Need help guys!!...I've got two big problems!(ps hose and over heating question)

[Sky240PWR]

Well i have the RB25DET in my 91 hb.....OK well one of my problems is i need a ps hose, and i know alot of you just take off your ps, so i was wondering if anyone had one lying around that they didn't need, and my second problem is my car is still over heating and my machanic said it's beyond his diagnostic capability, he performed numerous cooling system test, he checked the radiator for leaks and he checked the water pump and he took the thermostat off to see if that was the problem, he spent alot of time and couldn't find the problem, he dosn't think it's the motor but he thinks it's a air flow issue, i have a 14'' electric fan on there right now. I was thinking about putting the FAL duel fan on and see if that would help but i didn't want to spend 300 bucks on a fan if it isn't going to help....does anyone know where i can i get that fan at a decent price?..or maybe a used one....Has anyone had the same problem and could maybe fill me in on what i need to do?

[Joe]

You should be able to get a PS line from any import parts place locally.

as for the overheating, when does it overheat? idle? while driving?

do you have a front mount?

[Sky240PWR]

yes i have a Greddy front mount and as far as the hose, they are $80 brand new!!...thats alot for a hose.

[Valley]

what kind of oil do you run?

[rb250sx]

just use the ps hose off a KA. a little use of a tube bender and your good to go.

[themadscientist]

if you had an RB20 I would say it was airflow, they are notoriously hot-running motors. It freaks news out when I tell them they have a 25 just by the temperature of their hood.

Ok I would have checked to following things which your "mechanic" should have checked as well. Backflush the radiator, it might be clogged up with crud. Are you using a KA radiator? Are those one-core types? Yoy may need to step up to a bigger radiator if that is the case.

Flush the rest of the cooling system, be sure to turn on the heater too to get the heater core in on the action. Put a new thermostat in when you are done, if it hasn't been done already. with the hoses off you should confirm that your water pump is pumping. A bad water pump usually is accompanied by terrible noises but is worth checking while you are doing the flush.

With a clean adequate and funtional cooling system you should not overheat. If you are then the motor is stabbing you in the back. you have either a lightly blown headgasket or a crack in the head somewhere that is allowing heat and pressure into the water jacket. With the radiator cap off look in the radiator for bubbles especially when revving it up.

[Sky240PWR]

what kind of oil do you run?

10w30..I think

just use the ps hose off a KA. a little use of a tube bender and your good to go.

I thought they were differnt, my mechanic said the rb one had a bandjoe brace or clamp or something like that. can someone confirm if you can use the ka one or not??

if you had an RB20 I would say it was airflow, they are notoriously hot-running motors. It freaks news out when I tell them they have a 25 just by the temperature of their hood.

Ok I would have checked to following things which your "mechanic" should have checked as well. Backflush the radiator, it might be clogged up with crud. Are you using a KA radiator? Are those one-core types? Yoy may need to step up to a bigger radiator if that is the case.

Flush the rest of the cooling system, be sure to turn on the heater too to get the heater core in on the action. Put a new thermostat in when you are done, if it hasn't been done already. with the hoses off you should confirm that your water pump is pumping. A bad water pump usually is accompanied by terrible noises but is worth checking while you are doing the flush.

With a clean adequate and funtional cooling system you should not overheat. If you are then the motor is stabbing you in the back. you have either a lightly blown headgasket or a crack in the head somewhere that is allowing heat and pressure into the water jacket. With the radiator cap off look in the radiator for bubbles especially when revving it up.

as for you my ''mechanic" is honest and very good at what he does, he did backflush the radiator and did test it for leaks( vacume or pressure).and i have the aluminum Koyo radiator so it's plenty big enough. he also took the thermostat of and seen that the coolent was moving pretty good throught the water pump, and he did a few other test i can't remember at this time.....and i've been driving with my heater on and the car still gets pretty hot like up to 230 degrees. it hink he also said he did a pressure or leak down test on the motor and he said it was fine, but i could be wrong. but tomarrow i'm going to run the car with the cap on and look for bubbles.

[WDRacing]

Wow, so it overheats with and without the thermostat installed?

I was going to say you may have a vapor lock somewhere in the system. But if your radiator stays full and you never service it, it appears to be bled well.

Is your fan on all the time? What CFM does the fan flow?

WD

[Sky240PWR]

Wow, so it overheats with and without the thermostat installed?

I was going to say you may have a vapor lock somewhere in the system. But if your radiator stays full and you never service it, it appears to be bled well.

Is your fan on all the time? What CFM does the fan flow?

WD

he took it off and said it looked like the original one that came with the car, anyway he said he didn't know where to get one so i told him i would get one but he ran the car with and with out the thermostat and he said it din't make a bit of differnce it still got hot the same. and i just got the motor and new radiator in like 3 months ago and he tested it for leaks and didn't find any so i don't know! and i'm not sure about the fan, i know when i turn the car off and just turn the key to the on possition it stays on. I'll check tomarrow to see if its on all the time........don't laugh but what does CFM mean?

where can i get a thermostat for my rb25?

[themadscientist]

Cubic Feet per MinuteHere is a thought. I doubt this is it but it is easy to check. The highest point in the RB's cooling system is NOT the radiator cap. There is a air bleed screw on the intake. Fill the system up and put the cap back on and fire er up. Remove the bolt and and let the air eacape. When you get a solid stream of water coming out with no bubbles the system is bled. Worth a try.

[WDRacing]

I was going to suggest the same thing just as gee wizz.

[Sky240PWR]

well i only had a few min before work so i went out to check for bubbles. when i took off the radiator cap it was so full, it started overflowing before i even started the car!!...when i started the car, i could see bubbles and when i revved it up the coolant was going air born, i don't have enough time to check the bleed screw on the intake so i'll have to try that tomarrow...so since there was bubbles, can that be my over heating problem?( not bled right)

[WDRacing]

Ouch, thats usually a bad sign man. Air is getting into the water coolant system. Usually a bad head gasket or intake gasket. Run a compression test on the motor. A leak down test would also be a good idea.

WD

[Wulfgang]

The only time I have ever seen coolant go airborne is when I had a blown head gasket.

[Sky240PWR]

hey i see you live in illinois, is there a good shop that knows anything about our rb that you take your car to or do you do the work yourself?

[Sky240PWR]

ok i've got to go to work but one last question, you know when you put a electric fan on the radiator some people put those things( brackets) through the raidiator to make sure it stays in one place, well one of the two round things is gone, so could the air be getting in that way and making bubbles and causing my motor to over heat?well i'm off to work!!..i'm late!!

[WDRacing]

If there is a hole in the rad for air to get in, then water would getting out.

[Joe]

If there is a hole in the rad for air to get in, then water would getting out.

yep, not gonna get air in without water comming out, the cooling system is pressureized.

[themadscientist]

yuo have expatriot boost entering your cooling system, most likely a popped head gasket, do not pass go, this is going to cost more than $200.00. Sorry man

[Slo_240sx]

bubbles and splashing means popped head gasket. Expensive. You can goto a parts store and buy a block checker. All it is is a tube you stick in the radiator neck then fill it to a line with yellow fluid. It checks for Carbon Monoxide in the cooling system and the only way that happens is if a head gasket is bad or a head or block is cracked. If theres bubbles and you rev it and it squirts out its a head gasket. Probably wasn't the cause from the beginning but since you drove it and let it constantly overheat thats what popped it. A good set of fans is ALWAYS a good investment.

Your car will overheat with the thermostat OUT. Your water pump is flowing the coolant so fast that it isn't giving the radiator a chance to cool it all down. Alot of people don't know that but I've seen it happen all the time at my shop. A thermostat also acts as a restrictor.

Now, if your head gasket isn't blown 1 of 2 things or both. Switch the temp sender unit from your KA (dont know if you did that) and I'd get bigger fans.-Alex