95 p0306, changed plug&wire, still misfire

[wolfox]

There is and will be argument over "good or bad" as far as oil choices go, but the good thing is that you change it. You will be surprised how many do not, and wonder why they have problems. I would say to try switching your fuel brand and see if it helps the problem. They might have gotten a bad tank-truck full of stuff - they being your regular gas station. If your plugs are still glazing up, try swapping over to Castrol GTX - there are plenty of people that seem happy with that stuff if you are not willing to go to a synthetic oil. I personally swear by synthetics myself, and in my opinion, hasn't been much else better for our engines. Though changing oil at 3000 is a tad wasteful. Even the most God awful oil can go 5000 on a decent filter. GM/AC Delco filters are good. Never had any troubles with them. Be sure they get swapped @5k miles with your oil and you're good. Others may prefer a Purolator Pure One, or a Fram Extended Guard - go with what flows and your pocket can afford to part with. However stay away from Penzoil, and regular Fram filters, in particular Double Guard filters. The teflon they lace those filters with turns into white lumps of rock in your oil pan and engine galleries. (DuPont also says that they never intended Teflon for crankase use - so keep that in mind) Other than that though, I would definitely switch to a different brand of fuel immediately to see if your glazing/ashing problem at least slows - then on your next oil change try some Castrol 5w-30 and see if it cleans the problem up comletely.

However, there is a simple test to figure out in your valve guides/seals are leaking. Let the truck sit overnight. The first time you crank it over in the morning after it sits, stone cold for at least 6 hours - observe your exhaust. Are you seeing blue-white clouds of smoke? Your truck will seem (and smell) like it is burning oil for just a minute, but then it goes away. This is a classic, tell-tale sign.

[BlazerLT]

Good luck.

[cubanlorenzo]

if i let my car idle for about 7 mins, it will start to smoke. it smokes for the first 5 seconds of acceleration. other than that, it doesnt smoke. the smoke color is a light blue. smells like raw fuel out of the exhaust.

[wolfox]

You may benefit then from switching to a different brand of oil, but if indeed the truck is smoking like you describe, you now know why your plugs are glazing and ashing up. Sad to say it friend, but you are going to have to bring the truck in for a valve job. I am sure someone here can give you a better idea of what it would cost you, as I never had to have this done on any vehicle I owned. Good luck, man!

[BlazerLT]

Originally Posted by cubanlorenzo

if i let my car idle for about 7 mins, it will start to smoke. it smokes for the first 5 seconds of acceleration. other than that, it doesnt smoke. the smoke color is a light blue. smells like raw fuel out of the exhaust.

Sounds like your valve seals are gone.

Light blue smoke is oil for sure.

[cubanlorenzo]

yea it has been smoking for about 2 months, lightly. i only burn like a 1/2-3/4 every oil change. i add a little every now and then. thought that my engine might need some major work so i have been contiplating getting this one fixed or perhaps buying a new engine. or just a new car. who knows. how much is the valve job going to cost?

[BlazerLT]

If you were smart, you could go and yank the heads off a junker blazer and swap them on.

[blazee]

You can replace the valve seals without removing the heads.

[thomasrn]

Originally Posted by cubanlorenzo

95 4.3 W auto 4X4. about a week ago my SES light came on. scanned the computer, came back with a p0306, cylinder 6 misfire detechted. so i changed out number 6 plug and wire. i pulled the neg battery cable for 20 mins to reset computer. I started the car and right away the SES light came back on. took it for a test drive and that last about 2 seconds before the car was sputting again. scanned the code, SAME code again. suggestions?

Sounds like the 'old' tried and proven tricks are the best.

Pop off the plug wire from #6, and connect it to a spare sparkplug. Ground out the side of the sparkplug to ground. Give the engine a few cranks and see if you got spark. Shutdown the engine.

No spark, It's Cap and Rotor or new plugwire time! - Done

If you do have spark, shutdown the engine, re-connect the #6 wire.

Start it up again. Turn wheels hard left. You'll find a flap on the inside of the wheelwell. Lift it up, and peer into the spark plug. Do you see a coowel electrical light show happening in there? If yes, you'll have to fix the plug wire. You might try poking it with a stick to see if the engine all of a sudden changes.

If no, then we have to look at fuel injectors, valves, compression, etc.

Regards,
------- Robb -------

[thomasrn]

Originally Posted by blazee

You can replace the valve seals without removing the heads.

Coowel - How?

Regards,
---- Robb -----

[blazee]

Originally Posted by thomasrn

Coowel - How?

Regards,
---- Robb -----

Work on one cylinder at a time:
Remove the sparkplug, bring the piston to top dead center and thread an adapter in to the sparkplug hole so you can connect an air compressor to it. The air compressor will hold the valves in place while you work from the top.

The haynes manual has a walkthrough. I have not done this personally, but my father-in-law, who was a mechanic for over 50 years, told me about this several years ago, so it isn't just some BS that haynes came up with.

[BlazerLT]

Or you could replace the #6 injector if the engine is 1996 or newer.

[cubanlorenzo]

1995 blazer. i have no idea what im doing when it comes to swapping heads out of another blazer. how much do you think that valve seal job will cost me??

[BlazerLT]

If you do some reaerch, you can probably do it yourself.

[Turbocpe]

I'd hate taking a risk by swapping something like that with a junkyard. Who knows the history of that engine and what may or may not be wrong with what you're getting. Something like that, I'd be very careful of.