3.0 Occasional overheating problem

[john.wheelabrator]

Hi everyone, having owned my 1994 SSR-V limited for 5 years, I have just found this site and would just like to comment what a good job you all do.

My vehicle which is serviced every 10000km by myself, I am a time served plant fitter (is this correct interval I just thought more regular due to age and mileage), also any defects have been replaced using spares sourced from Roughtrax who I have found to be very good

Recently however I have noticed when towing a large caravan, It has towed this for years with no problem, when climbing a long hill not necessarily a steep one and it changes down into 3rd around say 55mph in order to maintain speed the temperature gauge starts to climb into the red and I have to lift off, otherwise I fear it would go into the red.(i never let this happen) My gut feeling is the thermostat may not be opening enough, but I have heard so many horror stories about cracking heads I thought I would see if you guys had any thoughts.

thanks in advance,
John

[Koi]

From memory oil change is every 5000kms...............

Could be the stat not opening, possibly rad blocked internally, viscous fan not operating correctly...

Would change the stat and flush the cooling system as these are the easiest and cheapest to do.

Has the veh ever been off road, rad could be blocked with mud etc not allowing proper air flow through it.

[Tallyman]

One problem when towing (presuming you have an automatic) is that the ATF gets much hotter because it has to do more work to keep the torque converter working to pull the increased weight. Have you checked / changed your ATF fluid recently? It should be within the limits on the dipstick when checked hot with the engine running and also a bright red colour. If it's cloudy or going a brownish red then it's time for a change.

The other thing to check is that your coolant level is correct, under the rad cap and in the expansion bottle. If all that is OK then consider fitted a supplimentary ATF oil cooler in line with the existing one in the bottom of the radiator. The hotter ATF fluid will re-heat the engine coolant after it's run down through the rad, as the inbuilt cooler is in the bottom of the radiator and partially restricts the flow of coolant back into the engine (it is visible through the bottom hose outlet).

I've done that to mine, including fittiing an auxhilliary water temp guage which is far more accurate than the OE item, and although mine does still start to get hot when towing up hill I can watch the guage to see what is happening and, if necessary, put the main heater on for a minute or so to give some additional cooling which helps limit the rise or even bring it back towards normal.

[john.wheelabrator]

Thanks for your help guys, will try these at weekend, have ordered stat, will flush system and blow out radiator and condenser if still no joy will look at auxilliary cooler

Many Thanks,

John

[john.wheelabrator]

Have done everything we talked about, and as I said the car is running fine, only when towing up a long incline did it occur (I wont be trying this again for a couple of weeks) but I did notice when I ran it up after changing stat, flushing and refilling with coolan, after it got up to temperature after running on high idle, I switched it off and the fan kept running for a few seconds. It could still turn fairly easily by hand although the temp gauge showed midway(which is where it normally sits) I think it should be hatder to turn at this temp, but I want to be sure as it seems quite expensive (£192 from roughtrax) any thoughts??? or do you know where I could source the parts cheaper

many thanks guys

John

[yorta2]

If, after you have warmed your engine up (via driving, preferably) you switch your engine off and the fan stops turning within a few blades passing your view, then the viscous fan is okay. If, however, the fan runs for longer, then you need to refill the fan clutch with silicone. See here:
http://www.toyotasurf.asn.au/forum/v...ht=viscous+fan

and here:
http://www.hiluxsurf.co.uk/forums/sh...ad.php?t=30243

[LockyBalboa]

Same happened to me the other week, when towing 2 horses. Overheat proper - cracked top tank on rad.
Sourced new rad, thermostat, hoses, coolant and 2x fan 1x air con belt from Roughtrax. The brand new rad is very good quality and a perfect fit. Did a full coolant flush, and now the temp gauge stays in the middle on normal running - doesn't move much past 3/4 even when towing the nags up hill! The only test is to tow a load up hill - that makes the car work and only then is it a good test of the effieceny of the cooling system.

Once I had the rad out, flushed with coolant and replaced thermostat it was pretty obvious why she was overheating. I am so glad I chnaged all the parts I did - the old rad was cack. It took me 5 hours to do the lot and an oil change to boot. Very good piece of mind and whilst parts did cost a bit, its far better than breaking down with 2 horses on the A3.
Tallyman makes a good point on the ATF - this needs to be check whilst enginer running and should always be at the right level.

Hope you sort it, cos they do tow lovely.

[john.wheelabrator]

Thanks for all ypur input, as I said have changed satat and flushed coolant and will be going on a long tow in a couple of weeks, so fingers crossed. All I need to do now is sort speedo as my wife is currently using sat nav (from my works van) as a speedo. I always thought the speedo was out as it didn't feel as if I was going as fast with caravan on as speedo indicated, however with sat nav on and speedo working (it is intermittent) its actually within 5mph. You're right it does tow well