Your ecperience with cracked blocks

I am wondering in your experience how often when you find coolant in the oil and white exhaust smoke that the block is cracked if it is cast iron?

Reply to
stryped
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Depends on what engine it is. Some are very prone to gasket issues, some don't seem to be. Cracked heads are more common than blocks, but sometimes blocks crack too.

--scott

Reply to
Scott Dorsey

The most common reason for cracked blocks was adding only water in days of essentially unsealed cooling systems, and having an inadequate freezing point on cold winter nights. CI cracks just as easily as aluminum if the coolant freezes.

Reply to
Don Stauffer

On a 3.9 dodge v6. It is cast iron blcok and heads. heads magnafluxed cracked. I am about to start it tonight and am nervous. I could not find any bad spots on the old head gasket. I replaced the head gasket and heads. If it still has an internal coolant leak the only thing it could be would be the block I guess.

Reply to
stryped

There is a chance the block (where the heads mount on there) could be warped.If you have access to a long enough steel machinist straight edge, you can check the block. cuhulin

Reply to
cuhulin

305, Light Casting Chevy's are notorious for cracking at the lifter valley and the galley's.
Reply to
thenitedude

Keep in mind that you're going to see a LOT of smoke from this thing for a while regardless of the blocks condition. It has been setting and you can bet that condensation has left some water in the pipes, as well as the amount from being run with the cracked heads and bad gasket from before. You will need to get it warm enough to boil out all that water before deciding that you still have any problems.

Once you get it running you can get a test kit from many parts stores that will tell you if there are combustion gases in the cooling system. BUT you don't need that yet. Get it started. Warm it up good and see what you have.

Hope you picked up more oil and filters because you will want to change those as soon as you get it warmed up.

Reply to
Steve W.

305, Light Casting Chevy's are notorious for cracking at the lifter valley and the galley's. ******* The GM 2.5 litre Iron Duke 4 cylinder engines of certain series were almost sure to crack. A GM guarantee to the customer, you might say.

So your point is well taken...Some engines are much worse than others.

The parent engine from which this V6 was derived was tough as nails, but that doesnt necessarily mean that the V6 variant is. Maybe somebody here has some facts about this particular block. It was my impression that it was tough, but even tough engines crack at times.

Reply to
HLS

How much smoke should I expect?

I plan on putting oil and filter in it before startign it tonight and again after it has shut off. Maybe let it idle for 20 minutes or so?

Reply to
stryped

As much as it takes to boil/burn out all the water coolant that has gotten into the exhaust. Since I don't have a clue how much that is ????

Not just idle, run it up some and put it in gear a couple times to load the engine as well.

The oil/filter change is determined by how much water/coolant got into the oil system and got circulated. Being that you drained out the old oil/water that was in there you MAY get lucky and have the second change be enough. You will want to get the engine good and warm and idle may not do that. Then drop the oil while it is still warm BUT let it set a bit so that any water should drop to the bottom and come out with the oil.

Reply to
Steve W.

How much smoke should I expect?

I plan on putting oil and filter in it before startign it tonight and again after it has shut off. Maybe let it idle for 20 minutes or so?

In not too distant past, I experienced several repairs which had to be driven several miles, and a couple (specifically v-8's) needing stopping & cooling & re-starting multiple times to remove all condensation from exhaust system. So be patient. hth, s

Reply to
sdlomi2

Those Quad-4 o/h-cam Pontiacs were even worse--in my experience--than the Iron Dukes. Q-4 cracked heads when they merely overheated, which they did too often; and ID leaked and cracked heads when their head bolts stretched upon overheating. [see:

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] But, wasn't that Q-4 power & performance noticeable, esp. relative to the I-D? Keep 'em cool(somehow?) and serviced, they both could give longevity! s

Reply to
sdlomi2

In my experience, they never stop smoking unt

Reply to
Steve Austin

I suggest you worry about the things you can do something about rather than the things you can't. For instance, you need to make sure you get the air out of the cooling system so that the heads do not overheat again.

-jim

Reply to
jim

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