Coolant flush recommendations

I discovered that the old radiator in my mustang is plugged up. I'm going to order a nice big fat aluminum radiator to replace it, but before I put that shiny new rad in there I would like to get all the crud flushed out of the engine. I'm going to wait a week before I order it, so I figure it would be nice put some sort of cleaner in the coolant now to break the stuff down. So what is a good cleaning solvent that will clean without eating up gaskets or seals in the engine?

Also, does anybody here have any first hand experience with ebay aluminum radiators?

Anybody? Dish soap? CLR?

Vinegar. Remove thermostat. Its Not so much the fluid, it's the process that you want to get right.

Pull the freeze plugs and scrape out the bottom.

Bend up a piece of welding rod to scrape out the bottom.

Flush, Treat, and flush again (With the plugs out).

Buy 50/50 coolant if your area has bad water or use filtered water to refill.

Vinegar sounds like a good option. I really dont want to remove the freeze plugs since the engine is already in the car.

Let the vinegar solution soak in the engine over night.

Gives it time to work.

Or you can get one of the thousands of cooling system cleaners from your local adzone.

After what I went through with my Disco.. I am leary of Vinegar. It might have just been all the junk that was still in my truck's cooling system, but two days (about 60 miles) of running a water and vinegar mix killed my brand new water pump.

Disconnect all hoses, remove thermostat, flush with garden hose until clear. Maybe some sort of acid soak/flush if it's bad. The dishwasher soap is for if you popped a headgasket and got oil in there.

Yeah, vinegar will really raise heck with new water pumps.

well.. it was spewing coolant from the weep hole.. I can only think that the vinegar ate something or that some of the dirt that was left in the cooling system got in there and rubbed through the seal

mad_machine wrote: well.. it was spewing coolant from the weep hole.. I can only think that the vinegar ate something or that some of the dirt that was left in the cooling system got in there and rubbed through the seal

Vinegar and water are not lubricants. Dry moving seal = leak would be a decent guess as to the cause IMO.

In reply to flatlander937:

Water and vinegar are both lubricants, just not very good ones. Plenty of race cars run straight water without blowing though a water pump every race. I can think of at least one dirt common marine raw water (salt or fresh) pump that uses a pair (redundancy) of regular old nitrile oil seals on the shaft, they go for years between rebuilds.

Kenny_McCormic wrote: In reply to flatlander937: Water and vinegar are both lubricants, just not very good ones. Plenty of race cars run straight water without blowing though a water pump every race. I can think of at least one dirt common marine raw water (salt or fresh) pump that uses a pair (redundancy) of regular old nitrile oil seals on the shaft, they go for years between rebuilds.

The point is if you want a seal to live, you don't want water alone as a first choice.

Many race cars will run some additive for corrosion/lubrication if its to be run for any amount of extended time.

I've seen enough water pumps fail when pure water is used to not do it myself. I'm sure some are more tolerant than others depending on RPMs, seal type, materials, and of course what kind of doo doo butter its pumping around.

Edit: are marine pumps under 15-20psi pressure on both sides of the water flow?

+1 for vinegar. If a few hours of running vinegar makes a seal blow out, it was on its last legs anyway.

(Edit: BTW, two days was too much. Keep it under 2 hours running time for sure.)

Baking soda is the main ingredient on the label of the stuff I used to buy as a kid at the local auto parts store... so that's what I use now when I need too. seems to work good.

Is anti-freeze a lubricant ?

In reply to iceracer:

Yep. There are lubricating additives in it specifically for that. Dip your fingers in it and rub them together.

Or spill it all over the floor when draining it. Summer time skating rink.

Anti-freeze is a pretty good lubricant. It is basically water-soluble synthetic snot. Seriously look at an ethylene glycol molecule and a gelatin molecule. It is constructed somewhat similarly (minus the Nitrogen and a dihydroxyl group)

In general, acids tend to be "sticky" and bases tend to be slimy. It has to do with the polarity of the -OH or H+ that defines them as acids and bases. The -OH tends to reduce surface tension and the opposite for H+. While vinegar does some good for cooking out nasty stuff, it isn't really going to do much for your application. Even in full-strength, if you dumped in 100% vinegar from the grocery store, it won't be acidic enough to do very much where its needed (removing rust and crusties from the water jacket) and it will be strong enough to eat things you don't want eaten (brass, crystallize the surfaces of any silicone on gaskets, and create a perfect electrolyte for bi-metal corrosion. It will also have a very intact surface tension (poor lubrication at seals).

I suggest baking soda as well. Not only is it mildly alkaline, it will react with the leftover acidity that tends to happen in the rust of the water jackets thus mechanically cleaning without etching or eating. Coolant starts out mildly alkaline, but through oxidation it becomes acidic, primarily due to the formation of formic, oxalic, glycolic, glyoxalic and acetic acids. Chances are, its already more acidic than if you replaced it with a gallon of vinegar and filled with water. Baking soda is also soluble in water so it can be flushed out, but make sure to flush it all out. You don't want a little pocket of it hanging out in the bottom of the block. Coolant uses silicates and phosphates to buffer the pH and starting out with extra alkalinity can throw it off.

Having said that, I usually use a quart of that Prestone flush stuff. It has baking soda and surfactants to properly lube seals. Dump it in, take out the stat, run it for a while.

I always wondered about filling a cruddy cooling system with store-brand cola and letting it stand for a couple days. Would want to follow with baking soda as described above. Reason for cola = fizz helps break up crud faster. Haven't heard of anyone doing it before.

And run some anti-freeze in your coolant, even a little bit, to help slow corrosion and add water pump lubricant.

I had a friend whose truck started overheating.

No water available but he had a six pack of Cola. filled the radiator, A few miles later everything was back to normal. Stayed that way for the miles he had to drive.

I like to run a cup or so of dishwasher detergent around the cooling system along with straight water, for the same reasons curtis recommends baking soda, above. I've had good luck with it cleaning out cruddy engines. You want to use dishwasher soap, in liquid form. Not powder (for obvious reasons) and not dish soap or hand soap- they get all foamy and bubbly. Some of the new HE detergents might work well, too (they're supposed to be less sudsy) though I've never tried that.

I'll remove the thermostat and put the garden hose in the radiator and remove the upper radiator hose and point it somewhere out of the way. Engine sucks up water, spews it out the upper radiator hose. You'll need a good flow of water to maintain it, or else periodically plug the upper radiator hose back into the radiator to allow the system to fill.

Do this until the water runs clear. Then do it again after some time running the engine normally. Keep doing it until you don't get brown coolant/ water anymore.

I've used hydrochloric a few times on nasty cooling systems.

Yes, it is "energetic" - it will boil over even without the engine running - and de-aciding the engine is a pain in the ass, and you'll be working your ass off for two hours or so even with a helper. But it WILL get a nasty cooling system clean. As well as your driveway

No issues with aluminum heads/intakes/heater cores/radiators doing this, either. It eats the rust before it eats the aluminum. Just gotta take the usual precautions - don't get any on you, don't breathe the fumes, don't get it in your eyes, etc.

Knurled wrote: I've used hydrochloric a few times on nasty cooling systems.

Pool acid in the radiator? Really?

I just received some......lets say unexpected sizable expenses. It looks like the new radiator will have to be delayed a while. I guess i will try to unplug my current radiator. I was thinking clr but on their website it says dont use it on copper brass or aluminum. I guess ill try vinegar and see how it reacts. Wish me luck.

In reply to codrus:

Yep. Pull the thermostat out (install a gutted one if possible, to ensure coolant gets forced through the heater core), flush engine/radiator out thoroughly with water - I usually just pull the upper hose off of the radiator and let it dump out, with a water hose into the radiator, full-loss cooling. Cold water of course. Then shut it off, drain the cooling system, upper hose back on, start the engine and add about a half-gallon of hydrochloric. Idle the engine. It WILL start to boil over, you'll need to add water/hose the radiator down to keep the engine from overheating. After a while of this then you get to rinse the engine out thoroughly (see step A) and I use a bunch of baking soda to neutralize what is left. This is where it gets REALLY energetic :) When it all settles down and stops being a science experiment in your engine bay, and flushing the engine nets clear water, you're good to go.

I did this on an Escort that was so bad the head was full of green sludge, the water pump impeller rusted into a paper-thin disk, and half of the engine core plugs were leaking. I have no idea how a cooling system got that bad. Everything was clean after that (of course this was after a new water pump and core plugs were installed, thank the Ford that the CVH didn't have core plugs in the bellhousing )