7000's 301 engine temperature in cold weather

Just curious, my 7000 is on manure spreader duty this winter (pulling a kuhn 1230 spreader, which isn't a huge load for the tractor by any means) and the engine on most cold days only gets a tick over 130 degrees.  I have cardboard in front of the radiator and oil coolers and there is all new foam around the radiator I put in when I put on the new radiator this past spring.  In the past I didn't have a problem getting it warmed up with cardboard in front, but it also turned out the head was cracked and the head gasket had been leaking slightly.  So... what is your all's experience with the 301?  Is it really hard to get a good fresh 301 warmed up or is my thermostat not working correctly? 

I'd start with the thermostat. It could be sticking open. Its cheap and easy. My 7010 warms up nicely without cardboard just idling at 1000 rpm.

Edited by David G. - 15 Jan 2015 at 12:37am

Heat isn't the only thing that will cause a head crack, and a cracked head doesn't neccesarily mean engine temperature will be too high, so don't dispose yourself to any narrow paths of conclusion.

First of all, look closely at the situation- can you tell by the nature and location of the crack, and condition of the gasket, of how LONG the crack has existed, and if it started short and grew? Did it leak coolant, combustion, intake, or exhaust pressure? Did it seal either when cold, or hot? Did you find any head bolts that were broken, cracked, or improperly torqued?

Compression-ignition engines generate substantially lower waste heat than other internal combustion designs, and although some warm faster than others, none warm very quickly, and they tend not to warm uniformly... a small area in the chamber sees the greatest temperature change rate, although most of the engine's mass is far away and very slow to transmit heat. Cooling and lubrication systems frequently CARRY waste heat elsewhere in the engine, where heat is absorbed as temperature climbs, and on many engine driven machines, the cooling system is plumbed such that it helps 'distribute' or 'equalize' temperatures everywhere to promote good operation. One example, would be in a forklift truck, where coolant lines run through the hydraulic reservoir, or a transmission cooler line goes through a radiator. The function initially appears to improve cooling of the hydraulic fluid, and while this is certainly the case, one finds that such plumbing helps bring the hydraulic fluid up to a reasonable operating temperature quickly, to get the hydraulic valving and servos to function properly. Likewise, if the hydraulic fluid were to overheat from aeration, the engine coolant temperature rises drastically because of the increased dissipation from the hydraulic heat-exchanger loop.   If a person errantly hooks up such cooling lines in an improper orientation, bad things happen in both sides of the system.

Look at it closely, and study how it's SUPPOSED to be set up, because you may just find that there's something awry... all things happen for one or more reasons.

The head crack I am pretty sure was something that had been there since the engine was rebuilt.  It never did run very cool and also it turned out the old radiator had a leak, so it wasn't holding pressure and probably allowing the coolant to boil in the hottest parts of the engine and cause voids where there was not coolant flow.  Since the new head, which was checked by a machine shop for any cracks right before putting it on, and radiator my engine temperatures have been much lower and the engine runs much smoother.  It's actually about due for an oil analysis which should tell the engine's story even better (have my finger's crossed it is finally sorted out!)

A head that has a compression leak to cooling passage, can push combustion pressure into the block, head, and water pump, with resulting bubbles preventing the transmission of local heat into coolant and other areas. An air bubble around a temperature sensor, or the thermostat's wax motor, will prevent temperature readings and thermostat operation. Likewise, bubbles reduce the circulatory pump's effectiveness, and finally, the combustion pressure drives cooling system pressure beyond the cap's relief pressure. The total result can be very confusing, so a good pressure test kit is a must for solving problems. Before pressure-testing a system, I always put my test gauge cap on, then start the engine, and watch the pressure indication- if the pressure rises faster than coolant temperature, I know there's a compression to passage leak, either via gasket, head crack, or sleeve... Since that trumps every other issue, I stop my diagnostic process and presumption there, then go in for a look.

Edited by DaveKamp - 15 Jan 2015 at 8:12am

ok, one more time. The 7000 had a thermal rejection of about twice that of the 200 - larger water pump and much larger radiator. The thermostat will do its job if functioning properly. The head on the 7000 was thicker than the 200. This was to take the strain of the extra hp. It worked and worked well. HOWEVER this head and the same casting on the 4.33 as in the F2's would CRACK when the temp went up to the boil over range. We used to keep built up heads from Barnett head in Carothersville Mo. We are talking dozens. It was that common. If you say it will not warm up and the head has cracked the logic is the radiator is plugged and it overheated under load and it was thought in the safety range. As posted get a thermal gun and check it compared to the temp on the dash. If you are ok that's great. If not you found the issue.