Feeling the heat

[europa88]

Fitting an addtional air to oil cooler is a good idea if you are thinking of doing any towing. I understand that the kzn130 has a strange design by which the ATF 'oil in' on the rad impedes the flow of coolant! This can be shortened by a specialist but some people use a manual rad with an additional air to oil cooler!

This is probably fine in colder european climates but for hotter ambient temps
this is definetly not recommended! You need to retain the rads standard oil cooler as they are more eficient than oil to air types!

I have just fitted an additional oil cooler(oil to air) and have yet to tow in the heat!

If I encounter any problems, as i intend travelling across europe with 1500kg
caravan, I am going to go for a manual rad TOGETHER with an external water to oil cooler! These can be bought from Demon Tweeks although they are expensive!

[kitesurf_phil]

why not fit a bonnet vent

Cos it makes yer motor look like a Paj**o. ( Sorry - nothing could be that bad ).


The rear facing vent would also be less susceptable to ramming in the water while fording (fjording is much more difficult).

Have you noticed that the Aussie site is much more disciplined and they can have serious technical discussions, without idiots like me chipping in?

[mart 870]

Just something to think about regarding my over heating problems.

I`ve not had chance yet to change the fluid in my fan clutch cos i`ve been too busy racing but on a trip out tonight down the motorway i thought i`d open it up a bit see what it would do (no trailer, nothing in the back and a flat level motorway) I got it upto about 110 with it still pulling when the the needle slowly moves up the gauge, it got to about 3/4 when i thought it would be best to back off and let it cool down, which it did and within about 2 minutes the needle was back to its normal self of a tad under half way.

With it doing this at that sort of speeds it cant be down to the fan not doing its job cos the theres more air passing over the rad from the speed than a fan could ever produce.
The transmittion shouldnt be under too much load at that speed i wouldnt have though (although iknow bugger all!) so i doubt its down to that heating the water.
It could be the stat not opening enough thus restricting the flow although under normal conditions the needle never budges.
OR its down to the fact that the rad simply cant cope with all the heat the motor puts out when its working hard - time to remove that crappy oil cooler blocking off the rad inlet/outlet me thinks.

To be honest i didnt think the rad was really big enough anyway - the whole cooling system holds less than my stock car which uses a taxi rad and doesnt have one let alone 2 heaters to fill! (The stock car needs a big rad cos its runs around a 1/4 mile oval at 8500rpm in second gear for 20 laps at a time lol)

Anyone have any thought about this?

[Rob]

Mine did that on the way back from Yorkshire - M1, slight hill, head wind, 90mph, warm-ish weather, a/c on. Reason was that the rad was caked in mud!

[Koi]

Mine did that on the way back from Yorkshire - M1, slight hill, head wind, 90mph, warm-ish weather, a/c on. Reason for was that the rad was caked in mud!

Yep not on the way back from yorkshire but other off road centres, hit 75+ and the temp creeps up. Good jet wash of the rad and its all back to normal no worries. Just needs lots of air over the rad and with part of it blocked with mud its not enough when the engines under more load.
Bullbars & A bars loaded with lights, placement of number plates etc can all restrict the air flow over/through the rad giving the same effect as a blocked rad, higher engine load more cooling required, not enough air flow higher temperature.

[mart 870]

Theres nothing caked to the front of the rad cos i checked when i flushed the rad out and theres nothing blocking the air flow to the rad neither so it cant be that.

[mart 870]

Latest update!

I decided to check the thermostat to see if that was causing my problems - it was a bit lazy and didnt fully open until a shade below 100 degees so refilled the system without the stat just too see what happend.
The car took longer than usual to warm up(to be expected) but got upto the usual operating temperature and stayed there, at low revs and moderate speeds i would have expected the gauge to drop with the unrestricted flow but it didnt it stayed steady but more interesting was that at high speeds the gauge rose again like before where it got to around the 3/4 mark when i descided to slow down!

This can only lead to one thing, the oil cooler in the bottom of the rad really does restrict the flow so i`ve took the rad off ready to have it the oil cooler removed and WOW it really is bad! there is a tiny hole for the water to pass through, no wonder it gets hot as soon as there is any real load on the engine.

The oil cooler pipes are just low pressure ones so its just a case of finding a replacment external cooler and somewhere to mount it, one or two of you i know have fitted extra coolers - where have you mounted your? i reluctant to put it infront of the rad as already it has the air can rad there and i dont want to restrict air flow over the rad any more.

[mart 870]

I forgot to add - when the car got hot i pulled over and checked the fan and it works fine.

[europa88]

Latest update!

I decided to check the thermostat to see if that was causing my problems - it was a bit lazy and didnt fully open until a shade below 100 degees so refilled the system without the stat just too see what happend.
The car took longer than usual to warm up(to be expected) but got upto the usual operating temperature and stayed there, at low revs and moderate speeds i would have expected the gauge to drop with the unrestricted flow but it didnt it stayed steady but more interesting was that at high speeds the gauge rose again like before where it got to around the 3/4 mark when i descided to slow down!

This can only lead to one thing, the oil cooler in the bottom of the rad really does restrict the flow so i`ve took the rad off ready to have it the oil cooler removed and WOW it really is bad! there is a tiny hole for the water to pass through, no wonder it gets hot as soon as there is any real load on the engine.

The oil cooler pipes are just low pressure ones so its just a case of finding a replacment external cooler and somewhere to mount it, one or two of you i know have fitted extra coolers - where have you mounted your? i reluctant to put it infront of the rad as already it has the air can rad there and i dont want to restrict air flow over the rad any more.

It may be worth getting quite a large air to oil cooler as the atf temps can get very high! I experienced 110degrees up some welsh mountains last week
and i WASN'T EVEN TOWING! i havn't had any overheating probs and as a precaution fitted a standard size trans cooler for when I towed my caravan.
(which I havn't tried yet)

You could mount it under the bash plate and fit a cooling fan, a couple of guys on the USA forum have done this and I am contemplating doing the same! But I'm concerned with pushing even more heat into the engine compartment. You could reverse the flow but that could pull already warm air to push through the trans cooler! A guy on the Aussie forum put a monster transcooler with twin fans at the space once occupied by the spare wheel!
But thats a long way for the transmission pump to pump the ATF!

I am going to do one of these options as the temps are way to high for long life of the transmission!

You could of course fit an external water to oil cooler to replace the one in the bottom of the rad!

Good luck will be interested to see how you get on!

[mart 870]

Done it at last!

I`ve finally done my rad/auto oil cooler mod and yes it does seem to make a difference, i tried the same bit of road as before at high speeds in yesterdays heats and the gauge didnt move! The oil cooler was hot to the touch but it didnt burn my skin off and the oil temp warning light didnt come on.

I had to buy the following to do the mod -

Have the Bottom tank of the rad removed and the oil cooler extracted - £41, this was done by my local radiator repairers Leicester Radiators. They were very helpfull and it only took them a day including repainting the rad although he said the cooler was a pig to remove.

19 row PMA oil cooler - £74, also bought from Leicester Radiators. It was the biggest one i could somwhere to fit!

2 90 degree elbow unions and 2 1.5 lengths of hose - £15, bought from A1 Hydraulics Leicester. Way too much hose but at least it gave me chance to change my mind where to mount the cooler if needed.

Genuine Toyota Thermostat and rubber O ring seal - £13, bought from my local Toyota dealers, they were very helpfull and knew which model it was although it did take 3 days to arrive!

A sheet of 1000x500mm Anodised Aluminium gause £20, a B&Q special! We wanted silver to match the bumper but its all they had in and looks quite good and not too much like it came off a Nova!

The job wasnt too bad , the hardest was removing the grill without breaking the clips!

Hopefully the porblems are cured now, im off the Isle of Wight on Friday to deliver a classic car on the trailer so that should give it the final test, if anyone wants to do the mod, give me a PM and i`ll my best to describe what i did.

[Mart]

Mart870 how did the mod work out? You mentioned you were going to the Isle of White and towing a car on trailer. Any heat probs ?

Cheers

[mart 870]

No problems so far, the trip went well. We went in the evening so it was cooler anyway but we did do a stint of 80mph plus driving so we could make the ferry on time and it didnt give us any problems. The final test will be in August when im racing at Buxton again and i have to go up that big slow hill.

Europa`s idea of moving the rad outlet over and keeping the present cooler in place sounds a good one although it might be quite expensive to do it.

Before they started my rad mod they told me that removing the bottom tank could disturb the soldering on the core and render it useless, they quoted me an extra £50 to put a new core in so if you have your rad done and they say it needs a core make sure they dont try to rip you off - i`ve seen a few people on here who have been charged loads to have a rad recored.

[AndyLala]

Gentlefolk,

More of the same.
Having explored the US site and the Aus site, and here of course. It would appear that some people suffer from time to time with the 2LTE overheats.

Investigating further to try and discover a permament cure to this, I have found the following:

Replace the broken 2.4 head with a 2.8 head (remanufactured after 1997), because it is much more substantial.

Replace the 2.4 radiator with a 2.8 radiator... (here is where it gets interesting) retain the water oil cooler, but shorten it so that it doesn't restrict coolant flow. Add an additional (read substantial) air oil cooler on the return to the Auto box.

The Australians mention using a Aus spec Radiator with the cap on the upper header tank (no idea if this is any different to JAP or UK spec).

Use a Toyota brand thermostat, and Rad cap, throughly flush radiator/coolant system, etc...

Questions which I can't seem to answer from scouring the forums:
Is the 2.8 head a straight swap?
Is the 2.8 head more substantial than the equivalent (redesigned) 2.4 head?
Does the 2.8 Radiator indeed have a higher capacity than the 2.4?

Will going through all this pain and effort result in a bullet proof coolant system so that I can use the vehicle the way that it was intented...?
IE. load it up to the gunwalls, with no care whatsoever, and not worry about my toy performing... or overheating?

Reason for my questions, after a week down in Cornwall with my two little monkleys and my good lady wife, and all their baggage, my toy did get a little warm on occassion and although the Kenlowe fan (16s) did perform as expected, there were a few interesting moments when the temperature did almost approach the red ever so briefly.

My feeling is that when under load, coolant temperature is rather high, Auto Box oil temperature holds the coolant temperature artificially high such that both the Kenlowe fan and the Toyota Auto box assist fan on the front of the Radiator just isn't enough under certain circimstances, low ground speed - heavy payload - high revs - Aircon on - high outside temperature, etc...

Comments?

andyL

[marky]

I went through the night to st-ives no cooling problems what so ever. I'd recently had a new head & all the cooling system overhauled including new waterpump also had viscous fan adjusted, On the way home daytime uphill all the way home A30-M5-M6 no temp fluctuations at all.

[AndyLala]

Marky,


I presume that wasn't overloaded though. As I mentioned previously, without any gear in, it works a treat. Kenlowe doesn't even kick in. Behaves as designed. Just like it to behave the same without having to worry how much crap I have on board (and on the roof)...

andyL