The General Cooling Issue Thread

[Twinky]

I thought I might start a thread to gather everyones issues and answers here so that information does not get fragmented.

What I would like to happen is that anyone who gets a problem with their cooling system post it up here and hopefully it can get resolved.

As a bonus various problems and solutions could be found by members easily.

[Twinky]

I will start off.

 

Model: KE55

Engine: 5k-c

Standard cooling system from KE55-4k-c

Modification: Thermo valve removed

Heater core disconnected at pump outlets (short length of hose with bolt blocking outlet/inlet)

 

Symptom: After about 15 mins of driving the coolant starts to fill up the overflow bottle.

Coolant temps don't go past half way on the in-car meter.

 

About 2 months ago when I fitted the 5k everything seemed fine, had the odd leak from pipes that were not tightened enough but all was fixed.

I haven't had any issues untill recently when I pulled up at home after driving from work I could hear a bit of hissing and saw a bit of coolant splatter

around the engine bay and saw that the overflow bottle was filling up. There was no other coolant leaking except for the overflow bottle. I could almost hear

like a constant weak gurgling noise coming from the radiator. Basically the top portion of the radiator empties untill the top hose empties and then it stops filling the overflow bottle. You can then open the cap whilst the engine is hot and no coolant escapes.

 

Possible issues:

Could the radiator be blocked?

Water pump nackered?

When the 5k was installed along with a 5 speed it changed the motor angle by a couple of degrees, could that cause an issue?

What should the height difference be between the top hose outlet of the radiator and the water pump inlet be?

Should I re-connect the heater core to change the highest point in the cooling system?

 

Pics up later when I get home.

 

Any help would be great.

 

Cheers

[philbey]

First of all, why do you consider this a cooling issue? Are you continuously topping up water? Do you have a return valve cap on your radiator. If you're not actually overheating, then what's the issue?

 

Also, put a thermostat in the car, it's not a modification, it's an 8 dollar replacement part that is necessary for proper operation of the engine.

 

When the first water comes out the overflow, how hot is it? Because if it's only warm to medium, then my money is on head gasket.

 

I had the same issue with my 3K, after running for a few minutes, but not long enough to get up to operating temperature, it was pushing warm water out the overflow. It's basically combustion pressure escaping and pressurising the water jacket.

[silverra23]

My observations on all old Toyotas continues to be that they are mostly 30 or 40 years old and the radiators are blocked full of rust and what ever other sediment is created from corrosion, due to not being properly maintained.

 

If you have not reconditioned the radiator (usually costs less that $200), replaced the thermostat and water pump and checked the condition of all your hoses, you will continue to have cooling issues.

 

People fark around trying to hose out their radiators to get the blockages out, but nothing beats the caustic baths that radiator shops soak a radiator in overnight to get the sh*t out.

[Twinky]

I call it a cooling issue because it is related to the cooling system.

I think the money is on Philbey with this one. Saying that becasue the overflow isn't boiling hot and the temp guage shows normal.

I call it a mod (no thermo)as it is in a non standard config, not that it has any benifits.

I have actually already ordered one from sprints too. Was on the list of things to do that I didn't really bother with as it wasn't giving me any problems by not having it.

 

 

With the head gasket could it be that the head was not tightened enough?

When I tighten up the head I usually go for inbetween the max and min specs for torque settings. Should I take it to max if that is the problem?

Anyhows I'll take the head off tonight and see if the head gasket has blown out. Iv'e added a head gasket to the order list for sprints.

 

Some great info guys. Glad I started this topic as I hadn't ever thought about the head gasket causing the problem.

 

On a related matter, the head gasket does not come with all the holes that are open on the block. Should I drill out the missing holes in the head gasket?

 

Cheers!

Edited February 9, 2011 by Twinky

[altezzaclub]

Theory is that they want more water flow at the back of the motor so they don't use the holes nearer the front. If you drill them out you might get lots of flow around the front and not enough at the back.

 

The blue streak started getting hot on a long hot trip inland NSW one time, and when I had the motor stripped some time afterwards I was amazed at the amount of rust blocking up the block. Seeing I never sent the block away as I was leaving the pistons in I cleaned it all out with wire/screwdrivers. I ran it with a stocking over the top rad hose for a few weeks after assembly, and its been fine ever since.

 

http://www.rollaclub.com/board/topic/42407-the-girls-ke70/page__p__445727__fromsearch__1#entry445727

 

Twinky, I go back over the head after a week, loosening off the bolts 1/4 to 1/2 a turn and doing them up to max torque. You loosen them first to get a good smooth turn started as they have a lot of static friction after sitting there. Naturally, when the head is off I clean the boltholes out and make sure the bolts screw all the way in easily. Shit builds up at the end of the block thread and stops it turning down the last bit after you have skimmed the head thinner. Any oil/water in there will hydraulic lock the bolt and give the wrong torque.

[ke70dave]

Shit builds up at the end of the block thread and stops it turning down the last bit after you have skimmed the head thinner. Any oil/water in there will hydraulic lock the bolt and give the wrong torque.

 

this is very important i think, especailly oil in the threads, if you have the block in the car it can be difficult to get the crap out, in the past i have used a rag on the end of a screwdriver to attempt to soak up any oil/water. or an old vacuum cleaner (we have one that is able to suck up fluid with out exploding, some industrial thing, works awesome)

 

if you have the block out of the car its a bit easier, turn it upside down on the engine stand and get excited with a can of WD40, then just let it dry with it still upside down.

 

in terms of cooling systems, especailly on the old 4k, there isnt much too it.

 

radiator: so long as fluid can go through it, and its not full of crap. it will work find under most conditions. the radiator in my car looks fairly beaten up (fins bent etc) but the inside is pretty clean, works great.

 

water pump: so long as its not leaking and the impella hasnt been eroded away, it wont give any troubles.

 

thermostat: very crucial component in the system, no idea why idiots throw them out to try and fix an "overheating" issue. buy a new one (like 10bucks) if there is any indication it maybe faulty, test it before you put it in of course. a good gasket on the housing and thats all there is too it.

 

then just make sure all your pipes are in order, good pipe clamps everywhere, and thats pretty much it.

 

things like headgasket dramas crap building up inside the block, really arent cooling system problems. more engine problems, but on the other hand everything is part of the same system (the engine) so everything must be considered at the same time if there is a problem with 1 component.

 

re: headgasket. compression test, leak down test. even the test that checks for combustion gases in coolant. and if you find a problem with any of them, then you can't really further diagnose any engine problems (cooling or other) untill this is rectified. the headgasket seals everything together. and if its not doing its job, any number of symptoms can occur.

 

twinky: have you considered your radiator cap is stuffed? if its not able to hold pressure then the coolant will just leak out when it heats up? are your coolant lines pressurised when the water is leaking out? most caps are around 0.9bar i think, fair amount of pressure.

 

try another cap before you go ripping apart the block with the mad scientist and replace the piston rings you fried (fast and the furious quote anyone?)

[philbey]

Yeh I would hold off ripping off the head like dave said. When mine failed I did not get cappucino foam on the coolant, nor did I get water in the oil, but once the cap was off, there were significant bubbles indicating compression leakage.

 

Get a comp tester or leakdown tester, that will pick up a leak.

[Andy43]

Most important, leave the bypass hose between the water pump and the thermostat housing in.

This gets the coolant flowing around the block while the thermostat is closed.

If you block the bypass house the thermostat doesn't heat up and hence fails to open.

 

Also leave the thermostat in, this controls the water flow and by giving the water pump something to push against stops hot stops in head and block by compressing any air that may remain in system.

lt also slows water flow down through radiator.

 

Cheers

Andy

[Twinky]

Ok new radiator cap has been placed, thermostat will go in today along with a new head gasket. I need to take off the manifolds today anyway

for two different jobs so I might as well take the head off while I'm at it. When I took off the old cap the spring compression seemed to be the same as the new unit

so I don't think that was the issue, all seems to be pointing to the HG at the moment.

[philbey]

Is it a recovery typr of radiator cap? Because if you went to the shop and asked for a KE20 type cap, they may have given you a Non-Recovery cap.

 

With a Non Recovery cap, every time your engine gets up to temperature, you push water to the overflow tank, but as it cools, it doesn't get drawn back into the system.

 

Tridon Recovery style PN: CA0750

Tridon Non-Recovery style PN: CN0750

[Twinky]

I'll have to look at the part number when I get home.

Had a different part number for sure, ended with something like 3009 or along the lines of that.

It was a multi car fitting cap.

 

How would you visually tell the difference between the two?

My original cap looks almost identical to the original.

 

Also the original cap did not let the coolant back into the engine (could be caused by the pressurisation problem). Even after the engine cooled there was pressure in the radiator.

Which leads me to beleive it is the HG causing the problem.

Edited February 11, 2011 by Twinky

[ke70dave]

i assume you have checked for bubbles in the radiator? ie leave cap off from cold, and let the engine warm up with the cap off, and wait for the bubbles?

 

if its as bad as it sounds, you should have some epic bubbles going on.

 

alternatively......did you bleed it properly? well on a k motor not much you can do other than park it on a hill, make sure the heater is on, and leave the cap off for a while, giving the radiator pipes a few squeezes to try and get the air out.

[Twinky]

Yeah I pump the hoses whenever i bleed it out, as well as filling up.

I'll try running the car without the cap when I get home tonight.

The first time I did see bubbles when I took the cap of whilst still hot.

 

Will find out tonight hopefully.

[altezzaclub]

Bubble test works best with a thermostat in and cold from overnight. Start it in the morning with the rad cap off and the throat filled to overflowing, and just let it idle while you watch.

 

If its bad, bubbles push the water over the rad throat then suddenly go 'bloop' and air comes out.

 

If it not so bad a stream of tiny bubbles comes out all the time after a few minutes.

 

Once warm water comes through the test has ended.