fms1day

So today, when I went out to drive my hatchback, it started to overheat. It's never overheated before which makes it quite odd as to why it would start now. Radiator is only about 3-4 months old. Thermostat, head gasket, and water pump are quite new with only 6-7k miles on them. Driving for over 6k with not one incident of overheating until today. I was driving a tad bit 'spirited', shifting around 3.5-4.5k RPMs, which even so, isn't very high. I installed a new slim fan recently, which is working properly, and blowing. I checked the coolant level when I stopped the car and it was at just about MAX in the resevoir. Any ideas as to why it would start to overheat with essentially new products?

BTW: This is on a d16z6-t.
Thanks.

freezerburnv2

Hard to narrow down what's going on here so I would check your Thermostat, you can put it in some boiling water to see if it's opening and closing at the right temps, you say there is a proper amount of coolent in the system so no worries about leaks.. I was reading how you put in a new slim fan.. you could have a problem here if you hooked up the positive and neg wires the wrong way according to if you mounted the fan in the front or the back of the radiator. it should be blowing air in the direction of the motor, ie new cooler air from the front into the radiator and pushed or sucked (depending where it's mounted Front pushed into the engine by and rear sucked though the radiator into the engine bay). So in short my guess as long as the fluids look good and are not mixing like the oil turning brown or coolent turning darker then I'd think headgasket. It's got to be either your Thermostat (easy to access) or your slim fan blowing the wrong way. if it's not one of those two, then check the water pump (harder) Good luck just remember I'd check the Thermostat and fan first.

spikiexmikie

turn your car on and right before it starts to over heat turn it back off. then check out the lower radiator hose and see if it is still cold (not really hot). if so then it is probably your thermistat or your water pump.

fms1day

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by freezerburnv2 &raquo;</TD></TR><TR><TD CLASS="quote">Hard to narrow down what's going on here so I would check your Thermostat, you can put it in some boiling water to see if it's opening and closing at the right temps, you say there is a proper amount of coolent in the system so no worries about leaks.. I was reading how you put in a new slim fan.. you could have a problem here if you hooked up the positive and neg wires the wrong way according to if you mounted the fan in the front or the back of the radiator. it should be blowing air in the direction of the motor, ie new cooler air from the front into the radiator and pushed or sucked (depending where it's mounted Front pushed into the engine by and rear sucked though the radiator into the engine bay). So in short my guess as long as the fluids look good and are not mixing like the oil turning brown or coolent turning darker then I'd think headgasket. It's got to be either your Thermostat (easy to access) or your slim fan blowing the wrong way. if it's not one of those two, then check the water pump (harder) Good luck just remember I'd check the Thermostat and fan first.</TD></TR></TABLE>

I mounted my slim fan on the back side of the radiator... and touched the wires to the + and - on the battery before plugging it in and it blew towards the motor/inwards into the engine bay... I checked that again today and it still blows inwards into the engine bay.. The coolant is still blue-ish (OEM Honda Coolant) so I doubt oil is getting mixed it... But I will check it more thoroughly.

Will taking the thermostat out, and then just dumping it into hot/warm water going to work?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spikiexmikie &raquo;</TD></TR><TR><TD CLASS="quote">turn your car on and right before it starts to over heat turn it back off. then check out the lower radiator hose and see if it is still cold (not really hot). if so then it is probably your thermistat or your water pump.</TD></TR></TABLE>

Well, I'm sure if I'm staying at idle, it doesn't overheat, it was after I've been driving the car for about an hour. Also, The rise in the meter is quite slow but steady.

freezerburnv2

heat the water and check the temperature with a thermometer. Check the temperature at which the thermostat first opens, and at which if is fully open.

don't let the thermometer touch the bottom of the hot container.

Measure the lift height of the thermostat when fully open

Standard Thermostat

lift height: Above 8.0mm (0.31 in)
Starts opening: 169 deg F - 178 deg F (76 deg C -80 deg C)
Fully Open: 194 deg F (90 deg C)



while your on that part might not hurt to test the Engine Coolent Temperature switch that is right next to the thermostat.

same thing

measure the resistance between the A and B terminals

ON there will be continuity
196 - 203 F (91 deg - 95 deg C)

OFF there will be no connection
5 - 15 F (3 - 8 deg C)


Modified by freezerburnv2 at 7:18 PM 6/14/2006

fms1day

will def. try on next day off. Thanks.

TheLastSpartan

My friend had this problem too but double check the thermostat. He replaced his and was fine for about a week or two. They didn't put it in right and had to re-do it. GL on solving it.

thahuhstunna

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by freezerburnv2 &raquo;</TD></TR><TR><TD CLASS="quote">heat the water and check the temperature with a thermometer. Check the temperature at which the thermostat first opens, and at which if is fully open.

don't let the thermometer touch the bottom of the hot container.

Measure the lift height of the thermostat when fully open

Standard Thermostat

lift height: Above 8.0mm (0.31 in)
Starts opening: 169 deg F - 178 deg F (76 deg C -80 deg C)
Fully Open: 194 deg F (90 deg C)



while your on that part might not hurt to test the Engine Coolent Temperature switch that is right next to the thermostat.

same thing

measure the resistance between the A and B terminals

ON there will be continuity
196 - 203 F (91 deg - 95 deg C)

OFF there will be no connection
5 - 15 F (3 - 8 deg C)


Modified by freezerburnv2 at 7:18 PM 6/14/2006</TD></TR></TABLE>

good replies, it's the thermostat... no worries, easy fix

Hesperian

you need a koyo radiator. the radiator you got is no good

fms1day

drove the car again tonight so here's a little more of what I was able to observe.

I drove the car regular and it was completely fine... Didn't overheat for a good 20+ minutes. Even when it wasn't overheating, I decided to check the upper and lower radiator hoses for heat. The top one was a bit hotter than the lower one but this wasn't too long after the temperature reached it's normal point.

After about 20 or so minutes, I did boost my car once in third gear and then drove it regular right after and noticed soon, that the temperature gauge started to rise, but ever so slowly. I turned on my heater (no AC) to the first switch with the settings on: defroster and in-car circulation and the temp gauge started to go back down to it's normal state.

Now I pulled over to check the hoses. The top hose was, my estimation, a good 2-3 second contact before my fingers felt it was time to remove it before I get burnt.

Now I let my fingers cool and then touched the lower hose and the estimation was about the same, so the lower hose is not cold at all.

Does this eliminate the thermostat?

Also, I continued to drive home regular, which was probably another 15 minutes and the temp gauge would almost decide to rise whenever it wanted to.. The rise is quite slow.

Just out of curiousity, as I'm also having a little turbo problem, could an exhaust restriction cause the engine to get hotter?

I'm asking because the temp gauge doesn't act as if something's really failing and if something is... It's like failing by a hair's width. The temp isn't really consistent as to when it decides to heat up and cooling it down is really easy, just by turning on the heater to the first switch pretty much tames it immediately..

Any other leads? I'm stumped.

fms1day

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by freezerburnv2 &raquo;</TD></TR><TR><TD CLASS="quote">

while your on that part might not hurt to test the Engine Coolent Temperature switch that is right next to the thermostat.

same thing

measure the resistance between the A and B terminals

ON there will be continuity
196 - 203 F (91 deg - 95 deg C)

OFF there will be no connection
5 - 15 F (3 - 8 deg C)
</TD></TR></TABLE>

So remove this part/piece as well and dump it into a boiling pot of water?

freezerburnv2

Yeah just dipping the ECT into the water, there are plugs so try not to submerge the contacts, on the top maybe fashion the plug to hang from a little wire connected to a cabinet in your kitchen so it’s not submerged just touching the water so the ECT gets the heat.

The Thermostat is like a plug in the bathtub, it restricts the flow of coolant so their is time for heat transfer. When it gets hot enough the thermostat will open up pretty much meaning you’re at operating temp and slow down the rapid heat increase. If it can't open or is damage it won't be able to control coolant flow ie stuck closed thermostat won't alow the water to speed up and keep normal temps.

I'd just get an OEM thermostat and be done with it; the ECT is screwed into the metal piece covering the thermostat. No real reason to test it, if it’s reporting coolant properly. Of course if you already have water on boil and feeling like Bill Nye the Science guy it won’t take you much longer to check it out.




Modified by freezerburnv2 at 11:19 PM 6/14/2006

Frozen E

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hesperian &raquo;</TD></TR><TR><TD CLASS="quote">you need a koyo radiator. the radiator you got is no good</TD></TR></TABLE>

And you're an idiot

fms1day

My thermostat is currently OEM but I'll check it.. I hope OEM didn't fail on me this soon

fms1day

drove the car to and from work today with no hint of overheating? weird.

I have a question though. When you're car warms up to its regular temperature, does the thermostat open up? Is that how it keeps the temperature at that constant rate?

Frozen E

Water temp gets up to a pre set temperature and the stat opens up, allowing coolant to flow through the radiator. As the radiator does it's job and cools the water down, the stat starets to close again, allowing the water to heat back up. It keeps doing this as long as it's working properly.
A failed stat won't open up to the radiator, causing the coolant to circulate around the block only. With no way of getting rid of the heat the water temp keeps going up up and away. This is why turning your heat on will help when you're overheating. Your heater core acts as a small radiator. It isn't great, but it's enough to bring the temp down a bit.

fms1day

Okay well, on regular driving... The temperature is completely fine. So is it still my thermostat?

SovXietday

Pics of the slimfan? Do you have an intercooler in front of the rad? Lastly, has it been hot the past couple of days?

Your thermo is fine if the lower rad hose heats up. If you have a cheap slimfan and an intercooler infront of the rad, you will have heating issues. Notice how a stock fan has a cowl, try fabbing one for your slimfan or go back to the stocker. It would be a good idea to bleed the system as well, air bubbles are a bitch. Lastly, make sure your fan is even turning on, and spinning in the correct direction (which you said it was earlier, just covering my bases).

Honestly, you probably blew the HG, especially if you keep sneaking back towards hot. Went through this ordeal myself, pain in the ***.

fms1day

If I blew my headgasket, doesn't that mix oil and coolant? Meaning my coolant should be quite milky and darker right? Because I checked this morning and it was still blue.

Yes the intercooler is mounted in front of the radiator but it's the same set-up my brother used to have and he had no heating issue. However, I'll double check my slim fan to check if it's at the correct specs to accomodate the heat. And yeah the fan is turning on, it isn't necessarily the most 'silent' fan there is..

sparkx888

Get the mugen fanswitch and thermo

fms1day

Weather is hotter nowadays in the city... ~75degrees. And my car is now overheating during regular city driving.

Here's a picture of the slim fan I have installed. Perma-Cool 19122 off summitracing.com
12" Blade Diameter.... 1200cfm



Both radiator tubings are hot *** hell when I checked them yesterday when my car managed to overheat to approx 80% of the gauge. So I'm ruling out the thermostat.

The radiator overflow resevior was over MAX. When it's cold, it's about in the middle. Is this level regular? Or does a MAX overflow show signs of why it's overheating?

plz turn off trial user

my car overheats also beccuase i have NO OIL in it check that which in turn can raise the water level

Slamaccord

iTrader: (1)

I would try pressure testing your radiator cap.
Sounds to me like a bad radiator cap.

fms1day

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Slamaccord &raquo;</TD></TR><TR><TD CLASS="quote">I would try pressure testing your radiator cap.
Sounds to me like a bad radiator cap.</TD></TR></TABLE>

How do I conduct a pressure test on the radiator cap?

Slamaccord

iTrader: (1)

If you were closer I let you use mine. You can use one of these.
http://www.stant.com/brochure....d=183