Long Cold Winter...

[Ski_Extra]

Yoda is still over heating!

After a new head the over heating has got worse. I've flushed the system and burped it real well. No thermostat and new rad cap. And it still goes in to the red with any real effort!

Being in Switzerland we're kinda stuck. The missus even called the s$$$$ dealer but they wanted to charge us to take it away (wish they'd take my missus).

So I've got permission to stick it in the garden for winter. Work is about to start big time for us and I'll have no free time until April.

The plan is to have another go in the Spring (should be warm enough to work outside then too).

Any thoughts on how to protect it for the 5 months of winter? I can park it under a couple of trees and then rig a tarp up so not to sit on the paintwork. Both batteries will come in to the warm...

Any other thoughts? Brick it up to take the weight off the tyres? Ta.

[MattF]

Is that a mistype, or do you really have no thermostat? If so, might as well get a new head on order. Get a 'stat in damned sharpish. Any over heating issues you may suffer will be compounded, especially if you're loading the engine, by running without a 'stat.

[MattF]

Oh, and with regards to storage, in gear/park, hand brake off, keep a check on the tyre pressures, (rotating them slightly occasionally), drop the diesel out of the tank, and make sure the antifreeze is good. Battery wise, whip 'em out and keep 'em trickle charged.

[KERRSURF]

It's worth putting some dessicant bags in (kiln dried clay dessicant or similar, like gel type) to help stop any moisture inside truck.

[plumb bob]

Is that a mistype, or do you really have no thermostat? If so, might as well get a new head on order. Get a 'stat in damned sharpish. Any over heating issues you may suffer will be compounded, especially if you're loading the engine, by running without a 'stat.

Nero is running w/out a stat, how will it compound the overheat, as the coolant will circulate through the rad all the time, therefore staying as cool as possible.

[Ski_Extra]

Is that a mistype, or do you really have no thermostat? If so, might as well get a new head on order. Get a 'stat in damned sharpish. Any over heating issues you may suffer will be compounded, especially if you're loading the engine, by running without a 'stat.

No, not a typo.

I've barely had it running since I changed the head. It's currently got no thermostat in as the old one was tosh. I've driven it twice, really short trips - each time I've had the engine running whilst stationary for between 20 mins and an hour (burping it). Then gone for a really short, but slowish and up hill drive and the needle runs into the red.

I'm usually wrong, so please correct me, having the thermostat out will just increase the flow of water? Or *am* I loosing the extra efficiency of running at normal temp thermostat closed, then when it gets hot the thermostat opening?

My plan for next year would be: another new rad cap, new thermostat and new radiator (either modified to move the ATF coolant pipes OR biggest radiator I can fit under the hood and a separate ATF cooler).

It's worth putting some dessicant bags in (kiln dried clay dessicant or similar, like gel type) to help stop any moisture inside truck.

I had wondered about this too but the air up here in the winter is unbelievably dry because of the altitude and temperature...

[KERRSURF]

true air will be dry but sunny days could cause condensation under glass and on cold surfaces. probably be ok though.

[plumb bob]

Have you checked/ had the water pump checked, as this would cause the same symptons if it were on it's way out/fubar'd

[MattF]

Both you and Bob are correct. Removing the 'stat does indeed increase the coolant flow through the rad. And therein lies the paradox.

If you were sat all day at idling speed, removing the 'stat *might* be useful. When you're running an engine at several thousand rpm however, with no flow restriction, chugging so many litres per minute through the rad is going to ensure that the coolant is almost as hot leaving the rad as when it went in. The thermostat puts such a high restriction in the flow for a valid reason, and that's the one. It needs to slow the flow through the rad so that the rad can actually transfer the heat away from the coolant.

Flipside is that under light duty use, in cold temps, you can also create engine wear issues with no 'stat, due to the fact that the coolant is being constantly flowed through the rad, thereby never allowing the engine and autobox to attain their optimal operating temps, which will in turn lead to excessive engine/autobox wear.

[MattF]

Btw, with regards to the rad, I'd have it recored with a good quality copper, (and yes I do believe this aluminium rad is better bumph is complete tosh), core, (one of the LC cores fits the Surf rad, btw). Leave the ATF cooler inline in the rad, however. If you want to fit an external cooler also, then do so, but have that inline before the ATF fluid goes through the rad. The coolant is used to heat the ATF fluid as well as cool it, so doing it that way ensures that the ATF fluid will never be overcooled, once the engine is upto temp. As mentioned above, it prevents excess autobox wear.

[Ski_Extra]

MattF thank you for your explanation. I can't believe how clear that now looks. Hope it makes a difference, I'll order a new 'stat first thing in the morning. And let you know.

RE the rad. The outlet tube for the radiator appears to be blocked quite significantly by the ATF tube. Like these guys found:

http://www.toyotasurf.asn.au/forum/v...o+radiator+atf

[Sancho]

And what about the water pump? Is it working? Does your engine go 'eek eek eek eek' when it's running.

[nero279]

one thing i have noticed without the stat is that it tends to heat up quicker on the motorway, with a stat i can drive at 75-80 comfortably, without i have been pootling everywhere at 60-65, no overheats, but definately a marked increase in running temperature at 75 rather than 65. But when slowing down afterwards, the heaters and temperature gauge go almost cold in the time it takes to slow down coming off a motorway sliproad, then return to normal again fairly quickly after normal driving is resumed.

I have been planning on refitting a stat, but just not got round to it yet, gotta have a surf day this week though, got a few things i wanna play with.

[MattF]

Hope it makes a difference, I'll order a new 'stat first thing in the morning. And let you know.

Nice one.

RE the rad. The outlet tube for the radiator appears to be blocked quite significantly by the ATF tube. Like these guys found:

http://www.toyotasurf.asn.au/forum/v...o+radiator+atf

It's bunkum. As TonyN, (I believe), once said, the 'stat itself introduces far more restriction in the flow than that devil does. I also asked the rad specialist when I had my rad recored regarding his opinion on whether that would cause a problem, and his opinion didn't leave much to the imagination regarding that theory either. Him I do trust implicitly with anything rad related. Honestly, if you're wanting to make sure your cooling system is in the best state possible, there are three things I personally would suggest.

1) Get the rad recored. You never know what condition it is in internally.

2) Replace *all* the coolant system hoses. Top and bottom hose should be okay unless they're going weak, but all the smaller hoses, whip 'em off and replace. The ones under the 'stat housing especially you will most likely find to be partially blocked and in generally poor overall condition.

3) Use a good quality concentrated green coolant mixed with distilled/de-ionised water. Green is my preference for the simple fact that it has all the plus points of red coolant, (apart from the 5 year lifespan, which is fairly moot anyhow), but has the ability to mix with other coolant colours unlike the red, if you have any residue from your previous coolant still in the system. Red will just completely refuse to mix with anything other than itself.

As the others have mentioned, it also may well be worthwhile replacing/checking your waterpump, if you haven't done so already.

[Sancho]

One good reason for having a thermostat, certainly on the V6 is that the auto gearbox won't go into top gear if the engine's too cold. Some tw@ cut the middle out of mine before I had it (to 'deal' with the blown head gasket) and when winter came it wouldn't go into top gear. I found out it would change up if I thrashed it for a bit, then changed down when it got cold again. Anyway, I worked it out in the end. Then got Tony to change the stat because I wouldn't know how......