Oil pump failure

[Banjo]

Hi Keith,

I can assure you the rear head & lower radiator temp sensors are hooked up to the correct data logging inputs.

It is however, a bit difficult to get your head around the rear of the head being cooler than the coolant at the bottom of the radiator.  If it stayed that way, then there would certainly be something wrong.  However, it doesn't, as & there are long periods, where the rear of the head coolant temperature is greater than coolant exiting the bottom of the radiator.  This changeover, only occurs when the car stops, & the air is no longer passing through the radiator, & the top radiator hose coolant temperature is not yet high enough, to switch the thermofan on.

You can clearly see this in graphs a few posts back on this page 10.

The problem is, that as soon as the car stops, the coolant at the bottom of the radiator rises in temperature very, very quickly.  The rear of the head has to play catchup.  This sort of things always occurs in "systems" that have "transport" lags.

First I am going to see what difference the radiator bypass creates.  

You will notice, that this occurrence, only happens in stop start traffic, but not on a long straight runs.

I was thinking, I could flatten the response right out, by fitting a N.O. relay contact across the thermoswitch, with the relay automatically coming on, whilst ever the ignition was on, (engine running), & the car was stopped.  That would result in air passing through the radiator at all times, and should reduce, & hopefully almost illiminate the sudden rises in lower radiator coolant temperature.

I can test this out, without fitting the relay, as I have this switch on the dash, that can bring the fan on, irrespective of the conditions.  I'll log a run in traffic, but every time I pull up, I'll switch the fan on.  Likewise as soon as I move off again, I'll turn the fan off. The resulting graph, should clearly show the difference in coolant system performance.

All fun, but learning lots at the same time.

Cheers Banjo 

 

 

[altezzaclub]

"& the car was stopped.."

Now if only we had ABS the relay could read that! 

Yeah, I have a manual over-ride on both my 70s, I flick it on at roadworks after a 100kph run, the only time there is heat to dissipate.  At least it gives me a running start at stopping the temp going up while stopped.

[Banjo]

Hi Keith,

               Well my 16 x 1.5M hose adaptor arrived today, so I can now install a radiator bypass hose, & see what effect that has on the  various logged temperatures in the coolant system.

I like your idea of using an ABS sensor to provide a signal that the car has stopped.  It is not a very important sensor, for our application; unlike the real ABS application, where you need a toothed wheel, so you can measure rate of change of speed, as well as actual speed.  I've been thinking about how I could mount a sensor, without too many issues.

ABS sensors are pretty cheap on ebay.

It's probably a bit difficult to modify a front KE hub, & fit a sensor.  I was thinking of maybe attaching the sensor to the diff housing, and have the sensor measure the tail-shaft to diff flange going round.  Probably no need to fit a toothed wheel.  Maybe just sense the heads of the four (4) flange bolts whirring around, with a Hall Effect Magnetic sensor.  After all, it's just a Go/No Go condition we are looking for. However, we could actually bring on the thermofan, above stopped, if you are crawling along in traffic, on a hot day, by switching the fan on when the speed is between 0 - 5 kph.

Actually, whilst writing this I just remembered I've got a little "potted" reed relay, that is used for sensing a tiny magnet clipped to the spoke of a bicycle for driving the bike speed module.

Could hook that up, real easy me thinks.  So when the ignition is on, and there are no pulses, that would indicate the engine is running, but the car is stopped, & the thermofan could be switched on.  You don't want the fan coming on, whilst you are doing a cold start first thing in the morning, so could add another condition, that the temperature has to be above some reasonably high limit.  That would limit the fan to automatically come on,  only when it is really needed. 

Lots of possiblities there.  I'll let you know how I go.

Cheers Banjo

  

Edited April 12, 2018 by Banjo

[Banjo]

Hi Guys & Gals,

                           Well my Silicon Chip May 2018 magazine arrived in the mail today, & there inside is a project for a "Deluxe Frequency Switch", on page 36.  It allows you to feed a stream of pulses from any sensor, into the unit, & it will trip a relay, with hysteresis, when the rate of pulses goes above or below, limits which you set. It has a timer builtin as well.

There are many applications this switch could be used, and the article lists a number of them, to get the readers mind working.  The very second suggestion advanced says  . . .

"Switching a fan on at low vehicle speeds, to provide improved cooling".

Just what we have been discussing, in this thread. 

Looks like just what the doctor ordered Keith !

Cheers Banjo

P.S.  Just waiting for this rain to stop, to get out there & complete this radiator bypass addition.  Hopefully, some sun tomorrow.  Well, it is Qld.  Beautiful one day, & perfect the next.

 

Edited April 20, 2018 by Banjo

[altezzaclub]

Nice!  You should fit the Hall Effect setup, just like a rally car tripmeter.  We only use one bolt head screwed in the back of the disc, but it depends on how many pulses you need.

[Banjo]

Hi Keith,

               I would certainly like to fit the sensor to a front wheel, rather than the diff input flange, as I indicated.  If only to keep the wiring short.  How difficult was it to fit to the front lower strut ?  What car did you do it on? 

I presume it was a gear tooth hall effect sensor that you used, if you were just detecting a bolt head?  Didn't involve any external magnets? Can you remember what particular sensor you used?  Was it off a later model Toyota?  I will pull a front wheel off this afternoon, & have a look, how much room there is behind the disc. I've ordered the Silicon Chip PCB & programmed micro processor, for the Deluxe Frequency Switch, so that should be here in the next couple of days.

I did a run this morning, so am about to download the data logger, & see what effect the raditor bypass addition, had on the rear of head coolant temperature, if any.

Cheers Banjo

 

 

[LittleRedSpirit]

I added a speed sensor to the front hub of an ra40 strut by simply drilling through the steel caliper mounting boss in the right radial location to allow insertion of a Honeywell gt101dc sensor.  I just had to drill a hole to poke it through, then drill and tap an m6 hole to mount it to, and it is pulsed 4 times a revolution by the 4 bolts that hold the rotor to the hub.  Works great.  The gt101dc sensor is a very good hall effect unit, and it only needs a proximity of sub 2mm to work effectively.

[altezzaclub]

Not hard, like Littleredspirit said.  We use the dust cover behind the hub usually, the sensor has two nuts on the outside so it locks into a hole at any depth you like.

The bolt is just an 8mm tapped into the inner part of the disc where the pads don't rub.

One bolt does fine. on a Terratrip T005 sensor.

http://terratrip.com/probes.htm

[Banjo]

Sounds great guys !  Was thinking it was going to be quite difficult.  Will let you know how I fare.

Well, I took the KE30 for a run today to town, after I reinstated the radiator bypass hose over the weekend.

Over the weekend, I also fitted a proper temperature guage, so I could see more closely and accurately, in real-time, what was happening.  I mounted it on top of the steering shaft cowling, so I didn't have to move my eyes too much whilst driving. The guage was surprisingly accurate, considering it originated from China, delivered, complete with mounting surround, & sensor for less than $ 10.00.

Well, after I got home, & downloaded the data, you could knock me over with a feather. The simple action of reinstating the bypass, made the whole coolant temperature variations, change dramatically, for the better.

It's like there has to be a constant flow, whether the thermostat is opened or closed, to stop the sudden changes than occur, when the thermostat closes, & the flow stops altogether.

Ever since I ran a return line from the back of the head, the rear head temperature has lowered considerably, but Keith & I were very puzzled as to why the rear head temperature,  at times, was actually less than the lower radiator hose coolant temperature.  From the graph above you can see that that has changed completely. Where we had a rear head coolant temperature about 10 deg C above the front of head temperature, now it actually less than; by 6-7 deg C. Now the whole system is stable, I might put a clamp on the rear of head return line hose, & restrict it little by little, to see if I can't get the front & rear head temperature even closer together.

On the right of the graph, you can see a "circled" area of the graph, where for 15 mins, I had a good long straight run, without any stops at all, all at about 80kph.

Here is that section, of graph, which is very telling.

Notice the top & rear head coolant temperatures, mimic each other perfectly, about 6-7 deg C apart. Gone are the ups & downs, of the coolant temperature, directly under the thermostat.  The rear head return coolant is now returned to a point directly under the thermostat, which is why these two temperatures look so much alike in shape.

The lower graph line is the lower radiator hose coolant temperature.  The zig zag nature of this graph is very easy to explain.  The outside ambient air temperature was fairly mild today, at an average of 25.5 deg C, as shown on the stats at the bottom of the graph. This resulted in the radiator hardly being needed at all.  You will notice the top hose (black trace) is averaging at 82.4 deg C.  The thermostat does not crack open until 82 deg, & is fully open by the time the coolant reaches 87 deg C. So what was happening was the thermostat would just crack open, & flow would commence through the radiator. The coolant temperature reduced very quickly, once the radiator was in circuit, & the thermostat instantly closed up again, stopping flow through the radiator altogether. i could actually see this happening on the temperature guage I fitted behind the steering wheel. The meter is damped, but, I could see it rising and falling about 2-3 deg C. continuously, at the rate shown in the graph. I was actual watching the thermostat crack open & close continuously.  On a hotter day, this will not happen, as the operating temperature will be nearer the mid point of the thermostats range of 82 - 87 deg C.

So riddle just about solved.  Just need to install this speed switch, so that in traffic, when you stop, the fan comes on automatically, to pre-empt, & flatten out all those sudden rises.

In the first graph, you will notice the electric fan only came on three times.  The first time was for 48 sec. Second time for 24 sec, & last time 48 secs.  That's a total fan operation of 2 minutes, in about 90 mins driving.  Keith's original statement is very true, that the fan is rarely needed.

Cheers Banjo

Edited April 23, 2018 by Banjo

[altezzaclub]

Nice!  Now it all makes sense.

Its impressive how hard that thermostat works!

[Banjo]

Hi Keith, 

On 4/23/2018 at 7:31 PM, altezzaclub said:

Not hard, like Littleredspirit said.  We use the dust cover behind the hub usually, the sensor has two nuts on the outside so it locks into a hole at any depth you like.

The bolt is just an 8mm tapped into the inner part of the disc where the pads don't rub.

One bolt does fine. on a Terratrip T005 sensor.

http://terratrip.com/probes.htm

Had a real good look at this possibility yesterday afternoon. My setup on my KE30 2 door front suspension, is not standard, with RA65 Celica struts & Cresida large thick rotors & giant calipers (compared to the original Rolla ones).

Removed the caliper & disc., & located the four (4) head bolts on the back of the hub, securing the disc. itself.  I removed one bolt completely, then refitted the disc, rotating it slowly with a very thick round pencil through the hole, from the outside, where the bolt had been. This marked an arc on the backing plate; then I removed the disc again.  The radius from the centre line of the axle was smaller than expected, & it was nearly in line with the four bolts holding the backing plate onto the strut flange.  There was only one spot where I could mount the sensor to detect the four (4) head bolts. Top & bottom where shielded at the back by the strut itself, & the forward side, had the caliper in the way.  I marked a spot, on the rear end, between the backing plate bolts, which had the strut flange behind it.  I drilled a pilot hole through the backing plate & flange, then refitted the disc. Pushing a piece of coat hanger wire through the hole , from the rear, I could measure the distance between the back of the backing plate & the head of the bolts. It was 35mm. The area of the bolt heads to be picked up by the sensor is 12mm in dia.

When I open the pilot hole out, & I wouldn't want to go much more than 14mm, as I will taking metal out of the strut flange. I've not been able to find on the net the dimensions of the Terra Trip T005, you suggested. Just looking at the pictures, it appears to not be long enough, & maybe a bit too big in diameter.  You don't happen to know what it's length & dia. were ?

I might have to make up my own sensor with a Hall Effect device, and a piece of threaded tube. Is the wiring to your T005 a 2 or 3 wire connection ?  Hall Effect devices usually require 3 wires, but some of the pictures on the net, seemed to indicate the T005 had only 2 wires.

Strangely, while Googling Terra Trip products, I came across a T007, which is a natty little device, that interfaces between the gearbox & speedo cable itself.  It is apparently made for Japanese cars, which would make for a very easy conversion. Unscrew speedo cable, insert T007, screw speedo cable into the rear end of the sensor.  Have you come across this device before ?

 

Cheers Banjo 

 

Edited April 26, 2018 by Banjo

[altezzaclub]

We drilled a hole in the backing plate at the top. I can't remember what the bolt arrangement is, but I'll take a look & photo it tomorrow.

[Banjo]

Thank you LittleRedSpirit & Altezzaclub, for your advice on this one. Like you said, it wasn't so hard after all.

The reluctor type sensors used to sense the heads of the bolts holding the disc onto the hub, produce a sort of sinewave output, where the frequency is proportional to the speed or rotation of the wheel. To get a good output from these sensors, requires a fairly small gap between sensor & bolt head in the order of 2-4 mm.  The output, (amplitude of the waveform), also drops off at low frequencies.  As I only want this sensor for detecting fairly low frequencies, that represent road speeds of 0 - 10klm/hr, I decided in the end to use a Hall Effect device. These are powered, & require a 3 wire connection, but their output amplitude is unaffected by frequency completely.    ie:  The output amplitude is maximum, whether the speed is 1 Hz or 10 kHz. The one I used was an OH090U, which looks like a small transistor.

I made up a sensor, very similar in construction to the Terra Trip unit, using a bit off 10mm dia. threaded tube, I had lying around, from an old desk lamp, or the like. 

I then drilled a 10  mm hole through the backing plate & strut flange to mount the sensor.

Simply then a matter of mounting the sensor & positioning it with the nuts, so that the gap between bolt head & sensor is adequate.  Here is the sensor mounted.

This is what it looks like from the rear. Just like a bought one !

To get the gap right, requires the hub & disc being removed & refitted a couple of times, until you get it right.  I was able to look inside, down the gap between rear of the disc & the backing plate, with a small torch from the end where the caliper is normally fitted.

A Hall Effect sensor can be configured to sense a ferrous protrusion, like the bolt heads, but it requires a small magnet fitted at the rear of the sensor, which has its field concentrated when the bolt head is close on the front side of the sensor.

I didn't want to go down that path, so simply fitted a small rare earth magnet to one of the disc to hub bolts, as seen in the following pics.

There was no need to attach a magnet to each of the four bolt heads, as in my application, to start the thermo-fan once the car slows right down, is very non critical, & the Deluxe Frequency Switch can switch right down to 1 Hz.

The rare earth magnet I used was 20mm lg x 4mm dia. I covered it with some adhesive heatshrink, & trimmed it off flush at both ends.  I then drill a 5mm hole in the centre of the bolt.  

I was a bit lazy, as I hadn't figured how hardened these bolts are in this application.  I wore out 2-3 drills, & gave up in the end when the hole was about 14mm deep.  I then filled the hole in the bolt up with good old Araldite & slid the magnet in.  That is why it is sitting 5-6 mm proud of the head of the bolt.

The great thing about using a Hall Effect sensor & strong magnet is that the gap between magnet "south pole" & Hall Effect sensor is not critical at all.  The Hall Effect sensor switches when the magnet gets to within 13mm from the sensor, & doesn't switch off until the magnet is 20mm away from the sensor. (built-in hysteresis)

All that was left to do was test it with a 12Vdc power supply & an L.E.D.

Worked perfectly ! 

For reliability, I used some Teflon coated 3 wire & shield cable I had floating around, & strapped it to the strut & up through the inner guard, through a rubber grommet. Do this with the wheel full hanging, so the cable is not compromised, as it will be moving up & down with the suspension.

Well, that's it.  Couple of hours work, & a good result.  PCB for the Silicon Chip Deluxe Frequency Switch should arrive on Monday, & then I can see if starting the thermo-fan, in stop start traffic, rather than waiting until the 95 deg C thermo-switch closes, will get rid of some of those wild swings in coolant temperature.

Cheers Banjo 

 

 

 

Edited April 29, 2018 by Banjo

[Banjo]

Earlier in this thread, I suggested improving/lowering the coolant temperature differential between the front & the rear of the head, by taking hot water from the back of the head, & feeding it back to the underside of the thermostat, in the thermostat housing. It worked perfectly !

I did this on my 4K-U, in the car, but was hesitant to remove the plate on the rear of the head,  in case one of the bolts was frozen, & snapped.  To "prove the effect", I simply removed the heater hose, from the spout on the rear of the head.

 

What I really needed, was a dual outlet, on the rear of the head, one for the heater inlet, & the other for the return to the front of the engine.

I've got a "distributorless" 5K, that will be going in the KE30 soon, for some road testing, so thought, now is the time to fabricate a dual coolant outlet on the back of the head, before the engine gets levered into the KE30.

This is how it turned out.

 

Just a simple Tee tap plumbing fitting , from Bunnings, silver soldered, to the rear head access plate.

Thought I'd just post a couple of pics, in case someone else, wants to do the same, or something similar.  A really worthwhile simple mod, that provides great results, & may even save you a blown piston, or broken rings on no: 4 cylinder.  

Cheers Banjo

 

Edited December 14, 2018 by Banjo

[altezzaclub]

hmm.. the T-piece looks a bit lightweight for the engine moving around the place under acceleration.  What we need is a stock heater takeoff pipe on the back there that leads to a 2-way valve.  When the heater is off the water goes to the water pump, and turning the heater on diverts it through the car.