Can a rediator flush actually do harm to an already properly functioning cooling system? If so, is this common at all?
I got one on my '93 Chevy Caprice Classic Wagon. It was purely preventative maintenance… the car was doing fine. The car is still staying cool while driving exactly as before, but now it gets hotter when I use the A/C during the day when it’s hot. I am about 80% sure it didn’t do this before (I don’t use the A/C much). I didn’t let it get too hot, but I have never seen the needle this close to halfway before in 2 years, and it just happened right after a flush. How could this be a coincidence?
Coolant is a mix of Antifreeze (Active ingredient is Ethylene Glycol) and distilled water. Water keeps things cool and Antifreeze does a few things. It raises the boiling point, lowers the freezing point, and has some additives that help to prevent corrosion.
Most likely what happened in your case is that the technican did not use a proper Glycol / Water mix (usually 50 / 50) Seems to me that your on the upper end of the spectrum with too much Glycol and not enough water. This will definately cause you to overheat with the right conditions (I see that your in Southern Florida, so the conditions are most likely right in this case)
Another possibility is that when the technician was flushing the system he may have dislodged some gunk which in theory could clog a cooling line or the water pump thus hindering flow. Yet another possibility is that your water pump is going bad or belt tension on the pump is not sufficent to maintain proper flow at higher RPMs.
There is one more thing it could be. I’m pretty sure that model car does not have an A/C condensor fan, but if it does I would advise ensuring that the fan is operating properly (or at all for that matter) This would be an aux. fan that only comes on when you have the A/C on, would be located near your radiators main fan(s). I reccommend this since you noted that this happens more with the A/C on.
well, flush eats away at the deposits, and also the welds inside radiators. and boom. leak.
also, no. 100% water is the best for heat transfer, well, pure distilled water, and a cooling system treatment called RMI-25 for rust prevention. if it never freezes there is no reason to even use antifreeze at all, its only in cars because the general population is stupid and if they put straight water in a car someone would go on a road trip and park their car in colorado and bam… cracked block. the main thing that raises the boiling point is the pressure… cooling systems are usually over 10psi
So to get this straight, in S. Fla. (temp. in the 90’s) in the summer there is no need to worry about the water boiling because the system is pressurized already, thus making the water impossible to boil? (I have heard this concept using 100% distilled water instead of anti-freeze before, I just never heard it explained)
RMI-25 available at any store?
Geez, I should have taken my own advice that I always give others: “If it ain’t broke, don’t fix it.”
dadon: If the condensor fan is not functioning properly, then the A/C wouldn’t work, right? How would this fan, not working properly, make the car get hotter?
Well, I drove my car 100mph for 10 minutes straight during a 3 hour 90mph average trip last night so things are still ok. “The Whale” lives on! I’ll note all your comments, Thank you.
A 50/50 mix of water and antifreeze is the best thing to have in there, unless you’re in an extremely cold climate, where it can be up to 70% antifreeze.
The two things that keep the coolant from boiling out of the system are the pressure cap and the fact that a 50/50 mix has a higher boiling point than 100% water. I would not forego the antifreeze, even in a climate where it never freezes.
A properly done flush will cause no harm. Failure to flush regularly can do plenty of harm, as the coolant becomes acidic and starts corroding the metals in the cooling system (radiator, heater core, cylinder head, engine block, pipes, etc.).
If a flush dislodges gunk that was plugging a hole, it simply hastened something that was going to happen anyway. Better to have it happen while the car’s in the shop than when you’re out on the road.
A failed A/C condenser fan won’t keep the A/C from working. It may keep it from cooling as much as it should, and it may let pressures rise to the point where some A/C part bursts, and it may contribute to the engine running hot.
This is not a situation where “if it ain’t broke, don’t fix it” applies. This is a maintenance procedure. A closer maxim would be “if you ignore it, it will go away” (if you don’t maintain it, problems will develop).
My old man, an engineer and long-time disciple of Lucas, the Prince of Darkness, used to tell me this: “do not ever clean a mechanical component that is working properly.”
Gary T is right on point with what he said. I was going to get back to the fact that boiling point is further increased with Glycol all the way up to 70/30 (Glycol/Water)
The reason I suggested the AC Condesor fan is because the gentleman said it only overheats with the AC on.
One of my race cars is a '97 Eclipse Turbo on which I removed the AC condensor fan to allow room for my bigger turbo. The A/C still works fine of course since all the fan does is force more air through the radiator, but in hot weather if I’m sitting still (i.e., traffic light, staging lane, etc) the water temp quickly rises until I turn the A/C off at which point it falls back to normal. Once moving again you can turn the A/C back on and temps will start to fall anyway due to the increase of air going across your radiator (no longer needs the fan to force flow you see)
