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Discussion Starter · #1 ·
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.

:headbang:
 

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Volvo C30 Polestar, Volvo 765, 95 Camry 1MZ wagon, 17 Mazda3 GT hatch
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1100 rpm / 60 seconds = 18.3333333 revolutions per second. Guesstimate? :lol:
 

· V8'sRGone
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1100 rpm / 60 seconds = 18.3333333 revolutions per second. Guesstimate? :lol:

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?
 

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Discussion Starter · #4 ·
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.
 

· V8'sRGone
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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. . .
 

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Discussion Starter · #6 ·
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.
 

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'93 Camry V6 LE
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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.
 

· V8'sRGone
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. . . . .

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.

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!
 

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Discussion Starter · #11 ·
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.
 

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Discussion Starter · #12 · (Edited)
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.
 

· V8'sRGone
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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.
 

· V8'sRGone
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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:eek: :facepalm:

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?
 

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Discussion Starter · #15 ·
#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.
 

· V8'sRGone
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So the gutted t-stat didn't change anything? It could increase the flow so much as to aerate the water making bubbles and/or reduce the amount of heat absorbed by the water thus no need to turn on the fans. << Seems unlikely!

Has this been an issue ever since the rebuild?
Is there a way to put the head gasket on wrong (I know, machine shop did it) but do you know the answer?

Have you been to the yard to grab a new switch?
Do you have any kind of temp gage you can monitor temps with? Even an external probe?
If everything tests fine but the fans never come on, either they don;t need to or the sensors don;t get a signal.

If I were you, I think I'd find a way to trick the sensors into thinking its hotter than it is just to test the system with known variables. In short replace the temp sensors with variable resistors.

As for overheating, you mean >> boiling over? You ever get that funnel or try jacking the right side of the car for fluid filling?

We must be missing something. . .

Where are you 3VZ guys with hyd fans????
 

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Just reading through the posts and it looks to me that it has a blown head gasket. What appears to be "boiling over" and spilling out its coolant is actually caused by escaping combustion gasses through a leaking head gasket. This causes more pressure than normal in the cooling system to build up and push the rad cap spring open, causing it to look as if it is boiling over. Bubbles in the reservoir are not caused by boiling coolant, they are combustion gasses. This is the cause of bubbling and gurgling sounds you can hear after you shut the engine off. The reason the fan don't run when it is "boiling over" is because the boiling isn't caused by the engine overheating, it is gas bubbles injected into the cooling system. When the coolant gets low enough, it will then cause the engine to actually overheat. A leak down test of the cooling system is not 100% fool proof. If it has a severly blown gasket, it will show a bleed down over time. Remember this the 10 or 20 PSI of pressure placed in the cooling system may not leak through the gasket, but the 1000 Psi plus from combustion pressures will certainly leak out! I had the exact same problem with my 3VZ-FE five years ago. I since bought two more that had the exact same symptoms, caused by blown head gaskets. Look no further, this is the answer. Good luck!
 

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Discussion Starter · #18 ·
indeed, but i need to prove it to the machine shop who built the motor because they have been extremely resistant on admitting anything is wrong. i cant just tell them i want to you strip down this engine again for free because i think this or that.
 

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indeed, but i need to prove it to the machine shop who built the motor because they have been extremely resistant on admitting anything is wrong. i cant just tell them i want to you strip down this engine again for free because i think this or that.
With the engine cold, (running) and the coolant topped up completely, can you see bubbles rising up in the filler neck on the rad cap at the top of the engine? (watch for a few minutes). If so, there's the proof.
 
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