Cooling the 1KZ-TE motor:

[Shayne]

What else did your mechanic do when he re-oiled your viscous ?

 

[froggy Steve]

rad flush, oil/filter, grease up underneath as well as coil change at front. the Viscus hardly worked before but is now on all the time - I will check for not fitting the fan back tomorrow!
coolant wasnt Toyota stuff but pink stuff from Froggy version of Halfords - maybe its shite!

 

[Shayne]

Viscous is a fair bet then there's only so many components in the cooling that can fail so it's a process of elimination . It's always troubled me that your viscous is permanently on , if it was meant to be that way why did mrT bother with a fancy coupling system ? Can you spin it by hand ?

I can't imagine why that would make it hot though unless at motorway speeds its supposed to be free spinning at the same speed your traveling and yours doesn't because its permanently engaged ? Maybe your thermostat is sticking .

 

[Beau]

I think having it on all the time could be what's causing your temps to rise. Having it on like this puts a strain on the engine when it's used to having more power. Not only that, but in theory I would have thought when driving a good speed the airflow created would be enough to cool the engine down, without the viscous needing to come on... Maybe when it's on now, it's disrupting air flow?

I'd put the correct amount of fluid in it and try again...

 

[froggy Steve]

Good points chaps. Just been out to check all is OK with coolant etc - Rad full, expansion bottle the same as it always is. Oil levels fine, gearbox oil fine. I tried turning the fan and it turns with a little resistance -
I think I will get a new rad as a precaution, and put the correct level of 10,000 cst oil in - (must be an amount on here somewhere!) It had a new rad about 6 years ago but for 150 squid, its got to be worth it - I will get some Toyota pink stuff too, lookout Roughtrax, here I come!
I have an oil cooler brand new in the garage, I wounder if I should fit that as well - in line with the new rad perhaps?

 

[BobMurphy]

Saw 107 degrees from aux temp guage that lives in the top hose tonight (on way to another members pad) 38 deg outside temp, but 107!

You probably had your Air-Con going at full blast as well. How hot did the Air-Con rad get?? It's pre-heating the air that goes through the engine rad. . . . .

Bob.

 

[Shayne]

I spent a week searching for the correct amount of oil in the viscous and have decided 60ml of 10k should give us a bit of an improvement over standard without insulting the designers original goal . My Roughtrax order went in yesterday and a couple of bottles of Forte coolant flush are included . I really don't want to change my rad its done its job for 17 years and i can't find a replacement that offers that kind of tried and tested reputation maybe i should ask mrT for a price ? . Plan is to remove inspect and decide then , the extra bottle of Forte for soaking the rad overnight if i am putting it back on . Might it be an idea to change the stat while its empty they aint expensive and it crosses another possibility off the list .

I guess yours is an auto and there's lots been said about the oil cooler though i have never paid attention to it with mine being manual , it's certainly worth doing some research on that .

 

[froggy Steve]

You probably had your Air-Con going at full blast as well. How hot did the Air-Con rad get?? It's pre-heating the air that goes through the engine rad. . . . .

Bob.

Mr Bob, you are quite correct - Aircon was on but only #2 setting as it was re gassed last year and gets bloomin cold! To be fair, this has only happened when the weather has become very hot - was very happy before, even giving it a boot full, temp never rose above 95 up hill!

@ Shayne - yes, going to spend my afternoon searchin tinternet!

 

[Beau]

I think adding the additional cooler would be great for the trans and also reduce the heat that goes into the main Rad. I was also thinking of using the coolant lines that run back to the rear heater matrix and add an additional cooler in place, underneath the vehicle with a fan. Does anyone think this would work.... I have the lines disconnected already as they had rotted away and as I'll be in Florida I'll never need to use the rear heaters.

Also Shayne, If you're still on your original rad I guarantee you'll be running cooler with a brand new rad, whether it be Milners or Toyota. I don't know if you've ever removed it but in between the AC rad and main rad, it gets packed with all kinds of rubbish that's hard to wash/clean. Plus with 17 years of abuse, your rad fins won't be looking too healthy either. The good thing is, being a manual you won't be susceptible to the coolant in auto box issue. When I was looking to change mine, I went for Milner which has been on my truck for a few years now without a problem. Or maybe you could get a custom 3 core Aluminum one

 

[Shayne]

Your twisting my arm Beau 3 core does sound good I can see between my aircon and rad but it's a bugger to clean and i am tempted to call in a specialist to have the AC rad moved forward to increase the gap .

 

[BobMurphy]

i am tempted to call in a specialist to have the AC rad moved forward to increase the gap .

NO! NO! NO! NO!

Strange as it may seem, the two rads have to be close together to get proper airflow through them. Something to do with turbulence being created between them if there is a bigger gap.

So I have read

Bob.

 

[Shayne]

thanks for that Bob ! funny thing is i looked at the KDJ90 aircon rad and ...... its not there closer inspection suggests the AC and coolant rads are of the same size and sandwiched together to appear as one unit

 

[froggy Steve]

I have ordered one from Rough Trax, we shall see if it makes any difference or not - going to go get my oil cooler out and see where it can go in a mo!

 

[fridayman]

My viscous fan has been permanently on for about 30000 miles (maybe more, I can't access my service log atm) under all conditions without any problems.

 

[Shayne]

NO! NO! NO! NO!

Strange as it may seem, the two rads have to be close together to get proper airflow through them. Something to do with turbulence being created between them if there is a bigger gap.

So I have read

Bob.

Would it tie in with what you read Bob if i said a 10mm gap between rad and condenser is acceptable but to increase the gap makes the aircon less efficient because the viscous fan will pull air to cool the radiator from the gap around the condenser instead of pulling it through the condenser ?

 

[jbecks]

Yes it's it inefficient in having gap between the radiators as it prevents the air being drawn though them, and acts more like an obstruction.

 

[BobMurphy]

Would it tie in with what you read Bob if i said a 10mm gap between rad and condenser is acceptable but to increase the gap makes the aircon less efficient because the viscous fan will pull air to cool the radiator from the gap around the condenser instead of pulling it through the condenser ?

I can't remember the details now (this came from a thread on here or 'elsewhere' some time ago). It appears that treating the two rads as one unit gives the best airflow through them.

I couldn't say what the 'cut-off' point is as regards a gap between them but suspect the smaller the gap the better (just my gut feeling).

Airflow is a science in its own right and I suspect there is plenty on the net if one cares to spend the time looking.

Me, I've a 90-Series Transfer Box to strip/repair (see 'elsewhere') .

Bob.

 

[Shayne]

That's how i read Bob's post jbecks but i cannot find reference to the A/C condenser having a detrimental effect on engine cooling other than via heat soak ?

 

[Shayne]

Best 3 core i can find is for a Surf Beau http://www.ebay.co.uk/itm/56MM-CORE...544?pt=LH_DefaultDomain_3&hash=item3f4dff0a18

Dimensions are 600mm x 645mm x 65mm compared to an aftermarket 90 series 2 core rad found on ebay Oz which offers 720mm x 680mm x 60mm , so height and width are smaller with only 5mm depth difference so yeah it should be easy enough to fit what are them small lugs with the blue caps on at the bottom will i have to cap them ?

I'm not sure its worth the extra price and messing about even if it does offer some small benefit over a factory rad especially as its an open question as to whether or not it will show an improvement at all .

 

[froggy Steve]

I bought this Oil Cooler last year, but havent done anything about fitting it yet. I am going to fit it in line before the rad, so as not to end up getting gearbox oil too cold in winter. (read my mech not me!) This is a solid bit of kit - more a big heat sink than a traditional radiator.