79 With Exhaust Smoke - Photos - Newbie Needs Advice

[WBPDX]

I'm tearing into my budget 1979 project. I purchased this car off of Craigslist for next to nothing, but it needs a lot of love. It did run and drive, and started quite easily. Someone has recently put a number of new parts on the car, but it's still quite rough. I figured I could help it turn the corner.

The biggest problem for me living in Portland, OR, is that it smokes. I didn't try to take it through emissions testing, but I was confident it would fail. I tried getting it truly warmed up a few times to see if the smoke would go away, but it didn't. Most disturbing was the visible smoke at idle; it definitely seemed to have a burnt oil smell, but my sense of smell is not very good.

So, the first step was a compression test:

From front to back, cold: 151, 152, 142, 148 psi. All the plugs were incredibly black\sooty. Judging by #3 and #4, I didn't bother with a leak down test, but now I wish I would have.

Second was a valve clearance check as I was getting ready to pull the head. All but two valves were significantly out of spec.

So, tonight I finally got the head off. I have been planning this entire time on pulling the engine, but now I am not so sure that is necessary. I am seeing a bad head-gasket between #3 and #4, which I assume caused the low compression readings on those cylinders. The cylinder walls look quite good. The only thing that bothers me is the large amount of carbon build up on cylinder #1's valves - Could this be from bad valve stem seals? I didn't drive the car enough to notice smoke on deceleration. I'm just having a hard time accepting (based on what I can see and my limited knowledge) that the smoke was being caused by bad rings.

I will let the pictures tell more of the story. I'm wondering if I should bother pulling the engine or not. This is a very low budget project for me; my plan is to get it fixed up, put maybe 4,000 miles on it this summer, and then sell it in the early Fall. As I said, the more important issue is passing the basic tail pipe emissions test. I have a sneaking suspicion that I could get away with some new valve stem seals, a new head gasket, and the new carb\intake manifold that I planned on anyway...

These are the 'better' valves (3 and 4 pictured)


This is the bad pair (#1)


The headgasket between #3 and #4


Cylinder wall sample:


Another one:


Overview (this doesn't really show anything useful obviously)

[WBPDX]

By the way, much of the oily mess pictured on the head is from turning the head over a few times while de-greasing. Lest anyone get freaked out by the gooey appearance of those valve chambers.

[baltobernie]

Those compression numbers are quite good, actually. And they're all within a few percent of each other. But of course you're going to be replacing the head gasket anyway.

What color is the smoke? Blue, black, white ....?

[WBPDX]

Well, #3 was off quite a bit - By about 10psi. But, that's where the head gasket problem is, as I mentioned.

The smoke was grey... I guess I could convince myself the 'smoke' was coolant possibly from the head gasket, but the plugs are\were insanely sooty. I guess it could have been running too rich? I have no idea. The oil pan needs to be resealed, so I guess I might as well pull everything anyway? And since everything is pulled, I might as well spend $70 on new rings?

[Daniel]

WBPDX Your bores look really good and the compression numbers are pretty good as well the oil
most likely is coming from your valve guide seals they are made of rubber and get hard, crack
and wear if you replace those while doing the head gasket and use High Millage Oil i am sure
you'll be just fine .

Good Luck to you .


Daniel

[WBPDX]

Thanks!

In that case, can the oil pan be resealed with the engine in place? [EDIT: I did some searching and discovered I can!]

If it can, I am going to feel really stupid that I bought a brand new shop cane, and I don't think I can take it back.

Good thing I didn't unbox the engine stand; at least I can return that!

[WBPDX]

One question I can not find an answer to: How do I turn the engine over with the head off to check the bores of the other two cylinders? I don't want to damage the accessory drive(?) or whatever that thing is. It was correctly timed when I took things apart, I'd like to keep it that way.

[majicwrench]

You can turn engine over with crank nut. Just bring it right back to same spot...mark it before you move it. You may hit the fuel pump drive, if so just rotate that out of way, put it back when done. Really can't hurt anything now.
Pan is a pain to do in-car. I would just snug bolts lightly for now, see how smoke goes before worrying bout pan..
I would not pull and try to replace the rings. Then there are the bearings, then a new clutch, and then, and then and then.
From a true backyard budget point of view, I would slap new valve seals on it, clean it all up, make sure head reasonably flat, new timing belt and stick it together. There are some products, GM Top Engine Cleaner is the best, that can help loosen sticking rings. If it still smokes after assembly, that can be tried.

[baltobernie]

Pan is a pain to do in-car. I would just snug bolts lightly for now, see how smoke goes before worrying bout pan..

If it ain't broke; don't fix it. Oil pan gaskets that aren't leaking should definitely not be touched. The torque spec for those bolts is only 5.8 ft. lbs.
You say it's gray smoke. That plus sooty plugs tells me that there may be nothing wrong with your cylinder head or walls. The 1979 model is the most "smogged" engine in the 19½ year history of the car. It is entirely possible that you have a mixture problem, and I would have advised you to check this before tearing the top off the engine.

"Burnt oil" smell would result from a blue cloud that would be slow to dissipate.

Heck, maybe the choke is stuck. I'd confirm that the ignition timing is correct, wires are good, then concentrate on the carburetor and related parts. Maybe some photos of the engine compartment can tell us what modifications might have been done to the car.

[WBPDX]

... It is broke. The pan seal\gasket leaks.

Too late to worry about the mix, but I agree with you, I should have investigated more. I am going to a 1800 intake manifold and new carb. The emissions stuff was mostly blocked off, but what was still connected was a mess. Again, I don't need to worry about it now, I will have a EMPI 32/36 DFEV shortly.

Wires and other tune up parts were good.

I'm throughly convinced I don't need to pull the engine, thanks. The trans is recently rebuilt (so I was told, and it is much cleaner than any other part of the car) and has a new clutch, so I guess there's really no reason.

[WBPDX]

You can turn engine over with crank nut. Just bring it right back to same spot...mark it before you move it. You may hit the fuel pump drive, if so just rotate that out of way, put it back when done.

This car as an electric fuel pump... unless I am missing something.

[majicwrench]

Electric...good.....the aux shaft...that would have drove the fuel pump if yoiu had a mechanical...may still have the lobe that can contact the rotating assembly as it spins. So if you turn crank and it goes "clunk" you know what it hit..no worries though...not at this speed!

[WBPDX]

Electric...good.....the aux shaft...that would have drove the fuel pump if yoiu had a mechanical...may still have the lobe that can contact the rotating assembly as it spins. So if you turn crank and it goes "clunk" you know what it hit..no worries though...not at this speed!

Excellent! Thanks! I've never taken the head off a car that had an 'aux shaft' and kept reading things that scared me.

[Daniel]

just turn it by hand no need for any tools the aux shaft should be your only concern if you turn the marker to 6
o clock it should be fine and miss the crank as you turn it over by hand . Remember to set this timing mark
correctly when you setup the timing belt again with the cams very important !

[Daniel]

Also to change the oil pan gasket you can remove the oil Pan by un bolting the front motor mounts and placing a jack
under the trans bellhousing and lifting the engine till it stops because of the trans tunnel once all the bolts are out
and you have the pan loose you'll need to turn the pan a bit side ways to work loose around the oil pump .