When is it just to hot?
 

So my stock temp sensor went out in my car a couple weeks ago, and I was planning on getting an aftermarket temp gauge for my car anyway, so I pulled the trigger and got a vacuum and temp gauge. I got them installed yesterday and I'm a little worried about my temps. I have a 80% grill block on my car and I see my temps with prolonged driving to work (it's like a 2% grade for about 15 miles so I run at quite a high load) reach around 230F. Is this to hot? Coming home I see max of 210 which I know is acceptable, but is 230 bad for my car's longevity?

2% grade for 15 miles?!?!?! :eek: Could be the location of the sensor? Do you know what the temps are to activate the low and high speed of the fans as well as when the t stat opens? My honda has a high temp before any alerts goes off, like 230 degrees, but when I see the temps go to 200 I start to get worried as low speed for the fan is at about that range and kicks off at 190.

With ac on my temps stay at 187 no matter the outside temp, but I also use water wetter in my cooling system. :thumbup:

Yes I would say that 230f or 110C is too hot
My car start the fan at 203f or 95C
Trying to keep it under 210 would be a good idea 99C

coolant will boil between 223 and 235 depending on ratio to water and system pressure. The coolant will boil more readily at lower pressures ie the cap fails or a hose fails. My car will peak at 198 which I think is where the fan cuts in. I think mine draws up to 30 to 40 amps easily a couple of horse power.

The bigest risk is the moment of cooling system failure and the amount of time you have to get things shutdown. The hotter you run the less time you have to react.

If you are running at 230 and the cap or hose fails it is nearly guaranteed that your coolant will boil adjacent to the cylinder wall causing damage.

my personal limit would be the moment that the radiator fan cuts in. A warmer engine saves fuel, but a radiator fan will burn fuel....

Mercedes service bulletin said 256 degrees with proper anitfreeze mixture. That being said, I would not want to see over 220 myself. Long grade climbs will make your temp peak, maybe a little less grille block.

regards
Mech

@Cobb, I'm not sure if it's 2% but I do have to use a fair amount of throttle to maintain 55-60mph going up it.

I'm not sure what temps my fans kick on, but I can tell when it does when I'm climbing the Cajon pass every night (6% grade) all the lights on my dash dim for a little bit and when the coolant temp drops all my lights un-dim(?) so I'm assuming that's my rad fans.

Thanks for all the help guys, I'll remove all except the lower rad block and see if my temps drop, if not I'll remove it completely. It could also be due to the fact the rad system hasn't been changed in at least 6 years, could be as much as 10 I honestly don't know for sure.

Might be worth it to do the trip a couple times with the block completely removed in order to get a baseline reading. Then you can add from there.

Yea I'm going to remove it completely tomorrow morning and drive to work, and compare my readings with what I saw today when I removed the side blocks, which was noticeably lower temps than yesterday even though it was hotter today.

My fan kicks on at 215 F, and you should not go warmer than the trigger point for when your fan kicks on. With a temp gauge, it's easy to see when it comes on, because the temp will go up to a maximum temperature and then rapidly cool until it falls below a set threshold.

40 amps would be about 500 watts, or about 2/3hp. Of course, the mechanical to electrical efficiency is low, so the total drag on your engine is likely around 2hp.

I second your statement about keeping the fan off.

Anything over 225 is heading for damage territory..
I swapped a puller fan blade on my VFR800 for a pusher fan blade from a Honda VTR, to fix a lack of cooling air flow causing overheating in traffic.
Before I did the swap, I'd be riding around on my non boosted VFR showing 175-180f coolant temps, stop in traffic and watch the temp rise to 220. The cooling fan would spool up, but the temp would keep climbing. Even if I broke out of the traffic and got moving again at less then highway speeds, the temps would still climb into the 230's.
After the swap, stopping in traffic the temps will rise to 220, the fan will kick in, then drop back down to about 214. As soon as I can get the bike free of the traffic and moving again, the temps drop right back down to 170-180.

I guess what I'm saying is, pull some more of the blocker out..
Just a question for you, is your radiator a vertical flow unit or is it a cross flow unit like so many of the new car's use. If that is, remember a vertical gap in the blocker will be more effective than a partial horizontal one. It also prevents uneven expansion of the core. I've had an aluminum/plastic radiator crack the end tanks from uneven heating and uneven expansion.