Removing air in cooling system

My experience with those systems is that they will purge themselves after the initial fill only after 3-4 warmup cycles. IIRC, it has a 3/8" hose that returns to the radiator neck from the engine. The hose is connected above the highest point of the cooling system such that air pretty much escapes to the radiator from there. The reservoir will replace any air purged with water as the engine cools. As the engine warms next time, more air is purged and the cycle resumes until there is little air relaining in the system. You should warm the engine until the stat opens on initial fill to make sure there is adequate coolant in the system. I usually fill the reservoir almost all the way up with the engine hot on initial fill. The first cooling cycle will drop it quite a bit.

If you are getting a noise in the heater after the first few starts and the noise level really comes in as the engine revs, you may need the restrictor plate that goes in the hose to the heater. I do not know that this was ever used from the factory in the trucks. It was used in many of the cars for that reason. Most service techs do not know of it's existance and many did not replace the restrictor orifice plate in the hose even when they knew about it. The presence of the restrictor does not seem to reduce the efficiency of the heater in the least since the normal flow it is far more than it needs anyway.

Lugnut

Got it.

I'll give that a try. One twist is that my driveway slopes downward, so the truck tends to cool head down. That would probably defeat what you a describing, right? I might back it down the driveway to hurry it along. Sound reasonable?

Is the noise a sign of any harm being done to the engine?

Thanks!

Bill

Air in cooling system tends to promote corrosion.

Whitelightning

Nose up woul tend to help the air toward the radiator where it may more be purged to the reservoir.

The noise you hear may the sound of air moving thru the system. If this is the case, cavitation is occuring and the inside of the cooling system is suffering damage just like a boat prop that cavitates excessively. The process is accelerated in warm water.

Lugnut

I will give that a try.

Understood. My question was more along the lines of other sources of noise. I think it is air and will let it cool nose up for a while. But the existence of the constriction plate suggests there might be other causes of sound. Are you simply not buying that theory?

Bill

I really have no explaination for the groaning sound that is corrected by the restrictor. AFAIK, it was first used in the Lincoln TC that had the problem. It also found it's way into the Tempo/Topaz in the late eighties. Those sounded like a bull with it's balls in a pinch when the engine revved before the t-stat opened. The restrictor just puses into the heater hose and then the hose is installed. If you don't know it is there, you will probably throw it away with the old hose and then spend the next month trying to figure out where the noise is coming from. I have never seen (heard) this noise in the trucks once the air is purged. If it does happen and you can't get rid of it any other way, you may want to try the restrictor. Sorry I don't have the part number. As of about 3 years ago, it was still a stock item in parts and was not expensive.

Lugnut

Lugnut

This sounds nothing like a bull in testicular distress, or worse yet, one who just got yet another tax bill. The noise I hear is more like water flowing into an air pocket.

I drove the truck twice today, and let it cool nose up. We'll see what happens. I _think_ it drank some coolant from the reservoir, but the plastic is so stained that it is difficult to see the level except at certain depths.

Got it. My guess is air that stuck around because of the slope of my driveway and my truck driving pattern (it seldom sits long enough to cool except at home).

Thanks!!

Bill

add a flush n fill kit to the top heater core hose. Fill your heater core from there.

I had wondered about something like that. So far, the nose up cooling appears to have at least helped, if not solved it. I do not typically drive the truck every day, so I hesitate to claim success just yet.

Bill