Coolant is slightly low...(intermittent low coolant light) on one of the cars in the household, the 96 Saturn.

Last coolant service (not sure of how it was done) was 2 years and 19,000 miles ago.

Coolant smells worse than dirty socks, and there's quite a bit of crap on the cap and filler neck area.

Coolant appears "unclear" in the yellowish tank, but when a piece of paper is dipped into it, it appears pink.

I'm unsure of what coolant was used at the last service, but I'm guessing it was Dex-Cool.

Ironically, factory fill coolant for this vehicle is a phosphate-free, but not silicate-free "green" antifreeze.

First service was done after 5 yrs (I know, way too long) with Genuine Saturn coolant, and that coolant was run for another 4-yrs, before the mystery (presumably Dex-Cool) fluid was installed.

Now, I'm wondering what fluid I should put in.

I can get Prestone All Makes/Models, 2-EHA based Ethylene Glycol OAT coolant for $8.XX at Walmart, or I can spit out the extra $2 for the HOAT and 2-EH based, low-silicate, pee-colored Zerex G-05. (Main advantage of HOAT based coolant is to provide instantaneous corrosion protection with its low-level of silicates, while the straight OAT based coolant requires several thousand miles to build up the layer of protection)

Of course, I plan to drain/fill the system with water first and add Prestone Super Radiator Cleaner, drive the car for 400 miles, then drain/fill twice with water before running a 60/40 mix with the new coolant.

Any suggestions on which coolant to run ??? Thanks.

 

I would switch to the ethylene glycol, I see a LOT of problems with Dex, its highly corrosive in cooling systems and seems to leak more often. It(Dex) always develops those funny white/yellow deposits on the caps, just imagine what its doing to your radiator, waterpump, waterjackets/channels and heater core.

I think you drain/fill procedure is a bit overkill, but if it makes you happy more power to you - it sure won't harm anything if Dex was in there.

 

My GM engineer pal says there's no problem....

Well, here's what I plan to do:

1) Drain radiator and engine block (if possible)
2) Fill with water, idle engine for 10 min with heater on "high"
3) Drain.
4) Repeat 2 & 3, add 1 qt of Prestone Super Radiator Cleaner (heard it is very strong)
5) Drive for 400 miles over the course of two weeks with the heater on at all times.
6) Repeat steps 2&3 twice to remove as much flush as possible.
7) Add 1 gal of antifreeze, top-off with water. (7.0 qt capacity, so 4 qts will put me at about 57%)

Tireguy, what flush products have worked well for you in the past?

Thanks...

 

Quick question for those of you who change coolant yourself: how do you know if there is an air bubble trapped in the radiator once you have replaced the coolant and how would you go about purging it?

 

Depends on the system, some have a bleeder on them, others bleed themselves. Any car made in the last 6 or 7 year shouldn't have a problem, bleeders were a poor attempt of a solution and even then the air will usually bleed itself out.

Bring the vehicle up to temperature(until you have GOOD heat coming out of the ducts) and keep an eye on the coolant level. They make special attachments so you can have a constant flow available but they seem like a waste with modern cars.

 

Of course he doesn't think there is a problem he works for GM

After your 7 step process, what do you think will be gained compared to a conventional flush? Your car will not run any longer, its life span will not be increased, it will be a pain in the ass though. I use an air powered flush machine, it has a clear output hose and you flush the system till it comes out clean, it works great - in/out through the upper hose and out/in through the lower hose(depends on if its a reverse flow system or not). Make sure you install some sort of cooling system sealer after doing any sort of flush, its good for the seals in the H20 pump, etc...

I've seen demo's of all the major flushing systems and most seem like a waste, using new fluid with a bit of pressure seems to be the best way to clean the system with out damaging anything.

I've also seen more demo's on brake fluid flushers and power steering fluid flusher's then I'd like to admit, and what's the benefit of it other then spending peoples money? Nothing for 99.9% of cars - you can see the benefits with a cooling system flush, and when performed properly can increase the life of the components in your cooling system and prevent leaks. So if you MUST do it yourself your 7 step process maybe a good idea, but not the most effecient way of doing it by any means.

 

Thanks for the suggestions. I will probably add some ground-up ginger root to the system as a sealer... (GM cooling system tablets... )

So, are you saying that I should not worry about any of the possible accumulated gunk in the system?

I am bringing the car to a shop that has a lift (so I may work on it), but the shop does not have a coolant flush machine...

What coolant are you using at your shop?

Thanks again..

 

Depends on the vehicle, but ethylene glycol is by far the most common, but we also flush with Dex and G-05 when required.

Instead of doing your 7 step process I would, assuming they have no means to flush the system, drain your car and fill it with water, bring it up to temperature. Then drain it again, it should be pretty clean by that point, perhaps include your prestone cleaner during that process for a little added protection/cleaning, then I would fill it up with the appropriate coolant(with sealer) and bring it back up to temperature to verify there are no air bubbles in the sytem and call it a day.

 

It's a Saturn, does it really matter what fluids you put in it?

 

I've talked to a few other people (thanks Tireguy and others) regarding this subject; of all the people I've talked to, it was pretty much agreed upon that a chemical flush is NOT the best way to go and may have long-term effects on an older system like mine, as I would rather not expose any leaks after a chemical flush.

I plan to drain the radiator (removes 6 qts) and the engine block (holds 1 qt), and refill with water. I'll run the system with the heater on high until the cooling fan turns on. I'll repeat this process once more. If time permits, I'll repeat this a third time, if not, two should be fine ? Then I'll add 1 gal Prestone All Makes/Models and top-off with water. Perhaps replace the thermostat, hoses, and engine coolant temperature sensor.

Thanks.

 

God...start a blog...and post on there.

I think its safe to say the vast majority on here couldnt give two shits about your coolant play by play.

but i will commend you on your attention to detail.

 

Well, just did the flush today.

Drained the block and radiator, stuff came out bright red. Smelled awful; people from the other side of the shop came over to see what was going on. One guy asked..."Wow...is that ATF?" Guy who drained it with me (buddy) said, you probably have rust...

Lo and behold, we closed both plugs and filled the reservoir with water. Ran the engine for about 5-7 mins and drained it. Fluid came out bright orange. Fluid at that time was probably 150F or thereabouts...it was steaming but wasn't boiling hot.

Closed up both plugs, poured out 1pt of coolant from the 1 gallon Prestone All Makes/Models jug, then poured the rest (3.5 qts) into the reservoir. Spilled some too along the way...so I added another 4oz for good measure. Topped off with water. Let the thing run cap off for 7-10 mins to bleed the system. Will have to open the cap again tomorrow morning to equalize pressure.

Not really sure what to do at this point. Its very possible that the system was rusted up quite badly. I really don’t want to use a chemical flush as that’ll probably expose more leaks. More than likely, I’ll flush again in 6 months at my next oil change…it only costs $9.

Suggestions?

Thanks.

 

^- When I come across cars with horrible coolant I just hook them up to the machine and run a shitload of coolant/water through them. I tell the customer to come back in a week to see how it looks. If there is a lot of rust/discoloration I will do it over with a cleaner and see if that makes a difference. Usually that takes care of it, although some cars have so much shit in the radiator the customer usually tells us to replace it.

 

I'm just afraid to use a cleaner as I don't want to expose any leaks...

I'm planning to drain/water flush/fill again in about 3000 miles and 4-6 months with Prestone All Makes/Models again...

 

The flusher's that I like and use don't use a cleaner of any sort, it just flushes coolant through the system until it comes out clean. But for only $9 you can afford to do the coolant drain/fill many times, so I would just try that again.

 

I'd just get a new radiator and coolant hoses. The car's 10 years old.

 

Yeah thats $150 for a radiator and upper/lower radiator hoses. I guess I should replace the water pump too for $30... I also have a van with 57K that's a 92 and it has the original belts, hoses, radiator, water pump. And the coolant is only flushed every 5 yrs...one time it was done with silicated coolant!

The point is I don't plan on replacing any of the parts until they begin failing...seems like a waste of money to me. If they fail...wouldn't they show signs of failure (leakage) first ???

 

Rust to me is almost failure. It's not a waste of money to have things working properly. Oh no, $180 for parts on a 10 year old vehicle! Fear!

 

Why do you consider rust almost failure? The only thing that may happen due to rust deposits in the radiator is slightly reduced cooling, and even that seems far fetched.

I am of the school if it ain't broke don't fix it, typically your just opening a can of worms for no reason, in particular with cooling systems. That's my

 

I like that approach.