Taking advice I read on this great forum, I switched my heater hoses on my EA-82 in order to backflush the heater core. On my first attempt at this, I ran the engine with heater full blast for twenty minutes and acheived immediate results, only to have my heaters performance diminish during the following week. I tried the reversal again yesterday and ran the car all day with the heater blasting like a foundry. I am going to eventually return the hoses to their proper places, but what I am curious about is if any damage could occur from operating the engine for prolonged periods of time with reversed heater hoses?

In a nutshell - no.

 

The heater core is like a mini-radiator. There is a valve that opens or closes to allow more or less flow through the core, but in principle it really doesn't matter which direction the system flows.

 

You are running it this way? I would definately flush the system out as you probably have crud that is free-floating in your coolant now, and that will settle somewhere if you don't take action while it's loose.... maybe back in the core, but maybe in your radiator too.

 

Get one of those cheap flush and fill kits with hose fittings for your heater core hoses - that way you can presureize the system with a garden hose and shoot that junk out of there.

 

It's a good idea to replace the heater core hoses too - 5/8" core hose is like $1 per foot at NAPA, and the peice of mind is worth it. I've had them split open on a hot day and spill every drop of coolant on the road - that sucks.

 

GD

nope! it's all the same to your engine. Make sure you flush out the whole system soon though cause that crap will settle somewhere else.

nope! it's all the same to your engine. Make sure you flush out the whole system soon though cause that crap will settle somewhere else.

 

I flushed the cooling system two weeks ago using some Prestone Flush product. You know the procedure, drain, flush, drain, flush with water, drain, the refill. I real pain in the rump roast, especially if you live in an apartment complex like me. Apparently, this whole procedure did not get all the crud out of the system.

I flushed the cooling system two weeks ago using some Prestone Flush product. You know the procedure, drain, flush, drain, flush with water, drain, the refill. I real pain in the rump roast, especially if you live in an apartment complex like me. Apparently, this whole procedure did not get all the crud out of the system.

 

I've noticed that heat tends to really help remove stuff - heat, and backflush. Sort of like steam cleaning I guess.

 

It's important to note that a properly maintained cooling system will never require this procedure. The coolant has many anti-corrosion properties, but if it's left in there for more than a couple years, you'll have problems. If you live around salt you may need a new radiator, but that's from rust on the outside, not the inside.

 

GD

I've noticed that heat tends to really help remove stuff - heat, and backflush. Sort of like steam cleaning I guess.

 

It's important to note that a properly maintained cooling system will never require this procedure. The coolant has many anti-corrosion properties, but if it's left in there for more than a couple years, you'll have problems. If you live around salt you may need a new radiator, but that's from rust on the outside, not the inside.

 

GD

 

Thanks for all of the advice. The blockage in my cooliing system could be from a bottle of Bars-Leaks that I put in there as a pre-caution last December after I drained and refilled the radiator. I think that using this stuff, especially when I did not have any obvious leaks, probably gunked up the radiator and heater core. Oh well, live and learn! Nice thing about my '88 DL is I could probably roll it off a cliff and it would still run afterwards!