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Off Topic Forums => General Chat => Automotive => Topic started by: gli7ch on March 08, 2008, 01:37:00 PM

Title: Cracked Block?
Post by: gli7ch on March 08, 2008, 01:37:00 PM

Alright fellas, Just went outside to check on the 96 Blazer to find anti-freeze in my oil

I know the main cause of this would be a crack somewhere in the block

What I am trying to find out is if it could be something else, as that would need an entire engine swap

I am thinking it could very well be a head gasket, or something

More information is needed.

Title: Cracked Block?
Post by: kirky1991 on March 08, 2008, 03:35:00 PM

head gasket or cracked block sounds the most likely, If its the head gasket....does you engine get hotter than it should be etc ?

Title: Cracked Block?
Post by: StrictPuppet on March 08, 2008, 04:19:00 PM

Intake manifold gasket.  Guaranteed.  Done tons of em.

However, coolant and engine bearings do not get along very well.

If it hasn't been going on for very long, you may be able to get away with just replacing the intake gasket.

Title: Cracked Block?
Post by: gli7ch on March 08, 2008, 06:57:00 PM

Thats what I was going to look at first was the intake manifold gasket, since my head gasket is a little harder to get to...

Well the truck will be at around 210-230 temp. range and my radiator isn't even hot at all

Niether were the hoses or the intake manifold.

Also It seems like I was pouring in antifreeze and it wouldn't take it all, used a whole gallon.

I am having to use this Dex-Cool GM antifreeze

This is a pretty recent problem, as I had done an oil change in late Jan. of this year and the oil was fine, kinda black but ya know

Title: Cracked Block?
Post by: StrictPuppet on March 08, 2008, 08:24:00 PM

Dexcool is somewhat nasty stuff.  Conventional green antifreeze doesnt seem to be as harmful if you leave it in too long without a change.  If you leave Dexcool in longer than recommended, it starts to eat alot of gaskets up.  However, the main problem with the 4.3 engine of those years is the fact that they use a plastic intake manifold gasket that has a bead of silicone built in.  Over time the plastic cracks and the silicone bead is left unsupported.  The pressurized cooling system forces the bead out of place.  Usually if you are lucky this happens on the outside edge at the front of the manifold, and you just find a coolant leak externally.  But if it happens on the rearward side of the front coolant port, the coolant runs down into the lifter valley and drains down to accumulate in the oil pan.

Expect to pay somewhere around 4 hours of labour if you take it to a shop, as it is a fairly big job to do.  A good tech can do it in under 2 hrs.  If you plan to do it yourself, make sure you mark the distributor, and rotor positions, and dont turn over the engine while the distributor is out.  The only other pain is the a/c bracket needs to be moved.  Whether it has a/c or not, it doesnt matter, they all have the bracket, which also holds the powersteering pump.  You need not remove the bracket, just all the bolts holding it to allow it to move forwards about an inch and a quarter.  This would also be a good time to fluch out the dexcool and replace it with conventional green glycol.

Title: Cracked Block?
Post by: gli7ch on March 09, 2008, 04:06:00 AM

Ah yes, no shop work for me

Rather do it myself, but I see what you are saying

$2,000 would get me a new engine straight from GM assembly line

I am going to look at it tomarrow, will post an update!

Title: Cracked Block?
Post by: gli7ch on March 14, 2008, 11:53:00 AM

Alright, finally got the intake manifold gasket on and sealed up good

But, the engine is backfiring on me while idling

I am thinking this could be an easy fix, as it could very well be some vacuum hoses,

My distributor cap was fucked, along with the rotor button so both were replaced

Coil was fucked as well, alot of Arcing marks on it, so it was replaced too

I am hoping the RTV does not have a leak in it

It is contining to get hot as well, but we haven't put any coolant in it yet

The radiator is still clogged all up with a rust/Dex-Cool type of sludge, So we didn't want to put any glycol in it just yet, just water

The water is probably making it run hot still, Not overheating, but run hotter than 191 degrees

Umm.....Yea i think that is it, we will probably have to get a new radiator cuz of that sludge

The good thing is that we got most of the sludge out of the block, and the water pump along with the heater core are fairly new so they shouldn't be too bad either

Title: Cracked Block?
Post by: gli7ch on March 17, 2008, 04:03:00 PM

Fuckin a!  Got the Blazer to run correctly now!

Distributor cap was plugged in the wrong order, causing the backfiring.

Overheating now seems to be a thing of the past, waiting for the radiator to cool down, then flush it again

DEFINITELY putting some Regular green antifreeze in it!

Thanks to all the suggestions and help!