I had to trade in my Duramax after I started getting HG issues and our Subaru was in the shop with a cracked piston. So I bought this truck almost 2 months ago, it has 57K original miles, straight up timing gears, Edelbrock intake / carb and Magnafows.

Ill try to provide as much documentation and symptoms as possible. The truck probably had 10K miles on it in 9 years so it did alot of sitting. When I got it home and started going through it I had to replace the water pump after it started leaking and the timing cover was leaking oil so I replaced everything, timing cover, water pump and water pump backing plate. Ive changed the oil three times, once when I got it and twice because the water pump I got from napa was rubbing on the backing plate and I had to do the job again.

Ive been noticing the coolant getting lower and I thought it might just be burping out air so Ive been refilling it. I then noticed quite a bit of water coming out of the exhaust on startup. I checked the oil this morning and found a milky glob on the tip of the dip stick. That got the gears turning so I noticed the left side of the engine around cylinder 1 has rust below the heads. I also noticed what looks like blow-by or something coming out of the valve cover filter things. The truck held oil well for a few days after doing the timing cover but then started leaking again and Im not sure where the leak is but Im guessing the oil pan.

I have a little bit of discoloration on the coolant but very little, I flushed the system while the water pump was off. I would like to figure out whats going on and will post some pics. Thanks for any help.

 

Sorry the last pic is so blurry. I just did a compression check on the left side and I got 155 across the board. There's been 75 views so far and no input?

 

The small amount of glob on the dip stick could just be condensation. Are the coolant and oil levels staying the same?

The valve covers could be leaking a bit of oil, which could look like the oil pan is leaking. Clean the engine and watch for leaks

 

The valve covers are leaking again but nothing I can see below the cover just on top around the bolts. the coolant and oil level has been going down. There is a decent drip of oil now and there was not one after doing the water pump and timing cover the second time, at least not for about 3 days.

 

I hope you are driving it alot, and the thermostat is good. Short trips and a bad open thermostat will cause lots of condensation inside the engine.

If you really thing you are burning coolant, you may or may not smell anti-freeze at the exhaust pipe(but you usually do get a funny smell) and if you pull the sparkplugs, the ones that are leaking will look funny with green deposits on them.

 

I am not driving it alot and I know where you are going there, the more driving the more your burning coolant I think. I thought it might be condensation until I saw the coolant level . I have not smelled anything sweet and I put a piece of paper under the pipes, it looked like water with no color at all. The plugs have looked very clean so far, really clean almost too clean making me think its running lean.

 

Where I am going is, the engine has to be run and has to be up to temperature to burn all that stuff out of the engine. If you don't, it builds up and you get that foamy stuff inside. The exhaust also fills with water, and it rusts it out. The engine needs to get up to temp, so running it on a good trip and making sure it's coming up to temp helps get rid of all that junk in the engine.

If it runs good, I would keep coolant in it and drive it. I have had lots of little external leaks on different vehicles, and sometimes it takes me awhile to stumble upon what it is. A famous one that happens to a lot of people are the radiator hoses. They will leak some when you first start the engine up cold, and as everything warms up they will quit leaking. They are hard to find sometimes.

 

A leak-down test will tell you FAR more than a compression test.

 

if you have a head gasket problem, the coolant will usually have a bad smell to it, much different from the usual coolant smell.

the vapor coming out of the breathers on the valve cover could indicate that the PCV isn't working, which would relate to your oil leaks.

if i've understood you right, you're seeing absolutely no sign of coolant in the cylinders, and minimal suggestion of water in the oil, which can be blamed on condensation.
so at this point, it would be reasonable to suspect external leaks of both oil and coolant, and a lot less to worry about

 

Thanks for the reply. There is no pcv, all the emissions crap was stripped off. Ill keep topping it off but I have only seen oil leaking not coolant. I know one of the symptoms of bad hg's is the water pump going bad from over pressure in the cooling system caused by the exhaust gasses but Im not sure if that only applies to diesels.

 

There's your problem with the gunk in the engine. No PCV. The PCV valve is a good thing, it sucks all the junk out of the engine and keeps it clean. All that vapor in your engine is just sitting in there and mixing with the oil, and it forms a acid. The acid eats away at the soft bearing material in the engine.

Even the old engines had a road draft breather system to pull the gook out of the engine.

 

franklin is right. the other advantage to the PCV is it maintains a slight vacuum pressure in the crankcase, as opposed to positive pressure without it. that means that without it you'll be pushing oil out every place it can

 

Thanks for the heads up, I fixed that today with a closed pcv setup. I doubt it will stop leaking oil but I guess its a start.

 

After doing the PCV the oil leaks are almost not existent. Nice one.

 

Whoever decided to "desmog" that engine had no clue what anything does. Can you get your hands on a cooling system pressure tester? Some parts stores will loan them out for a deposit. I would pressurise the radiator and see what happens. 460 head gaskets are pretty durable.