Cooling issue...has me stumped

[88daytonapa]

Well, driving my daytona up a very large series of hills, I noticed the temp gauge start to rise towards the H, it didn't make it fully, but almost...and I am worried.

Cruising on the highway in 5th gear at ~2500 - 3000 rpms it will slowly rise all the way up to H. I need to get off the highway and it will go down. If I go WOT, it rises rather high and quickly..

Getting off the highway and driving backroads and not keeping a steady RPM seems to fix this, I can drive 300 miles on a back road, but as soon as I hit the highway the gauge rises. Sitting in 80 degree weather this week at a stoplight had no effect on the cooling, it sat right at half where I am comfortable with it. Sometimes the gauge bounces, which makes me wonder if it is a faulty sender or gauge itself. I am considering hooking up my autometer just to be sure.

I thought it may have been the coolant in the car, it was sitting for almost 2 years. I drained it and replaced it with a 50/50 mix.

There is no white smoke at all during accel/decel/startup/idle
Although the car IS running very rich(+20's, 14 psi)...could that be related?


*edit* FAN does kick on at about 3/4 temp on the gauge
Thanks,
Joe

[turbovanman²]

Rich generally won't make it run hot but colder as there isn't really a good burn going on.

I would replace the thermostat and have your rad checked. I bet from sitting its all plugged up internally and when your cruising on the highway, the rad can't disapate the heat fast enough. Also check to make sure the lower skirting/air dam is in place or make your own.

[bobr19]

its all plugged up internally and when your cruising on the highway, the rad can't disapate the heat fast enough.
Big +1

[88daytonapa]

Sounds good, I'm just going to pull my other rad from the other daytona and clean it up good.

I'll post back when I do to let you know.

Joe

[inmyshadow]

Being a daytona with cooling issues like yourself, I ask this.

Do you have the black air dam underneath the core support? Not having that usually leads to hot temps on the highway.

Another idea, check the front of the radiator for rusted, damaged or missing fins. I've seen radiators come out missing a 1/3 of those fins before.

I personally had a problem with all the fins rusted on the front of the radiator. My car would overheat on the highway. If I went down a hill in netural, the car would quickly cool down. I replaced everything cooling related on my car, then my friend suggested checking the front side of the radiator.

[Lee'sdaytona]

I have/had a very similar issue...however, I have a freshly re-cored rad, new thermosthat....but I'm not sure exactly what you guys are talking about with the black air dam. I did have a plastic cover on the driver's side of the rad that would cover the front of the rad, and I think I ripped it off...is that the piece you are referring to? I also have only noticed this with the digital dash, so maybe its that...don't know
-Lee

[turbovanman²]

I have/had a very similar issue...however, I have a freshly re-cored rad, new thermosthat....but I'm not sure exactly what you guys are talking about with the black air dam. I did have a plastic cover on the driver's side of the rad that would cover the front of the rad, and I think I ripped it off...is that the piece you are referring to? I also have only noticed this with the digital dash, so maybe its that...don't know
-Lee

It runs along the bottom front of the car, airdam, a big plastic piece, it directs air up to the rad.

[boost geek]

Get it hot and feel your rad for cool spots. My rad was so clogged only the top two inches was hot. Plugged solid with radiator-stop-leak from the previous owner.

[88daytonapa]

I think the air dam is there, I'll check before work today. Will also feel for hot spots.