wot.
and yes agian defo on the overrun to where you re-apply the throttle.

i guess i need to know whats easiest to go after first, obviously the turbo, but whats best to look for?

am i going to cause further damage if i keep running it, can it be lived with???

also my idles been low/playing up a wee bit.

Gary14

si.c1978 said:
ive always got a sooty pipe!

Well, we didnt need to no that! 😃

Worn turbo seals can cause smoke, just after boost and decelerating?

How many miles on the clock and how hard has she been driven notsure.gif

si_c1978

around 50k but its a transplant and a experimental one at that!
basicly it runs aftermarket ecu and wont have run ideally for a while when we were getting it off the ground, but its been good for over a year now and otherwise tight bar a few electrical teething probs,
only recently ive been upping the power stakes and had no choice than grow some balls take the laptop out and try to tune the whole map with the datalogging.
i reckon it was maybe an error holding boost for that long on a hill on the dual carriageway!
it did go a bit lean for my liking for about 5 secs at 5.5k rpm in 4th but only 12.5-13:1 afr which i thought id sort out when i stopped.
could it be i overheated the turbo?

si_c1978

righto, i could see a bit this morning and last night,
it doesnt smoke generally but when any reasonable amount of decceleration occurs i get a small puff and a little smoking, if i run maybe 6psi up and let off ill get a medium size puff of smoke and higher than that and let off, a large puff but relatively little smoking afterwards.

this suggests oil is being sucked in under extreme vacuum notsure.gif

si_c1978

🙁 ive got that sinking feeling its my valve stem seals.......

i was kind of hoping that it was the turbo as its an easy (tho expensive) fix.

i would have thought that if it were a piston ring id be smoking all the time? anyone?? notsure.gif

is there any checks i can do to see what it is? i presume if its the turbo seals that id see oil in the run pipes?

si_c1978

ok, i had a bit of a auto nhs direct chat with the doctor last night, (much appreciated lee! thanks very much)

my feeling of despair has subsided, i have a few things to try at the weekend,

apparently its common on these saab heads once you run the boost up that the centre breather (3rd from left) pushes oil thro' to the breather hole at the inlet manifold face (where the funny rubber gasket goes on the z22se) when the camcase pressure builds up. and obviously sucks it in thro the inlet.

also im going to try to obtain a catch tank or knock one up in the week, all to reduce cam case pressure.

if this fails he will talk me thro some trouble shooting, but initial diagnosis is the main components should be ok 😃

again thanks doc!

Gary14

Has the engine always blown smoke or has the problem just started? if so the catch tank etc will not cure the problem.

We have a V70 Volvo 163 turbo diesel which when driven hard will puff black smoke all over the road. Never caused any problems and is very smooth running motor.

My advice leave it alone and enjoy the car :thumbup:

si_c1978

na the problem has just started after i caned seven shades of shit out of it on sunday.
i have been reliably told that these saab heads have a tendancy to blow smoke once you raise the boost up high (some of the supercharged z22se's have had the same issue)
and it only happens once the cars been up and running for a while and its boosted a few times.

i have a temporary plan in place i have a vent type filter that i shall attach to a large hip flask for now until i can get a proper catch tank delivered :shifty:

also further to mine and docs conversation it would appear that the oil breather pipe has been terminated. i presumed it was still attached to the inlet as it was a full working engine at time of delivery, but since have found a dead end/bunged pipe coming from the back of the cam cover, so it is pointiong at high cam case pressures

Gary14

si.c1978 said:
na the problem has just started after i caned seven shades of shit out of it on sunday.
i have been reliably told that these saab heads have a tendancy to blow smoke once you raise the boost up high (some of the supercharged z22se's have had the same issue)
and it only happens once the cars been up and running for a while and its boosted a few times.

Due engine mileage / ware, you giving the motor some beans, and the raised boost, the engine must be running much hotter than standard? This could also be an oil grade issue, as you state only blows smoke after warm up which indicates if nothing else wrong? oil thickness / thinning.

si_c1978

no once again 86 degrees and ive got my fan cutting in at just under 100 degrees, which only ever turns on when sat in traffic or kicks in a bit when i let the turbo run down so i know thats fine.

also i was being a bit dumb!!! it was dark when i got off the phone to the doc!

the redundant pipe was formerly a servo feed which i have gotten from elsewhere as the brake servo setup is still origional only utilising the vac pump on the rhs of the cam cover.

the oil breather is connected correctly (6"pipe from back lhs of cam cover to the cold side of the turbo,) im still going to fit a catch tank but need to make a blanking plate for the turbo end.

so ill wait till a proper catch tank turns up ill order one today.

im still going to block the 3rd breather, i have absolute faith in what the docs telling me.

smoke is generally a sign your engine is unwell, and in a custom build like mine, i need piece of mind as all the sensors elecs and half the ancillarys are all custom.

si_c1978

viewtopic.php?f=115&t=13927&hilit=+z20net
just so you have some idea of whats going down in my engine bay (as ive said before it was half oh dear im stuck with an engine that doesnt work in my car and half experimental :lol: )

for some reason the mrs never understands "but i had to cane the shit out of it honest!" :?

astra22bertoneauto

Catch can is definately the way to go there, keep the engine breathing without sucking the life (oil) out of it! 😃 Even if it doesnt solve the problem (but sounds like it will). You should notice you dont use as much oil either.

Matt

Are you also able to wind the boost back down and see if it's still happening?

si_c1978

yeah i can do, but i would say that it would as in normal driving (doc said i should be fine to drive it as i wont have caused that much damage)
i often encounter 4-6psi of boost cos of the way the turbo spools up early.(twin scroll) and it puffs a small cloud then, but only after being run for a few miles.

that is not to be said that it isnt something else, im going to get on and do my prescription then lee said we can start looking elsewhere if it still smokes.

oh its also well shitty weather down here and i have to work overtime till it gets dark every night this week so i cant attack it till the weekend.

the mrs & her parents are off to germany tomorrow for 4days for work, so once ive got over my wretched hangover saturday morning (while the cats away etc) ill wang it in the car port and ill have 3 days to sort it out. bar a footy match sunday.

si_c1978

https://www.youtube.com/watch?v=s9C_oBLSLSU

dunno if this link works but i noticed when i stopped yesterday that i had similar symptons,

not neccessarily the same issue but it defo points to a correct diagnosis from the doc!

si_c1978

whoops! what you cant see without going to you tube is the conversation that followed,
basicly same as me is it rings valve stems etc, however when the chaps that knew their stuff posted they said more or less the same as lee, blocked breather hoses oil forced down channels etc.

fingers crossed this is the problem, tiz a free (ish) fix!

rushy

si.c1978 said:
whoops! what you cant see without going to you tube is the conversation that followed,
basicly same as me is it rings valve stems etc, however when the chaps that knew their stuff posted they said more or less the same as lee, blocked breather hoses oil forced down channels etc.

fingers crossed this is the problem, tiz a free (ish) fix!

I think there is a common fault with the Z22YH (direct) in that the valve for the cam breather gets goosed. I'm sure ive also seen it on TIS. As a side affect it causes a ticking noise I think. I'll try and fire my old lappy up again and have a look. (The lappys fooked so no promises).

rushy

Looking at that Vid again it shows pressure not a Vacuum so the Yh breather fault doesnt come into it if you have high pressures.

It says "In case of customer complaint proceed as follows:
Open the oil filler cap (hard to open because of the vacuum); if the noise disappears the crankcase ventilation valve is the cause of the rattling noise.
Remedy: Install a new crankcase ventilation valve (partnumber: 24414343 / cataloguenumber: 56 07 496)."

i presume this would also cause excessive oil burning as the cam is constantly under Vac from the inlet.