I have a 90 Roadster with 94,000 miles. It's my first vet purchased last November. I've had it out several times this year with no mechanical issues although I'm sure it needed a tune up. After coming back from vacation and wanting to take it out after a week of vet withdrawls I took it for a spin. Blue smoke was coming from the exhaust and the car basically ran like ****. I parked it in the garage and it smelt like it was running rich and hot. The next day I brought it to a garage and the mechanic thought it might be sticky valves which he said with the mileage it's common with a vet. Shortly after I left the garage it stopped smoking. That week he tuned it up, plugs, wires, cap, oil change, fuel filter (which looked like it had mud in it), etc. He said the valves were fine. So for days I have no problem and the car seems fine. Yesterday I go to drive the car after it sat in the driveway all night (she was getting back at me for not parking her inside) and here comes the blue smoke again. Seemed like I was getting half the gas mileage I should and looked like I was running a smoke machine at stop lights. Once I hit the highway and got off at my exit, no smoke. Drove it after work and no problems. Help!!!! I noticed in some postings that maybe it might be and injector issue??? I was wondering if maybe fuel was leaking from them causing the rich condition etc. Any thoughts??? It's a sweet red convertable with a black roof, mint interior which I worked on this winter. 350 L98-5.7, K&N airfilter, six speed. Also, any thoughts on what I should be using for a fuel additive for injector maintenance? Thanks

 

I HATE TO SAY IT BLUE SMOKE IS OIL,NOT FUEL.COULD BE YOUR VALVE GUIDES,OR SEALS.OR RINGS,SOME TIMES WHEN THE CAR SITS THE OIL LEAKS DOWN THE GUIDES,THEN WHEN YOU START THE ENGINE U WILL SEE BLUE SMOKE THEN WILL BURN OUT AND THEN NO SMOKE,DO A COMPRESSION TEST ON EACH CYLINDER AND SEE WHAT YOU HAVE FOR COMPRESSION .IF UNDER 180 YOU HAVE BAD RINGS, ANDTHE CYLINDERS SHOULD BE CLOSE TO ALL THE SAME NUMBERS,5-10 DIFERANCE IN EACH CYLINDER IS OK BUT MORE THAN THAT BAD RINGS[]IT MITE BE TIME FOR A VALVE JOB.

GOOD LUCK

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Corvette king is right. Blue is oil, black is gas, and white is water. Valve seals will smoke for a short time untill the sealage burns off and will then clear up. However, I may be way off her but what about the egr valve in the vale cover. If these stick open it can cause yur engine to run funny because of the vacume and it will draw oil thrown at it by the vave train into the intake track and burn it causing the blue smoke.

corvetteking wayduyou think. possability? or do i need more coffee thismorning. It's an easy fix. Like $3.00

 

Thanks Corvette King and Crvttbass. I'll try replacing the EGR valve tonight. Can't run the car until tomorrow cause of the rain today. Would it be something the mechanic should have noticed during the tune up or was he just trying to be nice and hope that things cleared up? I'll talk to my son today about doing a compression check. I'll get back with an update.

 

I think I may have given the wrong name for that valve. Not EGR but PCV, PCV!! I can't believe I called it a egr.Duh!!??

 

Need to check your PCV system and make sure its not stopped up, because that will make your engine suck oil though the intake and smoke.

 

yes, i forgot to tell you that, check your pvc,in the valve cover, should be able to blow one way and should close the other way,if stuck open or closed no good could be carboned, up.i should of told you that first.if it ant that it is one of the other things up topi wrote.good luck let us no what you found out.

 

Thanks Guys, I'll replace the PCV valve after I get out of the station tonight. I guess with the tune up I expected that to be changed. If that doesn't work then I'm on the the compression test. Hate to sound stupid here but I'm a newbie to vettes. Loved them all my life and finally had the bucks to purchase my first. I guess half the fun is bring back or maintaining a true "American Sports Car". I'll try to get some pictures posted soon. It's defiantly a head turner.

 

you got it kid,just take your time and dont rush,it will all work out.and thats what we are all doing hear answering questions,i must say that is y i bought a vette we all stick togeather and i love that,good luck,and you dont sound stupid if you dont ask you will not know,[sm=signs003.gif]

 

Just checked the PCV valve and it was replaced during the tune. Next step, compression check. Now when I check the compression I'll be checking the rings? If the compression is above 180 and all cylinders are within 5-10 of each other then I'm looking at valves? Would that step be valves or valves and seals? I really appreciate everyone's help. [sm=thanx.gif]