1988 convertible:
On really hot days like yesterday, the car is running above normal operating temps at speeds over 100km/h, when engine load is anywhere above 'cruising'. For example when going up an incline on the 401 in 5th gear and I have to throttle down a bit more, or accelerating to pass a car... whatever. As soon as I get the car off the highway or anywhere under 80km/h it's fine, and I can feel the fan kick in on idle since it eats up so much power.
I know all the normal troubleshooting I should look into but I'm stumped now.
- I am using the undercover
-The rad is a used stock one that I had flow/pressure-tested last year before installing (checked out okay)
-Thermostat is new OEM as of last year,
- Water/coolant mixture is okay, and I'm picky enough that I even go out and buy jugs of distilled water rather than using hose water.
- Drive belts are all tight so there shouldn't be any slipping or anything
- Coolant levels check out okay and I can see coolant flowing with the rad cap off.

So the only thing I noticed is that the little foam strip under the rad that's supposed to seal the space between the rad and undercover is missing, but I really didn't think that that little 2" gap would be enough to prevent cooling.
So what's my next plan of action? Look for a new rad in case this one is somehow clogged? Thermostat is faulty? Drive below speed limit on highway? lol

And one more question: how helpful are this little bottles of coolant helper or whatever they're called, like royal purple's "ice" stuff, among others? Are they just a quick fix?

 

The stock rad was never able to keep up with heat... Driving on a highway at high temps is sorta like driving on a track at that heat and that is why no one uses them on the track They are not efficient enough to cool the motor. This is just my opinion but my convertible has a stock rad and I see this occur only when I push the car a little more than usual. But on my S5 coupe, it has an aluminum GM or Ford rad (Ill check after exams :P) which I really haven't been able to surpass the middle of the temp gauge as yet

 

Overheating on the highway is ducting to the rad 100% of the time.

thewird

 

But don't you feel that the stock rads are not that efficient?

 

Sure they may not be efficient enough... If i had any serious mods done. But we're talking about a 99% stock N/A engine with no ducting modifications under the hood. It hasn't always overheated on the highway like this and actually the stock rads do fine cooling a stock engine when everything is functioning properly. That's why I'm not sure what to check or replace next.

 

If this is a new problem, maybe the clutch fan is going? Spilling any coolant?

"So the only thing I noticed is that the little foam strip under the rad that's supposed to seal the space between the rad and undercover is missing, but I really didn't think that that little 2" gap would be enough to prevent cooling."

Look into that missing piece :P. You'd be surprised how much those gaps make a difference.

thewird

 

just replace the rad, i've never had any issues with any of my fc's in the summer with a stock rad that being said, its not worth going and buying a stock replacement go get a nice aluminum rad and be done with it

 

Running lean will also raise your engine temps.

I run water wetter, seems to work great.

I recently got a new motorcycle (same as my old one) but haven't added water wetter to the coolant yet, I find that the engine temps in traffic rise a lot faster and a lot higher than before with water wetter. As well, the rad fan is almost constantly on rather than switching on and off.

Ducting is very important, Aluminum tape is awesome for closing up gaps

Air bubbles in the coolant can cause cooling issues as well, get a radiator funnel and bleed your coolant system as well.

 

How are your rad caps and hoses? I replaced those and my car was cooler right away.

 

For the record, installing this was a complete and utter waste of time since my car runs very very cool. The highest I've ever seen my water temp is 90°C after several WOT laps on TMP.

http://www.youtube.com/watch?v=GHWWU...&feature=g-upl

 

Damnit why do all of these suggestions involve spending money... I was hoping for a "your gauge is faulty, ignore it." lol

 

Plug the gaps, that shouldn't cost much, just some time.

thewird

 

Yep I'm doing that as we speak. Thanks guys we'll see how the drama queen reacts.

 

lol

 

I tested this out by taping it up with some of that foil tape stuff. Looks like it's keeping the temps down where I was seeing it increase fairly quickly before, so I'll have to find a suitable filler that I won't have to replace every time I drop that undercover now.

 

:P

thewird

 

[QUOTE=CS13B;11105783]I tested this out by taping it up with some of that foil tape stuff. Looks like it's keeping the temps down where I was seeing it increase fairly quickly before, so I'll have to find a suitable filler./QUOTE]

suitable filler??
Hmm..try some Stay Free Maxipads!..(lmao!)..
good for 2 inch gaps.heh!.and come with their own adhesive strip!

 

LOL Dave that's awful

 

Stock rad should be more than fine for an NA - it's the same as the turbo's, and even turbo FC's aren't prone to overheating stock - it's when they're modded, or the fan ducting or other ducting removed that they need more than the stock rad.

Something to watch for also - years ago, the front of the rad and oil cooler on my FC were covered in poplar dander - we get a lot here in Calgary, and without a bit of rain to wad it up and rinse it away, it can blow around the streets like drifts of cotton ***** - which is what my rad looked like. Dropped the undertray, peeled most of it off like a sweater, and vacuumed out the rest. Even then, it wasn't overheating, but I hadn't had it on the track either.