two 85 6.9s for sale .
#1 2 wheel extcab lariat 4spd captain chairs console bench seat.
new ip new dual exhaust developed knock last week towed home said wasn't spending any more clean no dents no rust very nice int rhino lining in bed.
#2 4x4 standard cab no rust 4spd rearend out I knew this truck ran good when parked been parked 4 or 5 years.
#1 manu date 1 85 this will not be the good block will it

 

How bad is the knock.... a weak injector can produce one like a rod bearing.. when it fires too early.

According to the update I have the updated casting was implemented starting with block number 173828 (which translates to roughly halfway through the '85 model year). 85 Model year started in Aug 84 do you feel lucky....

Other info
6.9 blocks up to serial #u2u17900 had a thinner casting around the block heater. It is very common for these blocks to crack.

Check the serial number of the block or.......

Block casting........INTERNATIONAL HARVESTER DIESEL ENGINES
6.9L Old Style Block
Block Casting Number:

On left side of block (beneath oil cooler) 1805440C1
Note: Some 440 blocks are truly new style and must be visually inspected by raised donut around the block heater, frost plug (right rear). Old style below serial number 173828.
Visual Identification: *No counter bored area for block heater
*No defined area on side of block for dip stick
*Thickness of cast iron around block heater 3/8" (.375")
Head Bolts: *7/16, 12 point socket is used to torque head bolts
*Block tapped with 7/16-14 for head bolts
6.9L New Style Block
Block Casting Number: 1807996C1 Note: Some new style blocks have casting
number 440. Above serial number 173828.
Visual Identification: *Has counterbored area for block heater
*Very defined relief area cast in side of block for dip stick tube.
*Thickness of cast iron around block heater 15/32" (.470")
*Latest style (not all new style 6.9) has ribs around head bolts, rear two on left side go from head gasket surface to pan rail - same as 7.3
Head Bolts: *Same as old style 6.9

 

nobody I know of in this area had a problem with cracking at block heater hardly ever plugged them in. Idont ever rember plugging mine in is that the only problem why can't we install oil pan heater or is there other problems with this block.
I didnt start it hate to put an injector and make the guy mad.

 

If you live in an area where freezing is not an issue you may get lucky...... oil pan heater heats oil .....not the block so cylinders have warm air/fuel to explode. Some have used the old tractor style hose heaters..... others have used Mom's hair dryer blowing in the intake.

You could disconnect the FSS on the IP......then roll it over by starter and listen for any bad knocks.... Pull the valve covers and see if there is a rocker assy worn badly or push rod bent. Check for fuel pressure out the Schrader valve on the filter header could be the lift pump arm is broken off....... we can guess all day.

One other thing it could be a flywheel...... they will crack and break sounds just like a rod bearing..... take a good peak in the trans inspection cover.

 

I want be cranking it till it comes home.

 

Starmilt, I just had a bad injector in my 1987 F250 with a 6.9. It knocked so loud I just knew it was a rod knock. I loosened each injector line and revved it up. When I got to the bad injector it would stop knocking with the line loose. As soon as I tightened it up it would resume knocking. That's how I figured out which injector was bad. I ended up putting in a whole new set of 8 injectors. It's never run this good before!