Dieselcowboy 210 #1 Posted February 19, 2013 I have been noticing some oil running down my fresh overhauled engine. Finally checked it out tonight. The head gasket is bubbleing most of the way around it. Head was torqued at 25 ft lbs and then down to 30 after noticing that. Made no change being tighter. Has been loosing some oil on the dipstick also. Why would this gasket be leaking like this. I put a straight edge on deck and head during rebuild. Everything was flat. Should I have used some sort of sealer? Share this post Link to post Share on other sites
Jim_M 178 #2 Posted February 19, 2013 Put a new gasket in it and torque the head bolts to 35, that's what I torque the heads on pulling engines. Make sure you follow the torque sequence. Run it up to operating temperature cool it down and retorque to 35 ft. lbs. Your old gasket won't seal now no matter what you torque it to, buy a new one. Share this post Link to post Share on other sites
rmaynard 14,888 #3 Posted February 19, 2013 No matter how good the head looks with a straight edge, I always touch it up by placing a piece of 150 grit sand paper on the cast iron table of my table saw and run the head back and forth and side to side until I have equal hash marks over the entire contact surface. Then I follow that with 220 grit. Then get yourself a new Kohler head gasket and retorque. Share this post Link to post Share on other sites
Save Old Iron 1,563 #4 Posted February 19, 2013 Check for the head gasket sealing surface being flat in all directions. If you have access to a small pane of glass (known flat surface), wet the surface of the glass with water and lay a single sheet of wet dry 220 sand paper onto the wet glass. The paper will stick to the glass and allow you to place the head onto the wet paper and move the head in a figure 8 motion over the wet / dry paper. After a minute or so of the figure 8 motion, flip over the head and inspect the gasket sealing surface. You may find some spots on the gasket surface are shiny and some still rough and dull. The rough and dull areas sit lower than the shiny areas, indicating the head gasket surface is not completely flat. Any low spots present on the head gasket area will not receive a proper amount of "squish" and be susceptible to the pressure of the exhaust gases bypassing the gasket or eventually blowing out the section of the gasket. One other frequently over-looked item is the "fire ring" or lack of the fire ring on a new head gasket. The head gasket is a sandwich-like construction with several layers of different material built up to form the thickness of the gasket. Some after market supplier do not put a "fire ring" on the sandwich and exhaust gasses can delaminate or peel apart the unprotected area of the gasket in areas of low "squish". 2 Share this post Link to post Share on other sites
tunahead72 2,339 #5 Posted February 19, 2013 All good advice so far, I'll just add a few thoughts of my own... If you have a set of flat feeler gauges, try fitting a .003" feeler between the head and whatever "perfectly flat" surface you're using (glass, table saw table, whatever). If you can slide it in anywhere, the head needs to be resurfaced like Bob and Chuck have described already. Make sure the threads of your head bolts and the threads in the block are in good shape and clean, and give the bolt threads a little bit of oil before you thread them in. I usually thread mine in finger tight, then torque them all (in the proper sequence) to 20 ft.-lbs., then again to 25 and finally to 30. The torque spec for the K341 head bolts is 25-30 ft.-lbs. You shouldn't need a sealer if the head and block are both flat, but I do know some of the guys here use various products with good results. You mentioned you're also leaking oil around the dipstick, which makes me wonder --- is your engine leaking anywhere else? Is your crankcase breather working properly? Good luck! Share this post Link to post Share on other sites
rmaynard 14,888 #6 Posted February 19, 2013 Actually, glass is not flat. That is why I use the cast iron table of my table saw which is. Glass that is available today is called float glass. It is formed by pouring molten glass onto molten metal. Though it appears flat, it may be off by several thousandths overall a 24" length. A better surface, if you don't have a good table saw, is a quality granite counter top, although your wife may frown upon it's use for engine repair. Share this post Link to post Share on other sites
Mike336 55 #7 Posted February 20, 2013 Sounds to me like a breather problem or oil control ring issue ... Share this post Link to post Share on other sites
tunahead72 2,339 #8 Posted February 20, 2013 Actually, glass is not flat. That is why I use the cast iron table of my table saw which is. Glass that is available today is called float glass. It is formed by pouring molten glass onto molten metal. Though it appears flat, it may be off by several thousandths overall a 24" length. A better surface, if you don't have a good table saw, is a quality granite counter top, although your wife may frown upon it's use for engine repair. Good point, Bob, but glass is going to have to do for now. I don't have a good table saw, or granite countertops. Although my wife was lobbying for granite countertops a while back. Hmm... Nah, wouldn't work, she'd be able to pick up the smells of oil/gas/carbon before she even walked into the house! Maybe I'll stop by your place some time. 1 Share this post Link to post Share on other sites
