yep clean it, im asuming you mean the coolant reservoir plastic thing,,,

 

okay, I think is impossible to put all the grunk on the bottom of the radiator and the bottom of the reservior tank outside.
My mechanical said that it is normal and it is okay.
The new dex cool in two years have the same reaction.
I've wash 90%-95% of the cooling system and only with current water.

Do you tink it'is okay?
If inside remain a minimal part of grunk in the bottom it's really a problem?

 

The gunk at the bottom of the radiator reduces the effectiveness of the radiator IF the gunk is high enough to block the first flow port. I have seen radiators with as much as a 1/3 of its ports blocked. These cars tend to over heat in traffic jams or if pushed real hard.

These ports are just kind of a metal tub the connects the two tanks. As you can imagine if coolant can not flow through the tube it can not be cooled.

When I did my Project 96 I back flush two large handful of that brown crap out of the radiator. I serious doubt that amount would effect the cooling system. There is really no way to know without knowing how deep the gunk is.

One test you can do is with a Infrared scanner. You just check to make sure the radiator is as hot in the middle bottom as it is everywhere else. Might be tuff in a 4th gen. But if the car is not over heating on a hot day you are probably fine.

Non-Contact Infrared Thermometer With Laser Targeting

Edit: If you drained the cooling through the petcoc at the bottom of the radiator and it drained quickly then you are probably fine. When the radiators get real bad it is not uncommon to completely remove the petcoc and still just have dripping because the radiator is so plugged.

 

your fine, gunk will leave a stain. i use the green stuff. havent had this issue.

 

Okay.
I've wash the radiator and I've drained by the lower radiator hose.
The gauge cooling temp is in the middle in the traffic and a little bit under the middle on the highway.
The problem is than I dont want to use a produt to wash the cooling system but I prefer only water.
Some product may be acid and corrosive and I prefer don't use it.

Now I work only with water in the cooling system and i have to do the last flush and refill and replace the termostat.
I don't know if the bottom of radiator is ok but the temp on gauge i see is okay.

Do you think that I need to use a product to wash the radiator or it is okay now?
I see a little bit of gunk on the nek of the rad cap when I open it
thanks

edit: when I've drain the radiator by removing the lower hose the old dex cool coming out like a river.

 

i think I metioned for the price of a radiator when in doubt ,cheap $60.00 could have saved my lt1 ,couse as I look back I am sure I had atleast one blocked port an that can come from flushing its stirring up the pot is how I look at it ,if you got 95% of gunk out you may be ok but check it couse mine quickly broke down very fast again after a flush an it was dark green black mix after 1 year,looking back I should have put a new radiator in it ,I think a lot of guys fail to think about doing it .or just doing it ,for the price of what a shop charges for a flush $100.00 average ,now a good shop should be able to say ,you may need to change it out couse of to much gunk,an others just want to flush it get there money an move on ,wich is the mistake I made with mine,i had a flush done by a shop ,then about 2 years later did one myself garden hosed it ,wich I should not have done ,though I used the kit to flush it they sell at walmart it was not enough for my situation ,so next time I would change out the radiator an res tank ,rather then stirring up the pot wich ended up getting my cooling system in worse shape,then my manifold gasket started to go slowly needing gaskets wich I think of one does not do them all then it spirals from one to the other an thousands in work ,wich in my case I chose an engine swap ,this may be far from the case with you ,just what happened to me

 

take the radiator out and flush it.

 

Just a FYI. antifreeze itself becomes acidic over time. The cleaners primary job is to kill that acid. They are bases not acidic (think soap-ish). A name brand flush kits is a good thing. Water will dilute the acid but not kill it like a base will. Water with a weak acid in it is begging for rust.

Now you just need to add some Salt.

Yes that was my attempt at joke, but your system needs to get the acid killed a lubricant and a rust inhibitor. Water is fine for cleaning/flushing but I would not leave straight water in my system more then a day or so.

 

again if he is going to take it out why not replace it $56.00 on ebay or less for the 3.8l,the crudd that could be in it is unknown ,if i was pulling mine out i know the small amount one pays for a new one is a no brainer for me ,a new reserve tank too ,it takes few days to get one on ebay

 

You really need to be careful with super cheap radiators. They tend to not last long and IMO should only be used on a car when the OE radiator is not salvageable and you know the car has a limited life (less than 3 years). Many shops will not install the cheap radiators because of the high failure rate and the fact that they can take the engine with it if it leaks. I am a cheap guy but I would spend $60 for a profession flushing of a original radiator before I spent $60 on the cheap replacement.

I am not above using a cheap radiator but I will add a coolant pressure test to every other oil change. I am all about cheap parts but, radiators, rack and pinions, wheel bearings and of course engine internal parts you really don't want to skimp.