stevewaclo

Hello all,

A friend's Jeep (see sig) is in my garage waiting further attention, but I thought it would be a good idea to get input from the Forum before I button it back up. "Search" was very helpful but I didn't get all the answers I'm looking for.

Main problem is coolant as rusty as any I've ever seen. Started the clean-up by pulling the heater lines and flushing both ways. Filled a five gallon bucket at least 10 times before the water ran clear.

Removed and cleaned the coolant reservoir and the line from the radiator.

Removed the lower radiator hose and the large hose connected to the thermostat housing and collected at least 15 buckets of crud before the water ran reasonably clear.

Pulled the thermostat housing and T stat (will replace with 195F, right?) and tomorrow will remount just the housing and flush the block. From what I can see inside the head, it's rusty and scaly. Following the block water flush, I'll hook up all the plumbing and run a bottle of flush product for a few hours while driving. Then a final flush, install new T-stat, and fill with distilled water and ant-freeze.

My concern is that all my work may be wasted if I don't find a way to control further rusting. Suggestions welcome!

All the best.

dave1123

Welcome to CF!

If you're talking about the '00 WJ, I'd use a 210* thermostat, use premix anti-freeze (filtered water), and see if you can find a bottle of water pump lubricant to put in as well. That's a water soluble mineral oil that should kill the rust. This is also a good time for a new rad cap.

Prestone used to make a 2 part flush product that would clean up the worst systems I've ever seem. The first part was a mild caustic lye that you run for an hour at temp. Without the thermostat, you may have to put cardboard over the radiator to get it to come up quickly. Then you drain and flush that **** out and add the neutralizer (sodium bicarbonate) and run for 30 minutes. Then flush and fill with your coolant.

CAUTION!! That stuff was used with a brass radiator. IDK how it reacts with aluminum! Maybe you should use CLR or Lime-Away instead. I was reliving the old school techniques.

The old coolant must have been mostly water because IMHO that's the only way it could have rusted. See if there is a pipe plug on the block to drain the crud out of the bottom of the water jacket. You may have to probe the hole with a screwdriver to get it to flow. On Chevy V8's, there's one in the center on both sides.

bigbadon

Classic symptom of neglect. Follow up with a 30 minute run with plain water and a 1/2 cup cascade dishwasher detergent, then flush thoroughly. Replace coolant with conventional green silicate antifreeze and replace every 2 years. Why conventional? Because OAT is basically useless once rust develops.

dave1123

Thanks Bigbadon, I forgot to mention my '00 WJ was the last year they recommended using standard ethylene glycol (green) coolant.

stevewaclo

I already bought standard anti-freeze but will be sure to mix it with distilled water.

Time to find a sacrificial 3/8" extender to grind down for block plug removal.

All the best.

stevewaclo

Re, the block plug. A number of drawings I've found show it's location, but from top or bottom I can't see anything. Between 5&6 right?

How hard can it be?

Putting the thermostat housing on without the Stat and commencing flush.

stevewaclo

Spent several hours flushing the bock this afternoon, dumping one five gallon bucket at a time, so it's slow going.

I had already bought a container of Blue Devil flush the other day so, after the water started coming out somewhat cleat (still red) I buttoned up the plumbing and ran the BD and tap water with the rad cap off for about 10 minutes. Water turned rusty again which is maybe the BD working.

Temp gauge came up to 210F, but both heater hoses are cold which of course says no circulation through the core. Does the stat have to be in to direct water to the core?

Letting things cool and heading out for Cascade, CLR and water pump lubricant. Also read about a rust-stop called Mac 13 from NAPA. Any advice on that product?

In case anyone is wondering, I'm retired and can spend as much time as needed on this project to make sure the cooling system is stable before I do the final refill.

All the best.

dave1123

I would say you need the restriction of the thermostat to direct enough coolant thru the heater core to get it hot. You need to get your BD thru it also. Any rust scale will tend to plug it.

BTW, the hose from the thermostat housing should go to the bottom heater fitting so it will bleed the air out continually.

bigbadon

Agree. The max flow through the heater core is when the thermostat is CLOSED. When thermostat opens or is missing, most flow goes through radiator.

dave1123

Actually, Ive done a little dirt track racing in my younger days and we found we needed a restrictor in the thermostat housing to slow the coolant flow down enough to allow it sufficient time in the radiator to transfer it's heat. Generally just the ring from a thermostat did the trick.

stevewaclo

Thanks!

I'm isolating the radiator, heater and block (the worst) and continuing the flush of each, carrying away one five gallon bucket at a time...

All.the best.

stevewaclo

Hello all!

One things that really frosts my privates is when folks post a problem, get suggestions from the collective wisdom of a Forum, then are never seen nor heard from again .

I try not to be that kind of person, so here's the result of lessons learned from the friendly, knowledgable folks here, as well as considerable independent research. A lot of this may be absolutely "no news" to many, but for the 2 members living under rocks, here goes.

Also, if you have no rust in your cooling system, congratulations! You have been doing it right, so do yourself a favor and skip the rest of my post. Unless there is another way to kill rust, the process is tedious, messy and time consuming, but as far as I can tell, once a cooling system is allowed to go waaaay south, there is no easy way to bring it back to life. "Flush in a bottle" is fine for a cared for system, but not one long neglected...

First, to refresh memories, this problem began with "no heat" in the signature vehicle. No overheating, temp gauge at 210F. The owner had temporarily resolved the situation by pulling the heater lines and flushing both ways (and he still has rust stains on his drive to prove it!) but the problem always came back.

When I came on the scene, I found the overflow reservoir full of reddish/brown gunk with a coating of same on the bottom and sides. First job was to pull the bottle and give it a thorough cleaning. Also flushed the feed line from the radiator cap...Yuch!

Did some homework on the so-called () drain plug and decided I didn't want to tear off half the passenger side of the car (OK, it's not that bad) for access only to end up with a leaker anyway. Went with the tried and true, lower radiator hose disconnect. Really, really wish Harbor Freight still sold their constant-tension clamp tool and had to go with my jumbo vice grips. Put the GC up on ramps, got clamp slid back, then spread my EPA approved tarp, a 5 gallon bucket (for all the good that did) and a snow slider. As you may have guessed, I live in a retirement community and letting fluids run down the street doesn't cut it.

And be wearing full scuba gear when the lower hose comes off . Here's a very interesting factoid that I'll discuss later. The total measured amount of captured fluid (bucket and snow slider) only came to about 6-7 quarts. Remember, 4.0 systems contain upwards of 4 gallons (16 quarts!) of coolant. Allegedly, there is a block drain plug on the driver side between 5&6 cylinders, but considering I could not even see it, I passed on pulling it. What that 7 quarts tells me is that a simple lower rad hose drain still leaves 2+ gallons in the block! (I don't know if that 4 gallon number includes the overflow bottle, but still.).

Next step was to pull the two heater lines, upper rad hose and the thermostat housing. The view behind the t-stat was not pretty. Scaly, red rust as far in as I could see .

Then came the really fun part.

By pulling the indicated hoses, the heater coil, rad and block are separated and may be flushed individually. I started with the heater coil and found the supply and return hoses are different sized. Fortunately, I have a vast collection of plastic tubing, so adapting my garden hose and a drain line was not too hard. Correct me if I'm wrong, but the 2000 heater circuit has no valve so the coil is wide open all the time. I presume a damper controls heat in the cabin. First flush was rewarded with a massive slug of crap, that soon ran clear both ways. Also, I blew through the supply side to clear remaining rinse water. Surprisingly little (1-2 pints?) came out.

The radiator is also fairly easy to flush. I ran the garden hose into the upper rad hose and found a 1' piece of PVC drain, with an angle cut on one end to push up over the lower rad hose. The 5 gallon bucket would not quite fit so I had to jack the Jeep up about 3". Reverse flushing would mean putting the garden hose in from below, so I passed on that. Also, putting water in the rad cap hole is a waste, since it's a straight shot down to the lower hose. After many, many 5 gallon buckets, the water was still coming out slightly red, so I finally quit.

On to the block, and I put the stat housing back on (w/o stat) and adapted the garden hose to the connection for the upper rad hose fitting on the T-stat housing. Not totally essential, but easier to build pressure without water everywhere. Moved the large piece of PVC to the block fitting (tap the angled end up and it will jam in place) and started filling the bucket. The block was really, really grungy due to the rust in the cooling jacket and I think I could have run a hose all day to no effect. For those who can drain onto ground, this would be a much quicker process. Just keep drainage off the street since it will stain your driveway and will leave a traceable mess in the gutter back to your house.

Here's where my research came into play. Just refilling the system with active rust (even after a dish washing powder flush) does nothing to stop the rust and I've noticed a lot of posts where folks reported rusty coolant within weeks or days after regular flushing. Gotta stop that rust!

Come to find out, the old paper tube product, with a tear off on each end, was oxcylic acid powder on one side with a powder neutralizer on the other. Worked like a champ to dissolve rust and stop further rust, but the EPA decided it was too nasty a product to dump into the environment and it's no longer available. I've seen GM part numbers for it, but don't believe they sell it anymore. Oxcylic acid is also in wood bleach, but it may be too dilute for our purposes.

Further sleuthing and I found a link to a Mercedes Benz product that is much more benign and safer to use. It involves citric acid powder, and I bought a pound of it at a beer brewing shop in town for $6. Plus I got to meet the nice guy who runs the shop! The MB kit is mucho dinaro. A Google will find you an excellent set of instructions, with pictures!

OK, so I'm gonna do the citric flush. Remember, we still have maybe two gallons of city water, with chlorine and minerals, in the block from our flushing. Next step is to de-oil the whole cooling system or the citric acid solution will not contact the rust. Here's where Shout Spot Remover comes in (or powder dish washing detergent). Anything that bubbles will be really hard to rinse out so don't use anything that foams!

I mixed some Shout with plain water and primed the heater core. Then I used my HF hand pump to circulate the mix through the heater for 2–3 minutes and let it sit for 15 minutes and then a plain water flush. I mixed about a quarter cup of citric powder with plain water and used the hand pump to circulate through the core, then let that sit for 15 minutes. The first plain water flush came out really dark, and the second was clear! Wo-woo! I blew out the flush water, dumped in some distilled water, circulated and re flushed and moved on. That last step is critical, because city water is the enemy!

The reconnected all the hoses, and bypassed the heater core with a piece of tubing. Then I took the rest of the Shout (spray bottle) and dumped it into the radiator at the pressure cap. Using the garden hose again, I filled the system and started the engine, rad cap off. Here's where the snow slider helps again, since as the engine warms, the liquid in the radiator/block starts coming out of the radiator, then goes down, then comes out (WTF?) and pretty much makes a mess. After things stabilized, I put the rad cap on and idled the engine for about 20 minutes. I let it cool and pulled that #%$& lower radiator hose and did a plain water flush of the block and radiator as described earlier.

Now for the citric acid powder flush. Buttoned everything up again, mixed a 1/2 # of powder with plain water, poured it into the radiator and filled as before. After things settled down I replaced the rad cap and drove around for about 20 minutes. I let the solution soak overnight. BTW, I was concerned about the effect on aluminum, but from what I read, citric acid and aluminum get along OK, and I didn't spring any leaks (maybe they come later?).

Next morning (hey, I didn't say this was going to be easy!) pulled that %#$& lower hose again (and yes, I explored a big drain valve) and did the plain water flush again, block and radiator separately, as described. First flush was dark and nasty. Second was clear, unlike the rusty water I kept seeing earlier. I pulled the t stat housing and the only picture I made shows what I found. The rust had turned black and appears to be stabilized!

Now, on to refilling the system. Remembers city water, bad...distilled water, good and we have maybe 2 gallons of city water in the block. Here's where the 8 gallons of distilled water (@ $.90 ea) I bought come in. With the rad and block still isolated, I poured one gallon through the upper radiator hose for a purge of city water. I don't believe there are any "traps" in the rad so that should be enough. Remember the block still has 2 gallons of city water in it so I used thick tubing and poured 4 gallons of distilled water through the opening behind the t-stat housing to flush and replace the city water. Strictly speaking it would probably take a lot more than 4 gallons to flush all the city water, but I believe it should be adequately diluted with just 4.

Then I buttoned everything up again, connected the heater lines, and installed a new stat (O'Reileys only had a 190F).

Here's where the subject of anti-freeze comes up. I always wondered why anyone would buy the pre-mix. Well, it's because it's pre-mixed with distilled water! Of course most system flushes are going to end up with a lot of city water left in the block anyway (except the way I did it!) so I bought two gallons of O'Reileys green coolant. Lots of folks who mix their coolant in a bucket first are totally bummed when the discover only room for one more gallon of 50/50 mix and inadequate freeze protection . Do the math and you'll see that method only adds one (1) gallon of anti-freeze to one (1) gallon of mix water to the
two (2) gallons in the block. Not enough anti-freeze!

What I did was fill the overflow bottle to the "max" line with straight anti-freeze (it will mix in later) then with the engine idling and the rad cap off, slowly added the remaining anti-freeze to the system. Still had overflow issues but caught it in the snow slider (it ran down clean) and added back into the system as things stabilized. Had trouble getting the heater lines to warm up, but a short drive "mostly" fixed that (see below).

Bottom line, 2 gallons of anti-freeze and 2 gallons of distilled water in the system. Rust stabilized, and with proper maintenance, the fix should last.

Wish I could declare total victory, but there is still a problem and I think the water pump impeller may be badly corroded. At idle, temp gauge says 210, but heater performance is poor. Rev to 2500 and heat comes on strong! I'm confident everything is clean and burped, so WP is only thing I can think of.

Suggestions welcome. Maybe still trapped air?

And for anyone who read this whole post and didn't need to, you were warned .

All the best.

dave1123

Well Steve, thanks for your post. It was very informative and your approach to the problem was excellent. You seem to have done a nice, complete job and maybe it will last.

I've seen many a gunked up system in my years from people just running straight water, mostly in the south. We get a lot of classic cars brought up from the south with this problem. I do remember using the oxcylic acid product many times, but now I know why it was removed from the shelves.

I personally have a problem with using my well water. It comes straight out of limestone strata and is calcium rich enough to destroy my household fixtures in short order. That's when I started using pre-mixed coolant. My Chevy truck got so clogged up I had to run a gallon of CLR in it to get it clean. I used to always pull the block plugs on the GM V8s because they were easy to get to. As stated before, I usually had to punch thru the rust with a screwdriver to clear them if they'd never been done before.

I had to laugh at your pulling that &@$&$@lower rad hose. You almost always get a bath, and it's HOT! I don't remember what year the jeep in question is, but my '00 WJ's heater hoses are both 5/8". That's why I always tell people to run the thermostat hose into the bottom pipe.

As I said, good job and thanks for the info.

stevewaclo

Thanks Dave!

Coming from an old-timer like you, those props mean a lot.

I'll bird-dog the system and report the outcome.

All the best.

GuyGene

Whew Steve, wha' a mess! You've hung in there with'er though. Good job. I learned the hard way, waaaay back to flush me coolant system about every 3 years at least.