86 efi smoking

Ok today I went to take my 86 bronco out for a drive around the block and it started smoking more than usual (it has bad oil leaks onto the manifolds). It ran and shifted normally and I didn't notice any knocking or anything . I let it idle for about ten minutes before I hit the road, I checked the oil and its clean with no gas or water and the granny fluid is good as well. The smoke was a bluish white, can anyone give me some insight on what it could be.

smoking is a bad habit you should tell it to quit. other than that fix those other leaks, and was the smoke from under the hood or through the exhaust?

blue smoke means oil in the cylinders. #1 cause is bad valve seals. #2 cause is wore out piston rings, do a compression check to see if you have a bad cylinder that could be causing this. and #3 is a chip in the head gasket allowing oil to sneak into the cylinder, but typically a bad gasket will give you a huge constant cloud of blueish smoke and steam (coolant) not just a bit at start up.

valve seals are easy enough to change once you get the valve covers off, may be difficult to spot if they only have cracking and haven't shattered yet.

I bought a $20 valve spring compressor bar (not clamp) this allows you to do the job with the heads on the block. you just remove the rocker, put the bar on and thread the nut down to it.



the trick I use to do valve seals is a 3' section of nylon rope with a knot in the one end. remove the spark plug and feed the rope into the cylinder until you reach the knot. then turn the crank pulley by hand until you feel the piston push on the rope. this will keep the valves in place while you are compressing the springs. once you have both the intake and exhaust valves back together then you back off the crank pulley so you can remove the rope and start the next one.

its trickier to do the mopars cause the 318 uses rockers on a shaft that bolts down beside the valves but the same tricks work. fords have the rockers bolted down individually directly above the valves.

these are some pics of me doing the 73 318 from my plymouth.

yo 90bronco86,

Bluish smoke hopefully is just the PCV sys; inspect PCV valve; make sure it is seated well and vac hose is attached and not leaking/replace PCV valve if old

Check compression

piston rings may be worn.

valve seals/Guides may be worn

also consider this;

Vacuum Supply Hose Rerouting in 86-93 5.0 Bronco, F Series & vans; MIESK5 NOTE; Include 5.8; Failure of the #8 piston or the #8 rod or rod bearing; "...Failure of the #8 piston or the #8 rod or rod bearing in Ford 5.0L, V-8 gas engines. Solution: During engine installation, reroute the PCV valve vacuum supply hose. Follow these steps: Plug the 3/8" (pipe) thread hole in the rear of the plenum where the PCV valve hose is connected. Drill and tap a 3/8" pipe thread hole in the center of the plenum and thread the PCV connector into it. Reconnect the PCV valve vacuum supply hose to the new location. Be sure the drain hole in the baffle is open. The baffle is under the PCV location in the valve cover. Installers who have rerouted the PCV system and opened the baffle drain hole have not reported any #8 cylinder failures..."

Source: by fourstarengines.com via web.archive.org @ http://web.archive.org/web/20061 025155759/http://www.fourstarengines.com/techtips3.htm

after clicking on url above, in bottom right corner of site, click Impatient?

Location & Hose Routing Diagrams in 5.0 & 5.8



PCV valve is next to the passenger side valve cover below the intake plenum.

Vacuum Supply Hose Rerouting Video in an 86 5.0

Source: by JKossarides ("The Bronco", Jean) at http://www.supermotors.net/registry/media/742778



Info & pic, 1 port vs. 2 port for 5.0; "...That's a genuine Ford PCV valve. It's stock two port top (top of pic); makes it difficult to fit under the upper intake on an EFI 5.0 engine. Buy an aftermarket single port(lower in pic) and use the top on the Ford PCV..." miesk5 Note, often the rubber cap on the top port pops off



Source: by Sixlitre (Malcolm H, Eddie Bauer) at SuperMotors.net

White smoke;

since the smoke does not disappear after it was warmed up;

Auto tranny fluid may be entering the intake manifold through a bad vacuum modulator (if it is a C6); pull vac line from modulator, if tranny fluid is present, replace mod.

Cylinder head gasket(s) may be bad

Cylinder head(s) may be warped or cracked

engine block may be cracked

Krafty said:

smoking is a bad habit you should tell it to quit. other than that fix those other leaks, and was the smoke from under the hood or through the exhaust?

blue smoke means oil in the cylinders. #1 cause is bad valve seals. #2 cause is wore out piston rings, do a compression check to see if you have a bad cylinder that could be causing this. and #3 is a chip in the head gasket allowing oil to sneak into the cylinder, but typically a bad gasket will give you a huge constant cloud of blueish smoke and steam (coolant) not just a bit at start up.

valve seals are easy enough to change once you get the valve covers off, may be difficult to spot if they only have cracking and haven't shattered yet.

I bought a $20 valve spring compressor bar (not clamp) this allows you to do the job with the heads on the block. you just remove the rocker, put the bar on and thread the nut down to it.

View attachment 12057

the trick I use to do valve seals is a 3' section of nylon rope with a knot in the one end. remove the spark plug and feed the rope into the cylinder until you reach the knot. then turn the crank pulley by hand until you feel the piston push on the rope. this will keep the valves in place while you are compressing the springs. once you have both the intake and exhaust valves back together then you back off the crank pulley so you can remove the rope and start the next one.

its trickier to do the mopars cause the 318 uses rockers on a shaft that bolts down beside the valves but the same tricks work. fords have the rockers bolted down individually directly above the valves.

these are some pics of me doing the 73 318 from my plymouth.

View attachment 12059View attachment 12060

Click to expand...

I added some oil additive and it stopped smoking for about two days, but I let it sit for about a week and it started smoking out of the exhaust and from under the hood again