Get a good straight edge and some feeler gauges. Lay them across the surface of the head in all orientations. (across front/back/middle, diagnally across corner to corners) See if the feeler gauges will slip under at the end or the middle of the straight edge. (or you can see light...)
If so, it's warped. How warped is too much? If I can get my finger nail under it, it gets some attention.
Keep in mind that having it planed will make the surface flat, but bolt it up now and the camshafts are now continuously being bent ever so slightly...
Heads can now be heat straightened. This brings the cams back in too.
If it's not bad and you don't have a Torque to Yield head bolt setup, I've over torqued the head bolts by up to 10% to compensate on minor warpage. Seems to work. No leaks yet, although all car guys will probably say I'm on crack.
Most common seems to be heads warped away from the block in the middle. This is where I over torque the bolts just a tad in a reducing pattern out from the center. So, if the head called for 70 ft pounds I'd torque the middle bolts to about 78, next row out to 75, and so forth.
Don't blame me if it doesn't work for you or you snap off bolts.
engine wont be warped but the head may be if you didn't overheat engine too much and fixed problem pretty quick, it wont be warped above answer says about bent cam. that is bogus but if head is warped, just go buy anew one and replace specially if aluminum they cannot be straightened if torque says 70 use 70.if u snap a bolt off going over the proper torque then you got to generally take head off and hope there is enough broken bolt showing to be able to remove it with out drills and easy outs PS a camshaft will break before it bends.
rotted out headgasket and/or warped cylinder head . Aluminum head sensitive to no water in the engine.If it's just the headgasket it's not a big deal on a 4 cylinder datsun engine
Most likely causes are a failed headgasket or cracked/warped head.
That's usually a sign of a warped head and bad headgasket, a cracked head or a cracked block. Those conditions usually only occur when the engine has been overheated.
Either a warped head and blown headgasket or a cracked head. An intake gaslet will also blow and let it in on a 4.3. I had it happen.
Nothing good, I can tell you that. Anything from a warped head, cracked head, warped block, cracked block, and basicly, a blown engine.
It could be either the head gasket or the water pump is sucking a little air. Most likely the head gasket though. There are chemical tests to determine if carbon monoxide is getting into the coolant. If it IS, you have a bad headgasket/warped head.
You can blow a head gasket or the head can crack or be warped.
First of all how do you know your head is warped cracked or no good lets start at the beginning
You probably have a blown head gasket or a warped head
A bad head gasket , a warped head usually from overheating , would allow engine coolant into an engine cylinder
Overheated engines often cause the head to warp, resulting in a blown headgasket. If the engine blows out the coolant, you have a bad head gasket/warped head. If you're getting coolant in the oil, same thing. If one or two cylinders have very low compression, same thing. It's not news that anyone wants to hear, but I'd check that first since it's a very common condition after an engine overheats.
well, first throw it away then buy a new one.