jcg928s

Hey guys,

Well I did a coolant flush (ran a hose through the system, cleaned the radiator, etc), new thermostat (180F), new coolant level sensor (fixed the light)

The other thermostat would take forever to warm up and sitting still would start to climb to the second white mark. with the lights on it woudl go just above the white mark.

Now after the change.....
My temp gauge is reading just below the second white mark sitting still (No A/C). Now of course when I turn on the lights it goes right above the second white mark (I think I need to clean the contacts, behind the cluster)

So, I am going to Harbor freight and buy an IR Temp gun. I have a 1984 928S

Oh and I am VERY glad I did the flush. The antifreeze was green, but it was VERY cloudy much like a outdoor pool that has sit too long without any chlorine. Also the rear thermostat metal O-ring had no rubber on the inside. Glad I changed both.

Anyway, where should I read the temp from and what should it be? If the temp is correct I will just read the temp gauge accordingly.

Thanks guys!

jcg928s

Also, on the highway it reads maybe 2 needle marks below what it reads sitting still.

Landseer

That is very good news.

It means the cooling sysem is working well, except at rest. Just not enough air is passing through the radiator.

So maybe its time to refill the silicon fluid in the fan clutch. I've done it on two cars and it made a huge postitive difference. Not too hard a job, either.
Or, to shift to a good electric fan.

One thing you can do as a sideline test is this. Its a bit difficult to get hand in there, but pull the leads off the radiator temp sensor in the lower front of the drivers side of radiator. Bridge the two leads. ( or, otherwise get power to the fan motor directly ). That should make your pusher fan run constantly. See what that does to the temp. at rest. Should bring it down pretty well.

Fraggle has an S4 for which he logged radiator data, so you might search his posts in the last couple years if you want to go down the IR test path. You measure at inlet and outlet, looking for gradient.

Mrmerlin

Joey did you remove the block drains before you refilled the system if not then you should start over. the block will hold just about 2.5 gallons of coolant. You need 2 gallons of coolant and 2 gallons of distilled water to refill an empty system.

Did you replace the rear thermostat seal? IIRC you engine should have one this will make the cooling run cooler if the rear seal is good.
Do as Chris suggests to inspect the coolant fan.

jcg928s

Hey guys,

Thank you for the input.

Ok, lets see.

Landseer: Something funny about the fan clutch. last night first crank I ran the car and watched the needle rise. After I saw it was a little higher than my liking (right at the 2nd white mark). I shut it down. As I turned the key off I always watch the fan...... It spun like a roller skate wheel. DAMN! bad clutch. So I figured I would test my theory. I took her for a drive. Well the temp did the same thing. Heres the weird thing, when I got home (temp was the same). I turned the key off, fan stopped immediately. WTH! Can a fan clutch be tempermental? Oh and what I mean by two needle marks difference was the with of two needles.

Merlin: Yes sir, bought a kiddy pool and removed the drain bolts from the block....got a nice shower of cold antifreeze, LOL. Ran water through the expansion tank until clear water came out of the block holes. replaced bolts, replaced both seals on thermostat (front and rear). I ordered a 180F from Autozone and replaced it too. After letting it sit for a while during the refilling she took right at 4 gallons.

Landseer

It sounds in some respects like the fan clutch is working. As I read somewhere, there are multiple modes of fan clutch operation, triggered by both temperature and centrifugal force.

Am still thinking its the lack of good fan.


I tried all the normal advice to judge mine, and I was unsure, but ultimately filling them was the big win.
The Toyota 10,000 cp fluid is expensive, like $20 for a tube. Thick silicon fluid for the filling of RC model car differentials is supposed to work, too, and be more readily available online or via hobby store).

Try running that electric fan and see whether that helps?


Going in another direction, if the car is running and cap is off reservoir, hopefully you aren't bubbling in there --- happened to me on a Camry --- head gasket. Tell us that yours is OK in this respect, please.


For reference, I have two USA 84 cars with lots of miles on them. Both run and idle on/about the first white line, so that needle isn't even horizontal.

The 84 Euro we have doesn't have a viscous fan or an AC pusher fan, both were replaced with a small pusher electric. It runs with needle horizontal on the highway, but in town runs up towards the bottom of the red zone, not in it, but near it. Jadz928 told me it should have probably been a bigger diam fan. This car has 200K miles and different cams --- and I've never calibrated its dash gauge against the other two cars... just another data point.

jcg928s

So, I had an idea.....

Here are pics of the temp gauges with different variables. Also IR readings on the temp sensor on the water bridge. I am also including a video of shutting off the engine while videoing the fan clutch. Landseer I know you are a guru on these, can you let me know what you think?

(I apologize for the size of the photos)

This is 181C on the IR, no parking lights, no headlights...


This is 181C on the IR, parking lights only


This is 181C on the IR, headlights on as well


Here is 193C on the IR after A/C was on and electric fan just shut off.


Here is the video of the fan clutch........ I apologize for my morning voice, LOL.
http://www.youtube.com/watch?v=Vr5DnwiP5Y0


It looks like I need to pull the pod and clean the contacts, given the fluctuation of the needle with the light being on and off.

Is that temp ok though? The one the IR saw?

Thanks guys!

terry gt

IMHO your fan is done . some people have managed to refill them with toyata fan clutch fluid . Change your thermostat AND the SEAL behind it

jcg928s

Thanks Terry, but I think the clutch is working like it is supposed to. Correct me if I am wrong here, but when it is heated the fluid creates more drag on the clutch, making the fan spin closer to the speed of the motor. When it is cold, the opposite happens, more slippage and less rotation.

Also during the coolant flush, I changed the thermostat and both gaskets.



So I guess the real question is:

During idle no A/C and while on the highway the temp is at 180C IR on the temp sensor
With the A/C on and after sitting for about 10 minutes it creeps to 193C IR on the temp sensor.

Are those readings to high?

jpitman2

FWIW, my gauge moves the same when any lights are on - lifts significantly - pod contacts is my guess too. I adapted a larger more blades fan off a range rover once - can send you a document i wrote on it if you want. Have gone full electric now - 2 x 11" SPALs from thefanman.com
jp 83 Euro S AT 53k

Landseer

Your fan is working like mine. F''d.

Why else would it run low at speed and run high at rest?

jcg928s

Are the temps too high though? 180C A/C off and 193C A/C on?

jsherid1

FWIW--the upper rad hose on my 87 S4 is consistently around 164 F and stays that way even in very hot weather with AC on.

Chris Hansen

Changing the viscous fan clutch made a world of difference for me. It's not cheap, but it was well worth it.

jcg928s

Thanks jsherid1, I measured the hose and it showed about the same. This was at the water bridge on metal with the IR gun.


Sorry guys, I have been putting Cel instead of Feren. Im retarded.