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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.
Its 400 miles on a full rebuild. I'm pretty sure its the thermostat. Since the rebuild the temp gauge would climb and max out after a few minutes and then come down to 180 when the thermostat opened. I didn't think anything of it thinking the new sender I got was just not reading properly. Well I guess this time the thermostat never opened. After the gasket blew I looked down and saw the temp was still pegged.
My fault. I should have looked into the thermostat not opening in a timely manner instead of thinking it was a sensor.
Why don't you drop the pan to check a couple of bearings (I'd do at least the front main and #1 or 2 rod; they're furthest from the pump) before popping the heads. Then, if both they and the journals look OK (read, "perfect"), you can compression test your cylinders to see how your rings held up without waiting until you've gone thru the process of fixing the head gasket(s).
As for the thermostat, suggest pre-testing them for proper operation prior to installation. I've found brand new ones which didn't function anywhere near their rating right out of the box. It shouldn't likely take much imagination to figure out why I started testing them myself...
Why don't you drop the pan to check a couple of bearings (I'd do at least the front main and #1 or 2 rod; they're furthest from the pump) before popping the heads. Then, if both they and the journals look OK (read, "perfect"), you can compression test your cylinders to see how your rings held up without waiting until you've gone thru the process of fixing the head gasket(s).
As for the thermostat, suggest pre-testing them for proper operation prior to installation. I've found brand new ones which didn't function anywhere near their rating right out of the box. It shouldn't likely take much imagination to figure out why I started testing them myself...
You just confirmed my problem...my temperature gauge was showing approx. 205*...using my infrared gun the area around the NEW thermostat reaches 210*F, then begins to drop down to 180*F. I watched it do this for about 20 minutes.......seems like you nailed it "faulty 180* thermostat!"
I've been down this road and I've learned over the year. After a major failure, just pull the motor. Everything needs to be checked anyway and the extra time pulling the motor will definitely pay off when you think about all that time learned over pulling heads or laying on your back dropping pan bolts.
Murphy's law got me too many times and I ended up pulling the motor anyway.
Good luck!
I've been down this road and I've learned over the year. After a major failure, just pull the motor. Everything needs to be checked anyway and the extra time pulling the motor will definitely pay off when you think about all that time learned over pulling heads or laying on your back dropping pan bolts.
Murphy's law got me too many times and I ended up pulling the motor anyway.
Good luck!
You're absolutely right about the advantages of pulling the engine out. With my overhead chain hoist it only takes me 3 hours to pull an engine and then once pulled I mount it onto my stationary engine stand. With the engine out its so much easier to work on; especially when it comes to torquing the head bolts.
As his oil filter isn't showing any signs of bearing material I would say there wasn't any lower end damage done but what troubles me is his claim of his breather being blown off; indicating cylinder wall or piston ring damage. He'll certainly know more once he gets the heads off.
As an experienced engine blower upper, (3 this year) u definitely should pull it apart. And unless everything is "perfect" it's start over time. 3x I said it's good enough. U get sick of spending more time on a creeper, than behind the wheel
I pulled the heads this morning. Neither head gasket was blown and I put a straight edge across the heads and no warping. Now I'm starting to think the block failed somewhere. There was absolutely no oil in the cooling system but coolant in the oil. The cylinder walls look and feel ok. Below are the pics.
That's the #7 exhaust valve, not #1.
Just a question for thought. If the head gaskets didn't blow and there's no holes in any of the pistons, where did all the crankcase pressure come from?
Another thought. If coolant did get into the cylinders, where did it come from? The water passages are too far from the intake ports.
Cylinders 7, 2, 4, 6, and 8 look a little lean but normal. Cylinders 1, 3, and 5 look like they had a problem. None of them look steam cleaned.
Your cylinder #1 shows no signs of carbon on the top of the piston so I would look very closely at that cylinder. When a head gasket "blows" it usually lifts up on one of the ends and coolant from one of the little holes gets into that cylinder. Your head gaskets may show signs of coolant getting across the gasket. Look VERY closely at the stainless steel fire rings.
Time to tear it down and sonic test the block for sure.....
Odds are, after a tear down, good cleaning and inspections, most of your parts will be re-useable, even the bearings... but I would HAVE to do a full cleaning and boil that block to make sure you get the coffee cream out. Then you need to find where the coolant came from. Odds are, the block is cracked somewhere if you didn't see anything obvious on the head gaskets.
I will bet you have an intake gasket failure. VERY COMMON on new builds. The cylinders look to be sucking oil from the valley on the drivers side for awhile and I bet the coolant to valley area of the gasket finally let go when it got hot and pressure increased.
I dropped the oil pan. No metal. I then pulled a main cap and rod cap. Bearings look good. I went back and looked at the intake gasket that was mostly still on the manifold and it saturated to the point I'd call soggy. My best guess is the intake gasket failed which let coolant into the crankcase.
I also tested the thermostat which I suspected stuck. My 160 degree thermostat didn't open until over 200 and then it only partly opened.
Since I don't see any damage I'm going to flush the engine, reassemble and see how it goes.
I will bet you have an intake gasket failure. VERY COMMON on new builds. The cylinders look to be sucking oil from the valley on the drivers side for awhile and I bet the coolant to valley area of the gasket finally let go when it got hot and pressure increased.
08-12-2015, 07:11 PM
