Overheating Issues

[naughtika]

just did a bit of test earlier..

after going for a good drive.. nothing like stop n go or spirited driving.. just plain/normal A to B drive..

I reverse parked the car, left the engine running and had the a/c on full ON and looked at the gauge thoroughly.. at this time the gauge was sitting on its normal position as it normally does..

kept the engine and a/c on for a good 10 minutes, what do you know the gauge started climbing... not dramatically just slightly higher than the normal position..

I'll have another think about my fan setup.. i might make proper shrouds to cover between the a/c condenser and the radiator.. this will be installed to assist the push configured fan..

as for the pull type.. i'll probably make a proper shroud for it. when time and $$ permits.. but so far i dont think this 14" fan is not moving air through properly..

Carsten has the same problem with his, though he is running both fans in push + full alloy radiator.

One possibility is that at low engine speed with the bigger radiator there also isn't enough turbulence (water speed) through the core to get optimal heat transfer, also contributing to a slightly high temperature.

Carsten has been running his like that for ages, I wouldn't be overly concerned. If you are, get a electric booster pump to improve your idle water flow.

I remember him installing 2x 12" in pull configuration, but never thought he had issues with them.. I'll keep a close watch on my temp gauge.. Im actually thinking of getting a stock radiator..

Hi Christian, Have you checked that both fans are moving the air in the correct direction, that is from the front to the rear. They are DC motors and its easy to plug them in with the polarity
incorrect. With one in front and one on the back of the radiator they need to be connected with opposite polarity so that one pushes and one pulls the air through.

fans are definitely pushing air where they're supposed to as i tested them individually after installation..

I have a40mm radiator and it works fine.... These fans, do they floe more but against less static pressure perhaps? Do they move lots of air though the radiator out just out in the open? Also, what are the shrouds like?

no shrouds, just installed on the rad.. im cheap at the moment..

according to davies craig site the 10" flows a around 650cfm and the 14" does around 1500cfm

and they do move alot of air when installed..

U need to have both fans pressurising your radiator or she won't work 2 blowing one way or 2 pulling either or

not saying you're wrong.. my thoughts on this, why would toyota do the same setup on their cars? for example those damn camry's

 

[Schneider]

no shrouds, just installed on the rad.. im cheap at the moment..

according to davies craig site the 10" flows a around 650cfm and the 14" does around 1500cfm

Those numbers show they do flow well but the static pressure at those high flow rates is poor. Can you actually feel the air being pushed through the radiator by the fan doing the pushing? Sorry don't know how else to word that.

I think the issue is how well the fans can push/pull the air through the radiator (importance of static pressure). Flow rates of fans are given without obstructions. With an obstruction such as radiator in place its important to balance your flow rate with static pressure to ensure the fans can force the air through.
You may find if they run at lower flow rates the radiator temperature stays steadier since the fans have a better ability to force the air through.

 

[TME_Steve]

What you need is to see a fan curve, like a compressor map for fans.... No shrouds equals bad

 

[Nitephyre]

I get worried when Christian has to ask about something going wrong... O.O

 

[Gt_Galant]

Personally i think you have a faulty water temp sensor or/and your gauge temp sensor (2 sensors are next to each other near the thremostat)

Does your temp gauge actually start to go down and anytime like when the fans kick in ?

 

[jungle]

So what's changed then Christian- thermo fans? If that is all then most likely, there is your answer.
Davies craig are sh*t. I had one on my Sil80 and if couldn't control temp once up to temp. Idling. Fine driving but during stop start it was pathetic.
Changed to a SPAL, 3000cfm, never had the issue again.

As you have alluded to, look at placement and some ducting. I suspect that will be the answer

 

[naughtika]

Personally i think you have a faulty water temp sensor or/and your gauge temp sensor (2 sensors are next to each other near the thremostat)

Does your temp gauge actually start to go down and anytime like when the fans kick in ?

it does go down when moving.. so i dont think they are the sensors.. but i dont mind replacing it as well

now that i think about it more.. it happens most when stationary..

So what's changed then Christian- thermo fans? If that is all then most likely, there is your answer.
Davies craig are sh*t. I had one on my Sil80 and if couldn't control temp once up to temp. Idling. Fine driving but during stop start it was pathetic.
Changed to a SPAL, 3000cfm, never had the issue again.

As you have alluded to, look at placement and some ducting. I suspect that will be the answer

thanks for the tip. I was looking at spal fans at a stage, just didnt end up getting them due to postage cost from US..

also shroud and ducting is something I'll be looking into


everyone, thank you for the replies and help with troubleshooting this with me

 

[Gt_Galant]

Cause with my galant E74A, i basically had that problem, basically the needle started to climb to hot, but wouldnt actually go to "H" then fans kick in and needle drops down to normal temp, and it does that all the time.

I ended up changing first the radiator, plus the 2 fans, plus the thermostat, plus radiatir cap, and still did when passed half way in the temp, so my brother-in-law said try the 2 sensors could be faulty, i did and its been 3 years and stays just under half.

If you have that spare motor, might as well try taking the two sensors off that and putting onto the car, i have a good feeling that its one of those sensors, cause your car is doing what my car was doing.

 

[jungle]

it does go down when moving.. so i dont think they are the sensors.. but i dont mind replacing it as well

now that i think about it more.. it happens most when stationary..



thanks for the tip. I was looking at spal fans at a stage, just didnt end up getting them due to postage cost from US..

also shroud and ducting is something I'll be looking into


everyone, thank you for the replies and help with troubleshooting this with me

They're available from PWR

 

[veegeeta]

I can get spal fans through work if you need, but im sure you will get them down there. agree davis craig are crap, car was allways geting hot on idle, changed to spal fans and no more problems. Hope you figer it out bud.

 

[brackenridgevr4]

If you want to try out my old radiator with thermos it's in the shed just a thought

 

[naughtika]

I can get spal fans through work if you need, but im sure you will get them down there. agree davis craig are crap, car was allways geting hot on idle, changed to spal fans and no more problems. Hope you figer it out bud.

i'll get the SPAL fans when funds permit

If you want to try out my old radiator with thermos it's in the shed just a thought

thanks for the offer.. but i think i got it

I'll make proper shrouds first then go from there..

 

[veegeeta]

sorry for dragging out a old thread but i really need help with this issue. my car is building up pressure in the cooling system pushing the water out of the over flow bottle, then the car starts getting hot , have done a leak down test and found no exhaust gasses in cooling system, and changed head bolts thinking it was boost pressure lifting the heads . Ive got good alloy rad , new thermostat , new radiator cap, new waterpump, new arp head bolts,
new water temp sensors great fans, big hole in front end and hole in bonnet . please help guys im really at my wits end here done everything possible now im thinking cracked head.

 

[jungle]

How did the problem first raise its head.
I know you said new what what type of radiator car have you got?

 

[Gt_Galant]

I know you said you put a new thermostat, maybe it sounds like that thermostat could be faulty ? Have you got another to test it ? Well that's my opinion if it helps

 

[pretzil]

Does anyone know if there is a trick you need to do to bleed air from the system after filling up coolant?

 

[AKKO]

If there is I've never done it.

 

[NuffNuff]

There is a breather plug on the thermostat but it goes brittle and can break

Look up a few ways to burp your cooling system plenty of guides out there

 

[NuffNuff]

sorry for dragging out a old thread but i really need help with this issue. my car is building up pressure in the cooling system pushing the water out of the over flow bottle, then the car starts getting hot , have done a leak down test and found no exhaust gasses in cooling system, and changed head bolts thinking it was boost pressure lifting the heads . Ive got good alloy rad , new thermostat , new radiator cap, new waterpump, new arp head bolts,
new water temp sensors great fans, big hole in front end and hole in bonnet . please help guys im really at my wits end here done everything possible now im thinking cracked head.

Try a stock radiator cap

 

[veegeeta]

Radiator is made custom from radiator world in wa. Never was a problem before. Thermostats, rad cap ,pump all gen items. I had aftermarket ones in before thought that might be the problem so changed all back to gen mitsubishi items.Problem has been on and of for four years but is now a lot worse then before.I do get bubbles in cooling system thouh