6.9 Diesel Questions - Diesel Forum

tkulak · 10-25-2009, 06:42 PM

Hello, I have a 85 6.9 Diesel. It was running fine, then all of a sudden I am getting diesel in my oil the motor sometimes runs away after I turn the key off (I believe it is firing on the mixture of diesel in the motor oil). Could this be a leaking injector pump or something along those lines. Any help would be appreciated. I am a bit diesel stupid so any help with this would be appreciated. This is my cattle feed truck so I do not drive it every day.

Evel486 · 10-25-2009, 06:51 PM

First check the supply pump on the side of the block- if it's wet replace it. If not, it's most likesly the driveshaft seals in the injection pump. IP has to come apart, all seals replaced and a new drive bearing pressed in.(In other words an injector pump rebuild)

tkulak · 10-25-2009, 07:13 PM

Thanks, injection pump is what I was thinking as well. I appreciate the input.

Joe Mc · 10-25-2009, 09:47 PM

Evel486 suggested 2 different pumps, the IP, and the supply or lift pump.
Most of the Injection Pumps in use on these enginges have a weep-hole and will usually start leaking fuel on the ground long before it starts getting to the crankcase. The lift pump is the much more likely suspect than the IP, and it is cheaper to replace the lift pump.

Evel486 · 10-25-2009, 10:02 PM

Yes, cheaper to replace the lift pump. You can remove it and check for fuel leaking internally, but it is not common. The weep hole in the IP was introduced in the IH/Ford application in the 1986 model year. 1983-85 models had a brass bearing & no weep hole so seal failure resulted in fuel in the crankcase. These model IPs can be updated to the weep hole style but it involves replacing the pump housing & the driveshaft- both items a bit pricey.