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Oil pump failure


Lukaswg

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Yah my VDO temp gauge is stuck right next to the thermostat, When i turn off the engine for 5-10mins and come back the VDO gauge is often near 100degC, then you start the engine and it immediately falls down to its running temp of 82deg, which as mentioned is right on the temperature of the thermostat:)

 

Edited by ke70dave
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but ur thetmostat mustve opened, it appears to be regulated at about 70 degrees for about half an hour. half an hour shoukd be enough to get to operating temp surely? if it didnt open at all, it wouldve just continued to rise, as theres nothing except the radiator to cool the coolant. the bypass hose bypasses the radiator so has no substantial cooling effect at all, short of its rubber getting a bit of a breeze from the fan.

I just don't follow it, so maybe i am missing something or missinterpretting ur description of ur findings.

i recon ur thermostats opening early. the springs probably worn out. or perhaps, ur measuring system is just that much more accuratr than any wax pellet and thats how they all are. 

i just wouldve thought it should get up to operating temp (tstat equilibrium) faster than that

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2 hours ago, Banjo said:

You walk through a shopping centre car park, on a hot day, and you can tell the cars that have recently been vacated; all sitting there, with electric fans purring away.

hah my mums car, whenever she would get home, turn off her car, i always wondered what the ticking noise was that came from the engine bay. both her cars did it. is it oil dripping onto the metal slosh plate in the sump, or metal creaking from heat soak. 

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Hi Jeremy,

                   I can assure you the probes were calibrated at 100 deg C, and are accurate. I can assure you the thermostat is within spec. & opens between 80-85 deg C.

The "wiggly" temp line around 70 deg C, for 30 minutes, is not the thermostat opening & closing.   This sort of test, is best done on a long hard run, in the country.  This particular 1 hour trip was in the city & suburbs.  That means, you are constantly stopping & starting at traffic lights.

Every time you stop, the ram effect of air through the radiator stops, & you are left with the air drawn through by the fan only. The temperature always rises, then drops again, after you get moving again.  That's what is causing the wiggly line.  I've previously used an external O/S sensor in front of the grill, to clearly show, when the car has stopped, & it always aligns, as I describe.

The problem with fixed fans like our Rollas, is that the fan is going all the time the engine is running, whether it is needed or not.  A thermofan, only switches on, when needed, & would result in the temperature getting to optimum operating temperature more quickly, & stop sapping of power unnecessarily from the engine.  That's the way I'm going ! 

Cheers Banjo

Edited by Banjo
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i guess that one u zoomed in on,  at 16 january, is the only one of the lot that looks cold actually, and that probably would be because ur driving is very gentle in the city i guess?? 

ur cooling system is therefor probably approximately, twice as efficient as mine, as i constantly see the top hose and thermostat housing at about 75-80 degrees after only about 10 minutes of IDLING haha. thats just measured with a basic lazer thermometer, but id suspect its pretty close. perhaps its just the humidity and equator as u mentioned.

oh and as u know, i have no thermostat.

Edited by rebuilder86
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Nice work Banjo.  I'm sure the radiator cools quite well without a fan running, the hot metal will still radiate and conduct heat into the air.

Obviously better with a fan pulling fresh cool air through.

I have a 90deg thermoswitch on the fan and I think its only ever come on once. If your cooling system can handle the little heat from an idling engine then the fan isn't needed as the ram effect moves more air through than the fan from about 25kph up.

its always roadworks in the middle of a 100kph drive that heats a motor up.  I've been thinking of a turbo timer to run the fan for the few minutes after I turn the motor off, I've seen the heat sink effect raise the temp in the garage at home.

 

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Hi Keith,

               So not wanting to "reinvent the wheel", what aftermarket, or other vehicle's thermofans, are suitable for bolting onto the back of a standard KE3X - KE5X radiator, with a stroud ?

I don't really mind whether it is one big one, or two smaller ones side by side.  Had a quick look on here, & generally Googling the net, but couldn't find any images of a conversion on a Rolla.  Once you take the plastic fan blades off the water pump pulley, there is a heap of room, between the back of the radiator core & the front of the engine.

Alternatively, it will be off to the wreckers, with a tape measure, to see what fits the best.

Any suggestions, greatly appreciated.

Cheers Banjo

P.S.  Just after posting this, I came across your thread, using a Mazda 121 thermofan.

https://www.rollaclub.com/board/topic/68673-how-to-fit-an-electric-fan/

Would you still recommend that one ?  As I've already got a solid metal stroud that bolts onto the radiator frame, I was thinking of just getting an electric fan with same diameter as the stroud opening round hole, & adapt the mountings to the metal stroud, which should be strong enough. What do you think ?

 

 

Edited by Banjo
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I would look at any fwd car at tge wreckers and just see what fits. I would ve trying to get one that is as low profile as possible. The 80s fwd fans were all huge!

The other thung to consider is i would get the biggest single fan that fits. Mainly cause the smaller the fan the noisier it will be....

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Just a couple things I can add to.  My understanding about the little hole in the thermostat ring (usually with the little metal tang loosely fitting in it, is to allow air to pass beyond the thermostat in the line before the thermostat opens.  It speeds up bleeding, and is the reason why if you very slowly fill a cooling system without starting the car, the coolant will still ever so slowly find its way past the thermostat and bubble thought at irregular occasional intervals.  Since its really there for bubbles, then it should be rotated to the top of the housing, so the bubbles that fill the upper part of the line can pass and not be trapped 100 percent until the thermostat opens.

Secondly, a very experienced mechanic stressed to me once that its important not to rev a car (or drive it) without the cooling system bled fully, I think his concern was adding extra heat at specific locations around the cylinder head that can destroy the head gasket seal without even cooling in that area.  So rebuilder I disagree with your premature revving of the motor to speed up the thermostat opening on the bleed, that's just impatient I think.  A funnel that screws to the radiator cap and seals would be a great idea, not one thats dangling a metre above that doesn't seal on the rad inlet, that would effectively enlist gravity to push the coolant in and the air out, in fact I've seen a lot of people that use this over the years.

On my engine, I prefer the thermostat to stay open once warmed up so I'm not pumping coolant in a small bypass and its not an inhibition of the motors output, so I run my fan at higher temps than some, but this was really based off of reading Toyota data for the 2azfe fan controller that said that the fan turns on at a temp above 90 degrees, so I stopped being a worry wart and made it so the fan turns on at 94 centigrade and off at 87.  I never want the thermostat to close once open.  Motor seems to appreciate it.  This is in stark contrast to the cooling system I ran on the 20v engines with the thermostat in the wrong spot and the lack of an external by pass that meant the thrmostat opened and closed all the time and that you could see temps from 70 to 90 degrees at any given moment.  It worked but its probably not ideal.

Thirdly I always test a thermostat in the pot as described, but dont just see how it opens, tip small amounts of cool water in and see how it closes as well after it pops full open and this will give you a good indication and understanding of the real merit of the constantly variable thermostat system.  I noticed that usually they open a degree or two above the rated temp, but they begin to close a degree or two below the rated temp, so you see it takes a second or two for the thermostat to absorb the heat of the currently available coolant and react.  As such you dont really want a massively over rated radiator, that's a narrow minded fix, you really want everything working as it should be.  The thermostat to not have to work all the time, the radiator to dump the right amount of heat dependent on the work its doing and for this to vary on the same plane as the extra heat made to overcome the drag of the vehicle and the ambient conditions, tempered against the extra airflow at a given speed.  Think about all the work the oems do to provide the right amount of cooling for different situations, right down to the fans working independently and coming on at different temps or if more drag is applied to the motor ie when the ac and accessories come on.  If they care about clutching on and off with the alternators these days to preserve economy and performance, then there must be something to it.  For example you dont want your fans blasting at idle when the car is making minimal heat.  They should just come on occasionally and stay off for longer intervals being temp controlled.  SO with this in mind...

SO that brings me to the fans, yes mechanical clutch fans and worse still ficed blade non clutch fans are awful for performance.  Have a watch of the engine masters series where they test all the fans, its a real shock to be honest.  Electric fans are the way to go, there is no way around it.  I have sworn to bin every clutch fan my hands meet from this day forth having watched that.

Banjo your data is incredible.  Well done.

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Quote

My understanding about the little hole in the thermostat ring (usually with the little metal tang loosely fitting in it, is to allow air to pass beyond the thermostat in the line before the thermostat opens.  It speeds up bleeding, and is the reason why if you very slowly fill a cooling system without starting the car, the coolant will still ever so slowly find its way past the thermostat and bubble thought at irregular occasional intervals.  Since its really there for bubbles, then it should be rotated to the top of the housing, so the bubbles that fill the upper part of the line can pass and not be trapped 100 percent until the thermostat opens.

That's exactly what I've always believed the little tear drop valve in the thermostat plate was designed to perform.  Very well described, & a thoughtful explanation !

I pulled out a couple of old thermostats in a box on my shelf, from engines I have scavenged on.

Here is an old brass one, where you can see the rivet shaped tag hanging through a hole in the valve plate.

DSC00396.thumb.JPG.542f68fd925156103b1e180f0ebd5d2a.JPG

DSC00398.thumb.JPG.aa6527167ee9f8ae638aadf1e94bb13b.JPG

I don't really understand what the tag thing hanging there does, other than to wiggle around & keep the hole free of debri & build up.

It can only function, or do anything, when the coolant is below operating temperature, as normally the valve would be opened either partially or fully.

I have always assumed it was to bleed away air bubbles at the top of the head during filling, or allow the water coolant pressures either side of the thermostat to equalise, whist the thermostat is closed. 

There was another old thermostat in my box, that didn't have the tear drop thing in the hole in the valve plate, at all.  As you can see, some enterprising person, has created there own bypass holes around the edge.

DSC00394.thumb.JPG.467026b9dd73d6262368a976211858e4.JPG

If I have completely drained my cooling system, & refilled, I always let the car idle for 20 minutes with the radiator cap off, until any air is out of the system, then put the cap on, as the coolant starts to flow over the top of the cap neck.  If you want to be really pandantic, you can run the front wheels up on some ramps, to ensure the radiator cap & front of the engine are at their highest. 

The biggest problem I have seen on Rollas, is leaks or cracks in the rubber or plastic pipe, between the top of the radiator, & the coolant over flow bottle.

What happens then, is that the excess expanded coolant is forced into the overflow bottle OK, but when the engine cools overnight, the coolant in the overflow bottle does not all get sucked back into the radiator, as there are air leaks in the hose or connections between radiator & overflow bottle.  If you look in your overflow bottle when the engine is cold, & find the coolant level higher than normal, then that is probably the cause.

Thanks for the suggestions regarding suitable thermofans.

I agree that the ideal situation, is to use the thermostat, to do it's job, of getting the engine temperature up to design levels, as quickly as possible, & set the thermofan switch a bit higher than the thermostat point, below which it starts to close.  eg:  If thermostat starting opening & closing temps are 80 & 90 deg C, then the thermofan switch should be set 5-8 deg C higher, at something like 95 deg C.

Once I get it set up, a couple of weeks with the multi-channel temperature data logger probes at various points, should allow me to fine tune it perfectly.

I'll put the results up here, for anyone who has an interest in this subject.

Cheers Banjo

 

 

 

Edited by Banjo
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fans...  I just hit the wreckers..  Square blades are more efficient but noisier, curved blades quieter but don't move  as much air. I cover about half the rad, as the fan itself gets in the way of airflow when driving, and I spend more time driving that sitting with the fan on. You don't need much cooling at idle on a hot day.

We've only seen one problem, the fan we fitted to Mao just didn't move enough air. We changed it and the next one was much much better.

That data from the logger should be interesting. Can we get a probe into the back of the head via a heater pipe?

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Wow I need to remember to check this more, flushed the rad again the noise has changed, is less prominent.. leading me to believe there is probably some air still in there but as long as my motor isn't running dry like i thought I'm happy  !  I was worried that it also looked a little dry under the oil cap but maybe i'm being over protective and that's probably a good thing.

 

 

Thanks all

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On 21/01/2018 at 6:47 AM, LittleRedSpirit said:

So rebuilder I disagree with your premature revving of the motor to speed up the thermostat opening on the bleed, that's just impatient I think.

haha when did i say that?

I said I rev the engine to 1200rpm while trying to get air gaps out, in a car without a thermostat. and that takes all of 10 seconds with those revs, as opposed to "never" at idle. 10 seconds isnt even enough for heat to become an issue. at idle there is not enough flow to push the air from the back of the cooling chambers to the front, it will stay there FOREVER.

no funnel, no gravity is going to push it out, it must be pushed out by flow.

u saw my video, with the horrible sound right?

the problem is, my tactic wont work with a thermostat in place, as the thermostat just restricts the flow and the revving wont do anything. so ud have to remove the T-stat, temporarily reinstall the housing, do the air push out at ~1200rpm, then reinstall thermostat and fill up the top hose very slowly. being carefull not to fill it so fast u push air back down i to the head. (the thermostats presence should avoid this)

Edited by rebuilder86
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