Keeping it cool

[-Nemesis-]

Ok, time to brainstorm guys. I've a '94 Toyota 4Runner which now sports a 1UZFE engine. I'm using the existing radiator off the V6 for the time being, but occasionaly the engine runs warm. It was bad last week, which I traced to an airlock, which solved it mostly. It ram a little warm today around town, now mind you though it was high 30's (celcius.)

It's running a single 16" thermo fan on the back of the radiator. Initially it was on the front blowing, which was better. But now that i've re-installed the A/C condensor the fan must go on the inside. I also don't have room for my dream fans, the AU twin thermos.

I want to make it run cooler, but the priority at this stage is $. Our wedding is April, and at this stage I can't justify the $1000 or whatever for a custom radiator. So I need some ideas on getting it cooler, on the cheap.

I notice that the engine bay suffers uber bad heatsoak from the alloy block. So my first thought is getting a bonnet scoop and or vents on top. Do these make a huge difference on a hot motor? I have found some pretty cheap brand new through Sydney Special Vehicles... Like this one which is only $88
http://www.ssv.com.au/images/bs30.jpg


Then what about oil cooling? Is that expensive to set up, is it worth it? Does it make that much difference?


What else is there? I've thought about trying to fit a bigger thermo fan in the place of the little one on the A/C condensor. And have it switched by the temp switch also....?????

Any brainstorming ideas would help guys.... :feedback:


This is about the only engine pic at the moment on the web. It's from when it was almost 1st on the road last year.. Note the fan is on the outside here and no a/c condensor in place...

And I think this one may show some of the problem.. There's not alot of airflow in through the front. The spotlights are now a bit bigger to. Cut holes in the bullbar? Run cold air pipes up to the sides of the block?

 

[adxx]

Hmmm. Seems a bit complicated task. I mean - for cheap.
At least - vents will improve air circulation under the hood. We use household vent grill - which is couple of $ in the market. All you need - is metall cutting tool, drilling, and then you just rivet that grill to the hood above the hole cut Looks a bit strange, but it makes business.

 

[LO LYF]

Have you tried spacing the bonnet up from the hinges?

lets some of the hot air out and cost's bugger all to do!

On a side note what sort of air box are you useing? looks perfect for the hilux engine bay.

cheers, mark

 

[deankdx]

Have you tried spacing the bonnet up from the hinges?

lets some of the hot air out and cost's bugger all to do!

On a side note what sort of air box are you useing? looks perfect for the hilux engine bay.

cheers, mark

i was also going to say space the rear of the bonnet up, it could be poor circulation, air can get in but cant get out. you see it alot on drift cars.

looks like a Holden VN commodore V6 airbox? thats what i am using too if so but in a ford falcon.

 

[-Nemesis-]

VN airbox it is.......

I've actually already hinged the bonnet

IT ran fine since I found an airlock above the thermostat last week. Then today it ran a little warm driving low speed around a suburb looking for houses etc. I checked it just now and there was some air in the bleed point again.

Also, when it's been running, the overfolw bottle level increases, but overall it slowly gets lower. After a few weeks it needs filling up.... Hope I don't have a problem.....

 

[twisty_toy94]

Thats what mine started doing Nem....it wasn't running hot at all, but over a week it would drink all the coolant in the overflow bottle.....it did that for about 2 months, and then sh!t itself the other week......I'm about to reinstall my condensor in front of the radiator, and move the fan to the back when I put the new motor in, so it'll be interesting to see if I get any overheating issues.....

 

[deankdx]

i dont know about the water loss, but i still think its an air flow problem, the air intake on a falcon is no smaller really, but there is a mile of room after the radiator, but in your case the air cant go anywhere by the looks, i have not had the problems you are having, but i have seen it before, what happens if you space the rear of the bonnet with a 2" spacer for trial purposes? i would assume this would help.

i am only suggesting things that i would try, hoping you dont have some other problem.

 

[-Nemesis-]

I've spaced the rear of the bonnet a fair bit, enough to feel some of the air coming out when it's sitting there.

I still think it may be to do with heatsoak though. I don't think you had those dramas did you Dave? Could it be the Patrol scoop on yours pumping cool air into the engine bay?

I also think there's a severe lack of airflow in general. I might take it out on the next hot day and test it on some hills, then take the bullbar off and try again and see what happens.....

 

[twisty_toy94]

Nah, haven't had any problems with heatsoak, only time mine has got hot was in soft sand, and high revs for about 10 mins....and that was with the old std. radiator.

I guess the bonnet scoop helps mine, and I've still just got the radiator with the thermo on front....once the condensor is back on the front (adds more heat!) and the thermo on the back of the radiator, it has to place a lot more pressure on the cooling system.

 

[LO LYF]

Thanks for the tip on the air box, I'll head over to pick a part on the weekend and get me a vn one!

 

[twisty_toy94]

Just buy it from holden...its only about $40 brand new

 

[Zuffen]

Whilst this may sound dumb. Have you thought about using a length of 50mm pipe to hold some more water.

Part of the problem is you don't have enough water capacity in the V6 radiator to cool the engine.

If you used (say) a 1 metre length of pipe fastened to the bull bar or somewhere similar and hooked your lower radiator hose to it you may find an improvement. if you flowed the warter across the car and back again (from drivers to pasengers side and back) you would gain a heap of capacity.

To test if this would work next time its running hot turn the heater full on and see what it does.

 

[LO LYF]

twisty_toy94Just buy it from holden...its only about $40 brand new



Thanks for the tip i'll go to holden and get a price. Being NZ it will be more like 3 times that!

 

[-Nemesis-]

Hmmm interesting theory Rod... Actually when it runs warm and I turn the heater on the temp drops. I suppose using a metal pipe that would dissipate heat easily would help too....

I have a feeling the heat yesterday may have been another small airlock I found last night. My main concern is the water level slowly dropping now, very slowly. Assuming when it ran empty yesterday it ingested air causing the lock?

Here's another interesting one. When I got the motor I posted on here asking what certain components are, and on the drivers side there is a small pipe outlet which everyone told me goes to the overflow bottle. Anyways whilst on holidays and having problems cos of the cracked radiator leaking, I decided to connect it. I had been using the overflow point on the radiator instead. So I unblocked it and ran it to the overflow bottle, and blocked the outlet on the radiator just to see what would happen.
We left to come home the next morning and after about 30mins driving we pull in to a place we wanted to visist, and as i'm pulling in there's a bloke sitting on the horn behind me. (Note the temp guage reads normal) So I pull up and turn it off to hear a bubbling sound. I get out and there'd be 5 litres of coolant already underneath (OH F$%K!.) I pop the hood and luckily it's all coming from the overflow bottle, but it's coughing and spitting out boiling coolant and air! It dumped practically the entire cooling system and worsened the leak in the radiator; Remember the guage read fine, the radiator coolant temp was normal.
So in the carpark I switched them back around once it had settled down. I've blocked off that 'outlet' and reused the radiator one once again, without problems other than the current discussion.
Interesting?

 

[twisty_toy94]

I pop the hood and luckily it's all coming from the overflow bottle, but it's coughing and spitting out boiling coolant and air! It dumped practically the entire cooling system and worsened the leak in the radiator; Remember the guage read fine, the radiator coolant temp was normal.

Exactly what mine did the other week Bryan.....except my overflow was from the top of the radiator, and it would do it everytime you went for a drive within 5-10mins.....the radiator also bubbled with the cap off, hence the most likely blown headgasket.

I've never checked that air bleed bolt on the top of mine, but usally fill the radiator up, and drop a heater hose off and fill it from there too....

Have you checked for bubbles in the radiator?

 

[-Nemesis-]

Yeah there's no other symptoms really. No bubbles in the radiator or anything. But like I said that overflow explosion was only when I tried using the 1UZ factory overflow outlet, it hasn't done that since.

Hurry up and diagnose yours heheheheh

 

[-Nemesis-]

I just went out the back here at work and tried it. The coolant is still warm; I took the radiator cap off and started it. Straight away the coolant level started rising really slowly till it starts leaking over the top of the filler hole. I couldn't see any bubbles though.

Both the V6 and this V8 have always done that. Does your water level rise when the caps off too?

 

[deankdx]

I just went out the back here at work and tried it. The coolant is still warm; I took the radiator cap off and started it. Straight away the coolant level started rising really slowly till it starts leaking over the top of the filler hole. I couldn't see any bubbles though.

Both the V6 and this V8 have always done that. Does your water level rise when the caps off too?

well i dont Know about the 1UZ, but if you start my falcon 6 when the themosat has not opened while the cap is off, it will push water out.
but when the motor is running temp and thermostat is open, it should be fairly stable and this is when i'd be checking for blown headgasket bubbles etc

 

[twisty_toy94]

yeah mine would rise, as well as bubbles...then it would start foaming up like it had raybies!! (spelling)

 

[-Nemesis-]

But aren't you going to scald yourself opening the cap when it's at operating temp?

I tried it cold then as Twisty said elsewhere his did it when it was cold also (bubbles)