Is that smoke coming from me?!

[SHOYourYama]

I've put 140k on my clock and have done all maint items except the valve lash. I figured it wasn't a big deal.. untill now. When my SHO starts up in these cold mornings, I've noticed a tad bit of smoke spew out the muffler for about aprox 1 minute then runs like a charm for the rest of the day. Yesterday, I jacked my car up in the front to admire the undercarrage. it was like a 10-20? degree angle nose up (used the stock floor jack maxed out). 30 mins later after my daydreaming and under car admiration shrug was complete, I lowered the car and started her up. And then, holy crap! The car was spewing out smoke like a choo-choo train! This struck me as.. wrong. shrug Whats up, would a valve lash ajustment fix this oil consumption?? frown

 

[SHOtimer]

No, it won't. The valve lash simply adjusts the space between the cam lobe and the shim. Your smoke is not coming from that. It might be coming from your valve seals..which are totally differnt subject. It could also be your piston rings, some other more knowlegeable people will chime in soon, and be able to help you more. But, I do know, valve lash won't help you.
Doug

 

[ricksmol]

I recently had the same problem. Copious quantities of smoke spewing out of the exhaust. I replaced all 24 valve seals. This is definitely not an easy job. Took me more than 2 weeks to do it. I had to manufacture my own tooling to remove the locks from the spring keepers and get to the seals.You need the patience of a saint and the skill of a surgeon and the presence of mind of not removing a valve spring when the piston is way down in the cylinder or you might drop the valve into the cylinder. It worked though and eliminated all my smoke problem. The seals I removed were definitely gone.
But first before you even start on anything like this....add a quart of Marvel Mistery Oil to the engine and run the car for a couple of days. You might have some sludge built up around your piston rings allowing an oil leak thru the ring. This stuff loosens all the crap and really works. (I think it is basically transmission oil)

Rick shrug

<small>[ January 22, 2003, 02:33 AM: Message edited by: ricksmol ]</small>

 

[pete c]

Are you sure it's smoke and and not vapor? Most cars spew vapor on cold mornings. If it disappears shortly after leaving the tail pipe, it's vapor. No big deal, unless it does it in July (head gasket).

If it is smoke and was worse after jacking up the front end, it would point towards valve seals.

I personally would never go through the PITA of replacing seals just to cure a little smoke on start up. It's not doing any harm. Once it gets bad enough that it smokes after the engine is warm, then it's time to start looking for a nice low mileage 3.2 to put in there.

 

[SHOZ123]

Get some Auto-RX and treat the seals. It appears to have cut my oil consumpition in half if not more. You could also try plugging the PCV frsh air make up line.

 

[rangerj]

SHOYOURYAMA,

Thick bluish-white smoke, is oil burning smoke. This smoke on start-up is a common problem when valve seals are cracked, or become dislodged.

If you are concerned that worn piston rings are the cause of the oil burning, then do a compression and leak-down test. Worn valve guides are also a common cause of oil consumption, but I have heard of very few instances of this happening to a SHO.

If you decide to replace your valve seals yourself, remember to bring the piston in the cylinder you are working on up to Top Dead Center (TDC). If you drop a valve into a cylinder, you will have to pull the head!

If you have access to a source of compressed air you can get an airline fitting that screws into the sparkplug hole. The compressed air holds the valve up. You need to have a compressor that can supply about 90psi continuously, or as long as you have the valve "loose".

There are tools made to compress the valve springs so the "keeper" can be removed, and then replaced after the seal is replaced. All in all replacing valve seals is not that bad a job, but is not one for the faint of heart!

I still use an old mechanic's trick, cause I'm an old mechanic, and tie a heavy thread to the valve stem before I remove the keeper. This is just in case the compressor quits, or the hose bursts, etc.

Another "old mechanic's" trick is to push a bunch of heavy twine or string into the cylinder, leaving a bit of it out so it can be removed!

Then crank the engine, BY HAND, so that the piston pushes the string up against the valves. This way the valves will not fall into the cylinders. Neat, huh?

Anyways, unless you have a warm place to work, I would put this off till warmer weather. Make sure you check your oil regularly, and keep the oil level up to *****. rangerj

 

[SHOYourYama]

Sounds like a **** of a job if it is indeed the valve gaskets. Today I noted the color, it seems more like vapor then oil, but this doesn't explain the smoke in my garage after I had jacked her up.

Cold engines run a rich mix untill it reaches a warm temp, is what I'm seeing just rich gas in the water vapor? I installed a crome muffler a while back, and is cumbersome keeping clean the black "soot" that enjoys mating to the metal, in fact I find a specs on my bumber at times. Is that oil or rich gas? The "soot" wipes clean w/ little effort of a rag.

 

[SHOYourYama]

er bumper

 

[rangerj]

SHOYOURMAMA,

Black or dark grey exaust is caused by a rich mixture. So is the black soot in and around the exaust tips. Check your codes. Failing O-2 sensor(s) will put the engine into a rich mixture.

A failing Coolant Temperature Sensor will cause the IAB to stay closed, or not open as far as it should when the car is warmed up.

If you are running rich, and the O-2 sensors are working, there is a code for this also.
Do the KOEO and KOER tests for codes.

If there are no codes, then suspect the spark plugs and/or wires, or weak spark from the coil. Pull a plug and see if it is coated with black soot, or if it is wet with fuel.

This should not be your problem because you say it runs fine, other than the time you got the smoke, and the soot on your tail pipes. If it runs fine, and there are no codes, leave it alone.

Check your oil regularly. If you are not burning or loosing a large amount of oil, and it runs fine, leave it alone! rangerj

 

[SHOYourYama]

I was running rich indeed. I replaced the ECT temp sending unit today. The car runs good if not better then before. My temp gauge now runs inbetween the "o" and the "m" in "normal". Before it was on the "a".

But something wierd just happened that made me start worrying again. I was getting of the highway and took 3rd gear to 60mph, looked in my rear-view and saw a breif 20ft spurt of smoke shoot out of my tailpipe eek! . Is it possible my rings allowed a bit of oil to slip by, or does that point again to my valve seals??

Any info would be great, but I think regardless, I'm going to have my compression checked.

RangerJ, you ment SHOYOURYAMA, right? lmao! I really appreciate everyones help. thumbs_u