I am open to take suggestions on any high quality professional grade cooling system cleaners that can be used to help facilitate getting this gunk out of the entire system.

I do not think you have need to replace the core. but a good flush may well be needed. Granted it is a bit of a PIA to get to the hoses for the heater but get both of them off and prepare for a good spray under the hood.

You need to flush the core both directions, The back flush will dislodge a fair bit of crap. I flush them both directions a number of times.

I would expect the block has sediment in it too. Probably similar to what is in the reservoir.

If this was my truck I would,

1. Use a coolant system cleaner and drive for a few hours
2. Get a back flush kit and install it in one of the heater hoses.
3. Remove the thermostat from it's housing, but put the housing back on.
4. Remove the 2 block drain plugs (if you can get to them. They are a PITA) and rad cap.
5. Attach your garden hose to the flush'n'fill you installed and leave it running for a while with the heater core valve open.
6. Put everything back together and see what happens.
7. You may need to have you rad soaked and rodded out at a rad shop.

You may have to repeat to get everything really clean, although I would only use the cooling system cleaner once. Once everything is clean and stays clean, I would replace the heater hose with the flush'n'fill kit in it because I'm not sure how dependable the plastic is long term (they will last a few years though).

I agree with Charlie about not replacing the heater core or the rad yet. If you replace them with a lot of crap in the block you could clog them up.

I've been through the same thing as you, may be for the same reason or just neglect from the PO. My cooling system is fine now. It took quite a few flushes, but my 1 year old coolant was only a little dirty when I drained it recently. A few more flushes and I reckon it will be really clean.

Good luck <img src="/forums/images/graemlins/cheers.gif" alt="" />

thanks for the input guys, the only reason I say it had to have orange and green coolants mixed was due to the fact that there was so much sediment or 'precipitate' in the system that someone either vandalized the system by putting sand in it, or it was b/c coolants were mixed in significant quantities.

the surprising part is that it ran well, no over heating, nothing, just some noise under the dash when reving engine.

any further input is welcome.

Just a suggestion regarding the flush-n-fill kit. Rather than slice the heater hose to install the tee (like the directions state), pull the heater hose at whichever end is the easiest to get to, install the tee in the open end, and add an additional length of heater hose to reinstall. This makes it easier to just reattach the heater hose when you remove the tee.

My $0.02 based on experience and not adjusted for inflation <img src="/forums/images/graemlins/cyclops.gif" alt="" />

Eric W.

got it,

my concern is (and I need some more input from someone who expereinced heater core plugged up problems)

-does the garden hose flush with the T connector method work or are heater cores very difficult to clean out?

-what is causing that gushing sound, is it the heater core being partially blocked????

Insufficient amount of coolant. This forms air pockets which is the gushing sound you're hearing. This can typically be addressed by 'burping' your cooling system when you flush and clean it.

As for whether or not the flush process will also clean out the core, I'm not sure but I hope it does.

In terms of cleaning it out, you may also be able to connect your flush kit directly to the heater core hoses (bypassing the engine entirely) to focus the flush process on just the core.

Oh, I should add that I'm not a mechanic but I did stay at a Holiday Inn Express last night. <img src="/forums/images/graemlins/lol.gif" alt="" />

Heater cores are no more difficult to flush than a radiator. Heater cores are just little radiators. Even with the mixing of coolants power flushing the entire coolant systems - with the thermostat removed - should take care of it. I expect it's going to take a while before the system runs clean. It was suggested to me to periodically reverse the flow. I don't know how much good that does as I've never had a coolant system in this bad a shape.

The bad news - depending on how long it was run with the two coolants expect to be replacing a water pump in the near future. Replacing ALL the coolant hoses - everything in the cooling system with rubber (cap, too) - is just a given. <img src="/forums/images/graemlins/frown.gif" alt="" />

If you don't have a lake of coolant on the passenger side floorboard the rushing noise from the dash is air being flushed through the system. At this point you have bigger problems to deal with than bleeding the cooling system.

Edward

That's a great idea <img src="/forums/images/graemlins/kewl.gif" alt="" />

Of course if you haven't replaced that heater hose in a while, it may be a good idea to replace them anyways unless you want a hose blowout on the highway like I had w/ my blue monty before... <img src="/forums/images/graemlins/frown.gif" alt="" />