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Coolant in Oil, Frozen Block

17K views 54 replies 9 participants last post by  t.ashton 
#1 ·
I picked up a Truck that over heated after the coolant froze because it only had water. Oil looks like a milkshake and has coolant in it, coolant also has oil in it. The block heater plug came out of the motor when it froze. Bad head gasket or cracked block? Can the oil cooler freeze internally and crack? I don't see any external damage to the block. Engine still runs.

Any help appreciated.
 
#2 ·
Pull the heads off


2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, kory Willis tune on v2 for daily driver, 33x12.5 nitro at on 20 inch American steal wheels, modded factory air box, Profab Intake Horn, Batmo Wheel, Turbo port and polish, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust w/ 6 inch tip, 10mm lbz cp3 pump, Dual Yellow Top Optimas, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Contol arms, Drilled and Slotted Rotors on all four Corners, fed Y Bridge.
 
#3 ·
I don't know if it's common practice anymore, but blocks used to have freeze plugs that break at a lower limit than the block itself cracking.

Anything with water freezing in it could break, but being mixed with oil would mitigate that in the oil cooler. Things that had only coolant were more likely to break, which is probably where the oil coolant mix appeared anyway.

If it's still running pretty well at the moment; head gasket seems most likely.
 
#6 ·
Looks like my truck when I do injectors[emoji23][emoji23][emoji23]


2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, kory Willis tune on v2 for daily driver, 33x12.5 nitro at on 20 inch American steal wheels, modded factory air box, Profab Intake Horn, Batmo Wheel, Turbo port and polish, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust w/ 6 inch tip, 10mm lbz cp3 pump, Dual Yellow Top Optimas, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Contol arms, Drilled and Slotted Rotors on all four Corners, fed Y Bridge.
 
#8 ·
When you buy that cheap you can afford a lot. That sounds like a great deal, especially if you can fix the engine you have. If not then considering joining IAAI, Copart or one of the other auction sites. Sometimes you can get a truck that doesn't have many miles but has been burnt up or rolled for not much more than the value of the engine. You'd have a lot of spare parts for future reference too.

In Texas and the gulf coast there are lots of flood vehicles that go for cheap. If you can find one with clean oil then it could be exactly what you need.
 
#9 ·
Go for an early lly and throw some studs on it with all the electronics and youhave a bad ass deal bud


2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, kory Willis tune on v2 for daily driver, 33x12.5 nitro at on 20 inch American steal wheels, modded factory air box, Profab Intake Horn, Batmo Wheel, Turbo port and polish, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust w/ 6 inch tip, 10mm lbz cp3 pump, Dual Yellow Top Optimas, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Contol arms, Drilled and Slotted Rotors on all four Corners, fed Y Bridge.
 
#11 ·
Car? :frown2:
 
#15 ·
I found the leak. When I removed the water pump, the freeze plug that is behind the front cover was popped out. I might of gotten lucky. Question is, how do I clean 2+ gallons of oil / coolant sludge that is everywhere in the motor crankcase. Just pour fresh oil over everything and keep on draining? Any detergents that are safe?

 
#16 ·
Go buy a couple gallons of thinner or even better, use diesel fuel, then finish with gasoline. Then let it air dry.


2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, kory Willis tune on v2 for daily driver, 33x12.5 nitro at on 20 inch American steal wheels, modded factory air box, Profab Intake Horn, Batmo Wheel, Turbo port and polish, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust w/ 6 inch tip, 10mm lbz cp3 pump, Dual Yellow Top Optimas, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Contol arms, Drilled and Slotted Rotors on all four Corners, fed Y Bridge.
 
#18 · (Edited)
Step #1 is to seal the cooling system back up and see if it is complete. I'd be very surprised if that is the only problem. I'm thinking the radiator and heater cores may be in trouble too. Also look at all of the other core casting plugs to be sure they are in place. Be sure to look at the back of the block and heads.

If you go to a plumbing store you can get something that looks like a rubber freeze plug but it has a tire valve on it. It is used during construction to test sewer pipes for leaks. They come in assorted sizes. Use one of those in the hole in the water jacket behind the pump and then plug everything else that you have open with what ever you have at hand. Rubber freeze plugs work well for this but I also save all of the red plastic plugs that come on everything these days. You could use those if you have them. They are called carplugs which most people would pronounce car plugs but I call carp lugs. Pressure test the block to be sure that nothing has been opened up.

The good news about coolant in the oil is that antifreeze has corrosion inhibitors in it so it doesn't rust things. You didn't have antifreeze so you may have a little rust inside. If you were about to head out on an around the world tour then I would recommend that you disassemble the engine to check it out but if you are willing to accept a little risk and don't have an imminent departure then don't worry about it for now. Engines produce water as a byproduct of combustion. They are a little tolerant of water.

There are several ways to attack the sludge problem. All of them start with draining out as much junk as you can and putting on a new filter. If you have hot water available, spray it inside the pan through the drain plug hole. That will bring out a lot more sludge. There will be sludge under the valve covers as well as in the crank case and timing case. The best plan would be to remove all of the covers and clean everything out with solvent of some sort. Diesel works fine but perhaps kerosene would be better. Gasoline is also possible. You can buy a 5 gallon can of stoddard solvent that is used in parts washers. It has a little more affinity for water so it does better at removing it and when you are done with it you can save it for the next parts cleaning job.

A good way to apply the solvent, what every solvent you chose, is to use a garden sprayer that you can get from any home or garden center. You can pump it up to 30 PSI or so and it is like a really big can of carb spray. After cleaning it all up as good as you can fill it with oil, let it idle until it is hot and then do another oil change. Personally I would do a third oil change after a hundred miles or so but it may not be necessary. For sure, keep track of the oil level and condition until you are sure it isn't having more problems. If you can't start the engine for a while because you still have to put it back together then at least crank it to circulate the clean oil to as much of the engine as possible.

If you don't want to strip down the engine then fill it really full of stoddard solvent, kerosene or diesel and crank it over with the fuel injection disabled. By really full I mean as full as you can get it. Like 5-10 gallons. Remove the glow plugs or injectors and disable the injection. The idea is to slosh cleaning fluid all over the place to wash things out. You wouldn't normally do this but since the engine won't start it is ok. Only crank it for 15-20 seconds at a time. Crank it for a total of 5 minutes or so. Let it sit for a while and then crank it for another couple of minutes.

Now drain everything and crank it one more time with the drain plug out. Lastly, and only do this if you can finish the job right away, wash the engine out with clean hot water. Hot water in large quantities will remove more of the sludge than solvents alone. It won't rust things if you don't let it set inside the engine. Don't crank it while there is only water inside.

Put the drain plug back in and fill the engine back up with oil. Only normally full this time. You don't need to use expensive oil for this step because it isn't going to be in there long. Preheat the engine if you can by running hot water through the cooling system and preheating the oil before you put it in. Crank the engine again for a minute or two then let it set for a while so that sludge can settle to the bottom of the pan. Drain out any additional sludge you can but stop when clean oil starts to flow. Top up the oil.

Once the engine is back together and can run, let it idle until it is warm and then shut it down. Let it set for a few minutes and then see if there is more sludge at the drain plug. The oil will probably be getting milky again but it shouldn't be too bad. Start the engine again and let it get good and hot. Change the oil and filter. This time use good oil. After you get it back on the road go for a short drive. I'm talking 5-10 miles of gentle driving. Do another oil and filter change and it should be the cleanest inside it has been since new.

There is some risk to the bearings and cam from cranking the engine with solvent inside. You could reduce this risk by mixing the solvent with 50% oil but it really isn't necessary. At cranking speeds with no compression there isn't much load on the bearings and solvent will provide adequate lubrication.
 
#19 · (Edited)
If you get the engine clean enough to rust inside you will have accomplished a better cleaning job than I ever have and I've probably done this 50 times. Diesel and kerosene will not allow it to rust but gasoline or stoddard solvent may get it that clean. In themselves they won't rust the engine but they will remove enough oil film to allow residual water to rust things.

If it does rust it will just be a flash on the surface and of no consequence. If you clean it and then it will sit for a while before you can run it then you should put some oil down the cylinders and crank it to spread the oil. Rusty cylinders are probably the biggest risk. You should try to arrange the cleaning so that it ends with oil in the crankcase and fresh oil pumped through the engine to displace any water.

When I do this with an open engine I spray everything down as well as I can with WD40. It is literally the thing the stuff was designed for.

As far as rust around miscellaneous parts of the engine, try Evaporust. It is available in many places including the automotive section of WalMart. A wire brush and elbow grease works well for a lot of things too.
 
#20 ·
Thanks a lot for all this awesome info!

I drained like 5 gallons of sludge out of the motor so far. I got some kerosene and started cleaning it. Poured it on the valvetrain and behind the timing case. I'll get a garden sprayer tomorrow and attack the rest.

I'll pressure test the block asap as well.
 
#24 ·
Ok, I am almost ready to fire it up, but ran into a something dumb. I am hooking up the AC compressor and it has 2 plugs, one on the front and a red one on the back. I have 2 plugs on a harness nearby and the front one fits just fine, the rear one is not the same shape, it's round vs oval. Does the back plug not get connected? If so, anyone know where this other one connects? I don't see anything within the distance to connect it to.

Here are the pics.




 
#26 ·
The plug on the back of the compressor is also a pressure switch. It should hook to something unless the compressor has been replaced with one that had an extra sensor on it. Look around really hard for the connector.l

According to Alldata, it is a high pressure cycling switch. When the refrigerant pressure gets too high it opens and the compressor shuts off. There is another high side switch in the a/c line in the front and a low pressure switch in the accumulator up near the fire wall. The wiring diagram shows all three switches so I bet the a/c won't work until you find the connector. I think it will have a black and a dark blue wire but it may be light blue and dark green/white.
 
#28 ·
Everything comes from the harness over the top of the motor. Back track each branch


2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, Custom tune on v2 for daily driver, 33x12.5 nitro at on 20 inch American steal wheels, modded factory air box, Profab Intake Horn, Batmo Wheel, Turbo port and polish, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust w/ 6 inch tip, 10mm lbz cp3 pump, Dual Yellow Top Optimas, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Contol arms, Drilled and Slotted Rotors on all four Corners, fed Y Bridge.
 
#29 ·
It's alive!

fired it up, so far just idling it to get the oil to temperature so i can dump it one more time and put fresh oil again. Oil pressure is good, no leaks, no funny noises. I did forget to hook up one transmission cooler line and got 4 quarts of transmission fluid dump all over my garage and driveway lol.

Put a can of seafoam in the oil as well.
 
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