Diesel Doctor

[impalaman]

Have 2001 IH 9400 i with n-14 cummins had the rod bearings replaced at million miles and cam bearings,cam follower gaskets etc. This was in febuary of 09" just few days ago under load it knocked some when shifted down and powered up.Know under load it seems like might have a slight or light knock it seems anyways. I noticed it leaks very little but does between the 2 rear heads could it be a head gasket or injector? I had all the head gaskets replaced when had stuff replaced,doesn't take much oil couple quarts every 1000-1500 miles. I use shell rotella t 15- 40 . Just curious not to worried but also don't want to harm something eithier.

[dieselmech2]

Is the knock up high or on the bottom end? Can u tell? What does it look like it is leaking coolant or oil? Does it smoke out the pipes? If so what color? Who did the work? Cummins, or another shop?


Brian
Bleckman Diesel

[Peteguy]

The leak you see around the heads is normal. Cummins once made a film of the N-14 using high speed cameras. They ran the engine at full load. In that film you can see the heads actually "snaking" or walking on top of the deck. This has always been the case with the 3-headed Cummins. Not enough cross strength causes the heads to walk. This is why Cummins can wear out a head gasket faster than any thing else. Especially at full load and high constant rpms. However, this does not indicate a problem. It is simply seepage working its way out between the block and head. So if this is not a bad leak (oil dripping down) then disregard it.

As far as the knock:

Use a cut garden hose as a stethoscope and listen around the engine to see if you can narrow it down. The air compressors on these are notoriously noisy. So you may check that as well.