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Old 01-09-2006, 05:06 PM   #1 (permalink)
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Default Burning oil-will seafoam help?

So I decided to make another thread about the oil control rings on my Z block. My L24 is burning oil, and goes through oil quickly, almost a quart after a day of spirited driving, and a quart after 4 days of regular driving. I know for sure that it isn't my head, because the whole thing is rebuilt with new valves, seats, seals, etc., all gaskets have been renewed with the exception of the rear main crankshaft seal. I know (or at least assume) that it isn't leaking oil past the rear seal, because I don't see any oil dripping past the transmission, and I don't feel any oil when I put my finger inside of the clutch fork hole. This leaves only the oil control rings left, which I believe to be the culprit, because the Z smokes bad upon acceleration. Two of my six plugs are oil fouled, they are covered in black crust, whereas the rest of the plugs are the nice golden brown color that will indicate a good fuel mixture. I've tried a quart of Lucas oil stabilizer to see if it would help, and the motor still ate oil after that. The motor has less than 500 after the new head swap, and the oil is black (still has the new viscous look, but is just black). One of the guys here on Zcar said that if it were the oil control rings, the pcv valve would be sucking the oil past the rings, so I could put a filter over the crankcase breather tube. I didn't want to tamper with the pcv system, but I did take the hose that connects the two off and put my finger inside of the crankcase vent, and there was oil on my finger.

My compression, with throttle closed, was 130-140 across the cylinders, and with throttle open was in the 150 range across all cylinders (mind you, the motor has no carbon on the head or cylinders, I cleaned my pistons and cylinders off when the head was out). I know the motor can still have good compression, but the oil control rings can still be stuck.

I bought a can of Seafoam to use on my truck, and I've got about 1/8 of a can left. I read on the side of the can that Seafoam can be used to free up sticky oil control rings, so I searched on this site to see if anyone has used it for this. I did read a post about pouring in a mixture of Seafoam and Liquid Wrench into the cylinders via the spark plug holes, letting it sit overnight, and then drive it to see if it frees the rings up.

Is this safe to do to my motor? I know Seafoam can be used in motor oil, but is it possible for it to really free up sticky oil control rings, or should I just go through with my lower end rebuild like I had planned?
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Old 01-09-2006, 05:09 PM   #2 (permalink)
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Default Re: Burning oil-will seafoam help?

after 34 years, seafoam is probably not the answer.
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Old 01-09-2006, 05:19 PM   #3 (permalink)
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Default Can't Hurt...

What kind of mileage are we talking here. 1 Qt in 1000 miles is normally considered "not excessive" even though engines can go 3000 miles and still not be a quart down.

Pull your valve cover and make sure your valve seals have not popped off the top of the valve stems. This is very common.
As is having cut valve stem seals when guys recut the heads of the valve stems and leave them square and sharp instead of chamfered. On top of that, then they them without a bulldick or expander to keep them from cutting the seals when the valves slip over the stems.

If one or two cylinders are oiling up their plugs, then I'd be concerned. If they all are equal, buy another FULL can of Seafoam, and follow the instructions. Drive around spiritidly while it's in the oil in the crankcase, then do the "pour in through the vacuum booster line" method. Do it right, or not at all. It can't hurt it, all you have to loose is the cost of the Seafoam---your gains could be that is stops seiving oil so badly.

"Days" is an irrelevant measure of time on a vehicle. If you are driving 200 miles a day, I would say you are on the edge of "acceptable", whereas if you only drive 20 miles a day---then you need to do something fast!

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Old 01-09-2006, 05:44 PM   #4 (permalink)
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Default Re: Burning oil-will seafoam help?

Yeah, I'd agree, days aren't a very good measure of distance on an engine, lol. As an example, I was down by less than a quarter of a quart on my dipstick just the other day, and then I went for a 20 min. spirited drive, and the motor seemed to be down by another quarter of a quart the day after. In comparison, before that, I was driving it for a couple weeks before I decided to park it, and my round trip for the day would be about 20 miles. After 4 days, the oil would be down by 3/4 of a quart, and I would be driving normal, without spirited driving. This isn't my daily driver, I'm just trying to rebuild the engine so that it can be.

The valve seals are on all the way, I've checked that, and they look just fine to me. I haven't looked at it since I last did my valve adjustment, but I'll take a look today or tomorrow when I get a chance just to be totally sure.

The block I have in there now is a L24 out of a '71, and the previous owner gave it to me because he was moving and was doing a sbc swap on his 240. He said the valve guides were bad, and that he had tossed the head, but he believed the block to be fine (he claimed to be a mechanic for Lexus, and seemed to know his stuff). I did take the block down to the machine shop to get it checked out, and the guy there said that the block looked to be in excellent condition, and that there was very little to no lip at the top of the cylinder, which would mean that the block has very little wear on it.

As for the cylinders being oil fouled, there are only two out of the six that seem to be oil fouled, so I don't know what to think. I am saving up to do a lower end rebuild, so it doesn't matter what I do right now, since the Z isn't my daily driver at the time. I'd just like to save some cash on the rebuild if I could get the engine running right and keep it from burning oil.

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Old 01-09-2006, 06:20 PM   #5 (permalink)
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Default That's your answer!

"there are only two out of the six that seem to be oil fouled, so I don't know what to think."

Put your efforts into THOSE TWO cylinders!

I had ONE cylinder that caused consumption of more than a quart in regular driving every 500 miles. A "What the ****" run trying to blow the engine seemed to unstick it.

You should put your liquid wrench, and the seafoam down those two cylinders and let it work. Then drive the **** out of it. Repeat. Repeat maybe a third time, then assess what is happening.

They will unstick or they won't.

I would have to pull #5 plug because it would foul on the roadway like on the way to work. Pull it out and swap it with #2 plug, then drive off hanging in first and second till the misfire on #2 cleared. Then I would be good again till it was time to repeat! The plug would simply wet-foul.
Always swapped it with #2. Later got a small butane torch to "burn off" the residues before swappage. Seemed to clear by the top of first gear then! Sometimes just needed to idle a while!

Good Luck.

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