Hi, We run a D8N with 3406 engine. Temperature rises to 100 degrees after 30mins of use. After we turn machine off to cool..when we restart, temperature goes right back up to 100. What could be the cause of this kind of rapid increase in temperature?
Already Tried: Hi, We run a D8N with 3406 engine. Temperature rises to 100 degrees after 30mins of use. After we turn machine off to cool..when we restart, temperature goes right back up to 100. What could be the cause of this kind of rapid increase in temperature?
Hi. Thanks for using JA! I will try and help you out.How long does the engine sit before you restart it and it goes to 100?
Sits for about 20-30 mins.
I see. Thanks for the information.With the engune sitting for only 20-30 minutes, the engine temp will not drop much at all. Normally an engine will need to sit for 40 minutes or so to drop in temperature. Is it causing a problem by staying at 100 degrees F?
I'm sorry. I meant to say C, not F.Like I mentioned before, the temp will not drop much in that short amount of time. But it should drop some. I would suspect a faulty or inaccurate temp sensor.Let me know if you need more help.
Hi, Perhaps I am not being clear. The temp sensor works fine. Even after we rest the machine over night...it still increases rapidly to 100 C...what could be the cause of this kind of rapid rise?
Oh I see. I thought you were only letting it sit for 20-30 minutes.The first thing I would suspect is the thermostat. It sounds like it is not opening completely. If it is not, the temp rise rise like that.If the thermostat is operating correctly, I would next suspect the radiator. It is most likely partially clogged on the inside or outside which causes it not to cool as efficiently as it should. Let me know if you need more help.
Could this also be caused be exhaust gases in the coolant system? Apart from using an exhaust gast test kit...is there any other way to check if exhaust gas is entering the cooling system? thanks
Yes it is possible. Normally when exhaust gases are getting in the coolant, the coolant starts getting pushed out of the radiator. If coolant is being pushed out, a blown head gasket is ghe most likely problem.
Okay. Can you please provide step by step instructions on how I can confirm that coolant is being pushed out?
Sure no problem.First I would inspect the vent tube on the radiator. If it is wet with coolant, the coolant is being pushed out. If it is dry, I would not think exhaust is getting in the coolant.If it is wet, I always iinstall a radiator pressure tester on the engine, then run the engine until it gets to operating temp.If there is exhaust gas getting in the coolant, the pressure will continue to build very high in the system. If the pressure does not build, I would test te radiator cap, it is most likely fsulty. Let me know if you need more help.
thanks. How would I be able to locate the 'vent tube' on a D8N radiator? is it at the top of the radiator or bottom? right or letf? What does it look like?
You are very welcome. The vent tube should be at the top of the radiator near the fill cap. It normally runs down the side of the radiator.
Experience: I am ASE Master Certified.
Is vent tube also called the relief valve of the radiator?
or is the vent tube like a hose?
Yes that is correct. Same as relief. Some can have hoses that come off it and hang down.