53 Block FAQ and Information. This site is more info on 53 block.

 

Update -
I was unable to locate a "53" anywhere on my block. I was able to find several numbers on the drivers side under the injection pump. The build date on the truck shows 10-00. Perhaps the previous owner had the motor replaced or I lucked out and have one of the good blocks. The temp is still moving between 185-204.. Coolant level goes down in the radiator and up in the overflow. My buddy forgot his "tester" today and we will try for tomorrow. No signs of coolant in the oil. No signs of coolant down the side of the block or on the ground under the truck.. At a loss right now. I am thinking either sending unit or fan?

 

Try turning the fan by hand. Should be just a little bit of tension and turn smooth. If it's free wheeling in there the fan clutch is shot.

 

The fan does have tension on it. Does not continue to spin. Kinda hard to spin but no troubles doing so, if that makes sense. I was reading on here that if you have rear disc brakes then your truck is an 01.5 and I have rear discs, so I guess this means 01.5? Not sure if this has any effect on the diagnosis or not, but thought it may be helpful.

 

Well were narrowin things down here. Sounds like the fan clutch is fine.

Next item up for checkin is the hoses. Squeeze em, without burnin yourself. Doesn't matter if they are hot or cold but what your lookin for is mushy spots. Sometimes when the system starts pullin pressure through them if they have a bad spot they suck shut and block the flow, then when pressure stops, you shut the truck off or it cools down they pop back in place and look just fine. Check the top and bottom hose although the top hose is the typical one that will have issues.

 

Had the hoses off on Friday of last week when I cleaned everything real well. Hoses checked out ok. When the truck is warm/hot the hoses seem very full (almost pressurized) and normal. There is still nothing on either side of the motor from the head and I keep checking the oil and have other guys at work check the oil. Everything seems fine. One guy did say that since everything seems fine now with the exception of the temp gauge fluxuating and the overflow becoming more and more full, that he bets its the head gasket just starting to fail. Is it possible that once the motor heats up the head gasket crack (?) opens and starts to pressurize the coolant and push my temps up and coolant into my overflow without any other signs? And if I do need a new head gasket, any ideas on which one? The local cummins parts place has an oem one for a tad over 200 bux? Planning on doing more upgrades later down the road as money is tight right now, is there another brand of head gasket that less cost better quality? And finally, I would be making the repairs myself, is there any tricks to know when doing the head gasket on the diesel? Haven't done motor work on one before, but have on gassers. A million thanks for all the help.

 

Soooo... Today I took my pickup to the shop and had the coolant pressure tested (up to 170*). Everything checked out ok. The tech took his little heat laser measure tool and noted that the temps the gauges were reading were off. So I went to Cummins NW and got a new sending unit. I replaced that tonight and its still jumping up! I am thinking that I will go to the mechanic tomorrow and pressure test when the truck is warmer. Does anyone have any other ideas?? Im lost here and dont want to have a super costly repair on my hands that I cant afford to repair. I've had a pretty bad week and could really benefit from some good luck.

 

Only thing I can still see accounting for this is no flow through the block. I still think you need to flow test the system in whatever manner you see fit.

 

How would I go about performing a flow test?

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Sooo... I have tested my coolant pressure at two different places with two different testers. Both are showing nothing abnormal. Coolant is flowing thru the system. I am not loosing any fluid, just was topping off the radiator after every viewing is causing the overflow to continue to fill.. If I do not add more, no more comes into the overflow (imagine that) .. Soo.. Now I am thinking that there may be something to do with the Quad or possibly summer grade fuel?? I'm thinking about sending it in for the firmware update and seeing if that does anything.. Anyone have any pros or cons for the new firmware?? Any other ideas why I would be running 10-20* warmer??