2.0L EXHAUST VALVE GUIDES ? or ?, SMOKING BUT OK COMPRESSION VG LOOK OK Options

[thompson-mfr]

Hi All,

1974 2.0L Factory FI

Problem: Not running. Tries to start, then dies. Just a little bit ago was running, but smoking on decel, when you let up on gas, and shifting between gears. Then it would get warmed up and not like to run well. 10 minutes or so of driving.

Please see pictures below. I thought it might be Exhaust Valve Guides. My 914 started smoking, so I started doing some trouble shooting.

Compression is as follows: #1 115 psi, #2 115 psi, #3 104 psi, #4 112 psi

I know these are not ideal, but still seem good enough to run. I have read 93 or above can still run and or within 12 psi difference per cylinder.

Please help.

Valves are adjusted to spec. New plugs, wires, cap, rotor, ignition TP cleaned (looked OK)

[Elliot Cannon]

Yep. That looks vaguely familiar. (IMG:style_emoticons/default/biggrin.gif) Here's mine.

[thompson-mfr]

I do not see oil on my valves though. Can someone pleade chime in on the visual condition of the valve guides/exhaust chamber.

[thompson-mfr]

(IMG:style_emoticons/default/icon_bump.gif)

[SLITS]

#2 looks wet with oil & baked on deposits.

How is your oil breather hooked up? Stock to the plenum or to the air cleaner?

Are you overfull on oil?

[thompson-mfr]

#2 looks wet with oil & baked on deposits.

How is your oil breather hooked up? Stock to the plenum or to the air cleaner?

Are you overfull on oil?

First off thank you so much for responding!

Oil breather (port that is on the passengers side of the oil filler) I have going to the air cleaner. I thought that was the correct spot. I don't think I saw any oil on the air cleaner either for what its worth.

Perfect on oil. 2.5 qts and dip stick is right on the full mark. I just changed the oil thinking maybe I overfilled.

Is there a way the distributor can induce/put oil in the cylinder?

[914_teener]

What you are looking at seems to be oil coming from the combustion chamber or the valve guides.

Could be rings or guides. In any case it isn't a good sign because they shouldn't look like that.

My .02.

[SLITS]

#2 looks wet with oil & baked on deposits.

How is your oil breather hooked up? Stock to the plenum or to the air cleaner?

Are you overfull on oil?

First off thank you so much for responding!

Oil breather (port that is on the passengers side of the oil filler) I have going to the air cleaner. I thought that was the correct spot. I don't think I saw any oil on the air cleaner either for what its worth.

Perfect on oil. 2.5 qts and dip stick is right on the full mark. I just changed the oil thinking maybe I overfilled.

Is there a way the distributor can induce/put oil in the cylinder?

Distributor will not make an engine smoke.

There is a hell of vacuum produced (negative pressure) on closed throttle and especially when coasting in gear. The rocker boxes stay about 1/2 full when running so it is easy to suck oil into a cylinder ... and create smoke in the exhaust if the guides are worn.

The actual port for the PCV valve (oil breather) was connected to the plenum originally. Many changed it to the air cleaner so as to avoid the problem you are speaking of .... smoking because of lower vacuum.

The other thing to check before writing a check is the head breathers and where they are connected. Lines should go to the flashback valve and then to the air cleaner.

Other than that, #2 is still wet and that would be the suspect guide.

Back in the day we would install valve stem seals on the exhaust valves (racing engines) to prevent dilution of the combustion mixture by oil seeping past the guides.