The Stovebolt Site Forums The Shop Area Engine Shop I’m Dead in the Water, rather Dead from the Water!

Well it’s been fun, the last 6,000 miles that is. I’ve been living with delusions of reprieve but alas, I’m forced to admit that “we have a problem Houston”!!
Over the last month or so the old gal has developed a discharge. I’m still trying to isolate the source of the coolant leak. I was hoping that I could blame it on high humidity or the rings being worn but after pulling the VC and seeing the Jell-O buildup on the inside I’m shutting her down till I find the source of the problem. I have been trying to convince myself that the coolant level was just stabilizing at its hot operating level, but the coolant level has been dropping down very slowly below that level and I’ve added a pint or so before I drive it each time.
With the VC off I can see that the top end is beginning to show some minor surface rust in a few places. I drive it a few times a week long enough to come up to operating temperature and she is always kept in a dry garage and never driven in the rain.

Oil emulsion pictures: http://rides.webshots.com/photo/2411239930098611668DJTUkz

When I did the valve job in 2006 the original head showed a small crack after it came out of the caustic dip tank in no.3 combustion chamber. However it passed the 40lb. pressure test at the machine shop and a 120lb overnight pressure test with my setup here in my shop. Based on these results we went ahead and did the complete rebuild, hard seats, new valves, springs, guides and flatten the surfaces all to the tune of around $450. Could the crack be opening up just when the head is hot, sure, but it wasn’t a problem the first few thousand miles so my guess is the crack was just a surface crack and has begun spread into the water jacket. I’m still not seeing anything in the pan yet.
Well I didn’t want to tear into the engine for a couple more months but I think this may be the time.
Denny Graham
Sandwich, IL

I feel your pain my friend. Looking for a needle in a haystack is what you are up against. Ya know that it is possible to x-ray heads now but it is a little pricey. I am thinking as you probably are, that the crack is more than superficial. Good luck with that ol'buddy. Let us know what happened.

Denny, your valve cover indicates a leak, as you already suspect. Surface cracks have a way of progressing, so my guess is yours finally reached the water jacket. It sounds like you did a cylinder leakage test on the engine in the past. I would do that again. My limited experience with cast iron cracks is 1) they don't stop; 2) they are hard to repair, but repair is often possible. Good luck with your situation, and let us know what you find.

Harvester

Denny, I've done an in-the-frame leak check that doesn't involve a teardown to locate, or at least confirm the presence of a leak on some of my race engines. They're prone to develop pinhole leaks in cylinder walls that get bored way oversize due to casting flaws, and they don't show up until they've been run hard for awhile.

Disconnect and plug off both radiator hose nipples with expanding rubber freeze plugs, and figure out a way to plug one heater hose connection, usually with a threaded-in pipe plug. Adapt the other heater hose connection to a garden hose, and turn city water pressure into the block/head assembly. Leave it pressurized for several hours. A seep leak will either fill up a cylinder, or show a leak into the crankcase after sitting awhile. Id this procedure doesn't show an exact location for the leak, at least it will point you in the right general direction.
Jerry

The pressure testing that I mentioned is a standard cylinder head pressure test that any well equipped head shop should have. That's why I'm 99% sure that if the head is leaking it will show up in No.3 combustion chamber when I do get the head off.
In the mean time when I get a chance I'm gonna do a cylinder leak down test just to see if I can nail it before I tear it down. I have to machine a new adaptor for the 14mm plugs, the only ones I've got made up are for the tapered plugs and the 18mm plugs that are in the Lycoming in my Pitts. I used to do a leak down test on it every time I did my annual inspection.
Anyway you look at it, it's a bummer.
Before I decided to go ahead and use this head I got three other ones (the same casting number) and two of the three had more cracks than my original head, the third one had no cracks but did have some very large ugly deep pits on a couple of cylinders which showed up once we got it out of the dip tank. I sunk another $450 into it so I’m hoping that one should be OK.
Denny Graham
Sandwich, IL

Time for a 235.

Denny, keep the 216. Factory Chevrolet, bolt-on, VCCA Approved and it did a great job during World War 2. We won. I'm not sure if this quick procedure would help, but.. perhaps it worth a try, have you re-tourqued the cylinder head bolts? Could it be a leaking gasket? What about magna flux? If you pull the head, this could be cheaper than X-ray. Just my two cents.
Dale

Denny,
I had my head off this summer because of a stuck valve. It turned out that the previous shop put it together without addressing the worn guides. In addition, it had a crack in #3, along the bottom edge of the exhaust well. I had the crack stitched up and it seems to be OK. I ran the motor last year for a bit with no thermostat and no pressure. As soon as I put in a 180 deg thermostat and a 7 lb cap, antifreeze started to disappear. I now run a 160 with no pressure.

I have also discovered that warming the engine for five minutes and then retorquing the head after installation is absolutely essential. This procedure is not specified in the Chev manual for 1951 but it is in the GMC manual and also the manual for 1955. I found that the torque values dropped from 80 to 60 or less after the engine was run for the first time.

Fred

Dale, the machine shops that I take my head work to do, Magnaflux, that's how the surface crack in no.3 first showed up. I polished the crack till it passed a Spot Check at home before I decided to have all the headwork done to it.
Hi ya Fred, I have to admit, I haven't tried to re-torque the head. I'm just so sure that the crack has migrated into the water jacket that I've kind of pushed some other things aside. Re-torquing the head was one of the things that I had on the list.
I try to apply a little common sense to these things. When you think about it, virtually none of the new cars, trucks, tractors, lawn mowers, in other words, none of the new internal combustion engines require the cylinder heads be re-torqued after they leave the factory. So why would this be a requirement for a repair job??? I also have reservations about re-torquing a hot engine.
Not that it will hurt anything but I have never subscribed to this practice.

Denny Graham
Sandwich, IL

I have been tinkering on GMCs for over 50 years. They are famous for having "glass heads" because they crack so easy. I have learned over the years that if a head shows any sign of a crack during magnaflux, get rid of it. Cracks do open up wider when they are hot. I have tried everything from KW block weld to water glass to having them welded and nothing worked. And having coolant in the oil is a quick way to ruin your bearings and cam.

Denny,
I didn't used to suscribe to the re-torque theory either and I
agree that all the new engines produced over the years didn't undergo the procedure. However, the evidence that I saw of the values being way down after the first run was quite stunning. In addition, the writeup in the 1955 manual is very specific.

Where do you figure the antifreeze is getting into the oil? In my case it didn't get into the oil. It was strictly in the combustion chamber and I think got into the valve guide a little bit.

Crenwelge,
I am interested in what you are saying here. I suspect that some cracks do not leak at room temperature under a shop pressure test but do leak on an engine at operating temperature. Have you experienced that?

May not help, but often times when I find a coolant leak into the combustion chamber the spark plug on that cylinder is usually very different in appearance than the rest. Might take the plugs out one at a time and see if one looks extremely clean compared to the rest, or see if ther may be signs that coolant is getting in that one cylinder.

Good luck.

Denny, It probably is the cylinder head as they are all prone to cracking. even the 235's. Be sure and check the rocker arm oil feed tube where it enters the water passage on the push rod side of the engine. I had one seep water there once. Maybe you will be lucky and it's just the head gasket. Cleon

Fred that's exactly right, I thought that was what I was getting across in my earliy postings. I worked at Fermi National Accelerator Lab for 27 years and did a lot of leak testing on a large variety of weldments used for ultra high vacuum applications. I've seen may cracks that wouldn't show up with helium leak testing down to ten to the minus tenth yet when the object was warmed up it opened up. Quite common and it would be especially true with the temperatures that are encountered in an internal combustion engine.
That's true Roy, I've been taking a reading on the plugs about every 1000 miles for the past 6000 miles looking for just that symptom. That will build up a heavy tan calcified deposit from the glycol.
Cleon, I installed a new oil feed tube when I did the valve job and check it very closely quite often. And I learned early on that the
GM inline heads were prone to cracks in the combustion chambers as I noted earlier. As I said, I had to go through four heads to find one that would pass Magnaflux. In fact for those that are unfamiliar with what we're talking about, here are a couple of pictures of the area where it most often appears. http://rides.webshots.com/photo/2331152890098611668AqSsyV

Thanks for the comments guys.
Denny Graham
Sandwich, IL

Denny,
those photos are great. That is exactly where my crack was but not as long as that one. I was really surprised at the amount of coolant in your rocker cover. I don't understand how it got up there.

Thanks for the feedback on my question. And to add to this discussion, I worked in a shop in my teens where they did a lot of "stitching" crack repairs. They were mostly done on heavy machinery heads and they were very successful.

I know it STINKS denny ..but looks like the head has gone south on ya ..an well ya know what that means...I dont need ta say anymore.
other than this maybe its a GOOD WINTER PROJECT ?...I know it isnt the best ..but it sure looks from your valve cover pic there is a "Problem Houston"..
From what I have read an how YOU are on the particulars ..YOU will get it resolved an have that motor better than FACTORY when ya done.
keep us posted.
Tim

I'm sure it's just condensation Fred, as you can see there isn't any sign of froth on the rockers or head. And again, I get this stuff condensating in the road breather and dripping out on the floor.

Well it's time anyway to service the bottom end Tim. Just been putting it off as long as I can.
Denny Graham
Sandwich, IL

Again I am not as familiar with Chev as GMC. Another place where GMC is very prone to crack is in the block behind the push rods. This comes from freezing rather than overheating and blocks are seldom checked there for cracks. I take the push rod cover off and pressurize the system. It's not fun on a GMC because its a tight squeeze between the cover and the distributor and the oil filter is in the way. I still think you have coolant in your oil and that's not good. I used to block off the water pump hole on a GMC block and fill the water jacket with Diesel and let it set for about a week before I built on a block. Diesel will find small crack and it leaves an oily spot.

For those who are interested, here is a photo of the crack repair on my head:

http://rides.webshots.com/photo/2441303090041873203PUstHQ

You might try hanging a few of those moisture absorbing packets packed in electronics under the oil cap. Then run and check for water. I figure if it is atmospheric it will be absorbed if it is getting into the oil it should take awhile to show up. I may be off base. I am however waiting for the detailed account of your work with pictures. I have spent the last few night looking over your radio repair photos. You are a wizard.

That looks real good Fred. Having been in and around welding and metal working all of my life, I'm real leary of any cast iron repair especialy where the is a big swing in the temperature as there is in an engine.
Like I said Neil, I'm about 99% sure that the crack is in the head. I just don't have time right now to get into it very heavy so it might have to sit for a week or so.
Denny Graham
Sandwich, IL

Denny: Could it be possible at your getting some seepage at the oil line that feeds the rocker arms doesn't that go though the water jacket maybe the solder joint on the fitting has cracked. I think if were a cracked head you would have a lot of smoke and water dripping from the tail pipe. If you can get hold of a radiator presser pump takeing out the spark plugs and pumping up the cooling system and spinning it over water should come out a spark plug hole if the heads cracked Just a thought

Paul

Covered that back on page 2 Paul, but thanks. And they are compression fittings not solder joints.
Denny Graham
Sandwich, IL

Denny:On my 1952 216 the outside oil line has a compression fitting but where the line comes though the block on the push rod side the line come though a (for lack of a better word)brass pipe plug which is drilled though the center and the line is sweat soldered to the plug don't ask me why but that's how it is.

Paul

Truckernix,

Back in the 50's and 60's when these old 6 cylinders were still used hard as work trucks it was very common to have a head to be cracked and only leak at operating temperature which of course means the crack opens up wider when they are hot. We had a company here up until a few years ago that repaired heads. He put them in an oven and heated them until they were almost red hot before he "stitched" them. He showed me how much more visible the cracks became as they became hotter. He repaired a couple of GMC heads for me, but they failed. I think repair techniques have improved much over the last 50 years, but fact still remains that cracks open up with heat.

Denny,
does this posting of yours from long ago shed some light on the problem?

https://www.stovebolt.com/ubbthread...ip&topic=0&Search=true#Post82317

Fred

Yeah, I remember that, ya got a good memory old timer. I've kept a watch on that and there really isn't anything showing up on the bottom end and I check under there every week or so. I still think there might be a very tiny leak from the freeze plug but I haven't seen any sign of it since I buttoned it back up.
I'm taking a break for a few days to clean up some other stuff and I'll get back to the truck soon.
Denny Graham
Sandwich, IL

The reason modern engines don't require re-torqueing the heads after being built is that they have torque-to-yield head bolts that stretch and keep pressure on the gasket. You have to replace the bolts every time you replace the head gasket, but at least you don't have to re-torque.

J. if they are over torqued they then they theoretically have gone past the yield point and its at that point that they begin to loose strength. The torque spec is meant to keep the bolt within its elastic range. The bolts can stretch just as a strip of metal can bend and return to its original state. It’s only when you go past the yield point that it stays stretched or bent.
I've got 66years on me and have been around engines ever since I was a tot, pop being a mechanic. The recommendation to replace the head bolts each time the head is re-installed isn't new it's been around ever since I can remember. I don’t think I ever spent the money on new head bolts and never had one go bad on me. I worked as a parts man all through my teens and don’t ever recall selling a set of head bolts.
Denny Graham
Sandwich, IL

Back in the 50's when we used GMC's hard in commercial service, grinding valves was an annual thing or oftener. We would have never dreamed of buying new head bolts every time we had a head off. Of course we didn't look at books much in those days. I thought I was real "up town" when I bought a torque wrench and it came with a free little pamphlet with torque values and tightening sequence of then popular engines.

Sounds familiar Ken, accept torquing the head was the one exception in our household, we always were particular about that just to avoid stretching the bolts beyond yield. The rest of the torque specs went back in the drawer and we relied on the torque wrench that hung off our shoulder. Bout the only other spot that I would deem really important would be on some rear gears that had the crush sleeves.
When I installed the spacer/adaptors for the front wheels on my ’50, 3604 I did look into torquing the lug nuts which again, is something that I’d never been concerned about before. And judging from what I’ve seen at most tire shops, they never were either. The only tire shop that I ever saw haul out a torque wrench was just this summer when I had the coopers put on my ’97 at Farm & Fleet, surprise, surprise!

I still haven’t gotten out to the barn to check the torque on the head, or had a chance to make an adaptor for the pressure check. I was going to let it sit for a while to see if I get any thing draining into the pan or cylinders. The coolant level hasn’t moved one bit in the week plus that its been sitting so if it is a crack then it is only opening up when its hot, or from the negative pressure on the intake cycle.
My other possibility is that the rings are letting so much blow by that it’s bringing water vapor into the crank case. The only problem I can see with that theory is that there doesn’t appear to be any coolant building in the crankcase, at least on the dipstick. I suppose I should pull the pan and see if there is any froth in there.
Denny Graham
Sandwich, IL

It's a fool that won't admit that he's wrong and as embarrassing as this is, I was wrong!!
Finally got out in the garage this weekend to re-torque the head on my 216. And to my surprise the head bolts were quite loose, probably took a good 1/8-1/4 turn to pull them down to 80ft.lb.
I then topped off the radiator to about half way up the top tank cold and took a ride. Between yesterday and the one I took into town today I put a total of about 50 or 60 miles on her and the water level is holding right where I filled it to, bout half way up the top tank after she cooled down.
Before I re-torqued the head, when I took it out for any sort of trip, even a short one it would have sucked it down some and on a longer 100mile or so run to just above the cooling tubes.

Lesson learned; ALWAYS RE-TORQUE THE HEAD AFTER YOU HAVE A FEW MILES ON A FRESH VALVE JOB!!!!! Even if you have done dozens and never had a problem like I have over the years.
I'll keep my eye on things for the next few weeks and see if all holds OK.
The good part of this is that I changed the plugs also and the set that I took out were burning nice and clean. So from the plug readings I don't think the #3 combustion chamber is cracked. Hopefully this was just a dumb bullheaded assumption that there would not be any creep or flow in the head gasket if it was properly torqued the first time.
Believe you me, I got my fingers crossed on both hands for the next month or so.
So go ahead and say, "I TOLD YA SOOOOO DUMMY"!!!!!
Denny Graham
Sandwich, IL

what brand of a head gasket did you use Denny?

thanks
Don

So I guess we will have to wait on the pictures of the rebuild. Sounds like you may be good to go.

Neil

Denny, my dad always told me "pay back is Heii".....

I've got my fingers crossed for you to pal. Good luck and keep watch on the water!

I can remember when Fel-Pro came up with a radical new idea- - - - -a "no-retorque" head gasket! It was met with a great deal of ridicule by the oldtimers, until repeated experiences proved that the concept worked! I can also remember buying a special offset tool to go around the exhaust manifolds on small block Chevy V-8's when retorquing the heads. Before that, it was a race with time to try to get the manifolds off before the engine cooled down too much to get a good hot retorque. Burnt finger time!

For cast iron heads, the procedure was to bring the engine to normal operating temp, then retighten the head before it cooled down. For aluminum heads, the engine was warmed up, allowed to cool, then the head bolts were retorqued. For the steel shim type head gaskets, it was necessary to use a brush-on gasket sealer on both sides like Permatex Super 300 to prevent seep leaks of coolant.
Jerry

Hey Denny,

Just a few notes about the torque of cylinder head bolts. If the head bolts were loose for a short to a possible long duration, you may also want to check the following to insure efficient operation and prolonged life of your stove bolt. First and foremost, after you re-torque the head bolts you may have changed the clearance of the intake and exhaust valves. It is critical that you normalize the temp of the engine by stabilization of the oil temperature. Check your service manual for details for valve adjustment. Also, the cooling system may have been compromised. Rust in the cooling system is caused by oxygen in the water which has a corrosive action on iron and steel. A loose cylinder head gasket allows exhaust gases to be blown into the cooling system. These gases contain strong acids, and corrosion is produced in the cooling system. Preventing major motor repairs is key. I would seriously consider a back flush of your cooling system.

46Canopy
Dale

I've never had much luck retorquing a head once the gasket started leaking. There will probably be some soot from a combustion chamber on the sealing surface. Maybe you will be lucky. A person deserves to have good luck every once in a while. I would sure watch it closely. I'm sure you know what happens when anti freeze gets in oil. Even if you do have to pull the head again, its not going to be an all winter project nor will it be that expensive.

I bought a 3/4 socket with a universal on it to allow me to retorque the head without removing the rocker arm. The inner bolt front of center required that I move the rocker but other than that it was much easier and faster.

A crack in the combustion chamber would produce pressure (compression) in the radiator, and coolant out the exhaust. There are some diagnosics used to check for combustion gas byproduct in the coolant. I believe it is some kind of test strip. Many current production imports make retorque a requirement after head gasket replacement. If it was mine, I would retorque the head. It won't cost anything but a little more time and an oil change.

Good Luck,
PT