Literally sick over this. I've done the trouble shooting and have info and pics.

[Blessed66]

That sucks to hear, but if I were you, I'd start getting ready to pull heads and see if the problem is smaller than you're anticipating.

Gaskets can really make your day go from bad to worse, ask me how I know.

[weider1717]

Thanks for the advice and input guys I hate it happened but I do enjoy doing things like this myself and makes it a must to order new things for the garage, haha.

Just ordered a valve tray organizer always said next time I take a set of heads off that will be one thing I will have on hand

Will post a couple pics and what I find when the heads come off.

[esbstuff]

Originally Posted by bhc41051

It's a 1987

bhc41051, thanks for answering!

Thats what I thought... With it being low mileage, I suspect that the motor is original and is one of GM's recall blocks.

With that being said, in the 87 and early 88 model year there was a casting flaw in one of the cylinders. This flaw let antifreeze on the crank case when the piston is in the up position. Some motors leaked more than others and some got worse over time. Dad had an early 1988 NB truck (#937) that leaked a quart every 3K. When he brought that to the attention of the GM service guy, the dealer replaced the motor under warranty. With that being said, we noticed the leak at 15K, but drove the truck till 32k before getting the motor fixed. 1) We considered it free motor miles and 2) The leak got worse over time. Since GM was building NB and OB pickups at the same time and using motors from the same run and different plants, it was common to have the same problem in both trucks.

Basically, I would recommend to check the block out real good before I spent a lot of money rebuilding it. Odds are if it has not been replaced, the block is cracked.

[Damien]

Head gaskets, heads and block are all possible causes of coolant in the oil, but this is a TBI engine which are very well known for leaky intake gaskets. The intake gaskets usually leak to the outside of the engine, but it could be leaking into the valley. I would closely inspect the intake gaskets as you tear the engine down. If you are lucky that might be all you need.

[redneckwheelman2]

Damien
I think your thinking of vortecs. Tbi has the same gaskets and amount of bolts as a carbed motor just the two center bolts are vertical. Vortecs only had 4 on each side plus there plastic intake made the gaskets blow out pretty easily

[weider1717]

Well I left the drain plug out over night and the cap off to let all that mess drain the most possible.

Then I put in new cheap oil and filter tried to start it and it tries but won't turn over it's like it's locked up, bummed even more right now but thats exactly what it seemed to have happened is being drain and sitting over night what coolant was in there appears to have locked it up.

[68c10owner]

Originally Posted by weider1717

Well I left the drain plug out over night and the cap off to let all that mess drain the most possible.

Then I put in new cheap oil and filter tried to start it and it tries but won't turn over it's like it's locked up, bummed even more right now but thats exactly what it seemed to have happened is being drain and sitting over night what coolant was in there appears to have locked it up.

If its locked up you may need a new block. Hydraulicing a cylinder usually causes some damage. Pull the spark plugs and see if it will turn over.

I seem to remember a issue with the tbi intakes where some had small pin hes in the casting and it allowed coolant and/or oil usage.

[weider1717]

Originally Posted by 68c10owner

If its locked up you may need a new block. Hydraulicing a cylinder usually causes some damage. Pull the spark plugs and see if it will turn over.

I seem to remember a issue with the tbi intakes where some had small pin hes in the casting and it allowed coolant and/or oil usage.

thanks but lucky me it's not the engine seized something is dragging charged the battery good and hit it a couple times and it started possibly the starter dragging.

picked a bad time because nothing but the worst is in my head at this point

[68c10owner]

Years ago I did have a starter that wouldnt pull the gear back after it started and that would drain my battery. Took me forever to figure that one out.

[Corts60]

You should really perform a leak down test of each cylinder to narrow down the root cause of failure before you tear the whole thing apart and spend time and money you don't need to.

Buy or rent a leak down tester and follow the instructions very carefully.

[Damien]

Originally Posted by redneckwheelman2

Damien
I think your thinking of vortecs. Tbi has the same gaskets and amount of bolts as a carbed motor just the two center bolts are vertical. Vortecs only had 4 on each side plus there plastic intake made the gaskets blow out pretty easily

I have changed a lot of TBI intake gaskets because coolant was leaking either from the front or the rear of the manifold. I think this is a possibility and is the least expensive repair assuming the lower end is OK.

[weider1717]

A little behind but should be able to dig into it this weekend and see what the deal is. Best case it's the intake manifold but if not and the heads need to be pulled you can re-use push rods and rocker arms just not rocker arm nuts correct? What about head bolts?

Will get back with you with pictures of the outcome and if all else I will ask for help getting an order up from summit on a rebuild kit for this engine youtube videos make it look easy enough!

[redneckwheelman2]

They say you should replace the head bolts because they are torque to yields. But I've never had a problem reusing old bolts especially since a stock small block doesn't have that much of a compression ratio and the amount of bolts each head uses. I don't think I personally know anyone that has bought new bolts when redoing a stock motor or even slightly modified.
I'd just buy the complete top end rebuild gasket kit and any other gaskets you may need. I'd also pull the valves and clean all the carbon off them with a brass wire wheel in a drill then clean the block and heads up to all nice with the wire wheel too.
And put the new valve seals in too. If you have any oil consumption the new valves seals will most likely eliminate it or at least reduce it.
Just make sure you lube everything up good when you put it all back together.
Also you Could run a tap in all the holes in the heads and block if you want to clean up the gunk in them to make reasembley easier.

[74CustomK20]

When I resealed my 350 I reused my head bolts and just torqued them in the correct pattern. A couple problems later but none related to that.

[68c10owner]

TBI engines arent torque to yield. You can reuse them but make sure you use some sort of sealant on them.

Do not use a tap to clean the bolt holes. A tap will cut the threads as it goes in and will make the bolts fit loose which could cause them to strip. You need to use a thread chaser. A chaser will not remove any metal, just cleans up the threads.

['76 Big Block]

Something else to consider if you end up pulling the heads, is to look at the top of your pistons.
Chances are, if you're leaking coolant, one (or more) of the piston domes will be a noticeably different color. If you have a cracked head, that cylinder will run "cooler" than the others.
As for bad castings---I've run into this before when rebuilding a small block---some wouldn't even take a .030 over bore without requiring a sleeve. I personally junked that block and looked for a better candidate.....

[lgvl]

Any updates on this? I just read the whole thing and am dying to know what happened. Best of luck!

[SKT]

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Any updates on this one?

Certainly not the only one who is curious to know what it was.

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[SKT]

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Edit, appears the OP started another thread:

http://67-72chevytrucks.com/vboard/s...d.php?t=703004

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