Gen3 giving mixed signals

[yakooza2]

Hi all
I am new to the world of serious 4x4 and have recently purchased a surf 4runner with KZN185 engine 3.lt TD Automatic with 108.000 miles on the clock.
Its is perfect in every way and it is the best form of transport I have purchased to date, much based on the reputation it carries as a hard nut.

Since purchasing, it started and ran as it should and pulls like a Trojan.
Last Sunday, I towed a Spitfire from Dover to London, with the aid of an A frame towing device.
Halfway home, I noticed the engine laboring to pull at a steady speed and I disengaged the over drive to give it some boost, on and off. but after a while, I noticed the temperature gauge to go right down to cold and little heat from the heater unit. I also noticed the gauge go up again for a short time and down again.
I am aware of the weakness of the these cars to be the head/gasket/some form of cooling problems, but there seems to be no signs associated with any of the above, as you would expect to see with an average old petrol engines, like oil and water mixture, power loss, starting problems water loss, and so on.
Has anybody else experienced this? could it be a simple solution? or am I just in for a large repair job?
Any help would be much appreciated.
Nader.

[muddle]

Firstly hello, post a hello up in the general section.

First thing I would do, when cool, is check the engine coolant level, the symptoms could have been an air lock. Do this, take it for a drive with all the heaters on hot, check they all warm up and monitor the engine temp.

Post up the results.

[TonyN]

This truck isn't blue with the spare wheel under the back and Fuel Cat stickers on the intake is it?

Fluctuating temp and heating is normally a sign you're running low on coolant.

Cracked heads on Surf rarely effect how the truck runs and don't mix the oil with coolant.

[yakooza2]

Gen3 mix massages

Firstly, please accept my apologies for joining the forum as a newbie and jumping straight into a, got a problem can anyone help.

Thanks also for a speedy reply with some very helpful hints. But I think I need to elaborate a little more, here.
As a background for the surf, it was purchased 3 months ago and during its use every now and then, it reached a warm temperature, resonably quickly and stayed there, no matter what the speed or the load, with the gauge reading dead middle and not moving anywhere, up or down to suggest abnormality.

last Sunday, hooked up a Spitfire from Dover to bring home to London, half way up it seem to struggle uphills, so to try and help, I disengaged the over drive now and then.
Just as I got to M 25, some 35 miles from home, the heater started to blow cold air and the dial was reading cold. Having read about the only weakness of these trucks to be cooling and head gasket problems, I panicked and stopped to check the engine. All seemed fine, no leaks, water level right on, no signs of water in the oil or oil in the water, no bubbles.
So I carried on and over the remainder of the journey home, the dial went up a little and the heater blowing slightly warmer air and then down with the dial and cold again.
Today, I have fully flushed the system, reloaded with 50/50 mix and bled from the top hose, heater hose and filled the radiator again, after a few minutes, but it still does not reach the normal temperature.
Engine starts and runs as though nothing is amiss.
In my last 40 years of tinkering with cars, I have seen many head and gasket issues and almost all have given the normal visible signs, IE, mayo, over heating, lack of power, no starting and so on, but this is puzzling me.
This is where you good people come in.
Just a last thought though, could it be as simple as a faulty thermostat stuck open?
Apologies for the long essay, I will keep it short next time.

TonnyN, no the truck is Blue, but has the wheel at the back
Muddle, Thanks for the tip, but I have tried that already and no change there.

Nader

[s car go]

In my last 40 years of tinkering with cars, I have seen many head and gasket issues and almost all have given the normal visible signs, IE, mayo, over heating, lack of power, no starting and so on, but this is puzzling me.

As Tony said Toyota engine,don't show there symptoms with mixed fluids.They rarely pop gaskets,but do crack heads quite happily,and the net effect is pressure in the cooling system,that vents via the expansion tank with half of the water.The water leaks away inside the passenger wheel arch so is not always obvious with a bonnet up check.
My 4 runner ran for nearly a year with a cracked head. When the truck was under pressure IE climbing a hill it would start to "empty out" It would not run with any more water than just enough to cover the top set of fins inside the rad. If yours does'nt run with cooling water right up to the neck of the rad and religiously stay there then you have a problem.
Most folk try to convince themselves they have an air lock!!!

See this post here might help you under stand the Toyota head a little better:-
http://www.hiluxsurf.co.uk/showthrea...n+cracked+head

Regards

Mark

[muddle]

Could be air lock, could be faulty rad cap, could be head. Its hard to say to be honest. Would inspect/change rad cap and thermostat first and go from there. Cheapest and easiest first.

[yakooza2]

Gen3 mix massages

Thanks guys, especially the link Mark has attached here, very useful info, yet scary to think I might be in for a few hundred pounds repair cost that I do not have, but most of all, the wife's I TOLD YOU SO, that will get me all steamed up.

But I must admit, since the refill earlier today, the water has not gone down and I have only been driving for 8 miles or so.

I did unintentionally, do something that might be of an interest here.
I was filling the radiator whilst the engine was running and at the same time, loosening the heater hose to let some air out. What I noticed was that the top of the radiator was foaming with small bubbles, like shaking a can of coke and see the bubbles rise, so what I did to get rid of the bubbles and keep water going in, I half filled a 2lt bottle of coke and inverted it on the radiator neck, almost making a seal. What I saw then, was a whirl wind of bubbles coming through the bottle, every time I rev the engine. Apart from it looking quite entertaining to watch, it was worrying that this might be the result of the small crack on the head.
never the less, the car still is running and all is well,expect that there is no heating in the cab now.
i am going to buy a thermostat and a cap, just to make sure I have done all I could reasonably do, before sitting here and feeling sorry for myself before resulting to myself.
Happy Easter to all
Nader

[yakooza2]

Gen3 mix massages

Hi Mark
Thanks for the information and the link, but what I can't really digest is, why wood the head crack and show no signs of a defect and car would behave normally, except when its under load?

In all the years I have been tinkering with cars, it is the signs of over heating, water loss, sudden excessive heat, that leads to head unit problems and show themselves first, but it seems that things are in reverse order, when it comes to Toyota Hilux and alike. In theory, I can go on driving my truck for months, for as long as I avoid hills, I should be alright.

The other interesting point I found out since I became the owner of one, is that the thermostat is placed at the bottom and after the water is cooled from the radiator. I can't quite follow the water flow and the reason for the arrangement goes against all I had learnt in my early days in Technical College.

Thermostat is always placed at the top of the engine to let the hot water that rises to the top to go to the radiator to cool off, go down and push more hot water up again passed the thermostat and so on.

Thanks again for showing interest in my plight.
Happy Easter.

Nader

[wishbone]

here.
I was filling the radiator whilst the engine was running and at the same time, loosening the heater hose to let some air out. What I noticed was that the top of the radiator was foaming with small bubbles, like shaking a can of coke and see the bubbles rise, so what I did to get rid of the bubbles and keep water going in, I half filled a 2lt bottle of coke and inverted it on the radiator neck, almost making a seal. What I saw then, was a whirl wind of bubbles coming through the bottle, every time I rev the engine. Apart from it looking quite entertaining to watch, it was worrying that this might be the result of the small crack on the head.

Nader

If you have just had to add water then bubbles will come out. Leave your coke bottle (make sure the seal is perfect to the rad - I use a big funnel that wedges in perfect) sticking out of the rad and fill it until the coolant is higher than the heater hoses on the bulkhead. Start up and rev the engine at around 2000 revs until the engine is up to temp and the thermostat has opened. When it opens you'll probably get some big bubbles come out and possibly need to topup the coolant. Keep going until you're getting no bubbles. Switch it off and leave it to cool with the coke bottle in place (make sure there is plenty of coolant in the coke bottle at switch off)

Once cool, remove the bottle and replace rad cap,making sure the overflow resevoir is topped up the cold mark.

If you never get to the stage where the bubbles stop coming then buy a test kit to test for exhaust gasses in the coolant.

hth,

Rob (replaced my 3.0 head recently)

[Koi]

Also how recently did you purchase it, private or dealer, warranty?.
Has, did the previous owner pour in some treatment to temporary mask any head problems which has now come to light during your ownership?

[s car go]

why wood the head crack and show no signs of a defect and car would behave normally, except when its under load?

Sorry Nadar
I don't have the answer to your question! My theory is that these cracks begin to appear,but are not large enough to be allowing enough combustion gas to leak away and cause problems in the cooling system.When the engine is under load,maybe the extra power strokes and extra heat combine to open the crack a little more than just with normal use??

Both the 4 runner and the Surf I have now displayed symptoms,and carryied on running for months,but what I can say is bubbling as you describe,in my opinion,is a symptom. Once the heads have been changed no bubbles of any sort,and no gurgling(running water sound) from the heater matrix.

There's alot of talk about burping the system etc,but again in my opinion,when the head and cooling system are up to scratch just fill the cooling system, warm up engine ,top off and thats it. Anything more is pionting toward problems.

Hope your problem is just the thermostat or somthing cheap.
I'll keep my fingers crossed for you.

Regards

Mark

[yakooza2]

Gen3 mix massages

Thanks again chaps for all your input. I thought I had discovered somthing new with coke bottle, but it seems like, it's an old hat.
The car was purchased privately from, what I would like to think was a decent chap.
There certainly was no indication of anything amiss, up until the recent events.
I just drove back from work, a distance of 6 miles and about 1/2 hour's worth of driving, but all the gauge could manage to register, was just above the cold mark and equally lukewarm air coming out. when stopped at home, I opened the rad cap, no pressure and water to the top mark with the reserve tank at half mark. If I have a head problem, it certainly giving me signals, I am not familiar with.
Please keep all your ideas coming. I am going to try the latest tip with the coke bottle again to see if I can get any improvement on the heating front.
Wish me luck.
Nader

[yakooza2]

Thanks Mark
I guess I am either an eternal optimist, or I am hoping that this has not happened to me. ( head in the sand )

If the heads are so weak and the problem so common, what would stop the replacement head from cracking? or is there a head made out of Tongston or other similar materials that will stand up to the kind of work load required from these trucks? considering I was only towing a small car of just 750 KG, over 35 to 40 miles.
How can I be sure that, after spending over a grand to get the job done, the next head will not just throw a wobbly soon after?

I am sorry if I am boring you with so many questions that might have been asked before, but I am the sort of person who can not accept defeat and must have a plausible answer to the problem/questions staring me in the face. For that reason, I welcome all comments and discussions.

Thanks again for your input.
Nader

[s car go]

Nader,

I think what we need to accept is that age and milage is against the cylinder head.
There has been some discussion here as to, if the AMC head is a modified version or not,and the jury is still out,however if this head delivers another 100K miles and ten year of service then I'll consider I've had my monies worth.
They are not a bad truck really,because the only thing that gets discussed in detail here on a regular bases is the cylinder heads. The rest of the truck is fairly strong.Most of the time it's niggly sh1t,or damage caused by abuse.

The Surf I have now was running as you say barely warming the heater matrix and the temp gauge only rising to half way on hills.The previous owner had drilled the thermostat through,because it kept overheating. The water pump was leaking,and I think this was why it was overheating.I changed the thermostat,new water pump,flushed the system and all was good. 7 months later the head let go!! I think in my case the damage had already been done.
Sincethen ,with the new head,she tows the car trailer loaded with scaffold(probably about 2 ton) and no problems at all.

Your truck is not displaying classic head problems,but more over cooling caused by faulty thermostat.
As the other chaps said I'd change out the rad cap and the thermostat and see what happens.

Best Regards

Mark

[tashtego]

Hi all
I am new to the world of serious 4x4 and have recently purchased a surf 4runner with KZN185 engine 3.lt TD Automatic with 108.000 miles on the clock.
Its is perfect in every way and it is the best form of transport I have purchased to date, much based on the reputation it carries as a hard nut.

Since purchasing, it started and ran as it should and pulls like a Trojan.
Last Sunday, I towed a Spitfire from Dover to London, with the aid of an A frame towing device.
Halfway home, I noticed the engine laboring to pull at a steady speed and I disengaged the over drive to give it some boost, on and off. but after a while, I noticed the temperature gauge to go right down to cold and little heat from the heater unit. I also noticed the gauge go up again for a short time and down again.
I am aware of the weakness of the these cars to be the head/gasket/some form of cooling problems, but there seems to be no signs associated with any of the above, as you would expect to see with an average old petrol engines, like oil and water mixture, power loss, starting problems water loss, and so on.
Has anybody else experienced this? could it be a simple solution? or am I just in for a large repair job?
Any help would be much appreciated.
Nader.

Hi Nader, sorry to hear about your problems, my 3rd gen had similar issue, running cold expecially downhill, thermostat was stuck open! The bubbles in the system don't sound too good though...
From what I've read on this forum and also from knowing many surfs around here, if you think the head's gone, then it normally has. As the snail (escargot) says airlocks and the likes are not that common, especially in a 3rd gen.
As for the spitfire, do you mean the WWII fighter plane? ...Cool! Do you also pilot them?
If you regularly tow that sort of thing maybe you should look into something a bit more meaty, like a 4.2 landcruiser or something?
Good luck!