I have first to say that this is not for me but for a friend with a new to him 2001 disco that is over heating. Fitted a 180 t stat and a new top hose. When taking out the top hose we noticed fine copper particles in the pipe and the coolant, STOP LEAK
The disco is now seriously over heating, could be a blocked rad or heater or Head gaskets. There is no signs of HG's leaking, but will be doing a pressure test on it later.

So this is my question, is there a good comercially available product that could be used in the coolant to see if the rad or heater is blocked to unblock it?

Thanks

 

As Buzz mentions quite often, best test would be to measure the temp of the radiator at the top and at the bottom. If there are significant differences in temp (I believe more than 10 deg diff) your friends radiator is clogged and not cooling properly.

As Mike generally chimes in, these radiators cannot really be flushed with great results. New radiators can be had for about $200 and are not hard to replace, which is the good news.

 

if you have little particles of copper it is probably that Barr shLt, it sucks.
I used it once another truck overheat in a 1/2 hour.
I pulled the lower hose to dump it out twenty minute later when i took off the radiator cap the top half of the radiator was full of coolant, blocked it right in half.
All you can do is pull the hoses and try to back flush it, but it cost me a core.

 

See pix. When you have a problem older cooling system, several things have not happened... the PO did not change coolant on a reasonable schedule (like every 2 years), the Dexcool sludge formed, or plain old water was used and calcium formed. The stopz leakz formulas vary, but if the cooling system just has a leak everything will be fixed in no time. The problems comes when there is any kind of crud in the cooling system, and this gives the quart bottle of stopz leakz something to really work on. That makes the quick failure that many report, but the rad most most likely already partially blocked.

Pix of dex sludge, plain calcium crud - you can see why water flow would be less or none on lower rows, block off more and suddenly you have a 100% engine on a 30% radiator... Thermostat shows a buildup of "water glass", the active ingredient in most stop leak (sodium silicate). If it can build up in that spot, where water turbulence is fast, imagine what it can do in the flat horizontal craggy caves of crud that are the internals of the radiator. Most rad shops not interested in taking off plastic tanks (usually brittle). Old D1 rads had soldered on metal tanks.

 

Yes there are products over the counter that you can use, give it a shot, you have nothing to loose at this point.

 

Sorry I forgot to add this TSB from GM on how to flush a Dexcool system. Just don't refill with Dexcool. You will note it takes a while with vehicle at elevated idle. It uses over the counter flush that Spike mentioned.

Depending on sludge levels may get some, may not get all, etc. Any any before/after tests should be made with something digital, like scanner and IR thermometer, not the factory temp gauge and the Mark I palm reader (damn that feels hot!).

On a D1 copper rad, I tried the flush, I tried white vinegar (works for coffee makers), removed rad and tried muriatic acid (brick washing acid, makes copper bright, would eat aluminium) - all did a little, but big fix was rod out by a shop. For a D2, new rad is a lot more reasonable, although a $232 D1 aluminum one has started being installed with favorable results.

If a rad is this sludged, might not have good results. IMHO rad chemical flush is part or regular coolant service, and should be done on a calendar, not miles basis (chemical reactions are at work while the Disco sleeps), and at 24 month intervals.

 

passed all this on to my friend who now says the rad is dripping from the bottom, looks like the PO did a quicky fix and then sold the Disco on quick. Thanks for the responses and advised him that he is looking at a new rad. Was tryinging to save him a few bucks but that is not going to happen..hoo humm the joy of owning a Disco......

 

Let us know how it turns out. Because there was stop leak in the coolant, it may have only been for the radiator, but I would watch for coolant consumption and consider doing a coolant pressure test just to rule out a head gasket issue lurking in there.
Try and flush out as much of the old stop leak from the block before refilling it.

 

You know, I was prompted the other day to check on the cost of a Disco II radiator from the place I get my all aluminum radiators for another car from, and the price on their Aluminum/ plastic tank radiator is only $150 plus shipping. All thing being equal, that's not that big of a dent...

GenesisAutoParts | Radiators, Condensers & Other Auto Parts Online

 

Less than an alternator....., or a diag appointment with the "surgeon on duty" at the dealership.