What Coolant

[Lukaswg]

So long of the short, what coolant for 78 KE30?

New to this, but want to try to get it right.

 

Any help much appreciated !

[Clapped out]

Anything green, don't go for the red stuff as it eats out copper, brass and solder in older cars cooling systems,

 

cheers!

Edited August 21, 2017 by Clapped out

[Banjo]

Hi Luke,

             Welcome aboard !  Good question.  Really depends on the state of the inside of the engine.  When these engines get old, they can have a lot of buildup in the water jackets. which really needs to be removed, for best thermal efficiency in removing heat.  However, because the K series engines have a cast iron block & an aluminium head, they can suffer from electrolysis between dissimilar metals, so coolant leaks are not uncommon, to both the inside & outside of the engine.  As well as that, as the aluminium gets old, it changes its composition, & breaks down, & corrodes more easily.

A good automotive coolant, will help prevent this, but is not much good on an engine that already has got lots of crud & corrosion inside the water jackets.

You could put a good cooling system flushing additive to the water, run it as per the instructions, then remove top & bottom hoses & thermostat, and wash all the loosened crud out of the engine.  However, I've seen the results of this previously, with Welsh plugs all of a sudden becoming very thin & leaking, as all the crud on the back of them is really sealing as well.

I recently stripped a 5K engine, I acquired, and in the strip down process removed all the Welsh plugs. On two of them, a light tap on the centre with a screwdriver, resulted in the screwdriver going right through.  That's how thin they were.

When old engines are reconditioned professionally, they usually have all Welsh plugs removed, & the whole block acid washed, then new "brass" Welsh plugs fitted, instead of the original pressed steel ones. 

The K series engines also have poor coolant circulation, at the rear of engine around no: 4 cylinder.  This is primarily about the design of the engine, as coolant enters & leaves from the front of the engine.  With less flow at the rear, crud builds up, and the results are not good in the long run. 

If a piston or rings are going to give you issues, it will quite often be number 4 cylinder.  I've had a 3K & a 5K over the years, both have issues with no: 4 piston & rings.

So it's up to you, & sometimes it is better to "let sleeping dogs lie", unless you want to take the risk of having to take the engine out and change welsh plugs, or maybe a head gasket.

Others on here may have other suggestions, but mine would be to . . . .

Remove top & bottom radiator hoses & flush the engine out with a hose, without adding a flushing agent before hand.

Replace the thermostat & radiator cap.

Refit hoses, if they are in good condition.

Add a good automotive coolant.

These actions will probably help, but are unlikely to result in any unwanted immediate leaks !

Cheers Banjo

 

 

 

 

Edited August 21, 2017 by Banjo

[Lukaswg]

Thanks guys, I was using green coolant, was just concerned when i read up on green coolant diminishing ally heads + Toyota using red etc etc

In terms of build up there is build up in the radiator ( as seen in photo) i flushed the system twice yet it keeps presenting itself, not as bad so I'm thinking maybe just as said above adding a flush additive might clean the last of it out. On that the car also doesn't tend to heat up stays quite cold.. yet that could just be the Melbourne weather.

 

Thanks again!

Edited August 21, 2017 by Lukaswg

[Banjo]

New thermostat possibly required.

Could be jammed open.

Cheers Banjo

Edited August 22, 2017 by Banjo

[LittleRedSpirit]

There are two colours of Toyota Coolant, the red long life lasts up to 40000ks and is fine on older stuff, the pink super long life is for the newer stuff and in that application it lasts double the red mileage.  You can also use the red on the newer motors as long as you change it twice as often.

I have heaps of the red if you want some cheap and you are around Brisbane.

[peterd]

My brother in law has worked for a radiator company for 20 years. His advice for coolant was don't use cheap stuff and never mix different ones, even within the same brand. 

 

[Lukaswg]

I already changed it banjo, it hasn't made much of a different to be honest.

Thanks mate but i live in Melbourne haha.

Could it be just the cold weather/because the fan runs all the time rather than heat cycles ?

it does warm up a tad when driving up a hill as well because it's working abit harder.

I really have nothing to compare it to as my daily is a 94 and my folks cars are newer again.

 

[LittleRedSpirit]

You need to remove the thermostat and test its opening temperature in a saucepan as it heats up.  It may open early, late or not at all, or stay open if faulty.  Judging by the fact the car doesnt show super hot on the temp gauge, or seemingly up to temp, theres a few things that can xause this. 

Make sure you have accurate temp readings, so try and install a new temp sender for the dash gauge, or still better, install an aftermarket electronic gauge like a speco so you can talk in real numbers and not in hot cold or the red bit terms.  If you think its working ok, maybe just remove and descale the probe on the gauge and make sure its clean enough to absorb heat from the water directly.

Now that you know your temperatures for certain, i would remove and test the thermostat as described above, usually if a car fails to get fully warm its because the thermostat inst correctly regulating the flow of 82 degree water.  Basically, the thermostat has a wax substance inside it that expands when hot to force the thermostat open, they are designed to open at a certain temp, and close below that.  Basically your thermostat is probably staying open, so Id suggest a simple replacement of that, and any physical removal you can do of crud will help the cooling efficiency.  Most Toyota motors have a block drain where you remove one bolt and all the coolant runs out the bottom of the water jacket.  If you remove this bolt on a full cooling system and little to no water falls out, then its will be pretty heavily scaled up inside and it will benefit from being picked out with a tool so it drains again and even try running muckowt for a while.  Motors perform at less than their best when run too cool.

[LittleRedSpirit]

and if you replace the thermostat, test the new one before it goes in, they are often bad from new.

[Banjo]

The "block drain" LittleRedSpirit is referring to above, is a long hexagon tube type fitting, on K series motors, screwed directly into the block, just below the water pump, at the very front of the engine.  It has a bolt head at the end, which acts like a tap.  My experience is that on many K series engines, you undo the bolt head, and little or no  coolant comes out.  If that is the case, it is usually easier to unscrew the whole long tubular fitting out of the block.  This is almost the lowest point inside the block water jackets, so lots of scale & crud build up, down behind there. By unscrewing the whole assembly, you provide a bigger hole & opening, for the scale & rubbish to get flushed out.

Cheers Banjo

 

Edited August 23, 2017 by Banjo

[altezzaclub]

Fire it up with the radiator cap off and a 0-110deg thermometer in the rad.  Just let it idle for 15minutes, or slip a sheet of cardboard down in front of the radiator to speed up the warmup. It shouldn't heat up at all, then suddenly get warm all at once. That's when the t'stat opens.

If it is gradual all the way then the t'stat is stuck open.

Some radiator shops will clean the block out by removing the radiator hoses and sticking a giant water-blaster hose in. You can do the same by removing the water pump while you have the rad out for a flush sometime and sticking a hose down the side of the bores. As banjo said, the dirt and rust builds up at the back of the block around #4 cyl.

[Lukaswg]

Thanks for the advice all !

[LittleRedSpirit]

So called because

On 23/08/2017 at 5:01 PM, Banjo said:

The "block drain" LittleRedSpirit is referring to above, is a long hexagon tube type fitting, on K series motors, screwed directly into the block, just below the water pump, at the very front of the engine.  It has a bolt head at the end, which acts like a tap.  My experience is that on many K series engines, you undo the bolt head, and little or no  coolant comes out.  If that is the case, it is usually easier to unscrew the whole long tubular fitting out of the block.  This is almost the lowest point inside the block water jackets, so lots of scale & crud build up, down behind there. By unscrewing the whole assembly, you provide a bigger hole & opening, for the scale & rubbish to get flushed out.

Cheers Banjo

 

its always blocked.