flushing of cooling system---different ways?

I was assuming a "cooling system flush" was always a chemical flush, where you flush it out with a special cleaner? The shops around here all generally charge around $100 for a "flush", but when I asked the shop that i chose to use (a shell station) if it's chem. flush he said no, that's about $20 more ($120). He said which one you want... I said i don't know which one i need. I told him it's been around 4 years since the the last drain/replace....then he quickly looked inside (opened the cap for 1 second) and said your'e fine, just get regular flush. so i did that. What's your opinion on this? Is a non-chem flush really any different than a drain and replace? (He said yes, because it drains it from the engine block as well as from the radiator???). thanks.

Reply to
mac
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A lot would depend on how dirty the system is and year make and model and engine and mileage. If the coolant is changed regular at 3 years or 50K you ususlly do not need a chemical flush. Just change coolant. MT MT

Reply to
MT-2500

Chemical flushes are a last resort for a sick cooling system, especially with modern antifreeze corrosion inhibitors. A chemical flush actually CAUSES a certain amount of corrosion along with dissolving the corrosion by-products that are causing the problem, so it should be avoided unless there is already severe corrosion and plugging in the system.

The best way to keep a cooling system healthy is to keep it full and keep a good radiator cap on it to keep it as nearly sealed as possible. Severe corrosion tends to happen when the coolant level gets low and a lot of air is getting into the system. And when you do a coolant change, drain the block as well as the radiator (there are usually plugs on the sides of the engine block). Flush with water, allow all that to drain, and then fill with the correct mix of the recommended antifreeze/corrosion inhibitor mixed with DISTILLED water (or buy pre-mixed, but that's a waste of money compared to mixing it yourself.)

Reply to
Steve

But they told me they did a non-chemical flush, not just a drain and replace. So that PROBABLY mean they drained the engine block and radiator, and then flushed with water? (in my original post, i distinguished between (1) D&R (2) non-chem flush (3) chem flush,

Reply to
mac

Thanks. So i guess i'm glad they didn't do a chem flush. So they "flushed" with water? (since they called it a "flush", rather than drain/replace). Yes....i do plan to ask them, but i wanted to get some opinions here first.

Steve wrote:

Reply to
mac

He is right and is implying they are very unusual and do it the right way by opening up the engine block drain. He also didn't try to sucker you for an un-needed chemical peel.

Most places here in Canada that do 'flushes' do not remove this engine drain for some strange reason. They put a hose bib fitting in the heater hose and run water from there through the heater core and out the rad. This is a rip off in my mind.

It is amazing how many older vehicles I have 'flushed' where nothing would come out the engine block drain once removed because it was so crudded up, mostly with rust flakes. After a ream with a coat hanger most started to run.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

I'd avoid a chemical flush unless the radiator was clogged because deposits are often plugging leaks. Don't use a cleaning chemical unless you intend to fix the leaks, and that can include replacing the water pump (not easy if it's driven by the timing belt).

Reply to
do_not_spam_me

I just asked the shell station that did it, and he said the $100 "flush" that he did is actually an "exchange"....a machine forces out the old coolant from the block and radiator, while (it seems) at the same time putting in new coolant. That seems like it would be mixing the old and new fluids together, doesn't it? When i think of the word "flush" i think of flushing it out with water or something (totally), then adding in the new. Seems like he did more of a "forced drain". But when he very quickly opened the cap and looked at the fluid when i first got there, he said the "flush" (exchange) was all i needed. p.s. But the word "exchange" has a negative meaning in the health field....just think of "exchanging body fluids" with someone who has HIV or something....

Reply to
mac

That doesn't flush the crap out of it either. It is amazing the amount of debris that will come out the bottom hose of a rad and the drain plug on the engine block.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain
1] Locate the engine block drain plug, remove it

2] Disconnect lower radiator hose

3] open radiator draincock

4] Have plenty of fresh water avail.

5] Start engine and keep filling reservoir with #4

6] Turn on heater to high

7] Keep filling reservoir

when all runs out clear. Reverse the above.

Reply to
Knifeblade_03

I have a couple of thoughts on your method. I realize that the original poster didn't specify the make and model of car, but here are my thoughts: Not all cars have an engine drain plug. Not all radiators have a draincock. Certain late model cars (GM cars and Jeeps come to mind)don't have the radiator cap (poor terminology. It should be coolant fill cap) on the radiator. They have it on the coolant overflow reservoir. Adding coolant to the system is a lot slower than what is running out your disconnected lower radiator hose. And speaking of the lower radiator hose, you advocate running the engine with the lowe radiator hose unhooked? Once again, the system could be slow to refill thanks to the design of where the fill cap is. Your method might work, just not on all cars, especially late model cars.

Reply to
Kruse

I have issues with running the engine with no rad hose on it. That can fast burn out the valve guide seals and head because there will be no coolant up top.

The pressure from the hose should circulate the fluid and flush it. They sell flush kits that put a hose bib into a heater hose for flushing through the heater and then out the drains or bottom rad hose.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >

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Reply to
Mike Romain

I have had 3 cars that were older. Over 100,000 miles, over 12 years old. As far as flush, this has worked for me: If the radiator looks clean, I use one gallon of white vinegar. Vinegar costs less than $2.00 is not hazardous and can be safely drained on the ground. Vinegar cuts through lime and calcium. A lot of people use to to clean the chrome on faucets, shower heads and water fountains.

If the radiator is dirty, I use CLR or LimeAway. After system is totally drained and flushed with water, I pour in the whole bottle of chemical and rest with water. Run engine for 15 minutes, shut it off then let it soak for another 15 minutes. Drain it. Then flush it again with garden hose until water is clear.. When I look in radiator it is bright and shiny inside like new. I think CLR, LimeAway is cheaper (3 to 5 dollars) and does a better job than any radiator cleaner I have tried.

I did not remove the freeze plugs to do this. The parts store said if you don't get the freeze plugs replaced properly they could leak or even pop out.

All thee cars I used this with did not leak worse afterwards. The did run cooler. I did replace the radiator cap, radiator and heater hoses. and thermostat at same time. All 3 cars had slow leaks (heater core) and a bottle of Barrs Stop Leak (Silver plastic bottle with black top) stopped the leaks for at least 2 years.

To replace the heater core would be 7 hours labor, $140 for heater core which adds up to over $650 dollars. On all of these cars the entire dash has to be removed to replace heater core.

Reply to
J J

Hmmm. My NEWEST car is 13 years old with 240,000 miles..... Yours aren't broken in yet :-p

If you had only used distilled water in the cooling system, there would BE no calcium deposits. Using only distilled water mixed with antifreeze is the best single thing one can do for ones' cooling system.

As for vinegar- its still an acid and still etches the metal in the engine, heater core, and radiator unnecessarily, thus removing the protective layers built up by the corrosion inhibitors in your antifreeze. Good as a "last resort," but the only reason for ever needing to do something like this is because of previous neglect of the cooling system.

Hydrochloric acid. If you're going to abuse your cooling system like that, why not do it the cheap way and buy a gallon of muriatic acid from a swimming pool supply store?

I have to wonder why a car only 12 years old with only 100k miles had a leaky cooling system in the first place.

I did replace the radiator cap, radiator and heater hoses.

Penny wise, dollar dumb. Things that leak should be fixed, not gooped.

Reply to
Steve

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