worn out radiator ~ dual core?

[j12piprius]

My radiator's getting worn out. The fins are smashed, coming loose, and it's clogged up with bugs. I'm thinking to get a dual core radiator, as my goal is to keep coolant in the 190's range, without going over 200, and the dual cores have a higher capacity for keeping a more even range. My concern is with it getting to 190 early enough but think this won't be an issue, as I can get there currently in 3 miles with grill blocks.

The honda has a 190 degree thermostat, which is perfect, so I'll replace it with a new one that's the same.

However the temperature switch turns on the fan at 185, before the thermostat even opens, which seems quite redundant to me, as once the temperature reaches 185, the fan stays on for the rest of the trip. I think a 194-203 switch would be better, as the fan wouldn't come on at all until the temperature reached 203, and would go off again at 194. Ideally I can regulate the temperature with grill blocks, the temperature will stay in the 190s range, and the fan won't ever come on.

Let me know your ideas and suggestions.

[ecomodded]

You should put a 180 degree thermostat in it,Or it may be the one in there now is sticking & opening late and is currently a 185 degree one. You would think they would want to set open the water flow before the fan not at the same time and surely not after.

In the summer a cooler thermostat will help keep the fan off.

[2000mc]

i think i would dig into the issue with the fans coming on at 185. seeing 185 on a vague factory gauge or scangauge, or some other digital way of reading? know if the ecm uses the ect sensor to turn the fan on, or seprate sensor/ temp switch? i'd also make sure the hvac is completely off when tring to figure it out

[redpoint5]

A radiator that isn't leaking doesn't need to be replaced. Just get a fin straightener and clean those bugs out.

The fan is turning on at too low of a temperature. I'd get a switch that turns on at 210F or so.

[user removed]

Radiators die slowly. Eventually they can not transfer enough heat to keep the engine cool. The symptoms, other than leaking, are coolant temp rising when the engine is under high sustained loads, which is usually not going to happen to a driver focused on economy, unless he has to climb sustained grades or other situations where loads are high and sustained.

I have seen new radiators actually hurt mileage and I don't need to increase capacity in a replacement radiator beyond the increased capacity of an exact replacement.
You definitely either need to raise the cooling fan activation temperature or reduce the thermostat opening temperature.


regards
Mech

[user removed]

A radiator can get clogged up enough to not cool the engine properly and still not leak. Most radiator shops can check it with a digital thermometer and it's easy to see when the radiators capacity gets low enough to require replacement. A very simple test is to hold your hand on the top and bottom hoses. There needs to be about a 50 degree minimum temperature difference for the radiator to cool your engine properly. In most cases the top exit hose will be too hot to hold your hand on for more than a few seconds without getting burned or blistered. The bottom return hose will be much cooler and you caneasily keep your hand on it for much longer. The least temperature difference will be in the hottest weather you experience.

The visible damage you have observed, combined with the age of your vehicle, would lead me to assume it is the original radiator. My ranger still has the original radiator and it is working fine at 17 years age (1997 model) but I would not be surprized if I had to replace it this summer when it gets real hot here in eastern Va.

The risk of a radiator on it's last leg is a blown head gasket.

regards
Mech

[j12piprius]

My honda radiator is probably the original, going into it's 16th year, so I'm going to replace it. An oversize with higher thermostat and blocking the grill will hopefully not hurt mpg. I want to get a 195 thermostat, aiming for a constant temperature of 195-200, which will hopefully keep the engine warm enough with an oversize radiator.

The fan coming on at 185 is an issue. I want it to not come on until 200-203 degrees but haven't found a civic coolant temperature switch in this range. I might need to install a remote switch, or a temperature gauge adapter with a different switch. In the meantime, I've unplugged the switch and will keep close watch on the gauge.

Below are three of the radiators I'm considering. Let me know your comments.

1) $55 ~ .63" standard radiator with plastic top like the one I'm replacing;
2) $50 ~ 2" all aluminum that I like the best;
3) $62 ~ dual core all aluminum, that I might get because of the fan.

[cowmeat]

I replaced my old, tired single core radiator with a dual core, and replaced the 195 degree thermostat with a 180 degree, and even with the full grill block my temp gauge doesn't budge after the thermo opens up.

[j12piprius]

During my last trip, the coolant increased to 183 within 2.5 miles, stayed below 195 for 50 miles without the fan being plugged in, on a mid 90's degree day, and my mileage was the best it has been. The OE thermostat temperature appears to be 170 degrees.

Is it true that a larger radiator doesn't affect the temperature until the thermostat opens, and doesn't keep the temp any lower before that, but simply prevents it from going higher as quickly after the thermostat opens?

[Superfuelgero]

Just use the push though fin probe style, or modify the signal for the stocker.
***ECT fan switch : (green - black wires)
A and B terminals should test for continuity above 196 - 203*F

Should double check your engine readings too.
k-ohm: temp (celsius)(*F)
12 - ( -20) (-4)
5.0 - 0 (32)
2.0 - 20 (68)
1.2 - 40 (104)
0.7 - 60 (140)
0.4 - 80 (176)
0.2 - 100 (212)
0.1 - 120 (248)

Good call on replacing the radiator, mine was really soft when I replaced my hoses.
Fyi, a dual core aluminum is heavier than the plastic tank units by a few pounds.