Really Confused

[tctwaites]

Ok, so I just replaced a headgasket and all my intake gaskets as I had coolant leaking into cylinder 3. I got it all done, checked the head for warpage, and put her all back together. I drove her for a couple days, and it is still smoking. I pulled tge headers to see which cylinders and it is still just 3. I pulled the coil plug and had someone crank it a few times, and just smoke comes out and no liquid. The valve itself is wet, as to oil or coolant I am not sure.

Could I have missed something? Or is it just left over residue? It doesnt overheat or anything. Just smokes some and it does it worst on first startup. Then when she is warm it almost disappears.

Thank you in advance for the help.

[royster]

The symptoms certainly sound like valve seals. If you have not replaced them, that is likely why you have the smoke at start up. Also, the EGR valve is located in #3, if I'm correct. It might be good to assure that the passages are clear.

[tctwaites]

Ok. I will definitely be doing the valve seals. And is the egr passage incorporated into the intake manifold? Ive always delt with external ones. Haha

[geezer101]

The EGR gallery is one of the most pointless features built into these engines. It starts as a small gallery inside #4 exhaust port and travels on an angle directly though the head to the other side under #3 inlet port and recycles a minimal amount of exhaust gas from one point. Due to it's less than brilliant design the moment you get a dead valve seal on #4 exhaust valve, it starts to draw an ugly mixture of carbon and fouled oil into it. After that, it's only a matter of time before the gallery is completely coked up and the EGR system fails (which actually isn't a bad thing as this stupid EGR crap ruins your engine tune...) If you can get away with it, seal off the EGR system. Your engine will run smoother and you'll be able to get a better tune out of it.

[royster]

I've only been working on the 4G64 engine for just over a year, but it has been an intense learning experience. Before I replaced my valve seals, I read about others who did, and "miraculously" ended a smoking-engine problem.

I didn't believe it.

Until I did it. My experience was a few starts afterwards contained some smoke, but less and less, until there was none on start up.

It seems typical of Mitsubishi engines to smoke when the seals go bad. I'll bet Jasper has sold a lot of rebuilt engines from the ignorance people have about this simple repair. (Relatively simple). And there's report after report of replacing valve seals correcting smoking problems that had folks baffled...just like you.

Please DO let us know if replacing the valves seals does the trick (once you conduct the operation).

[LSR Mike]

The reason engines smoke when the valve seals are bad, especially on startup, is that the oil in the head leaks past them into the cylinders when the engine is off. it then tens to lessen or go away as you drive. Smoking all the time usually means the rings are bad and oil gets past them because of crankcase is pressure.

Oh BTW I have 2 complete sets of valve stem seals from my Engine Gasket Kits from the dealer... how much are they worth?

[tctwaites]

And just double checking real fast before I tear into everything again. When I pulled the headers, it was just cylinder 3 that was wet. The valve itself was wet, and when cranked it smoked, but no liquid. When the spark plug was pulled, I turned the engine until the piston was at the top, and it was covered in dark build up and wet, didnt look like coolant. Which is why I am leaning towards the valve seals. Could it be the rings with it just being on cylinder and the valve itself being wet on the exhaust side?

[geezer101]

A compression test will let you know what shape the pistons, rings and bores are in. I'd still be putting money on the exhaust valve stem seal - they go hard as a rock and are no fun to pull off when they are that bad. The sealing edge of the seal (the very uppermost point) can crack and split apart.
Get onto your stem seals so you can ride in the non smoking area again! :))

[royster]

It's possible the valve guide has slipped down, displacing the valve seal. This was the case on my #3 and #4 cylinders. The valve guides DO slip sometimes, and when that happens, the valve stem seals pop off because there's nothing to hold them in place. The valve guide needs to be tapped back into position and a retainer clip installed.

Read my report and see what you think http://www.mightyram50.net/vbulletin/showthread.php/2956-Roy-s-Garage-90-2-4-4G64-5-spd-D-50?p=26192&viewfull=1#post26192

The repair, itself, was not expensive...$25!...it's the head gasket set that's the primary cost.

You can check to see if this is the condition your truck has by noting the seals' height compared to the others (photo on page 3 of my thread).