What will it take to rid this cancer?

In my cooling system...

'99 4.0 AW4 145,000 miles. Bought it 10k ago with a "blown head gasket" turned out to need a water pump, and the coolant had NEVER been changed.

I'm so sick of the corrosion buildup in my cooling system... It is literally plagued. My heat goes out about every month from gunk clogging up the heater core. I'm sure my BRAND NEW water pump is bound to fail at some point, and I'm willing to bet my BRAND NEW csf 3 core is shot.

Now, I am rebuilding an engine at the moment. It's water jacket and head are completely rust and corrosion free, and I want to keep it that way. If I blast the hell out of my radiator do you think I could still use it? If it's going to be a problem I'd much rather shell out another $200 than deal with this again.

I'm planning on replacing everything (on the new motor) that needs to be. Are there any hardlines or anything aside from the obvious I should be replacing as well?

-Water pump
-Thermostat, and housing
-Upper rad hose
-Lower rad hose
-Heater core
-Heater inlet tube
-Heater outlet tube
-Radiator (if needed)
-Overflow bottle and hose

Anything else/any suggestions on keeping my current system going and preventing this on the future engine?

I'd probably just replace the radiator. A CSF brand all-metal runs about $140 delivered.

You're on the right track. Replace the entire system and don't worry about it down the road.

If you have not flushed you system before you replace your parts you may end up having to redo it again. Man, heater cores are a bummer to replace. I personally would not want to do that to many times in a row.
Use a chemical flush from the auto parts store, but make sure you are able to hook a hose up to your heater hoses to push the crap out of the engine too. You splice these "T's" with caps into your heater hose that have a cap on them so you can remove and hook up your garden hose to them. Most of the time the flush stuff wants you to add it to radiator then drive it for like 15 minutes. undo your lower radiator hose and drain, then hook you hose up to the heater hose and blast out the crud.
Always, always use some sort of coolant mixed as recommended (best to use name brand). I have seen systems that have just used water and I was amazed at how much crud can build up from just water. Amazed anything could even flow through.

Oh I forgot to mention, I flushed and backflushed the entire system literally 25 times when I first got the car. I would do it about every 2 days, and finally topped it off with some pre mixed name brand coolant after everything was clear. Opened it up for the first time last night after my heat stopped working. It looks just like it did when I bought it. Like the coolant was never
changed...

Edit: bought the Jeep in June.

Ok, there are "flushes" and then there are FLUSHES.

The plain old "I ran the garden hose until it all came out clear!" is nearly worthless. The 15-minute commercial flushes are not much better. Use a RADIATOR CLEANER, the kind you put in and drive for 3-6 hours and then flush it out. Follow the directions on the product. Prestone, Zerex and others make them. Repeat this a few times and things will get better.

Which coolant are you using. I have found the best at keeping corosion down is the good old fashion green etholyne glycol. The others,Red.orange and so and so . Seem to attract rust if the system is not completely full. This is my experience from repairing stationary generators. If they are severly coroded I put plain green in and change it after a few months. It seems to stop the coroding which cost waterpumps,gaskets and radiators.
I agree whole hardedly with Joe to flushing. Are you flushing the heater core both directions? This is a problem that is repairable so keep at it.
Ron

joe_peters said:

Ok, there are "flushes" and then there are FLUSHES.

The plain old "I ran the garden hose until it all came out clear!" is nearly worthless. The 15-minute commercial flushes are not much better. Use a RADIATOR CLEANER, the kind you put in and drive for 3-6 hours and then flush it out. Follow the directions on the product. Prestone, Zerex and others make them. Repeat this a few times and things will get better.

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I did both. I used the chemical flush then the hose one. Then I did it again. Mine had some saw dust "stop leak" run through it sometime in its life...


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Too bad about your 99.

As you are finding, it can take a LOT to completely clean out a badly abused cooling system.

For anyone reading this post, a lesson that with cooling system maintenance, you can pay me now, or pay me a lot more later.......

This is the most work I've done in terms of flushing a system, ever before in my life. I made 2 special plates that bolts over the water pump mount, and the t-stat housing mount. Both had holes drilled and tapped for plumbing nipples which I could hose clamp the garden hose to. I blasted the block out (switching from one plate to the other) until everything was clear.

Then I did the same with the heater core. Flushed it one way, flushed it the other way, repeat, repeat, repeat. In the end I filled the system with Peak eth-gly. I tried the flush fluid where you leave it in and are supposed to drive 100 miles or so then flush. Same disgusting coolant would come out every time. This is beyond me. From all the gunk coming out, I feel like the walls of my water jacket are just gonna break right into the compression chambers lol

You are certainly doing all you can do. Eventually, it has to clear.....(doesn't it??) lol

I had a similar problem with a clogged heater core on my 93 xj. I tried flushing and flushing, still no heat. As a last resort, before having to replace the heater core, I flushed the core with muratic acid. If your core is brass the acid will not eat through it. Disconnect all hoses to heater core, fill with acid, let sit a few minutes, flush with water. Repeat till no more gunk comes out. Rinse the core completely, you don't want that acid getting to your aluminum parts in the cooling system. I now have heat like I've never had before.

DanMan2k06 said:

In my cooling system...

If I blast the hell out of my radiator do you think I could still use it?

...I'm planning on replacing everything (on the new motor) that needs to be.
-Water pump
-Thermostat, and housing
-Upper rad hose
-Lower rad hose
-Heater core
-Heater inlet tube
-Heater outlet tube
-Radiator (if needed) :skull1:
-Overflow bottle and hose

Anything else/any suggestions on keeping my current system going and preventing this on the future engine?

Click to expand...

All of your hoses, housings and channels with the exception of your heater core and radiator have relativly large openings (huge, even) compared to the radiator. My bet is on the old, never maintained radiator. The channels in the radiator are MUUcccch more succeptible to clogging. There's also a possibilty of tranny fluid pollution through and opld radiator (if so equipped)

birchlakeXJ said:

You are certainly doing all you can do. Eventually, it has to clear.....(doesn't it??) lol

Click to expand...

Not if you don't replace the radiator.

JJacobs said:

You're on the right track. Replace the entire system and don't worry about it down the road.

Click to expand...

...or spend $140-$150 on a new radiator. Of course all the other things, hoses, t-stat (minus the housing) are all just mantainence items.

Hint: for the heater core, block off the bottom outlet and fill it with CLR, and let that sit for half a day (available at your local supermarket) then flush it,if it's not leaking you may be able to get around replacing it.

And: I am careful to not use TOO much pressure on the hose, the system isn't made for much more than 25 psi.

sw4218 said:

I had a similar problem with a clogged heater core on my 93 xj. I tried flushing and flushing, still no heat. As a last resort, before having to replace the heater core, I flushed the core with muratic acid. If your core is brass the acid will not eat through it.

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From what I've seen, not all cores are brass. Some are aluminum. Muriatic acid wouldn't be good if you don't know the exact composition of the heater core.

If you don't know, CLR is as strong as I would recommend.

lawsoncl said:

I'd probably just replace the radiator. A CSF brand all-metal runs about $140 delivered.

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Where did you find it so cheap? The cheapest I can find is $169 delivered.

BTW - make sure you drain the block 100% of the hose/tap water when you are finished.

How hard is the tap water in your area? If it is very hard water and has lots of calcium and other minerals dissolved in it, this will heavily promote sludge forming.

Ah, forgot to mention another important item. When I first bought it, I DID in fact replace the radiator with a CSF tri-core. Along with the t-stat and a new water pump. Could my new radiator already be clogged? Surely this sludge can't form THAT fast. It seems like it's almost overnight.

Are you using DISTILLED water in your coolant mix?

jeeperguy21 said:

Where did you find it so cheap? The cheapest I can find is $169 delivered.

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http://www.radiatorbarn.com. Their CSF brand all-metal for a 1999 XJ is $142.50 delivered.

lawsoncl said:

http://www.radiatorbarn.com. Their CSF brand all-metal for a 1999 XJ is $142.50 delivered.

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Oh I see. I was under the impression that you could get the 3 row all metal radiator for that price, not the 2 row. Now I get it. Thanks.