Cooling Issues, Frustrating

[KENut]

Yes does sound very similar (sorry for thread jack).

Will try to remember to let you know how mine goes but might not be fixed (read: new engine) for a month or two.

 

I'd def be leaning towards water pump. The previous engine in mine with cracked head didn't really get hot, that is until it ate most of the radiator water. Even then it didn't get hot like this 'new' engine. Although this one has a broken head bolt at the front, and oil leaks from HG here. I used the same waterpump on both engines, and it looks relately new on the outside, but was run with water for probably 6 months. So I think waterpump, as has been said theres not much else.

[Evan G]

i have also got this issue,

 

- highway doing 100 - 120kph

- a/c OFF

 

and the temp needle sits a good 3/4, water in the over flow doesnt get sucked in when cold?

 

if i had the a/c on i reckon it would of boiled

 

game plan

- electric temp gauge

- install new thermostat

- water pump

- radiator?

 

i hope its a dodgy temp gauge

[kangaroosa]

i have also got this issue,

 

- highway doing 100 - 120kph

- a/c OFF

 

and the temp needle sits a good 3/4, water in the over flow doesnt get sucked in when cold?

 

if i had the a/c on i reckon it would of boiled

 

game plan

- electric temp gauge

- install new thermostat

- water pump

- radiator?

 

i hope its a dodgy temp gauge

 

If it doesnt cook at idle, but it does it at speed.....Then the radiator isnt getting good air flow and isnt cooling efficiently when its got load on it.

Some tubes in the radiator could be blocked which provides enough cooling at idle with the fan, but when the engine is under load the cooling system is sub par.

 

The Water Pump may need looking at aswell.

 

Get a digital thermometer with a probe. Shove it in the top fins of the rad and then the bottom. If there is no noticeable temp difference then the rad isnt doing its job.

Stick the probe in the radiator water and see what temp its really at. I had a speco gauge tell me my car was on 97deg, whereas the digital probe and a mercury cooking thermomter both read ~86deg.

 

Don't believe whatever the Std gauge reads.

I had this exact issue with the rotary a few weeks back.

Edited December 23, 2009 by kangaroosa

[drc_ke20]

i would check the impellers on the water pump,i reckon its worn out and not enough water flow when at (engine)high speed.

[corollaart]

Also check your radiator hoses are not soft ,they can close up at constant reving .

 

Which it would be on the highway .

[BReNt]

just turn the heater on while you're driving that'll fix it haha

[Bamboo]

A trick an old mechanic taught me. Get the engine to operating temp. Get 4 (or however may cyls you have) room temp screw drivers. Whip out the plugs. (on K motors leave the tubes in). Put them in the holes for one minute max. whip out the drivers and look for condensation. if you see it, head is leaking. Also gives the advantage of finding out where it's leaking. If you leave them in too long the water will evaporate.

 

For a radiator check, use your hands. If the engine is hot and it has obvious cold spots, rad is blocked.

 

good luck

[Bamboo]

Almost forgot. This won't fix your cooling prob but a fav of mine. USE RED TOYOTA COOLANT! same price as the aftermarket shit but the quality is awesome. Out in the bush where the Toyota rules this is ALL they use. There is a reason!

[crispyke35]

i have also got this issue,

 

- highway doing 100 - 120kph

- a/c OFF

 

and the temp needle sits a good 3/4, water in the over flow doesnt get sucked in when cold?

 

if i had the a/c on i reckon it would of boiled

 

game plan

- electric temp gauge

- install new thermostat

- water pump

- radiator?

 

i hope its a dodgy temp gauge

 

 

Well after all the troubles i had i replaced the radiator with a brand new one and it fixed the problem immediately.

 

Your car seems to be doing exactly the same as mine so i would recommend and new radiator. I also stuck in a new rad cap (stop it boiling over as quick and going into overflow), and a i put in a new thermostat.

 

Also when i pulled the old rooted one out i noticed it had only been put in 2005 so goes to show how quickly they can erode away. (click on my thread to see how stuffed)

 

cheers, Jacob

[Evan G]

i just do the best thing for my 4k and my wallet and insanity.

 

i put a digital temp gauge

 

went for a small drive, sat on 76 degrees and 79 with the a/c on

 

76 degrees and the toyota gauge was showing half way?????

 

ill monitor the progress and let you guys know how it all goes

 

BEST $49.99 SPENT!

[KENut]

Will try to remember to let you know how mine goes but might not be fixed (read: new engine) for a month or two.

 

Ok, so I have rebuilt and installed my new engine, its pretty much run in now too.

Still gets hot on 30 + days, although the temp only increases from the 1st line (normally sits here) to halfway. Gets hot when sitting at over 3750 rpm.

Having the heater tap open helps, didn't replace water pump or anything cooling related (has new thermostat though).

Coolant doesn't get blown out the radiator cap like it used to, so thats a plus haha.

So new rad cap may help, and pump. Seems to me like an inherent issue with K engines, I don't really like how the coolant is supposed to flow between head and block, the headgasket doesnt allow for efficient flow (just my opinion).

[KENut]

Well after all the troubles i had i replaced the radiator with a brand new one and it fixed the problem immediately.

 

Ah, just read this..

Mine has a reconditioned radiator, ie full clean, and end tanks rebrazed early 2009. Didnt fix mine...

[Bamboo]

Another thought.

 

Sometimes headgaskets only blow one way from piston to cooling system. seems fine but compression can build up in the cooling system and make excess pressure.

 

other alternative is an extremely f@$ked rad cap. highly unlikely but possible

[Evan G]

i wouldnt trust ANY toyota temp gauges! mine shows 3/4 hot and temp gauge shows 80 degrees (normal temp)?

[KENut]

Another thought.

 

Sometimes headgaskets only blow one way from piston to cooling system. seems fine but compression can build up in the cooling system and make excess pressure.

 

other alternative is an extremely f@$ked rad cap. highly unlikely but possible

 

True, this was part of the problem I had before. I really should replace the radiator cap, it can leak a little.

 

Evan, my temp guage is consistent, even though it doesnt give an accurate temp indication. So I'll leave it for now at least.