crank position sensor on a 93 k2500?

[bx8lugger]

hello everyone, i just bought a 1993 chevy k2500 with a 6.5 trubo diesel with automatic 4l80-e in it. it has 211,00 miles on it as of right now. it needs alot of work so i have been removing and replacing alot of parts to make sure it is reliable since i have everything removed right now and its easy to work on. i noticed when i removed the crank pulley and harmonic balancer that there was a crank position sensor in the lower gear housing with the harness running up to the injection pump. as far as i understand the 92-93 6.5td doesn't have a cps cause the injection pump is mechanical and has no pmd. also i was trying to find the engine serial # on the block under the a/c compressor and on the top of the block on the driver's side front and there are no numbers etched in the block. the only # i found was at the driver's side rear under the oil pressure sensor casted into the block.

is it safe to say that i have a replacement engine in this truck? or did gm just put a sensor in with no use for it?

[DaveBr]

Cast on the back of the block on the drivers side between the head and the firewall you will find your egine ID #. If it is an 92 - 93 engine the last three digits will be 599. Newer years will be 506 or 929.

[bx8lugger]

i found the casting number and it ends in 506. so i have a 94+ engine in this 1993 truck. now i might have a problem with buying parts, i already bought a harmonic balancer and crank pulley cause the other were cracked in the rubber. the front pulley shows the same number for all years but the harmonic balancer shows 92-93 has one number and the 94+ has a different part number. should i return the one i both and get on for a 94+. what is the difference between the years?

[JohnC]

The '94 pulley is shorter to accommodate the reluctor wheel for the CPS.

[bx8lugger]

so if i use the 92-93 harmonic balancer it will hit the ring in the gear housing where the cps is? i should buy a 94 one then and return this 92-93 one i bought?

[DaveBr]

Use the same one that is on the engine now. I would guess it's for a 94+. Pull it and compare it to the one you bought. If it ran well before then don't mess with it.

[bx8lugger]

i have to change it, it has chunks of rubber missing and cracks all around the rubber on both the pulley and the harmonic balancer. i did a little more research and i found that my casting number ends in 506 , so it a 97+ block. i'll measure the harmonic balancer shafts tomorrow to see how much of difference there is.

[JohnC]

Someone else probably knows for sure, but, I think, if you remove the reluctor wheel (or if it has already been removed) you can (must) use the early pulley.

[bx8lugger]

ok i have got the final answer to my own question. i checked the casting and production cod on my block. i have a 12555506 block,( 97-01 block). my production code was G200( pita to get at this number) the G is the 7th letter making it the 7th month and the 20 is the date of the month produced, and the 0 is the year for 2000. so now i know i have a 2000 "506" block , thats why i have the crank sensor there not hooked up. also i found that the block is a replacement, due to it not having any engine serial numbers to match the vin etched on the front top and front pass. side of the motor. im a little happy about this cause since its not a junkyard motor removed from another truck it has less mileage than the truck has. as for the harmonic balancer situation, 6.2 and 6.5 engines up to 1993 use a harmonic balancer with 1 1/2" shaft that goes into the gear housing on the crankshaft due to no cps sensor and reluctor ring. this one is dorman part number 594-128. the 94+ 6.5 engines habe the cps to assist the pmd, so there is a cps and a reluctor ring in the gear housing on the crankshaft. so this on uses a harmonic balancer with a 7/8" shaft that goes into the gear housing for clearance of the cps reluctor ring and sensor. this one is dorman part # 594-170. the front crank pulley is the same for all 6.5L engines with serpertine belt, dorman part number 594-037. the front pulley is different for the 6.2 engine cause of the v-belt setup.

i hope this will help anybody that had the same problem i had. but at least i now know what i have in the truck for future reference.