Service difficulty report · Guide

Difficulty date
December 5, 2013
Submitted
December 20, 2013
Operation
General aviation
Part
Guide
Part number
AEC630262
Part serial
SA631496
Condition
Misinstalled
Location
Cylinder Head
Stage of operation
IN
How discovered
V
Nature of condition
W
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

DURING DISASSEMBLY OF ENGINE, DISCOVERED THE INTAKE VALVE GUIDE SEALS WERE INSTALLED ON A LONGER AFTERMARKET DESIGN THAT DOES NOT REQUIRE SEALS. AFTERMARKET VALVE GUIDE DESIGN IS SLIGHTLY LONGER THAN THE CURRENT FACTORY GUIDE. BY INSTALLING THE LONGER VERSION GUIDE AND SEAL, IT CAUSES THE RUBBER AND SPRING TO COME IN CONTACT WITH THE ROTO COIL WHICH INTERNALLY DESTROYS THE SEAL. WHEN THE SEAL DISINTEGRATES, PIECES OF THE RUBBER SEAL AND SPRING DROP INTO THE OIL PAN AND CAN POTENTIALLY CAUSE ENGINE METAL CONTAMINATION AND POSSIBLE BLOCKAGE OF OIL PASSAGES. THERE IS VER LIMITED INFORMATION ON INSTALLATION OF THIS GUIDE AND SEAL COMBINATION. CSB95-4 TOUCHES ON THIS PROBLEM BRIEFLY, HOWEVER, IT ONLY COVERS THE CERTAIN MODLES. THERE IS NO SUCH INFORMATION REGARDING OTHER ENGINES. IT HAS NOT YET BEEN DETERMINED HOW MANY SEALS HAVE BEEN INSTALLED INCORRECTLY. WE ARE CURRENTLY RESEARCH PREVIOUS RECORDS TO DETERMINE ACTUAL NRS.