Engine cooling

my 95 riv with 50k on it has a 180 thermostat, i noticed after i put it in that it will stay around 180 when im driving no matter how hard or easy i am on the engine, but when i stop and idle for a while whether im at a stop light or a food place, the temps sometimes jumps up to like 210 or 215, but one i start driving it again it lowers back. anybody have any ideas?

Lack of air flow while sitting is the reason it heats up. The solution is changing the fan turn-on settings to take advantage of the 180 t-stat. A 180 t-stat does not mean your engine will run at that temp. That's just the temp the t-stat will start to open. I don't know what options you have for making that change on a 95.

Your description is normal. 210F is high, but not dangerous. You could wire a manual fan turn on switch to cure the problem.

AA wrote:

Your description is normal. 210F is high, but not dangerous. You could wire a manual fan turn on switch to cure the problem.

Any schematic or write up on this? I'm assuming you are just tapping into the existing fan wire harness, but need to know which wires to piggy back off of.

Yes, I don't think it's that big of a deal to be concerned with until you are at 220º, at which point the fans should turn on. If you were racing the car, or had some other reason to keep it extra cool, the switch could be wired directly at the fan's connectors. Sorry, I don't know which wires these are.

AA wrote:

Yes, I don't think it's that big of a deal to be concerned with until you are at 220º, at which point the fans should turn on. If you were racing the car, or had some other reason to keep it extra cool, the switch could be wired directly at the fan's connectors. Sorry, I don't know which wires these are.

Engine temp doesn't get above 205ish, but the trans definitely does ( shares the same radiator, which could hinder the cooling to the engine) My trans can get up to 220+ in the summer from with few WOT pulls real fast. Not that big of a deal, but would love to be able to kick the fans on manually if in traffic to keep the temps down.

On long drives, and hot days, nothing can keep trans temps below 220ºF except for a separate trans cooler. I installed a 180º t-stat + tuned both fans to come on at 185ºF, and still the trans will get hot. I finally went with a rather large trans cooler (not too expensive) and now trans temps will usually not go above 190º, and hardly ever over 200º, even pulling a trailer. Here's the write-up: https://rivperformance.editboard.com/t1748-write-up-transmission-cooler-install

So the change to the fans didn't indirectly keep the trans temps down? Ok, thats good info.

I was thinking of a trans cooler, but I'm not towing...and 220/230 is about operating temp, so Ill just keep an eye on it for now. Thanks AA.

Mine was topping out around 220ºF before, I think that's within acceptable operating temp. If you're concerned, change the fluid every year or 25k miles - cheap insurance. A cooler will delay the temp climbing, and ultimately cap the peak to around 200ºF. I would also add I'm not using TCC lock-up anymore, so that says a lot for the trans cooler. Tours might run well below 200º.

AA wrote:

Mine was topping out around 220ºF before, I think that's within acceptable operating temp.

Yes, thats within the normal operating temp. Although your trans is much better than mine (I have a 96, so non-HD)

you could also get a tune from sinister like robotennis did, and have your fans settings changed, probably a more expensive idea, but if you wanted the tune, it would be a good thing to add on.

RidzRiv wrote:

you could also get a tune from sinister like robotennis did, and have your fans settings changed, probably a more expensive idea, but if you wanted the tune, it would be a good thing to add on.

True, but I'd rather wire in a manual switch for $1.00, than tune the PCM just for that, but AA is saying the lower fan setting didn't affect the trans temp too much. Im going to remove the weather stripping to see if this reduces engine bay temps at all.