coolant temps during winter

[turbowop]

So I'm on a quest to pull some epic fuel mileage out of 503 for long trips. I swapped out the MAFT/GMmaf setup for a 2gMaf/SAFC setup and threw in a new o2 sensor. No chip, but fuel trims look good so far. I've run into a bit of an issue with the recent cold weather though...

I can't seem to get the coolant temps to go over the mid 170's when outside temps are below freezing. I figured the car needed a new thermostat so I picked up a new OEM 88C one from the dealer to install. The one I pulled out was a 180F unit but was functionally okay. Even after installing the new one today, same deal. /ubbthreads/images/graemlins/dunno.gif I can see o2 trims so I have an idea where I need to make adjustments with the SAFC, but without the car seeing over 180F, the fuel trims never adjust and the thing stays in warm up mode.

Anybody ever use the cardboard over part of the radiator trick during the winter? I'm thinking about giving it a try.

 

[ilotalo]

I got same problem. I think that coolant temp sensor is broken. I covered 1/4 radiator and still logger shows 76C coolant temp. /ubbthreads/images/graemlins/bawling.gif

 

[Polish]

I think the cardboard idea would be a good easy solution.

You could also try less water and more antifreeze in the coolant mix, perhaps the water content is a bit on the high side right now. I know it does more actual cooling than the anti freeze itself.

Also another simple thing to try (And this would only be for winter) is to pull the upper exhaust manifold heat shield to get some more heat in the engine bay. Since the temps there are so low I don't think you'd see any negative effects. However this is pretty much the only situation where I'd suggest doing this as I am a heat shield Nazi like most of you know.

 

[toybreaker]

Mark,

I deal with this problem on my winter beaters every year. I live at 9200ft, and it's almost all downhill to civilization, so I've developed a couple of coping strategies.

I still use cardboard on my truck, but running cardboard on the vr4 blew the seams out of a o.e. radiator climbing the last hill to the house a few years back. On the flats, it worked fine, but under boost for ten minutes (fresh snow /ubbthreads/images/graemlins/devil.gif ) it went "poof" within sight of the house.

First, try a 90*c thermostat. It works out to ~194*f, and it works well enough to let me go up and down the hill with good heater output, and without hurting the motor or cooling system with excessive temps.

I also modify the stat bleeder dingus for winter duty. It's there to help bleed the air out of the system, but the teeny little bit of coolant it bypasses prolongs the warm-up, and will also draw the temps below the stat rating in brutal low temps or low load situations. Just cut the pin, pop it out, and put a rivet in there to block the hole. If you're worried about the system trapping air, you can drill a teeny little hole in the body, but I've never had to. ( I use a tall funnel in the radiator fill neck when I service the cooling system and run the engine untill the stat is fully open and no more bubbles appear in the coolant stream in the funnel.)

It works well enough I don't need cardboard, even on days like today, where it's -11 farenheit... (with a -23*f windchill factor)

If all that fails, be sure to check and verify your ignition timing. /ubbthreads/images/graemlins/wink.gif

 

[prove_it]

^1, I used the cardboard trick for a while, works good. I only use it on my NA cars though for the same reasons Toybreaker mentioned.

Now in days I use a piece of metal though. I found in my accord that by spring the cardboard had gotten wet and froze several times and when I went to pull it out the cardboard was a mess. With a piece of metal you don't need to worry about it breaking down and falling apart.

Like he said check your coolant concentration. It gets cold around here, real cold, so I use a 65/35 coolant to water mix. Works way better than 50/50 at keeping my engine temps higher without overheating when playing in the snow.

 

[iceman69510]

Not just for this reason, but when I lived in WI, I usually always used about 60/40 coolant/water.

 

[belize1334]

Don't overdo it with the coolant to water mix. The freezing point is non linear with the coolant to water ratio. If you put too much coolant in it actually becomes less effective as antifreeze. A 50/50 mix is good for -34F. A 60/40 mix is good for -45F. A 70/30 mix is only good to about -15F.

 

[iceman69510]

Exactly. Thus my choice.

 

[turbowop]

Coolant mix is 50/50. I would like to try something that I don't have to reverse come summer, hence the cardboard. Well, I guess I'd have to reverse that, but that's pretty easy. /ubbthreads/images/graemlins/smile.gif I figure I'll just experiment with sizes and blocking just parts of the radiator. Driving the car around town today produced good heat, but the logger still showed temps consistently in the 170's.

 

[Jesh]

being in Alaska i can tell you the cardboard idea works pretty good, the temps here were -20F couple days ago, its warmed to 15F since then. i just swapped out for a 195F degree thermostat, it makes good heat, the 180 just didnt put out much heat at all. even on long trips with a load.

 

[ilotalo]

But what if my logger shows coolant temp 87,5C and my fans starts. Fan should start somewhere over 90C. I still beleve my coolant is showing 10C wrong. I hope i will get new coolant temp sensor in monday. So i can see is that the problem. Other idea is change the trim temperature 10C lower in ecu. Ecu starts to trim at 88C when engine is full warm. If you have small thermostate leak it will stop trimming. Thats why we thik that litle tweak in ecu will be good.

 

[thecman02]

Ohh and I Mark I believe the ECU doesn't go into learn mode until you reach 190F. 2nd Gen DSMs on OBDII go into learn mode at 180F. I definitely have the same problem as you in the winter though, My temps have been hanging in the 170's and I only have a little Koyo Civic Radiator.

 

[turbowop]

I'm pretty sure the point at which the trims start changing is 180, not 190. I can actually sit at idle and watch the coolant temps come up to 180 without a change in low trim, but as soon as it hits 182, the trim starts moving.

 

[turbowop]

So I cut up a couple pieces of cardboard. For guys with the AC condenser still intact, the cardboard can squeeze right in between it and the driver's side fan. I cut both pieces to be 12.75" tall and then a couple of different widths so I can pull one out if need be. Still have yet to drive the car with them in, but I'll try that out later. Hope it works. At least it's adjustable. /ubbthreads/images/graemlins/wink.gif

Couple of pics:

And a pic of the newly installed 2gMaf and RRE upper intercooler pipe. /ubbthreads/images/graemlins/smile.gif

 

[turbowop]

Okay. Took the car out for a nice drive. Same temps according to the logger with half the radiator blocked. /ubbthreads/images/graemlins/rofl.gif Although, my heater seems to be blowing hotter air? Is that possible? /ubbthreads/images/graemlins/confused.gif

 

[Polish]

Placebo effect perhaps? /ubbthreads/images/graemlins/dunno.gif

Even 503's engine bay is really clean. I always like the color RRE uses on their IC pipes.

 

[ilotalo]

Buy new coolant temp.

 

[turbowop]

The temp sensor is fine.

 

[atc250r]

Don't use regular cardboard. Get the cardboard from a case of beer, it has a waxy coating that keeps it from crumbling when it gets wet.

John

 

[turbowop]

I actually thought about throwing a coat of glossy spraypaint over the cardboard to help repel moisture. It's dry out at the moment and just wanted to give this a try.