Cool95vette

Well the head gasket blew on my engine. I believe my thermostat was stuck close and didn't open. Didn't notice it getting hot as it was running fine and didn't smell like an overheating engine does. I noticed some smoke coming from my left tail pipe so I got on the gas some and then it went. It blew the cap off my oil filler tube and was shooting oil out of it. Luckily I was a few blocks from home.

I drained the oil and it was milky. At this point I don't know what to do about the short block. It wasn't knocking and was still carrying 60 psi of oil pressure when I pulled it in. In fact other than the oil coming out it was running fine.

My question is should the short block be torn down or can I try flushing out the old oil and refilling it with fresh? The engine only has about 400 miles on it.

'75

I would remove the oil filter and cut it open, take out about 1/4th of the pleated filter paper, squeeze the oil out of it with a vise, then open it up like an accordion, this will tell what's in your oil and give you a better idea of what needs to be done. With oil blowing out the breather, you may have scored a cylinder too.

doorgunner

If there is no metal flakes/shavings in the oil filter pleats......remove the head causing the problem.......rotate the crankshaft while inspecting all the cylinder walls/Pistons for damage.

Check the head sealing surface for warpage.

Check the compression on the other head/cylinders.

Post your results with pictures if possible.

If everything looks good...flush the block

Cool95vette

I'll cut the filter tomorrow and pull the heads this week. They're aluminum heads and I know they're more susceptible to warping. I figure I might as well pull both heads if I'm pulling one to check both.

I'll post pics of what I find.

ddawson

With aluminum I'd pull both. One did warp enough the other may be close.

Then get them milled so they are flat.

cv67

Coolant usually takes bearings out with it. Might get lucky might not
If its blowing that much coolant out the pipe if you have the means to just pull it out and freshen it up some doesnt have to cost a fortune.
Edit: dont forget the cam bearings!

TimAT

New bearings are cheap when you consider what can happen when you lose one-

bluedawg

I agree with Tim, cuisinartvette and Dawson, you'd be better off to pull the engine check the crank, reset bering clearence and have both the heads and block checked for flatness.

TheSkunkWorks

Coolant usually kills the oil, which means your bearings are probably wiped. I'd definitely pull it and go thru everything. That said, don't cut corners, but try not to contract shipwright's disease while you're at it.

ddawson

LOL but it can be fun just expensive.

I went from needing a clutch to finding a bad pilot bearing, which needed a new crank which of course meant a 4.25" crank, which needs new rods.

Of course we might as well go roller cam while it's all apart.

rebel542

Replace the gasket and drive your car.

TheSkunkWorks

Run it with galled bearings and ruin expensive parts.

Scottd

I went from doing a rear main seal to finding a cracked engine block and total engine replacement. I feel your pain.

rebel542

Who said it had galled bearings? It's easy to spend other peoples money.

TheSkunkWorks

Until it's inspected, who can say that it doesn't? JMHO

flyeri

How hot did it get? Pull the heads and have them checked, repaired if needed. Check the block too.

The bearings are worth looking at. Drop the pan and remove a bearing cap, maybe two, and see what the bearings look like. If anything looks suspicious then its time to pull the engine for closer investigation.

Cool95vette

I cut the filter open. No metal anywhere. I got the intake and valve covers off. Below are the pics. I still have to remove the side pipes to get the headers out of the way to remove the heads.

After I remove the heads I'll have a better idea of what direction I have to go.

The service manager at our dealership suggested if there is no visible damage to use kerosene to flush the engine with a priming tool. Drain it. Then run shortly with oil. Then drain and refill with fresh oil again.

I'll post more pics when I remove the heads.

doorgunner

When you drain the oil/coolant,check for metal in the drain pan.

As things progress........If necessary....remove the oil pan/remove one main bearing cap and one rod cap to check for galled bearings.

toobroketoretire

Are you running the stock 7-blade clutch fan and full shroud or one of those goofy electric fans with NO shroud? I suggest you submerge your thermostat into boiling water and test it. If its even half way new it shouldn't have stuck closed. Yes, you have most likely blown a head gasket but you must find out WHY it blew before slapping it back together and having it blow again.

fathernson

400 miles and a blown head gasket?? Is it 400 miles since rebuild or since new ? Either way have you considered if you gotta bad rebuild or a bad initial build? Any warranty??? Good luck either way my sons 80 overheated and blew off the upper radiator hose on his way to work. He did good and pulled over immediately.