SaabGuy

I recently purchased a 87 tII. Pulled the plugs and OMG theres a ton of carbon built up. I suspect a bit of low compression and a ton of carbon build up, hey the car has 141k original miles and purrs like a kitten anyways.

Since I just purchased this car, it needs to go through emissions in CT. Should I do the ATF trick after or before? Wil it hurt the CATs or improve emission testing?? whats the deal?

What about O2 sensor??

jimmyv13

I would do it b4 the testing. Let it soak for as long as possible. ATF will harm the o2 sensor and cats, but MMO will not, but I don't think MMO works as well IMO.

Icemark

In therory since the ATF doesn't have lead based lubricants it should have no effect on the O2 or Cats, But

I can see how a load of carbon (liqued or otherwise) unburnt Hydrocarbons and O2 being dumped into the exhaust, causing the metals in the Cat and O2 to radically heat, in order to process all those extras. The over heating could possible melt the core in the cat if it was in sufficent high amounts.

So as long as you don't dump a whole quart of ATF in, and you drive the car reasonably after the treatment it should not affect the Cats or O2 in too bad of a manner.

But if you dump a ton in, and just idle the car in the driveway (smoking out your neighbors in the process) and don't drive (to air cool the cats) I can see it possibly damaging the system.

Remember to change the oil after the ATF treatment as the ATF will soak past the seals and contaminate the oil in the pan.

Rxmfn7

iTrader: (4)

Ive heard that it will harm the cats, thats why I havent done it yet, I dont really feel like disconnecting my exhaust. Ill do it soon though. Ive heard that Marvins Mystery Oil wont hurt your cats, but ive also heard that it doesnt work nearly as well. As for the O2 sensor, Ive heard nothing about it harming that, but if ur car has that many miles it might not be a bad idea to replace it anyway.

Icemark

Thats right. The O2 should be replaced every 60k or so miles anyway if you want your computer to read the mixture correctly.

TristanTII

I did the ATF treatment, and left my cats on, no noticeable damage.

However, before starting up the car I got as much of the atf out as possible. Pulled all 4 plugs, stuffed some paper towels all down in there, and cranked the engine for a couple seconds, repeat, blew out alot of ATF, and you could see that a lot of black gunk came out dissolved in the ATF.

Started the car up, brought up the RPMs and let it smoke for awhile, then took it out for a few nice redline runs on the highway, getting a few stares as I drove my bat-mobil down the back roads on the way there.

Having never done this before I can't comment on the relative amount of smoke, but it did die down signifcantly one I got it out on the road, and was gone by the time I made it to the HW

Mallard Duck

How much ATF are you supposed to pour in? A few tablespoons?

TristanTII

well, don't get ridiculous.

I ended up using about half a quart, maybe a little more little less depending on how much spilled out. I don't know if you can use too much, especially if you blow it out before starting it up.

scathcart

A guyt old me he does it with a mix of atf and kerosene, claims it works better... wnayone else hear of anything like this?
Also, how often should the atf trick be done? I wanna use it to decrabon my enine before seals stick, not after. I got no cats to worry about, and I know to replace the oil and plugs after its done.
Shouldn't need one for a while, brand new motor, but I'll keep it in mind... high revs also kill carbon eh? Guess I should just cruise on the highway in first... j/k
Sean Cathcart

yamatokh

TristanTII

You didn't share with us whether your car runs better after the treatment. Does it?

My car has 56K on it only, do i need the treatment?

turboren

I don't think I've ever used more than 4 oz. Good call on pulling the plugs and purging the chambers before trying to start it, though. I didn't even think that people wouldn't do that first. Only makes sense to prevent possibility of hydrolock.

Yes, it makes a difference. 56k, though? I'd have to say not necessary yet. You can stick a mirror down by the the leading plug hole and shine a light in there. If it looks crusy, then, yeah, give it a whirl. The best way to tell if if works or not it to perform a compression check before you do it, then like a day after you do it (after car has been driven). You can also usually tell because it will idle and start easier.

Ren