Small Engines (Lawn Mowers, etc.): Briggs Oil Consumption, blown head gasket, gpm pumps

Question
Hi,
I have four Briggs 18 hp Vanguards Model 350447  1375-E1 and I have the same problem with all of them.

I get oil in the air cleaner housing fouling the air filter.

I am a mechanic by trade 20 + years but not a Briggs expert. I use these in my Powerwashing business coupled by direct drive to 6 gpm pumps.

All of these engines are serviced weekly 10-30 synthetic oil (Mobil 1) and filters changed every third time.

I did a leak down test can’t seem to find any problem, pulled the motor apart down to the block and everything is within spec. Total rebuild including new crank , pistons and seal kit which fixed the problem for three months  then it occurred again.

I called Briggs and they suggest I test the crank case vacuum while running they said 10 inches is the norm. I have about 3 inches.

I pressurized the crankcase by putting 10 psi in to the dipstick to look for seal leaks and found nothing.

I’m looking for ideas, any suggestions?


Answer
Hello Brian:

Have you Cleaned or Replaced the Crankcase Breather? Usually the Problem you Described is Caused by the Crankcase Vent Not Operating Properly, a Cracked/Broken Compression Ring Allowing too Much Cylinder Pressure Into the Crankcase or a Blown Head Gasket. I Use SAE 30 Synthetic Oil in All my Equipment and have Never had Major Problems with the Synthetic Oil. Also the Synthetic Oil Seems to Provide Better Protection to the Internal Engine Components. You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.smallenginepartswarehouse.com/parts.asp and Select the Shop Online Parts Look Up. Then Select the Model Tab. Then Select the OEM and Enter the Model and Type Numbers. Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 9pm EST (US). My New Day Starts then. Thanks.

Respectfully

John