In The News

Blown head gaskets on Caterpillar engines

Over the years we have noticed that many shops DO NOT check the liner protrusion on Caterpillar engines when installing a new head gasket or rebuilding the engine.  Every time an owner-operator had a head gasket replaced, or engine rebuilt I asked him what the liner protrusion was and he can never tell me.

When I have them go back and ask the mechanic the answer is always "It's within spec".  I'm sorry, but that’s not a good answer, it's a cop out. The mechanic never checked it or took the time to write it down. 

If you don't have at least .005 to .007 liner protrusion the head gasket will blow.  Right now in our shop sits a C-16 600 horsepower Cat with 499,000 original miles on the engine. Sixteen months ago an authorized Caterpillar shop replaced the head and head gasket, and now its blown again.  We removed the head, cleaned the block surface, cleaned the spacer plate, installed a new shim gasket (the gasket between the block and the spacer plate), and installed the hold down bolts which hold the spacer plate tightly to the block so you can mike the liner protrusion. 

What we found was .002 liner protrusion, which is not enough and that head gasket only lasted 16 months. Cat should have removed the cylinder packs, cut the counter bores to .026, and added a .030 stainless Cat Shim then reinstalled the cylinder packs in the engine.  Now the protrusion would be .006 and the head gasket would not have failed.

Lets face it, if an engine runs for 500,000 miles and looses a head gasket, that is not so bad, however fix it right the first time, do what it takes to get the liner protrusion where it should be and the owner-operator won’t have any more problems.