White smoke is cracked head or gasket

[tk1251k]

Drove 5 miles sat. parked the truck go tout smoke billowing out the exhaust pipe and where the exhaust header connects to the tailpipe. Drove it back home with a trail of smoke parked it checked water filled it up water coming out the exhaust manifold flange and tailpipe. Ran good all the way home. I then checked oil for water it was good and no oil in rad. Ran some more at idle with smoke still coming out then notice today the oil very milky and several quarts over. Pulled the pluges on passenger side and noticed the plug on the front wet . Fired the truck up water coming out that cylinder.Truck body wide great shape and I have had it since 1981 . Its a 1972 Sierra Grande. Not sure if I want to fix it myself or just get rid of it. I rarely drive it any longer but just need some input as to what it might be other than the worse which I beleive it is.

[Grumpy old man]

Stop running it , stop driving it , once you found the milky oil you need not start it again , time for some head gaskets . Or since you don't sound like your attached to it sell it to one of the guys in here at a deal and let them fix it and drive it while the price doubles ! Oh that got your attention now didnt it ?

A set of head gaskets are cheap and 1/2 a Saturday and your done .

[tk1251k]

Have not driven it since I got it home just idled briefly checked oil afterwards and it looked fine until I let set for 2 days and the oil turned to milk.I drained the stuff out today.

[CCCC]

Could be lucky and it's a blown head gasket, but that seems like a lot of coolant leakage for a gasket issue. If it's a head or valve seat crack, you should know when you get the head off. After that, it seems to get worse.

[LongBox]

Since we don't know the condition of your truck, it's hard to give advice, but this could be an inexpensive fix (head gasket(s), mid-price (a replacement head), or you might be needing a new engine. A crate engine is not all that expensive when you consider the value of these trucks if they are in good condition, and well-optioned. You say it's in great shape, and a Sierra Grande, that usually means higher value. If it were mine, I'd get it fixed, even if I needed to buy a crate engine.

[tk1251k]

Can the intake leak coolant into the oil by any chance?

[special-K]

Originally Posted by tk1251k

Can the intake leak coolant into the oil by any chance?

Yes. That is what makes the oil milky. You can have a coolant leak that doesn't get to the oil also.

I would fix the truck, no matter what it is, whether you keep it or sell it. You have owned the truck since '81. It has gone way up in value. Worst case it needs an engine. Put a crate engine in and continue to enjoy or put crate engine in and get best dollar for your truck and sell way easier than as a project...unless offered at give away price.

[67 chevelle]

Possible causes
gasket
warped head
cracked head

Did it overheat right before this ?
I would take heads in and have them refurbished

[tk1251k]

Originally Posted by special-K

Yes. That is what makes the oil milky. You can have a coolant leak that doesn't get to the oil also.

I would fix the truck, no matter what it is, whether you keep it or sell it. You have owned the truck since '81. It has gone way up in value. Worst case it needs an engine. Put a crate engine in and continue to enjoy or put crate engine in and get best dollar for your truck and sell way easier than as a project...unless offered at give away price.

I have water in the front number 7 plug well.If intake is leaking could it just leak into this one cylinder only then down the cylinder into the oil?

[GASoline71]

You won't know anything until you tear it apart. I wouldn't start it again. All you're going to do is more damage.

Gary

[tk1251k]

It is sitting in my driveway and getting cold so I don't think I want to mess with it and may dump some sealer into it just to get the thing moved and sell it as is nothing to lose by trying to seal it shut just to get it moved. From what I have read the engine is probably damaged even thought the oil was not contaminated until I let it set for 2 days then cranked it up and let it idle a few minutes then shut it down checked oil and it was milky quite a bit. So I think I will try something just to get it running long enough to add some sealer and stop the leak. It is rarely driven anyhow maybe tear it down later. I would never sell it without letting the potential buyer know the facts.I would never ever do that under any circumstance to someone.

[Daves70]

Mechanic in a can won't fix this. It's most likely a bad head gasket and it'really not that huge of a deal but....if you keep starting it and runnig water through your bearings then it will be a huge deal for sure. I'd say to tow it to a mechanic you trust and have it fixed properly then if you still want to sell it then you won't be selling a problem with the truck. A shop shouldn't charge to much. This is a fairly common issue to have on a older engine that has been siting alot.

[tk1251k]

Originally Posted by Daves70

Mechanic in a can won't fix this. It's most likely a bad head gasket and it'really not that huge of a deal but....if you keep starting it and runnig water through your bearings then it will be a huge deal for sure. I'd say to tow it to a mechanic you trust and have it fixed properly then if you still want to sell it then you won't be selling a problem with the truck. A shop shouldn't charge to much. This is a fairly common issue to have on a older engine that has been siting alot.

I don't think draining the oil a couple of times between letting it run for a minute or so will do any further damage if any has been done.I'll get the oil cleared and then add the quick fix for now and she what happens. Even if I have it fixed it would be the same procedure I would imagine.Taking to a garage for a head job would be expensive and no one to trust here.

[WorkinLonghorn]

If you have water in a cylinder and try to start it you will bend a rod, then it will no longer be a simple fix.

It really is pretty easy to take off a head on these. Just do it. I'm about your age and I don't especially like this kind of work like I did earlier in life, but still, I would do it. One Saturday and a few dollars and you will be back in business with a smile on your mug.

[GASoline71]

It beats a blown engine due to catastrophic failure and leaving you stranded somewhere. With a blown head gasket or a cracked head or block there is no "band aid" fix.

Gary

[tk1251k]

To cold to do anything right now. I have been read a lot on info before tearing into it. Some say these heads rarely blow head gaskets if of course torqued properly which these were. The hasn't been run hot if at all very short time and according to gauge not very hot. Can the intake leak into the number 7 cylinder as it seems I am hearing some talk about. Guess I won't know for sure until I get it off.

[GASoline71]

My main concern would be the water in the oil pan. Once coolant hits those engine bearings it act like a solvent and strips the oil from the bearing surface. If you keep running it, the crank and rods will dig deeper and deeper into the bearings. It's only a matter of time. Plus with over 350,000 miles on the ticker... it's long past its intended service life and ready for a rebuild/replacement.

Gary

[tk1251k]

I thoroughy drained is as soon as the oil got milky. When I first parked it the oil looked normal after sitting for awhile it milkly and I of course never drove after that but drained 3 times of oil after adding new oil. So hopefully no damge done to the bearings.Cranks as good as always. I have removed all water from the coolant since it is getting very cold here.