Lights blocking airflow?

[Mike1919]

I noticed when cruising on the freeway above 60 mph the engine starts to warm up. Not get hot, just rise to the "m" or "a" in "normal" I first thought the single core radiator could be plugged but it occured, could the lights in the grill be causing it? It never runs that warm except if I'm cruising 65 with ac on.

 

[Stormtrooper]

Doubtful but if so an electric fan from a junkyard could help.

Sent from my SCH-S968C using Tapatalk

 

[97RangerXLT]

looking at your grille setup, your lights are taking up half of the opening. however, it looks like you have modified the original grille so that it is more open, so probably you have it blocked 1/4 to 1/3 of the OEM design.

that shouldn't cause that significant of an issue. I would take the truck to the carwash and power wash the bugs/ grass out of the radiator as a first step. next step would be to make sure that your fan clutch is working properly. usually it will stick so that it is "on" but maybe yours is not engaging the fan all the way. (I would think that you would notice that at idle or in town driving tho)

Another thing... my 97 has a little scoop or air diverter right at the bottom of the core support that kind of funnels air upwards into the radiator. if yours is missing that might be part of the issue.

AJ

 

[Mike1919]

Well the grill is just chicken wire. I bought the truck like this. The lights do take up wuite a bit of space but air does still get through, I just don't know if its enough. Would the fan clutch be a suspect if it only involves speeds above 60 mph?

 

[adsm08]

If the problem only occurs above 60 the fan could be involved, but I would suspect the water pump first.

The fact that the AC seems involved makes me think an air-flow issues or possible an AC issue could be at fault.

 

[Mike1919]

Could the radiator be a problem causing this as well?

 

[RonD]

What engine do you have?

No, the added lights wouldn't cause it specifically but you may notice a cooling system fault sooner because of the added lights.

Make sure you have a thermostat in, a 192-195degF t-stat, running without a t-stat can cause symptom you describe, coolant is flowing too fast thru the rad to cool down, so temp starts to climb.
It could also be the current t-stat is not fully open, limiting flow.

Make sure A/C condenser(in front of the rad) is clear, no debris in the fins, and if it has an e-fan make sure it is working.

You can do a Flip test on the rad to see how plugged up it is.
Next time you have to drain coolant pull out the rad, 4 screws, all at the top.
Flush it out with water as best you can
Put rad cap on and put rad on it's side, so tubes are up and down
Put your hand over the lower rad hose outlet
Use upper rad hose outlet to fill rad with water
Once full, stop filling and remove hand from lower outlet
water should rush out very fast, tilt rad a bit to get all the water out

Now the test
Flip rad upside down
No water should come out
If any water comes out it could only come from blocked tubes that couldn't drain out

Water pump is also a good guess, impeller fins can start to corrode which limits the amount of coolant the pump can circulate, so lower flow.

Not sure if fan clutch could cause this symptom, usually fan clutch issue is when engine/coolant temp rises when stopped, like at a stop light, because fan is not fully engaged so is not pulling enough air thru rad, when moving again air flow thru rad is back and temp drops.

 

[adsm08]

I would say the fan should be considered a non-suspect component at this time. It is literally the last thing I would look at in the scenario described because at the speeds you are telling us this happens at just the movement of the vehicle is going to push more air over the rad than the fan is capable of pulling.

 

[Mike1919]

I just replaced the thermostat with a 195 and I can definitely hear the fan engage and disengage. So is there any way to test the water pump or is it anybodys guess?

 

[Mike1919]

And it's got the 4.0 ohv with a manual transmission.

 

[enjr44]

When you changed the t-stat did you flow test the radiator as suggested? You got to remember that when going down the highway, you are cooking a lot more fuel than when puttin around town. The water pump is sort like the last guy in the line. After everything else has been eliminated it is what's left.

Sort of like, first, is there coolant in there. Second, it the radiator clean on the outside. Third, does the radiator cap hold pressure. Fourth, does the t-stat open. Fifth, is the lower radiator hose collapsing (probably not if the rad cap is good). Sixth, is the radiator partly plugged. Ect., etc.....

 

[RonD]

If you don't know when the water pump was last changed then I would just change it on spec, they do wear out.

I just changed the water pump on my '94 4.0l, weep hole was starting to drip.
Took about 90min., including drain and refill
Pump was $50
You do need a Ford fan clutch wrench set, or a darn good gripping tool for pulley

 

[Mike1919]

I changed the t-stat when I first got the truck. I'll probably end up testing the radiator as suggested, but I've also heard of guys upgrading to 2 row radiators from the automatic transmission equipped rangers. I'll look into that.