1G New EVERYTHING Still Runs HOT

[breaksdaily]

Car has started to run hot in 80 degree plus weather here recently, No issue in cold weather or morning/ night... It has a new Radiator, Rad Cap, Temp sensors, Stock working fans, Thermostat, Head gasket, Water pump. Zero coolant leaks and got up to 240 on me today on the interstate.

Im not losing any coolant, No smoking or anything stupid car runs great besides this.. No idea

 

[breaksdaily]

Interesting.. Has anyone seen any improvements in coolant temperatures switching to aluminium radiators? I've always thought they were a joke and not neede, Hope I don't have to mod up some kind of ducting...

 

[91talonts1]

Most of the aluminum radiators are larger, and provide more surface area to dissipate heat. So yes, they typically reduce coolant temps. It will still eventually overheat if not getting airflow, it'll just take longer than on a smaller radiator.

 

[Kapok6]

Man, that's odd because my car actually runs cooler on the freeway, though I did fab up some ghetto duct work.

 

[91talonts1]

^ That's how it should be. The faster the car moves, the more air moves through the radiator, in turn removing more heat.

My car would get to 213+ in a hurry once you got over 70mph. Added some ducting and now it will drop to thermostat opening temp from 200+ within a few minutes of cruising.

 

[gofer]

If it's overheating while you're at speed then it's more than likely the lack of airflow through the radiator causing your problem if you know for sure the t-stat is operating (even though it's new doesn't mean it's working). After ~40mph the speed of the air hitting the front of the car is moving faster than the fans can push it so at that point fan operation doesn't matter and you're relying on airflow and ducting to direct air through the radiator.

In your case the air hits the FMIC, A/C condenser, and THEN the radiator which is why most DSMer's have this problem after going to a FMIC. Before you spend a lot of money on ducting material or a larger "race" radiator try mocking up something temporary out of thicker cardboard or ABS plastic and lots of tape. Doing this will let you test different ducting designs without spending a lot of money and you can test them to see if it helps the overheating issue you're seeing. If it fixes it then you can look at fabricating the ducting with something a bit more permanent like aluminum/rivets.
I have no idea what kind of DSM you've got because you have no car profile built but here are a few examples of radiator ducting...

Tape Ducting

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[breaksdaily]

Thanks for the input guys, I will see what I can do... Is there an easy way to tie the drivers side AC fan to come on with the passenger main radiator fan when it comes on so both are operating even with the AC OFF? I know 2Gs have the fans always on option in link but this is a 1G car and we do not have that option in ecmlink.

 

[boostdawd]

Thanks for the input guys, I will see what I can do... Is there an easy way to tie the drivers side AC fan to come on with the passenger main radiator fan when it comes on so both are operating even with the AC OFF? I know 2Gs have the fans always on option in link but this is a 1G car and we do not have that option in ecmlink.

Just wire in a jumper from one fan to the other providing 12v power. Maybe use a relay to not overload the circuit.

 

[gofer]

Dedicated power switch.

 

[ceedawg]

240 degrees! You are lucky the head gasket did not blow. Issue sounds like lack of ducting. A lot of us here have gone through the same thing till we resolved it with ducting! It's a must with a fmic and AC condenser.

 

[zedicus]

*sigh*
15psi cap instead of the stock replacement one you put on.

some of us here have front mount IC, no ducting, stock old dirty radiator, 1 working fan, and 115 degree summers. and never seen a bit over normal operating temp. it is almost like there is some little thing that people ignore but then spend countless hours and dollars trying to overcome.

 

[Ludachris]

Did it run hot before the FMIC? When did it start and what changed? For me, my car always ran hot after installing the FMIC. I ended up venting the hood and that helped quite a bit on the street. I also went with an aluminum radiator and high temp coatings. But I think venting the hood with a proper hood vent helps a lot more than people realize. You also need to ensure air is being directed to the radiator with ducting.

 

[red_devil]

*sigh*
15psi cap instead of the stock replacement one you put on.

some of us here have front mount IC, no ducting, stock old dirty radiator, 1 working fan, and 115 degree summers. and never seen a bit over normal operating temp. it is almost like there is some little thing that people ignore but then spend countless hours and dollars trying to overcome.

Just slapping a higher pressure cap will not fix some of the issues we face. 2Gs definitely seem to suffer more to running hot than 1gs and increasing the pressure can help but it's still just a bandaid. Running too high of a pressure can cause other problems if some hoses or clamps are old.

 

[ceedawg]

*sigh*
15psi cap instead of the stock replacement one you put on.

some of us here have front mount IC, no ducting, stock old dirty radiator, 1 working fan, and 115 degree summers. and never seen a bit over normal operating temp. it is almost like there is some little thing that people ignore but then spend countless hours and dollars trying to overcome.

Remember he has the condenser on his car as well I believe. So with the fmic he will overheat in hot temps. Any car.

 

[ceedawg]

Did it run hot before the FMIC? When did it start and what changed? For me, my car always ran hot after installing the FMIC. I ended up venting the hood and that helped quite a bit on the street. I also went with an aluminum radiator and high temp coatings. But I think venting the hood with a proper hood vent helps a lot more than people realize. You also need to ensure air is being directed to the radiator with ducting.

The hood vent and a bottom diffuser under the front bumper helped me a lot.

 

[zedicus]

these cooling systems are old to begin with. but START with the cheap things first because a 600$ aluminum racing radiator will not fix an overheating condition if the radiator was not the cause to begin with.

airflow on these cars even with a front mount is not that bad. adding even very minimal ducting is great. but just tossing on a vented hood with no ducting will actually disrupt flow and make things worse.

and the 15psi cap actually fixes a design flaw on these cars that can cause burping and small amounts of air and or low pressure to occur in the system.

my 2g with a front mount, and no ducting, and A/C has never had overheating issues. fix what needs fixed and do not through money at the problem.
my 1g has a huge front mount, no A/C, and no ducting. never had overheating issues on it at all iether.

 

[Ludachris]

Most of the aluminum radiators are larger, and provide more surface area to dissipate heat. So yes, they typically reduce coolant temps. It will still eventually overheat if not getting airflow, it'll just take longer than on a smaller radiator.

I wouldn't say that most of them are larger. They're just supposed to be more efficient, in theory. Some larger options are available though - and by larger, I mean thicker. The problem with the thicker options are that the stock fans won't fit, so you need to also buy good quality slim fans. The higher cost of the thicker radiator and the added cost for good fans will scare most DSMers away.

 

[Ludachris]

these cooling systems are old to begin with. but START with the cheap things first because a 600$ aluminum racing radiator will not fix an overheating condition if the radiator was not the cause to begin with.

airflow on these cars even with a front mount is not that bad. adding even very minimal ducting is great. but just tossing on a vented hood with no ducting will actually disrupt flow and make things worse.

and the 15psi cap actually fixes a design flaw on these cars that can cause burping and small amounts of air and or low pressure to occur in the system.

my 2g with a front mount, and no ducting, and A/C has never had overheating issues. fix what needs fixed and do not through money at the problem.
my 1g has a huge front mount, no A/C, and no ducting. never had overheating issues on it at all iether.

Adding a hood vent to allow hot air to escape from the engine bay is always going to help keep underhood temps lower. Just doing that alone made a major improvement for me many years ago on the street and at the road course. But improving ducting is very important as well, since air tends to escape before and after the FMIC, before it can be forced through the radiator. And looking over the entire system is important too obviously.

My issues were with a 1g though, and they came about soon after the FMIC install in hotter weather. I had to drive my car in traffic somewhat regularly, and that's when the temps would get pretty high. I also had higher temps at the track, but that was pretty typical for those of us that did road racing. Ducting and hood vents were very common on these cars when you road raced them.

 

[breaksdaily]

Threw on a new Evo 16psi rated cap, no difference.. I feel like the engine bay heat of having no lower heat shield may be playing into this as im melting A.C. side fans and blades etc... Anyone have the stock lower shield they will sell me? May try heat wrapping the o2 housing and downpipe for now.

In weather less than 75 degrees this car never goes above 206, very frustrating... Today it was 90 and temps were up to 230 again without the heater on wide open.

 

[zedicus]

out of curiosity does your valve cover get SCORCHING hot and does the cold side of your turbo seem warmer than it should when you are in these overheating conditions? you might need to drive it around a while and pull over right after a boost romp or something.

yes there is a reason why i am asking that could be causing overheating.

 

[Ludachris]

Threw on a new Evo 16psi rated cap, no difference.. I feel like the engine bay heat of having no lower heat shield may be playing into this as im melting A.C. side fans and blades etc... Anyone have the stock lower shield they will sell me? May try heat wrapping the o2 housing and downpipe for now.

In weather less than 75 degrees this car never goes above 206, very frustrating... Today it was 90 and temps were up to 230 again without the heater on wide open.

Heat shields are functional and DO protect things like fans and alternators. They might not look pretty but they do help for daily drivers that sit in traffic in hotter areas.

 

[breaksdaily]

Yep have my upper on but not lower..

 

[jaytec4g63t]

Same issue I faced at one point with slim fans, and I ended up putting back the factory fans with an aluminum mishimoto radiator and problem solved.

 

[ceedawg]

A couple more 230 and 240 degree heat readings and you are going to blow that head gasket. There are some good threads here on fan placement and ducting for cars with huge fmic's. I recommend SPAL fans

 

[breaksdaily]

A couple more 230 and 240 degree heat readings and you are going to blow that head gasket. There are some good threads here on fan placement and ducting for cars with huge fmic's. I recommend SPAL fans

While there is some truth to this, it doesn't happen all that easy... trust me

 

[ceedawg]

While there is some truth to this, it doesn't happen all that easy... trust me

Ok tick tick tick! I trust you tick tick tick tick