Well, my VL has been slowly loosing auto trans fluid, and it has been blowing white smoke on startup/after it has been idling for a while. I didn't think the problems could be linked, as the smoke is coming out the exhaust, no it isn't fluid burning off of the hot pipe, it is blowing out. i googled it a bit, and found out about the "vacuum modulator/diaphragm" and this somehow lets the fluid get sucked into the exhaust? any help on this would be greatly appreciated, thanks in advance guys. Shane. this is somthing i found on JC. I fixed my 'white smoke out the exhaust /disappearing auto fluid from slipping auto trans problem' it was the 'auto modulator /vacuum diaphram' got one from REPCO $69 bit expensive but anyhow its fixed. at first i thought the valve seals or head was stuffed,mechanic quoted $1000 to take head off and never said any thing about Modulator go figure! anyway to fix I just disconected vacuum hose and unscrewed old MODULATOR and screwed in new one ,about half a cup of auto fluid up vacuum tube to inlet manifold poured out onto floor!stuffed diapham! While i was at it i took the pan off the auto drained it and gave the pan a good clean before puting new fluid in the auto only lost the fluid that was in the pan about 1.5lt auto took about 3lt to top up .Now the engine and auto are perfect no smoke no slipping auto.So thanks to every one who helped on this Forum i saved a heap of bread and know how to fix this small but mysterious problem and feel bloody good about the acomplishment.cheers Donhomer

Quote: Originally Posted by N/A 88 [View Post] found out about the "vacuum modulator/diaphragm" and this somehow lets the fluid get sucked into the exhaust? Yeah champ the post you have quoted is on the money and your symptoms sound right for this to be the cause. It's not sucked into the exhaust. It's sucked up the vacuum hose that provides the vacuum for the modulator and into the intake and combusted; hence the smoke.

yeah ended up finding that after about an hour of google searches lol. do you think this could make it idle rough aswell? cheers, shane

Could be. I don't imagine igniting trans fluid does anything for the lifespan of your spark plugs.

my problem certainly is this little modulator ******* thing. checked the vacuum line to the eccs, got trans fluid in it. put the car up on ramps, ripped the stupid little thing off with some difficulty, gettin a new one from repco for $71 today. thing thats got me p*ssed off is the fact it was a recond trans from just commodores 12 months ago, and cars only done 2,000 K's tops in that time, as i am only a learner at the moment lol. shonky parts much :|

i think my trans has the same problem but im unsure what part the modulator/diaphragm is. i have got under and looked and noticed that there is fluid coming out of a little hose on the passenger side of the trans the hose is short and does a 90 degree bend into the trans then onto a metal line going up the top front of the trans is the the right thing?? there is fluid coming out of the hose but no clamps or anything on the hose as if there shouldn't be fluid in there

yeah thats the right part and no fluid shouldn't be leaking through the diaphragm. Just check to make sure it's just fluid that has just dripped down onto it rather than out of it.

nah its definitely coming out of the little hose. how do you remove and replace the diaphram? it looks as if its pressed in there.

bump

You can't. You just buy the whole modulator. Just grap it with some multi-grips and screw it out. Some original photos have not been recovered yet.

yeah sorry mate i meant the modulator i wasn't to sure how it came out and i didn't want to start prying at it with a screw driver. cheers mate

yeah bro ive done about 4 of them in recent time on customers cars lol its a laugh coz they think there cars fully F#kED lol then i tell its the trans vac modulator and they wtf is that good stuff dude who needs a mechanic wen u got google

Did this fix your white smoke problem? I've got the same thing