My first thread here, I've got some questions for the nailhead experts. I just rebuilt my 401. The motor has maybe 350 miles on it. The heads and block were supposedly magnafluxed before they were machined and checked out OK. I've got a brand new timing chain cover. I've got water in my oil. Water with anti-freeze. I'm trying to think of all the ways I could get water in my oil, some are obvious and general to all engines, some might be specific to nailheads. Any help from you nailhead experts would save me some trouble and be greatly appreciated. I'd hate to pull the heads and disassemble the block to have them magnafluxed only to discover the problem was something else, something easier and cheaper. Here's my list of possible problems: 1. blown head gasket (very unlikely) 2. cracked head(s) 3. cracked block 4. cracked timing chain cover (unlikely, it's brand new) 5. leaking past head bolts that protrude into water jackets 6. leaking past timing cover bolts that protrude into water jackets Anything I'm missing? I'm thinking I'll pull the valve covers and oil pan this weekend, leave water in the radiator and pressurize it. Maybe I'll be able to identify the source of the leak that way. Maybe not. Have I run it long enough to worry about replacing bearings damaged from antifreeze?
Sounds like you have a good idea of possibilities. One more I would add as a question is: Did you have hardened valve seats installed? Also I wouldnt rule out the head gasket so easily. I'm not sure why you would dismiss that as "unlikely"??? Another way is to open you radiator cap and blow air in your spark plug holes one at a time and see if you get bubbles or a rise in the level. You will have to turn the engine over with the crank bolt so that the valves are closed when you do this. That will at least tell you which head you will have to pull.
I didn't have hardened valve seats installed, I've heard about the problem with that. I rule out the head gasket because I recently had the heads off to correct a machine shop mistake. The valve guides and bosses weren't cut down to account for the additional lift on my cam. The spring keepers were smacking the top of the guides and beat the seals to pieces and bent a pushrod. The head gaskets were fine then and I put another new set on when I reinstalled the heads after I had the guides cut down. I had some water in my passenger side valve cover when I did that, but thought (hoped) it was condensation from a pcv valve that was too small.
I have had the Timing cover leak behind the water pump before. I know you said you checked it but maybe it has enough porosity to start leaking. It would not take all that much to recheck it, just pull the water pump.
I haven't checked the timing chain cover. I didn't think of the timing chain cover as a source of the problem until this morning, because, like I said, it's brand new. But I assumed it would leak from a crack, or around the bolt that passes through it and into a water jacket, you're suggesting it could be porosity in the aluminum? Will that be apparent from just visual inspection, or would my pressure test idea reveal it? Pulling and replacing it would be easier and cheaper than heads and/or block. Although, that brand new cover wasn't cheap.
I haven't checked the timing chain cover. I didn't think of the timing chain cover as a source of the problem until this morning, because, like I said, it's brand new. But I assumed it would leak from a crack, or around the bolt that passes through it and into a water jacket, you're suggesting it could be porosity in the aluminum? Will that be apparent from just visual inspection, or would my pressure test idea reveal it? Pulling and replacing it would be easier and cheaper than heads and/or block. Although, that brand new cover wasn't cheap.
Man that sucks. How much water? enough to raise the level on the dipstick or just a small amount. Were you running the engine before it was torn down for rebuild? Is there verification there was no water/oil issues before the rebuild? What was the extent of machine work done to the block and heads? How well do you know the shop who did the work? Could they have possibly screwed something up and tried to repair it without telling you. Did you assemble it or did the shop assemble it? Unless you got a defective timing cover, I'm tending to think heads or block.
Enough water that I wondered why my oil level kept creeping up to a quart overfull. I was driving it before the rebuild, it was the original motor, it's a long story, but it overheated on my way home one night and that forced me to rebuild it. So, there were no water/oil issues before I burned it up and I asked the machine shop to magnaflux it and make sure it wasn't cracked before I wasted my time machining and rebuilding it. The heads and block got the full treatment, but no hardened seats. I know the machine shop pretty well and they've got a good reputation around the area, but they did screw up the valve guides, so I've got some reason for doubts. I don't think they would have screwed something up and kept it a secret, but I do think they might have screwed something up and just not known they did. The shop put the valves, springs and keepers in the heads and assembled the short block, I put the heads on the block and did the rest of the assembly. I'm hoping my pressure test will reveal the leak, and I'm hoping it's the timing chain cover, that'll be cheaper and easier than a head or block. I'll be using a different machine shop if it comes to that.
First try to find the general area where it is leaking.... If you can , pull the oil pan and then pressure up the cooling system to see if the water is coming from a cyl. or crack or pin hole in the block that the machine shop missed, or from inside the timing cover ... Was the engine bored???? I have seen engines rust from inside the cooling jacket so deep that when they were bored it cut thru to the rust hole and that cyl had to be sleeved.... how ever the most likely is a head bolt that is leaking or head gasket leaking...into the oiling passages....
Thats a lot of water in 350 miles. I agree if you installed the heads and are confident in the gasket quality and your installation, it would be unlikely a gasket problem......even though that is typically a more common problem area. Its so hard to speculate in a situation like this. When troubleshooting things like this I tend to look for anything that happened out of the ordinary or out of my control and I am a little concerned about your comment the engine had overheated especially if it wasn't driven much or at all after you got it home? Hopefully theres no connection. Sounds like you are on the right track with your testing starting with the least invasive checks to the most. Hopefully you will find the problem and it will be an easy fix.
No, it didn't overheat after I rebuilt it, it overheated before I rebuilt it. It's why I had to rebuild it. Other than the water in the oil, it's running fine. The plugs are clean, it's not missing, so there's no water in the cylinders/combustion chamber. I was under the car last night beginning to remove the oil pan when I noticed water dripping from one of the timing chain cover/water pump bolts that pass through both and into the block. I removed that bolt and it hasn't got any silicone sealer on the threads...could that be the source of the problem? Will enough water leak through those threads into the engine? I'm thinking I'll check all those bolts, put silicone sealer on them, fill it with fresh oil and a new filter and drive it a few miles around the neighborhood, bring it back in the garage and drain the oil and check it again. If it still has water in it, then I'll try the pressure test. The problem with the pressure test is getting the oil pan off without lifting the motor. Anybody know a trick to getting the pan off these Rivieras? I tried just dropping the center link by removing the pitman arm from the steering box, but there are two pan bolts above the frame crossmember that cannot be accessed without lifting the motor...and even if they could, it doesn't look like I can slide the pan out without the back end bumping into the torque converter.
While you have it down to this point, it would be prudent to do as Doc recommends. You're in a perfect position to pressurize the cooling system and look for that/those leaks. Ed
When i was putting my engine together , I sealed the timing gear cover and its water jacket bolts with permatex 300....You could do that by pulling each one out and painting the threads with the stuff...it never hardens and will definitly seal....also prevents corrosion....
If the iron isn't cracked somewhere, I'd say the most likely leaks would be from either the head bolts, timing cover (bolts or gasket), or head gaskets. Only 3 head bolts on each side go into water jackets....the 3 in the center of the center row. Only a couple timing cover bolts see water jackets, so I'd think it's more likely the gasket. Old corroded timing covers CAN leak water into the oil, but yours is new. Water has a long way to go to leak past a head gasket and into the crankcase. Pull the valve covers...see any water? ....head bolts. Pull the valley pan...see water?.....head gasket. Maybe you could drop the front edge of the oil pan, slide some cardboard between pan and front of block, then pressurize cooling system....water leaking from timing cover area would drip onto cardboard. You can add a dye to the coolant and inspect for leaks with a blacklight. Might give you some clues. Hope you find the cause, Good Luck.
So,,if its one of the head bolts that didn't for whatever reason,,get any sealer put on them,,,can the bolts be pulled and re torqued,,or does the head need to come off and have a new gasket installed??? I have a fresh 401 with water in the oil also!!!
It's OK to remove one at a time and re-seal them and then retorque. I've done this before without any problems on a small block chevy, the previous owner did not use sealer on the head bolts ( All the head bolts hit water on small block chevy's)
Thanks!!! I thought it would be ok,,but thought id better ask!!:beers2: Anyone have a chart somewhere for what torque values are for a nail?? Cylinder head,,water pump etc etc?? Thanks!!:TU:
Taken from Team Buick Reference section: These are "slightly lubricated" treads measured in Ft-Lbs- Spark Plugs 25-35 Crankshaft Bearing Caps to Cylinder Block 80-110 Connecting Rods 40-50 Cylinder Head to Cylinder Block 65-80 Harmonic Balancer to Crankshaft 200 Minimum Fan Driving Pulley to Harmonic Balancer 18-25 Flywheel .to Crankshaft (Auto. & Manual) 50-65 Oil Pan to Cylinder Block 9-13 Oil Pan Drain Plug 25-35 Oil Pump Cover to Oil Pump 8-12 Oil Pick-Up Tube & Screen Housing Assembly to Oil Pump 6-9 Oil Pump to Cylinder Block 30-40 Oil Gallery Plugs 25-35 Oil Filter to Cylinder Block 10-15 Timing Chain Cover to Block 17-23 Water Pump Cover to Timing Chain Cover 6-8 Fan Driven Pulley 17-23 Thermostat Housing to Intake Manifold 17-23 Intake Manifold to Cylinder Head 25-35 Exhaust Manifold to Cylinder Head 10-15 Carburetor to Intake Manifold 10-15 Fuel Pump to Cylinder Block 25-40 Motor Mount to Cylinder Block 25-40 Fuel Pump Eccentric and Timing Chain Sprocket to Camshaft 40-55 Rocker Arm Cover to Cylinder Head 3-5 Rocker Arm Shaft Bracket to Cylinder Head 25-35 Delcotron Bracket to Cylinder Head 65-80 Delcotron Bracket Brace 18-25 Delcotron Adjustable Mounting Bracket to Cylinder Head 25-40 Delcotron Mounting Bracket Thru Delcotron to Cylinder Head at Pivot Location 35-45 Starting Motor to Block 40-55 Distributor Hold-Down Clamp 10-15 Synchromesh Lower Flywheel Housing Plate 9-13 Flywheel Housing to Cylinder Block 45-60 Fuel Filter to Cylinder Head 7-10 Cheers! Erik
