I'm pretty much grasping at straw here, but could removing an intake while there is coolant in it cause coolant to get into the oil?

Backstory: A couple months ago, my Vette overheated. Long story short, I replaced the radiator, and it was good. But it was using oil and blowing white smoke on startup. So I changed the headgaskets. Never did it before, but fairly straightforward, right? I had the heads re-surfaced, and put it all back together. Put a new Edelbrock intake on it. I changed the oil and ran it for a few minutes. But when I checked the oil, there was coolant in it. I pulled the intake, checked the gaskets, made sure everything was good, and put it back together. Another oil change, started it up, and still coolant in the oil.

I took it to the garage, and they pressurized the coolant system, and only lost about 1 psi over 15 minutes. Pulled all the plugs, and they looked good. Compression on all the cylinders was good. So I took it home.

Again I drained the oil, and changed it, but like a dummy I forgot to change the filter. Ran it for a few minutes, and again coolant in the oil, but it didn't seem quite as much. I didn't run it as long though.

So basically, I probably have a cracked head or block. But each time I pulled the intake, I only disconnected the hose and pulled it off. Could that have spilled enough coolant into the engine to be what I'm seeing?

 

Yes, Any coolant left in the intake will run right into the engine straight to the oil pan.

 

The coolant will sit at the bottom of the pan. Drain until oil comes out the oil drain, that should remove the coolant. run the car some more. after it cools, see if there is more coolant in the bottom of the pan by draining again.
I'm hoping for you but it doesn't look good.

Later, Rog.

 

Did you use any thread sealer on the head bolts ?
Peace,,, moosie

 

Did you resurface the heads.

 

Yes, and yes. I'll be pulling the heads off tomorrow, to get them checked for cracks. Hoping to not have to pull the block, but gotta do what you gotta do.

 

It's surprising that whoever resurfaced your heads didn't check them for cracks before they did it. If they turn out not to be cracked, make sure to use sealer on the head bolt threads as moosie mentioned...this is essential on Chevys since the threads go into the water jackets, and it would be a good idea to put a thin bead of sealer around the head-to-intake water ports as well. This still applies even if your heads are cracked and you get a replacement pair...

 

Was there coolant in your oil before you pulled the heads the first time?

 

There was not, at least not anywhere near this much. The heads were warped a bit though. I talked to my local engine builder today, and he is optimistic. We shall see.

 

I'd replace the heads if you can afford it.

 

It was about .006 out, and I had them resurfaced, so it should be good. They will be magnafluxed, so if that comes out ok, I'm gonna try to use them. I have too many projects right now, and this wasn't supposed to be one of them lol.

 

Nice of them to want to mag them AFTER they got you for a surfacing

Hope for the best anyway keep us posted.

 

Lol, yeah, but I didn't ask him to. He checked them visually and they looked good. We have a pretty good relationship, so it's cool. He built a 383 for me, and has helped me with a lot of little issues for no charge, so I don't hold it against him.

 

If removing the upper hose to drain the coolant before removing the intake is all you did to drain it then quite amount of the coolant could have entered the engine, as much as one +pint.
Just a thought, .006 is not much, check the fit of the manifold to the heads and block and dont forget the RTV sealer around the coolant ports in the head to manifold, insurance.

 

Yes Sir; Some times when you mill the heads, you need to mill the intake also. How much did you mill the heads?? Yes, when you overheat the engine, some times you crack a head. I would of thought that the guy that milled the heads, would of checked for cracks first, before milling. Have you talked to the shop that did the job for you? Sorry your having the problem. Put a set of Vortex heads on it, it will add around 45 H. P. without any changes. Have a great day. Gene

 

Sorry I haven't replied until now. The heads were only milled about .006" so I don't think that should have affected the intake. I have a good relationship with the guy who milled them for me. He did a complete build of a 383 for my truck a couple years ago, and did smaller jobs for me both before and after.

He checked for cracks visually on the heads, multiple times. He also came out to my house and checked the block. It is still in the car, but any cracks big enough to cause the problems I'm seeing should be visible. We're talking a massive influx of coolant. He says he's almost positive this issue can't be caused by a crack.

With fresh oil, the engine doesn't need to run for even a minute before the oil starts to look like soured milk. There is also an odd sound, like glug, glug when it turns over. Funny way to put it, but I don't know how to describe it. It sounds as if liquid is being pumped through somewhere...

Could there be an issue with the intake? It's new, and there are no noticeable cracks. If this was a head or block issue, why would it only show up now, and not before pulling the heads? Yes, I was loosing coolant, but not into the oil. New heads certainly aren't in the budget. If I have to, I will, but only as a very last resort.

 

Yes Sir; Please keep us posted on what you find. Have a great day. Gene