My Sho is putting out smoke, alot

[GreenLanternSHO]

I bought a 94 mtx (manual correct,3.0) SHO with 120 k a couple months ago, and when i was driving around today, i gunned it at a stop light and looked in my mirror and noticed a lot of smoke coming from the rear end. My father is a x-mechanic and seems to think its the Valve seals, can anyone back this up, or tell me other reasons its "smokeing"?

 

[SHOtimer]

All depends what kind of smoke. Black smoke = running rich. White smoke = head gasket (coolant in chamber). Blue smoke = oil. If it is blue smoke then your rings are probably what is shot. Worn valve seals to my knowledge exhibit themselves when the motor sits for a long time and then blue smoke comes out when it is started. While worn rings exhibit themselves while the motor is running and a load is put on it.

Doug

 

[GreenLanternSHO]

yea its blue, anyone have any idea what a new set costs? Me and my father are gonna tear into the engine tomorrow so..and the funny thing is it still runs extremely strong and stays cool..

 

[GreenLanternSHO]

Wow.. I just realized you meant the piston rings, i must have misread or been spacing out ********, umm that means uhh some compression tests.. and if compression isnt right REBUILD
But, if the rings are shot, its gonna be losing power.. and maybe getting hot, and like i said it runs strong and stays cool so.. If anyone else has any ideas let me know

 

[cmichaelo]

Hi Green,

I have the same problem as you do. And interestingly my car is also a 94 MTX but with 128k miles.

Anyway, I get the blue/gray smoke too under heavy accelleration.

I just pulled the sparkplugs out the other day and noticed clear signs of oil in cylinder #2. The other cylinders are ok.

Most likely it is the piston rings in cylinder #2. But before replacing them, I'll try to "seal" up the scratches and remove possible carbon build-up on the rings with som Auto-RX (see http://www.auto-rx.com.)

At least one other SHO owner has had good results with this product and significantly reduced oil consumption with it.

What's your oil consumption btw?

Michael

 

[Joe'sSHO]

It seems to me like a rich running condition wouldn't cause a loss of power (that's noticable) and wouldn't cause overheating. How old are the 02's? I know you said it's blue smoke and most likely oil related, but b/c you said you didn't notice any power loss or overheating might it possibly be bad 02 sensors? Just a thought (probably incorrect) for consideration.

 

[SHOtimer]

Your rings could be shot allowing the blue smoke, but that doesn't necessarily mean that it will run hot.

Doug

 

[GreenLanternSHO]

Some funny **** happened late last night... I was with my father And getting on it so he could listen, and I hit 2nd gear and heard a Thump , And my car got really Loud, like REAL loud.. set off a few car alarms the way home.. anyway, This morning when we looked at it, my y pipe was broke off from my exhaust.. i have no clue how this happened, i never bottomed out or anything. But i was driving to school, got on it and noticed no smoke
Tested it some more after school a lot more and it hasnt been blowing smoke.. Is this a miracle or has anyone ever had somthing like this happen before? Seems like maybe one of my cats was clogged or somting.. but im not sure
let me know if you know anything

And to the oil consumption, yea it eats quite a bit im guessing.. 1 quart every 400 miles

 

[cmichaelo]

400miles per quart? That's as bad as mine. You should fix that pronto. Finf out where theil leaks are. If you have excessive oil burning, that could destroy your cats. And do you know what can happen if your cats die? Your engine could very well be next!!!

So it's important you determine where the oil is lost.

Michael

 

[NJSHO]

I had a problem similar to this. What mine turned out to be was a bad oil pressure sender on the back of the engine. At idle or low speed I didn’t get any smoke. When I got on it, it was like a smoke screen out the back of my car. The sender would leak and drip onto hot exhaust, and as the oil pressure built more oil was squirted out, burned, and created more smoke. My oil consumption was probably around where yours is. After I got a new oil pressure sender my consumption went back to normal and I had alot less smoke and oil burning smell. Something to check anyway.

 

[cmichaelo]

Hmm. Interesting. Though I replaced the oil pressure sender a few years ago. But I'll check it out anyway.

I just replaced front oil seal and oil pan gaskets. Now we'll see if that reduces the leakage.

Michael

 

[GreenLanternSHO]

hmm , ill do some checking and now that the smoke has stopped, ill record my oil consumption, and as i said im not even running cats, as everything is coming straight from the exhaust manifold (y pipe broke)