OK, the rookie is back again. I have a question, then I will do an update. Again, my thanks to all, I am making progress in getting the bugs worked out on my new 95 LT1 Coupe (158K miles, owned one month with no prior history available.

Question: My coolant temp roams - is that normal?

The car will reach 200 on a summer day - at 2 miles distance from a cold start. It settles there. Then begins to roam, it might go up to 204 then start working its way down to 194, holds for a bit, goes up, then down. Then sometimes holds in the 200 level. Mostly, the temp is always moving around.


Update. I found the manual fan switch installed by a prior owner. Now, with the switch the right side fan will work on high only. No other combination of fans or speeds works. The fans will not activate on their own. In traffic I will activate the fan if it goes to 210, because it takes about a minute sometimes to see a drop. Buut when it drops it drops

The right side fan will active on high via the manual switch and the temp comes down quick. I had a flush done of the system 4 weeks ago and there is no trash in the airway. Replaced the air filter for whatever good that would do.

With my FSM in hand, I am going to switch out the relays for starters.

My trans and oil are much slower to reach temps than the coolant. Oil holds at about 10-20 more than the coolant which I believe is normal.

The trans gets hot 220 on a normal drive in daytime is much slower to cool down than the coolant and it will go down to 199-200 and no lower.

I may have air in the collant system. Would that explain the coolant variance? I am working to resolve some coolant temp issues as that might be tied to the trans issue.

Thanks guys

Cruise on.

 

Sounds normal to me. I would only worry if it was overheating or there was a big difference between oil and coolant temps. Coolant temps usually rise quicker than other temps, I think cause its 50% water and oil is more resistant to temps.

 

From what I've read here on CF and seen in my own car, you don't seem to be having a problem. And you've done the maint. that's needed in addition to checking betw. the rad/a/c for junk that might be causing higher temps. The 20 or so degree diff betw. coolant and oil seems about right, again, from what I've read here and on my own car.

Not sure why the prior owner(s) put on fan switch but it is there and you can either keep it as is, or go back to automatic switch on/off.

Atlanta is HOT now, so maybe the runup to 200 in a couple of minutes isn't too unusual. You're not low on coolant, it's been burped, there are no air pockets, the mix is right, and the thermostat is working correctly, right? Coolant temps do fluctuate from all kinds of conditions. Your fluctuation doesn't sound too bad, altho maybe a bit more than some.

Keep working on the bleeding/burping to get it right. That may be some of it. See the thread in this section re "coolant troubles."

Tell us an update when you can.

 

I live in atlanta too, that is true i drive 40 miles one way to work I85-I20. I too have a switch to kick both fans ON at the same time, my custom chip turn fans ON at 195 and shuts down at 185. Iam running 180* thermostat, coolant temp roams between 195-224 in this hot summer. If i get stuck in traffic man this goes way too high like 220-224 who knows it might go beyond that ?. Gotta resolve this roaming coolant temps?. specially if u turned A/C ON. Let me know if u resolve this issue, tried but gave up.

 

Thanks for the replies.

I have not bleed or burped the system yet. Since I have the FSM now, I will do the bleed this weekend. Oddly enough, I could not get the cap off from the top tank. I have been checking things via the surge tank that is in front of the pass side front tire. Everything seems OK.

Yes, a prior owner placed a manual fan switch in the car. It works only the pass side fan, on high only. No low speed nor the driver side fan works. That is a project.

Really, while not ideal, I feel that I have the coolant temp under control. I do need to bleed it this weekend and resolve the fan issue. I do not want to take it on a long trip until that is done.

My concern now is the trans temp issue. I understand that 180-200 is the normal temp. When I get stuck on 1-85 (just love the new work they are doing to connect 316 there) or Jimmy Carter or Pleasant Hill, the trans can go to 220. I have not let it go higher (I pull off and let it cool). It wants to stay at 200 or slightly higher, even if I drive her for 45 min at night, temp about 78-80 outside but no traffic or a lot of stops.

Thinking of driving her in D and not overdrive D to see what that might do.

The trans going high and the collant getting high occur together. The coolant can go down and be OK, but the Trans stays high - or comes down quite slowly.

So I wonder if I have a trans heat issue. Pete K if you see this, any thoughts sir?

I would like to take this on say a Atlanta to Memphis drive. But until I have a clearer picture I feel unsafe in doing so. Also, the hills on 26 between Chattanoga and Nashville will be hard on any car - harsh on my Vette if I do have a problem.

 

You may still have a low coolant issue. Not getting the actual surge tank cap off is a bit off to me. Yes, you can fill most of the cooling system from the plastic overflow tank, but not completely IIRC.

The cap on the surge is not easy to take off. And, as you've noticed, the whole tank kind of bends down when you lean into the cap to try and remove it.

Rather than break it off some pivot point that I can't see (don't know if this is possible, but I'd bet it could be done---if anyone can break something---it is I ), I support it with one hand and push down on the cap to remove it. That cap (and mine) probably haven't been removed in a while and they get somewhat "welded" tight. Just be careful and it'll come loose. Take a look inside and see if the coolant level is up to the top. Then do your bleeding procedure.

I hope someone chimes in on the trans issue(s). You should be able to go for a nice, Atlanta to Memphis trip!!! (maybe you now want to re-title this thread: Trans Temps Too Hot???---just thought)

 

hey thanks.

your hint on the removal of the surge cap worked great. It's full and the fluid looks good.

 

You don't have a coolant temp. problem. What you call roaming is normal. Until you reach around 230 to 240 coolant temp. don't worry about it. You don't have a oil oil temp.problem either. It will range 15 to 20 degrees above coolant temp. Relax and enjoy the ride.