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Buick 263 Cooling Oh no...


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OK...I've got a rebuilt 263 that was redone 5 years ago, and has 6,000 miles since. I checked the antifreeze yesterday for the first time in awhile, and noticed it was low...I had to add a couple of quarts. Just for the heck of it, I rented a cooling system pressure tester from AutoZone, pumped it up to 7 pounds, and it held pressure fine. I took it for a ride and got it nice and warm, waited 15 minutes, took off the pressure cap, and tried again. This time, it lost maybe a half pound of pressure in 2-3 minutes.

It runs great, no smoke from the pipe, no missing. It runs cool, never comes close to overheating. The only clue that something may be wrong is that it leaves a little drop of water from the road draft tube and snots up the oil filler with condensation. Neither smells like antifreeze.

I've got bad vibes of cracked heads/blocks, etc. Any ideas? I'm not feeling good about this...

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It is apparently leaking somewhere....

Check external first, may even have to install leak detector. Pull the plugs: if leak is in a combustion chamber one or more will be very clean compared to the others. An empirical test for coolant in oil is to place a drop from the dip stick on a very hot surface: if it smokes only it is oil; if it sizzles there is coolant present. Slobbering from the breather and draft tube should happen only if it is habitually driven only very short distances.

Willie

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It gets warmed up quite often...I drive it quite a bit. I'm going to keep an eye on the anti-freeze level, pull out the plugs and check them out, and I may even double check the head bolt torque...it has a coated steel head gasket and I never retorqued it after the engine was rebuilt. I did add the GM sealing tabs the other day, so we'll see if that helps. Thanks for the tips...

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You are probably aware of these but I will mention them anyway. Check around the passenger floor in case the defroster core is leaking, under the front seat in case the heater core is leaking and also the transmission cooler. Do you see any white smoke out of the exhaust pipe? Hope it is an easy fix.

Joe, BCa 33493

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Hi Joe...just yesterday, I opened the vent and felt around inside the defroster core area, I am going to crawl underneath and check out the hose clamps at the transmission cooler and check it out when I get a chance too. No exhaust smoke, just a little breather steam, which doesn't seem out of line...Thanks!

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Well, not much turned up. The head was torqued normally, all fittings are tight. The inside of the valve cover was filled with snot, and it never has been before. I'm pretty convinced I have a head gasket issue (hopefully not worse). I don't believe it's into any cylinders, however, because none of the plugs looks washed out. Sigh. I think I'll be taking the head off to check things out, especially since the coolant level is going down on a daily basis now. I heated up a piece of metal with a torch and dropped oil on it and it sizzled...still doesn't smell like antifreeze, but it's got water in it for sure.

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I am usually the last to recommend "miracle-in-can" to fix a problem, but removing a cylinder head especially on a straight-8 overhead valve engine has to be be a big pain. It was 45 years ago (when I was a broke college student) that I discovered the oil level in my 55 Special was overfull. After starting the oil looked like a milkshake. I spent 1/2 day to go through the procedure outlined on a can of KW BlockSealer then went for a long drive to evaporate the water out of the oil (could not afford an oil change). It worked(!) for 250,000 miles until I retired the car. I have not had a reason to use it since, but in that on case it worked well.

Willie

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I am usually the last to recommend "miracle-in-can" to fix a problem, but removing a cylinder head especially on a straight-8 overhead valve engine has to be be a big pain. It was 45 years ago (when I was a broke college student) that I discovered the oil level in my 55 Special was overfull. After starting the oil looked like a milkshake. I spent 1/2 day to go through the procedure outlined on a can of KW BlockSealer then went for a long drive to evaporate the water out of the oil (could not afford an oil change). It worked(!) for 250,000 miles until I retired the car. I have not had a reason to use it since, but in that on case it worked well.

Willie

You make a good point on over full with oil. The crank will dip in the oil and create a frowth(air bubbles). This will cause low oil pressure as air is coursing through the oil gallery. I'm not sure if the frowth (milky mess of bubbles) will reach the heads.

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I am usually the last to recommend "miracle-in-can" to fix a problem, but removing a cylinder head especially on a straight-8 overhead valve engine has to be be a big pain. It was 45 years ago (when I was a broke college student) that I discovered the oil level in my 55 Special was overfull. After starting the oil looked like a milkshake. I spent 1/2 day to go through the procedure outlined on a can of KW BlockSealer then went for a long drive to evaporate the water out of the oil (could not afford an oil change). It worked(!) for 250,000 miles until I retired the car. I have not had a reason to use it since, but in that on case it worked well.

Willie

You know, I thought about doing that, but I don't know if I can bring myself to do it. There are so few real signs of trouble though, that tearing it apart is bothering me. It's only the valve cover/draft tube snot and, obviously, the lost antifreeze. It really doesn't seem to be leaking into a cylinder, but it might be slight. Who knows? Thanks all for the insight, as always!

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Reading your first post is it possible this minor leak has been present since the rebuild? You mentioned you checked the fluid for the first time in a long time. Two quarts added is significant. I too would have trouble bringing myself to using a stop leak product but in this instance you are willing to tear down the top half so if the stop leak does cause a problem it can be flushed after the heads are removed.

I used a stop leak product about 25 years ago. It stopped a radiator leak. I eventually replaced the radiator about three years after the stop leak was used because the radiator sprung another leak at a different spot. The coolant Gods where telling me something!

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It had probably been a year since I checked it. I'm fairly sure I know exactly when it started...I noticed a dripping from the draft tube in fall 2010, and when I changed the oil last year, the breather was all messy, which seemed abnormal to me. There's really not all that much to getting the head off this thing...the real pain is lifting it! I may just use my uncle's engine hoist to pluck it out of there. I'm still tossing things around in my head right now...

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Aaron65, you might want to try the water additive ( can't remember the name of it) that after adding you use a black light (UV light) and check things out with it. Works like a charm. You will be able to check for leaks everywhere and spot places you may not of seen and the black light will pick em all out. Also take off the valve cover and disconnect the heater hose to the core(s) first by plugging up with a large bolt and clamp. This stuff comes out with the oil as well and the froth will be glowing to if water spiked with this stuff is there.

That is what I would do before tearing down or taking out.

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You make a good point on over full with oil. The crank will dip in the oil and create a frowth(air bubbles). This will cause low oil pressure as air is coursing through the oil gallery. I'm not sure if the frowth (milky mess of bubbles) will reach the heads.

No air froth in this case, just an emulsion, which will maintain oil pressure and is still a decent lubricant...

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Well, I ran the combustion tester over the radiator and it showed no signs of leakage. I reran the pressure test and it dropped a half pound quickly and stayed there for at least 5 minutes. I think the half pound was in the instrument itself. I don't know what happened, but at this point I'm just going to keep an eye on it. Maybe the GM sealing tablets sealed the leak. I am going to switch back to a 180 thermostat (it's at 160 now) and put a new radiator cap on it. I'll keep everyone updated should things change.

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