Abe,

Unfortunately, I've been thru 3 head gaskets on my two trucks. Two of the three times I drained the oil and it was filled with water, and one of the times it was just plain oil with not saturation. Also, one of the times (this past time on my 92') the head gasket took a dump, I didn't have any steam from the exhaust pipe either. This is what threw me off when I thought head gasket, cause I was getting all the symptoms of one, but no watery oil and no steam. But, sure enough, it was blown when I tore it down.

I hate to do a head gasket on this truck, and then it turns out that's not what it was. BUT, I don't see what else it can be, and like I said, I don't see how a set of rings "just goes out", yanno?

 

headgasket was done maybe 6-8 months ago, 10,000+ miles on it

The block and head were checked for cracks at that time

Underneath (checked yesterday) the valve cover seemed normal

Plastic timing chain guide still looks like new

What concerns me a little is that last time the spark plug in cylinder 3 had that white washed looks, this time it was sooty black, not wet though.

Sorry for the slow and crappy responses, trying to finish off a move in between posts

I'll try to get a side shot

 

Really can't see anything from the side, looks normal

It's not actually as dark as it looks in the pictures, but the sun is overhead right now.

 

So to recap:
misfire,
low compression #3- 130 dry, 150 wet,
pulling wire= no idle change,
pulling injector = idle changes,
#3 plug- sooty black but not wet fouled.
valve adjusments okay.

Anything else?
Well, other than the inconclusive oil.

 

That just about covers it

It's possible that pulling the wire makes a slight idle change, but it's difficult to tell, unlike the injector, which changes the whole tone.

I have no tach with me, so I could miss a small idle drop in all the rest of the noise

There seems to be a thin layer of maybe water on top of the oil, but its probably just psychological (since that's what I want to see, kinda)

Both antifreeze and water are denser than motor oil, so I'd assume they should be at the bottom, rather than the top. Then again, since the oil is somewhat dirty and has some suspensed solids...

Oil inconclusive

Coolant seems clean as well

 

Bad news

The timing was off last night and we were out of time and daylight, so I left it over until today.

After wondering why the hell I couldn't get it started when everything was lining up just fine, I realized that the intake valve on #4 was stuck open.

Figuring since our timing was messed the first time we tried to start: it got bent?

Crap.

 

What do you mean it's stuck open?

 

The valve spring is compressed

There's about a quarter inch between the bottom of the rocker arm and the top of the plunger

 

 

I suck when it comes to terminology, so bear with me.

Underneath the valve cover, you have the valve springs putting tension to retract the valves, opposed by the rocker arms

On the intake valve for the 4th cylinder, the valve is stuck down beyond the reach of the rocker arm.

From what little I know, this means the valve is bent. Is that true?

 

If the spring can't pull the valve up to the head, then something is wrong. May not be a bent valve... could be an issue with the valve stem, guide or even seal... or even the spring.

Odd that you could get a good compression test on #4 if the intake valve isn't closing though, don't you think?

 

The good compression check on #4 was before we pulled the head yesterday.

I assume the valve got stuck after we tried to turn it over with timing at 180

I haven't check the compression since that happened.

 

Sorry to say, but it sounds like you're in it far enough to start over from scratch with at least rebuilding the head.
The issue with #3 is on the back burner, so to speak, but it wouldn't hurt to check that the rings on #3 are clocked properly.

 

Yeah, it's gonna be a busy week

If anyone knows of a good machine shop in the Sacramento Area, let me know.

Otherwise I'll pull the head off tomorrow and google around.

 

Can't say I know anyone in the area but there are a few reputable shops and used parts vendors (read as 'wrecking yards') around Rancho Cordova that may be able to help.

 

So it looks like the gremlin was found. I ended up taking the head to Cascar machine shop on 47th; they did a good job.

The original culprit was a bad intake valve on #3

We accidentally bent #4 while putting the head back on. The machinist figured the valve adjuster screw wasn't set properly on top of the valve and we bent it while torquing it down.

The cam and crankshaft were off and I couldn't find our marks, so I started from scratch and lined the tdc with the little dot on the cam sprocket at 12 o'clock. It wasn't exactly at 12, but as close as I could get given the position of the links.

Compression on all cylinders is almost 200 across the board.

Started up without a problem, but the timing was lousy. It's now at 5 degrees, but to get it there I had to turn the rotor as far as it would go. Oh well.

Thanks for the help here on the boards and especially thanks to Erik, who drove his ass all the way out to Sacramento just to help.

 

sounds very similar to my issues. combustion gasses in coolant, losing coolant, spews from overflow when full, #3 is washed here's a link to my older post -

https://www.yotatech.com/forums/f116.../#post51227719