LetsTurboSomething

Standard procedure is to loop the heater circuit and never block it. Cavitation and other problems start cropping up. The pump doesn't flow perfect when its blocked. I doubt that is the whole issue though. Maybe part of it.

I had one of the fans stop working in my 5.3 conversion and with just the one fan running it would spike up to 230+ degrees in any traffic.

But honestly I wouldn't be sweating over 210, that's only 5 degrees over a stock thermostat. If its 100+F outside that's not hurting anything. If it goes up more I would start looking at an auxiliary heat exchanger. Like the aluminum finned ones the bolt to a frame rail they use for transmissions a lot.

blueday

I'd be fine with 210-215 but it climbs to 226 when 95+ out, idling with both fans and ac on. If it would maintain 220ish I'd be ok with it but that temp keeps climbing. I have a 45+ minute commute of basically idling for 6 miles so needless to say I don't trust it yet. My goal is to make it a reliable driver which is why I'm trying to hunt this down.

Thanks,

Ryan

kingtal0n

iTrader: (1)

Are the fans you are using have a shroud, and is the shroud air-tight

I find many times overheat issues with fans that don't use a shroud properly. It isn't the size of the fan that matters most its the size of the shroud which directs airflow through the entire radiator and not just fan area, or even worse, through passages at the sides

LetsTurboSomething

Do you have room for a pusher fan on the front to aid the two pullers? The other thing that I was told was about vacuum filling the coolant too. Air pockets cause over heating. Did you vacuum fill it or just burp hoses with it running? Have you tried adding a bottle of water wetter?

blueday

Yes spal fans are shrouded and even have cut outs and flaps to allow air movement while at speed. The Ford focus fans i had prior to the spals were shrouded too.

Pics for the fun of it.

blueday

No room on the front because of ac condenser, trans cooler and how the hood opens. I drained the coolant out of the radiator/ block and then filled it with the vacuum tool. If i were to put the water wetter in it seems i may be patching and not fixing a problem.

kingtal0n

iTrader: (1)

five twenty five it

laughs at the size of toy fans

probably need more

blueday

525 it?

I thought it wasn't the size of the fans but the shroud that matters?

G Atsma

Are you stoned?

LetsTurboSomething

With what you have to work with, I would be moving the trans cooler out from in front of the radiator first and remounting it under the car else where. Though I have no clue how much room you have anywhere else. Getting any extra heat out from in front is the easiest. If you can get the trans cooler or condenser relocated it will probably give you the room for a pusher. At least maybe a small one even if it's only 8" or less. Something is something.

Water wetter isn't really a band-aid fix if it works. It's just better cooling properties for coolant. Upgrade fans, upgrade radiators, upgrade coolant...same difference in the end if any given one works. Water wetter really does lower the temps a few degrees on any car you add it to provided it doesn't already have a surface tension additive in the coolant already... You are within the parameters that it might just be enough and its about $11.

The other thing, are you cooling the oil at all? That's a lot of oil in a big engine and oil cooling counts for quite a bit of engine cooling...

blueday

No luck with water wetter. I added a bypass in order to loop heater core coolant back into the system. Even went so far as to putting in a dual pass aluminum radiator and no change in 95 degree weather. Seems to take a little longer to get up to 230 while idling.

I do have an ecm programming question for those that might know. So my iat or underhood temps rise with the coolant temps (or other easy around). Could the ecm be retarding engine timing at idle enough (due to iat reading) and causing the engine to run hot? I read that hot iat will make ecm retard timing and poor performance. Wondering if it'd retard it at idle if temps hit hot enough. My torq app shows timing @ 12.5-13, iat @201deg and coolant temp @225deg.

I can open my hood at these temps and the iats drop quickly within seconds and not far behind are coolant temps.

Thanks.

Ryan

LSswap

My C3 LS (also factor in that I've got a turbo in there) gets a little over 210 on hotter days and drops to 200 on cooler days with a low temp thermostat. It runs hotter when moving fast and cooler when idling. My IATs change alot with outside temperature.

The C3 generally doesn't remove heat well from the engine bay. I added a vent in the hood, close to the nose to get some of the heat out.

So apparently opening the hood in your case helps which leads me to think that it's just heat buildup in the engine bay and some additional venting may help.

I'm going to try an experiment and block the heater return, only once the thermostat is open, just to see what happens to the temps.

slogo

Cool looking car, I like the very first pic's wheels.

blueday

Sounds like you have just the opposite problems I'm having. I started out with a 160* and now have the stock 186* in....ecm controls fans (set at stock temps) so with stock tstat the temp swing with fans on/off is small. My intake setup reflects about ambient temps when moving (even just idling down the road). I'm also running ac, can't remember if you are or not. I'd also guess your setup puts out a lot more heat with that turbo and pipe routing.

I've recently read the same about c3's and engine bay heat. I'm not sure why is any different than any other car (smaller space). I just ordered the trackspec vent for mine. I'm tying to rule out the tuning and timing option before i cut up my hood.

In my case i added an "H" to my heater hose setup so when the ac closes the heater core supply it'll loop back through. No change with my set up. When digging around on internet, some people swear by the loop some don't have any issues plugging the pump holes to the heater core.

I'll have to go look at your thread again. I don't remember your exact setup. I'm sure you know with the c3 is to have all the radiator seals in place to force air through radiator. Both radiators i have had were dewitts.... the recent is the lsx swap one they offer. Quality was a little rough. I had to clean up some threaded holes and actually remove metal shards from when they threaded the temp switch fitting.

Ryan

blueday

Have you ever tried Heatshield Products header armour wrap? Another option to try top reduce under hood temps before i cut my hood. I don't care for the look of any header wrap but gotta do what ya gotta do. Reviews look decent but idk.

Ryan

Michael Yount

iTrader: (1)

If opening the hood at the back solves the problem, you’re gonna have to work on a path to make it easier for air to exit the bay.

DW SD

Same. But blast radiator with a hose. If temp is the same you aren’t maxing out heat transfer.

blueday

Just opening the hood in general. I'm looking at a vent in pic below.

Michael Yount

iTrader: (1)

Can you secure the hood with it open a bit in the back and do some driving/testing?

blueday

I can prop it open a little bit while temps are up to see if it'll "vent" properly by itself while parked/idling. With the hood vent I'm assuming the hot air will rise at idle and vent through the hood vent. Am i understanding what you're saying correctly?

Ryan