Underhood Temperature Issues
 

Hey everyone -- it's been a while (took a hiatus but still Eco-Driving as always...)

With the warmer weather firmly making its return, I'm running into some cooling issues.

To preface the discussion, these are the mods that may effect the situation: grille partially blocked by license plate, sealed hood gaps, hotter t-stat, and a warm-air intake (simply took the lid off of the filter box). These help warm up the quickly and operate more efficiently.

Issues:
-The SG constantly shows 200-213FWT in weather warmer than 50F.
-The fans kick-on more frequently
-Valve cover gasket (relatively new) is starting to ooze a bit (more on the oil choice in moment)
-Fan engagement has determined to occur while at highway cruise, incurring a heavy electrical demand (similar to an A/C compressor, but a bit lighter)

My inclination is to ventilate, but I'm at the crossroads of FE and Longevity. Teggy has 142K miles and is virtually all-original. Right now, we really need it to last, but not at the sacrifice of too much FE. I've already loosened-up the shifts on the tranny and performed the 3rd (and final for a while) synth fluid change. Engine oil is Castrol GTX High Mileage (first time using). But the 7-year old battery is just fine, even with ~5% EOC and extreme temps. Coolant is 50/50 and the reservoir is full.

I just worry about that transmission mostly and now having seen the new gasket very lightly ooze makes me wonder.

Thanks guys!

-Rick / RH77

RH77 -

I'm not a car dude, but if your fan is coming on a lot, then I think you need to remove some of the grill blocking. The amperage load of the fan is defeating the purpose of the MPG gain anyway, right? What's the fuse rating of your fan as compared to your A/C? Does your fan come on when your A/C is on?

When I am being diligent, I modify my grill block strategies based on the weather. It sounds like Teggy needs a "winter look" and a "summer look".

I have a manual fan radiator switch, and I am turning it on when I hit traffic jams. My car automatically turns on the fan at 220 degrees F and off at 210 degrees F, but I usually turn on the fan myself at 211+ degrees F and turn it off at 191 degrees F.

CarloSW2

I'm not comfortable with running a thermostat hotter than stock. I would start by going back to the factory temperature t-stat, which should have a huge impact on the amount of time your fans spend on. Yes, hotter oil is thinner, but you can get the same effect at lower temps by mixing a little 0W20 with your 0W30.

You should also inspect your radiator. I've seen some pretty bald radiators while combing the junkyard. After a decade or so, the fins start to come off, and they lose much of their cooling capacity.

p.s. your battery is going to die soon, and there's little you can do to save it. Most batteries last 5-7 years depending on climate and service conditions. You should be able to buy a gently used battery at the auto parts store for ~$35. Call around when the time comes.

maybe your water pump is going bad??

Or, related to the water pump - maybe the antifreeze isn't up to snuff, and the coolant needs flushing and changing? (I'd check the water pump and belts/drive to it first, though)

To me this sounds more like a fluid and radiator issue. I'll second the notion from ChrstphrR and say do a flush and change. When you get done flushing it fill it with more water instead of antifreeze. Instead of the regular 50/50, try mixing it at 40antifreeze/60water or at most 35antifreeze/65water. I had a ton of issues when I first got my jeep with overheating of the I6 motor in it, and running a higher amount of water helped a ton. I also use some types of "super coolants" that you can get ant any Autozone, Napa, Advanced Auto, or whatever is closest to you. One to look for is made by Redline and it's called Water Wetter, and it's supposed to help reduce the temperature by 20 degrees if you run only water in your radiator (more of a racing thing to do that, but it will reduce temps by 10 degrees if you have antifreeze in your fluid mix). The stuff works pretty dang good, and it helps prolong the life of the fluid in your radiator.

I think this is your easiest route to go, especially if you don't want to constantly change and swap parts out for the different seasons you drive in.

Thanks for the replies guys...

I forgot to mention that the radiator is about 2-years old -- the stock model had a small leak at the crimped top. The system was flushed, and a new rad was installed (basically the biggest failure/replacement).

It just smells hot most of the time. After inspecting the overflow bottle, it's rarely even warm and doesn't seem to be transferring fluid (no leaks or whatnot). The water pump and pulleys were replaced 60K miles ago with the timing belt. 20K more miles to the planned timing belt/water pump/pulleys/belts replacement.

Even without A/C usage, fan engagement draws a considerable power at cruise. You can feel a distinct power loss on engagement, then a burst of efficient power when they release. This is an old problem, though. But yeah, the fans engage when the A/C is on. If I'm in work attire, I modulate the air: recirc with 75% blower, and manual compressor start/stop (off up hills and from a stop; back to On during decel / steady cruise it comes back on).

The reason for the concern is the change in temp compared to similar conditions last year this time...

Regarding the T-stat, a distinct improvement was noted when the hotter variety was installed ~3 years ago. Whether its the oil, or other factors at work, that may be the last option. In the Winter, it's nearly a necessity.

So, it looks like I need a coolant flush to start, with a different percentage mixture. I perform 90% of the work myself, but responsibly disposing of the coolant is tough. Is there still the requirement to attach a garden hose and run water through? If not, I can likely collect the contents for recycling.

In the meantime, the license plate is getting moved. I know it opens-up that huge air dam, but we gotta do what we gotta do.

Any second opinions on the Water Wetter product?

Thanks!

RH77

Do you have any way to monitor trans temps? I can program it as an X gauge for my Escort. I had my lower grill blocked during winter. The first warm day I drove it like that I noticed coolant temps were 5-10* higher than normal. But trans temps on the highway were 30-40* hotter than normal. So basically I think you are right to be concerned about how this heat is affecting your transmission, and I would definitely add more airflow and consider putting the stock thermostat back in.

What's your intake air temperature? On my car I'm using IAT as basically the underhood temperature as the whole intake is plastic and shouldn't heat soak much. My stock Neon IAT is at about 135F with 60-70F ambient temps driven at 55mph. This also puts the coolant temp at about 186F. I can see though when the thermostat actually opens as the IAT starts to go up. When I'm coasting the coolant temp hardly drops but the IAT does as the thermostat is closing preventing flow through the rad and therefore the engine bay temperature is dropping.

I don't think there is any advantage to having a hot engine bay, you've already got the hotter thermostat and cooking all the rubber and electronic bits under the hood for 1 mpg isn't going to be cost effective. I think you should open up the airflow atleast until your fans never come on driving on a 55mph highway without the air conditioning on. My cooling fan comes on at 208F so most days driving to work it never comes on, even in the short stretch of stop and go at the end of my drive. Also if your engine bay is smelling "hot" you are probably smelling all the plasticizers evaporating out making the rubber and plastic stuff more brittle...

air dam
 

I added an air dam directly under my radiator. It seems to pull more air thru the radiator that way. My guess is that it creates a low pressure area below and behind the radiator and pulls the hot engine compartment air into it.