Hydraulic fan AGAIN... - Toyota Nation Forum : Toyota Car and Truck Forums

rusty9 · 08-04-2010, 11:03 AM

Ok, so should the fan be at max speed like super fast and loud when you jump e1 and op1 or should it just increase slightly? the manual says it should be spinning at 1100rpm...but i'm afraid i don't have a fan tachometer...

anyway, if it only raises slightly, where would the problem lie? the solenoid on the pump? i would imagine its not opening all the way if its not kicking up to high.

***LynchburgCSI*** · 08-04-2010, 11:22 AM

1100 rpm / 60 seconds = 18.3333333 revolutions per second. Guesstimate?

73sport · 08-04-2010, 02:34 PM

Quote:

Originally Posted by LynchburgCSI

1100 rpm / 60 seconds = 18.3333333 revolutions per second. Guesstimate?

Look Peps - Ken is thinking like Randy! haha >> 1100 rpm / 60 seconds = 18 rps

When I went to lunch, that was my post as it gives perspective that's its moving fairly quickly. Put a piece of tape on one blade and take a swag at it.

One has to wonder if 1100RPM (which is fail safe speed) is full speed or something less than full speed? It doens't say.

You have a pressure gauge capable of 500PSI? It says at 2000 engine RPM the jumpered system should yield 290psi. If the pump is worn it will have a tendency to aerate the fluid so pull the res cap and look at the return. It shouldn't be full of bubbles. On the flip side unless I'm missing something, the solenoid valve controls the volume. If it doesn't work (defect or temp ECU defect) then both the pump and the fan could be OK. Can you monitor the signal to the valve or bypass the valve for a momentary test?

What I don't like is that is LOOKs as if when the solenoid is closed the pump is forced to run against its internal bypass which takes power and would tend to aerate the fluid. Is the valve a single high pressure pipe in and a single pipe out or does it by chance have 3rd pipe dumping into the reservoir?

Did you test the solenoid valve for proper resistance? 77F = 7.6 to 8 ohms?

rusty9 · 08-04-2010, 03:42 PM

yes ive checked the resistance, as per the manual, and you can see my trials in the diagnostic checklist thread i posted.

does your 1mz still have a hydraulic fan? can you jumper those pins and see if the fan goes to HIGH or just spins up a bit faster?

as far as i can tell the pump is dual chambered, one side for fan, one for steering.

i dont have any bubbles in the fluid, and i dont have a gauge or adapters for testing the pressure.

i dont know any more...i have the car at the engine shop now, im having them do a compression test and cooling pressure test to rule out head gasket issues. if they turn out ok, ill head off the salvage yard to see if i can find another pump with the solenoid.

73sport · 08-04-2010, 03:59 PM

Mines DC! Sorry. . .

OK - a couple of last minute things.
Power steering is fine, yes?

Is there one feed or two feeds from the reservoir feeding the pumps inlet? Is it possible the pump inlet on the PS side is plugged? Mine has a fine mesh screen inside which was loaded with crap. You can siphon some off the screen, but I'd pull the res and back flush it.

Rambling:
Is there a way to bypass the solenoid valve? Tests both fans and pump for hi-speed operation?
Is there a temperature difference between the high pressure (H/P) line feeding the power steering vs the H/P line feeding the fans? More work = higher temp. Loose pump = lower temp.

Can you detemine the type of signal the cooling ECM output feeds the solenoid valve? Lets say its a steady DC like:
12v = full speed
6v = 1/2 speed
3v = 1/4 speed

Or it could be a duty cycle thing with a pulse. If its voltage, we can send it a signal. Even if its duty cycle, you could test it with like 6v or maybe 12v (idk) which would equal 100% duty cycle and full speed fans.

Does it change when you unlplug the solenoid, just no high speed?

Just thinking out load. . .

rusty9 · 08-04-2010, 04:46 PM

i believe its duty cycle, and digging through the manuals i think i remember that 7 volts should open the solenoid fully to set the fan to high.

unplugging the solenoid does not induce fail safe, unplugging the temp sensor on the thermo housing does nothing as well as unplugging the ECM's own temp sensor on the outlet pipe.

camry6 · 08-04-2010, 06:50 PM

Unplug the A/C pressure switch connector near the battery, just in front of and below the battery, above the filter/drier. This should give you full hydraulic flow to the fan. When you rev the engine up above idle it should pull strongly and roar a little. The fan valve has a three way flow. It by-passes fluid back to the reservoir when the fan is stopped and diverts fluid through the fan motor when it receives the signal. The pump has two independent circuits. One for the fan operation and one for the power steering circuit. They share the same suction line from the reservoir and have two separate output lines.

rusty9 · 08-04-2010, 07:14 PM

my a/c isnt charged. =/ i finished the engine swap in the fall/winter so i put it off...

73sport · 08-05-2010, 01:54 PM

Quote:

Originally Posted by camry6

. . . . .

The fan valve has a three way flow. It by-passes fluid back to the reservoir when the fan is stopped and diverts fluid through the fan motor when it receives the signal.

The pump has two independent circuits. One for the fan operation and one for the power steering circuit. They share the same suction line from the reservoir and have two separate output lines.

Quote:

Originally Posted by 73sport

What I don't like is that is LOOKs as if when the solenoid is closed the pump is forced to run against its internal bypass which takes power and would tend to aerate the fluid. Is the valve a single high pressure pipe in and a single pipe out or does it by chance have 3rd pipe dumping into the reservoir?

So the valve does have a return to circulate the oil! This makes WAY MORE sense than stopping the flow completely as the pump would be screaming against the pressure relief valve. The flow daigram I saw doesn't show the 3rd leg on the valve.

Speaking of noise. How does the pump and motor sound when you place a listening device to them? Wood handle to the ear, long screw driver. If the pump is whining, maybe its gone bad or is starving from a plugged p/u screen. But the weakest link IMO is the control valve!

73sport · 08-08-2010, 12:46 PM

Rusty, whatcha know about this? Fixed or still in limbo?

rusty9 · 08-08-2010, 12:54 PM

oh yeah, still in limbo. the car is still at the machine shop. i assume its getting good flow because when i jump the diagnostic pins i get a 2-3 inch jet of fluid out of the reservoir when i take the cap off. i still dont know if the fan should be at max when those pins are jumped.

i have to call the shop again tomorrow and see what they found.

rusty9 · 08-27-2010, 08:08 AM

welp, i did a compression test this morning

cyl#1 - 205
cyl#2 - 190
cyl#3 - 202
cyl#4 - 200
cyl#5 - 196
cyl#6 - 196

dunno what else to do. mechanic said cooling system held pressure for over an hour. but driving home from his shop it overheated within 15-20 minutes of highway driving. after it cooled off, i was refilling the coolant and noticed the fan was cycling while idling, which i havent seen it do before. still get bubbles coming up from the overflow tube in the reservoir. still bubbles and gurgles after i shut it off after driving around in town for a while.

on second thought, just a compression test isnt conclusive. i really need to have a leak down test done.

73sport · 08-27-2010, 09:59 AM

Quote:

Originally Posted by rusty9

oh yeah, still in limbo. the car is still at the machine shop. i assume its getting good flow because when i jump the diagnostic pins i get a 2-3 inch jet of fluid out of the reservoir when i take the cap off. i still dont know if the fan should be at max when those pins are jumped.

i have to call the shop again tomorrow and see what they found.

Although that sounds like good flow, it also doesn't sound normal (as in kinda extreme jetting out like that).

I don't know I'm guessing jumper = full speed but still no proof.

73sport · 08-27-2010, 10:04 AM

Quote:

Originally Posted by rusty9

welp, i did a compression test this morning

cyl#1 - 205
cyl#2 - 190
cyl#3 - 202
cyl#4 - 200
cyl#5 - 196
cyl#6 - 196

dunno what else to do. mechanic said cooling system held pressure for over an hour. but driving home from his shop it overheated within 15-20 minutes of highway driving. after it cooled off, i was refilling the coolant and noticed the fan was cycling while idling, which i havent seen it do before. still get bubbles coming up from the overflow tube in the reservoir. still bubbles and gurgles after i shut it off after driving around in town for a while.

on second thought, just a compression test isnt conclusive. i really need to have a leak down test done.

Ultimately I guess this doesn't change anything but I thought you're was i4

So was whole #2 a problem to get the wip in? Any chance it was leaking making that number drop?

I think my next step would be to pull the thermostat and boil it. Need to win by process of elimination.

Recap, you measured with an ohm meter all of the engine temp sensors, the fans work when jumpered?

rusty9 · 08-27-2010, 03:54 PM

#2 is the first cylinder(left) on the front bank, so its no problem getting the hose in. manual says 178psi or higher is normal and 142 would be the minimum.

already boiled t-stat, works fine. there is a gutted t-stat in there now.

indeed ive tested all the electronic cooling system components and used it to make the diagnostic post i made. when jumpered, fan speed increases but not to "high". I did notice it was cycling to "high" when i was bleeding/refilling after a short drive, but it wont cycle if i just let it idle to normal temp from a cold start while parked. it wont overheat if it just idles, just get slow steady bubbles.