Water pump, thermostat, coolant flow question.

[bebyb]

Hello all, quick question. A few months ago I discovered just in the nick of time that the previous owner of my truck had put straight water in the radiator. So I drained it out and replaced it. So I started it up and idled it for about 10-15 minutes and the coolant I could see through the filler cap was just stagnant. This got my cencerned that maybe the water pump impeller was messed up, but the lines going directly into the water pump seemed like they were getting warm, but I don't know if that is warmth from being that close to the engine. My temperature gauge is down and i am going to replace it soon, but I can't use the temperature gauge as a reference because of that. Well anyway, a little while later I took it on a long trip from Nashville, TN to East TN, and through the 3 and a half hour drive it continued to purr like a kitten, didn't show any signs of overheating, even going over some of the grades on I40. However, does this sound like a water pump issues or is everything normal? It isn't the overheating I am worried about but I just want to make sure the antifreeze got circulated through the block like it was supposed to, because it got down to 8 degrees about 2 weeks ago.

Thanks

 

[cattlerepairman]

From what you describe, you had left the thermostat in place and, naturally, the thermostat's job is to cut off coolant flow through the radiator (for the most part). That is why hoses/coolant parts close to the engine get warm, but the rad stays cold.

You already replaced coolant (you did use Diesel-rated coolant, not the green stuff, right?) so "how to drain and flush" is a mute point now. If you do a search for coolant or engine flush, you will find planty of pointers!

 

[bebyb]

From what you describe, you had left the thermostat in place and, naturally, the thermostat's job is to cut off coolant flow through the radiator (for the most part). That is why hoses/coolant parts close to the engine get warm, but the rad stays cold.

You already replaced coolant (you did use Diesel-rated coolant, not the green stuff, right?) so "how to drain and flush" is a mute point now. If you do a search for coolant or engine flush, you will find planty of pointers!

Oh man, I just used the universal green. I can drain it out though, it hasn't been in there long. What kind am I supposed to use?

 

[pjwest03]

Oh man, I just used the universal green. I can drain it out though, it hasn't been in there long. What kind am I supposed to use?

As cattlerepairman stated, a diesel heavy duty coolant. They have different chemistry than gas engine coolants. Different additives are used to prevent cavitation in the liners. Lower level of silicates to cut down on sludge formation. More corrosion inhibitors. Most of the diesel coolants aren't green as they are the extended life variety. Some are good for up to 600K miles if you test/adjust the additives periodically. They are available at the usual places NAPA, Tractor Supply, truck stops.

You can also get the supplemental additives (SCA/DCA) separately and add them to what you have. There are also test kits available to make sure that you have the proper amount of additives in the coolant.

 

[rustystud]

OK, we have dealt with the coolant issue before but I guess we all need a refresher course. Most engines can just use the old "Green" anti-freeze (ethylene-glycol ) and have no problems. Now diesel engines that use "wet liners" have special needs. Due to the vibration caused by combustion pressures the wet liners will have "cavitation" issues which will actually corrode the liners and eventually cause pin hole leaks in the liners damaging the engine. The "special" diesel engine anti-freezes have additives like "nitrite" or "molybdate" or a combination of both. These additives coat the liners and prevent the cavitation bubbles from damaging the liners. Since our MultiFuel engine has "dry" liners we really don't need to worry about these additives. Now there are other benefits that these special antifreezes have like corrosion inhibitors that will help any engine but they are extremely expensive. If I was to use one though I would go with "Shell ROTELLA Ultra ELC" antifreeze. It meets all the manufactures of modern diesel engines recommendations.

 

[bebyb]

As cattlerepairman stated, a diesel heavy duty coolant. They have different chemistry than gas engine coolants. Different additives are used to prevent cavitation in the liners. Lower level of silicates to cut down on sludge formation. More corrosion inhibitors. Most of the diesel coolants aren't green as they are the extended life variety. Some are good for up to 600K miles if you test/adjust the additives periodically. They are available at the usual places NAPA, Tractor Supply, truck stops.

You can also get the supplemental additives (SCA/DCA) separately and add them to what you have. There are also test kits available to make sure that you have the proper amount of additives in the coolant.

Okay I might just go with adding the additives to it. You don't think I have screwed anything up do you? I think that antifreeze has been in there 250 miles at most.

 

[bebyb]

OK, we have dealt with the coolant issue before but I guess we all need a refresher course. Most engines can just use the old "Green" anti-freeze (ethylene-glycol ) and have no problems. Now diesel engines that use "wet liners" have special needs. Due to the vibration caused by combustion pressures the wet liners will have "cavitation" issues which will actually corrode the liners and eventually cause pin hole leaks in the liners damaging the engine. The "special" diesel engine anti-freezes have additives like "nitrite" or "molybdate" or a combination of both. These additives coat the liners and prevent the cavitation bubbles from damaging the liners. Since our MultiFuel engine has "dry" liners we really don't need to worry about these additives. Now there are other benefits that these special antifreezes have like corrosion inhibitors that will help any engine but they are extremely expensive. If I was to use one though I would go with "Shell ROTELLA Ultra ELC" antifreeze. It meets all the manufactures of modern diesel engines recommendations.

Okay good to hear. Now I can breathe a sigh of relief haha.

 

[drivebymashing]

I used normal green 50/50 in my deuce. It liked it.