1kz - coolant leak???

[badman9]

Greetings everyone! Happy new year. 2000 Hilux Surf 1KZ-TE here

Has anyone with a 1kz ever seen what appears to be coolant leaking from what I think is the head gasket but leaking outwards? (yes yes, it is green, yes I know it should be toyota genuine coolant but that stuff is hideously expensive here in Jamaica)

Not the best picture, but is this familiar to any of you?

Thanks

 

[roscoFJ73]

Its got to be a head gasket.

 

[badman9]

Its got to be a head gasket.

Sad part is that you are probably right. I've only been working on my own vehicles for about 12 years, but I've never seen a head gasket leaking outwardly. The few that I had to done were leaking coolant into the combustion chamber, so this is quite new to me.

Worked the engine hard running up a hill at full throttle today at noon and thankfully the temp gauge didn't budge and the coolant level hasn't dropped noticeably. How much of a risk will i be taking driving the vehicle (gently) for the next 2-3 weeks, at least until I can get married and pay some of those bills?

I guess if i'm pulling the head I should do the obvious and check out the sleeves/liners, see what condition pistons and rings are in, consider changing valve seals etc.... Sigh. Expenses I would want to avoid right now due to wedding exppenses.

 

[roscoFJ73]

You will probably be ok if you take it easy. Did you do something to make it overheat prior to it leaking? My ex gf had a Hilux headgasket leak coolant just after a full engine rebuild and it was still going strong 15 years later, although this was a petrol engine

 

[badman9]

You will probably be ok if you take it easy. Did you do something to make it overheat prior to it leaking? My ex gf had a Hilux headgasket leak coolant just after a full engine rebuild and it was still going strong 15 years later, although this was a petrol engine

Nothing recently to lead to that that I know of. Thankfully she hasn't overheated for about 6 months.

I have had my fair share of overheats since the last time I changed the HG back in 2015 though for reasons as diverse as leaking radiator core, busted radiator tank, sticking thermostat, faulty genuine cap etc etc. I figured at some point i'd have to do some work as a result, but I just need it to safely go another few weeks.

 

[GTSSportCoupe]

Could try giving the head bolts a re-torque. Make sure to do it in the right order etc. Might buy you a bunch of time. Friend of mine with an hdj81 had oil leaking out the side of the headgasket. Re-torquing fixed it.

 

[badman9]

Thanks for all of the advice.

Can anyone please explain the labryntine world of toyota head gasket marks and revisions? In the catalog for this vehicle, I'm seeing two totally separate part numbers and multiple versions of each

For example,

11115-67040-01 ie mark 1
11115-67040-05 ie mark 5
11115-67050-03 ie mark 3

Also, when searching for parts on ebay there are others.
11115-67050-05
11115-67050-01

 

[roscoFJ73]

You need to take the head off to determine which one you have, unless there is a visible piece of head gasket with the marks on it hanging out the side somewhere. These HG come in various thicknesses. You can go thicker and suffer a small amout of power loss, but can never go thinner.

 

[badman9]

You need to take the head off to determine which one you have, unless there is a visible piece of head gasket with the marks on it hanging out the side somewhere. These HG come in various thicknesses. You can go thicker and suffer a small amout of power loss, but can never go thinner.

Oh, that makes sense, and I have to assume that the higher number the greater the thickness? This really makes me wonder if I'll ever know which to use then.

Dilemma is this, in Jamaica there is only 1 size available in genuine toyota as far as I know, and I will have to go to the shop to see the part number since they won't tell me over the phone.

Alternatively, by time I pull the head to check, it is too late to then order the "right" one online, and i won't put the head back on and then do it over.

Of course, the HG in there right now isn't genuine toyota to begin with, so it is going to be a total guessing game when I do get around to changing it... fun fun!

 

[roscoFJ73]

Also take into account your head may not be 100% flat and may need machining or it will blow again. Some engines have "thumb print" . Its a bit like a thumb shaped depression that can be used to measure the HG thickness, I havent played with this side of engines for years so Im a bit rusty on it.
But you still have the unknown state of the cyl head

 

[badman9]

Also take into account your head may not be 100% flat and may need machining or it will blow again. Some engines have "thumb print" . Its a bit like a thumb shaped depression that can be used to measure the HG thickness, I havent played with this side of engines for years so Im a bit rusty on it.
But you still have the unknown state of the cyl head

Very very true indeed.
I will need to plan and prepare a bit to be without the vehicle for a while. None of the mechanics I use will do this for me in under a week, no chance

Oh well, will redo my front diff bushings while at it i guess

 

[badman9]

So in planning to get this work done, I decided I would finally invest in an aluminium radiator and get it done at when doing the head gasket (and whatever other fun surprises the engine might have for me)

My dilemma is this. The engine/rad currently has some cheap green coolant in there . I wanted to switch to either Toyota Red/pink or Zerex Asian, but I'm worried about being unable to properly flush out all of the green stuff that is in there.

Should I try to flush and switch to red/pink, or should I just stick to a decent quality green (prestone, valvoline etc)

 

[roscoFJ73]

I'm worried about being unable to properly flush out all of the green stuff that is in there

You just have to fill up with plain water, drive around , empty and flush with water again and empty. Then put the coolant/water mixture in. I would make sure the coolant is suitable for a aluminium rad.
Dont forget to turn the heater on.
Even if you used a green coolant, I would still be trying as hard to clean the old green coolant out.

 

[badman9]

You just have to fill up with plain water, drive around , empty and flush with water again and empty. Then put the coolant/water mixture in. I would make sure the coolant is suitable for a aluminium rad.
Dont forget to turn the heater on.
Even if you used a green coolant, I would still be trying as hard to clean the old green coolant out.

Good advice as always man. Just ordered the aluminium radiator from australia today, so it'll be a while before it gets to Jamaica. Will let you know when i'm all set up etc

 

[roscoFJ73]

What made you go with aluminium? Ive always liked the blurbs that come with them but owner reports are often dismal, leaves me undecided.

 

[badman9]

What made you go with aluminium? Ive always liked the blurbs that come with them but owner reports are often dismal, leaves me undecided.

Honest answer is that for whatever reason the stock radiator just doesn't seem to have enough cooling capacity for me (and other 1kz guys I know here).
For context, my clutch fan is good, water pump has been changed, relatively new oem-style radiator, separate tranny cooler, etc.

A perfect example is the main north-south highway in Jamaica has a 7km section where you gain about 700m (1/10 grade!!!) and almost every 1kz I know overheats going up there. Going slower helps but even at 50kmph the gauge will start creeping before you get near the top.

Basically, there isn't much space on the surf to get a larger copper radiator because of clearance issues with the fan, so I'm hoping for the increased cooling capacity of the aluminium. If it doesn't have the desired effect, only thing left to do after that would be to set up a water injection system to bring down intake temps and therefore EGT.

Running hot in the mountains has been a persistent thorn in my side with this surf, and sadly I'm not alone in that predicament. I'm sure you have seen the massive "cooling the 1kz" thread as well, so it seems to be a common challenge.

Thanks

 

[badman9]

Hi everyone,

Just thought I would follow up on this MONTHS later. This may morph into a long post depending, since I have some serious horror stories about this rebuild......

Firstly, let us focus on the radiator itself. I got it on e-bae from Australia. Aluminum Radiator for Toyota Hilux Surf KZN185 Diesel 3.0L 96-02 Manual MT | eBay

The fitment isn't perfectly level and flush, but I honestly think that is because of some previous damage to the front of my Surf from long before I bought it. Overall, the welds look good and the fitment was good, and i still have sufficient clearance between the fan and the rad. Usually, refilling the radiator on this vehicle would take just about 2 gallons of coolant, but this time it took a full 3 of Zerex Asian (less than half the cost of the toyota oem in Jamaica), so hooray for increased capacity (this rad core is 42mm vs the stock toyota 28mm).
Anyway, I've been breaking in the engine and driving around for the past month or so, and i've seen no sign of any leaks or overheats.
I changed the noname cap that came with the rad for the equivalent Sankei (made in Japan) and kept the one it came with in the car as a spare. I can't risk my VERY expensive rebuild for the sake of a 8US rad cap.

I also installed the much spoken about 71 degree thermostat, more for peace of mind than anything else, as well as a new GMB water pump, new hoses

The engine seems to take a bit longer to get up to temperature on a cold start, which isn't ideal, but i'll take that tradeoff for extra cooling when things are hot.

I even installed and set up a basic (stage 1) water injection system (see the extra washer bottle on the right) which I can turn on only when needed (long hill climbs) for extra protection.

I'm still deciding if to catalog my long list of problems during the rebuild here, or if to start another thread. I think some of my experiences, particularly with using high sulphur diesel could be helpful.

 

[Jdub94]

.

 

[Jdub94]

Hi everyone,

Just thought I would follow up on this MONTHS later. This may morph into a long post depending, since I have some serious horror stories about this rebuild......

Firstly, let us focus on the radiator itself. I got it on e-bae from Australia. Aluminum Radiator for Toyota Hilux Surf KZN185 Diesel 3.0L 96-02 Manual MT | eBay

The fitment isn't perfectly level and flush, but I honestly think that is because of some previous damage to the front of my Surf from long before I bought it. Overall, the welds look good and the fitment was good, and i still have sufficient clearance between the fan and the rad. Usually, refilling the radiator on this vehicle would take just about 2 gallons of coolant, but this time it took a full 3 of Zerex Asian (less than half the cost of the toyota oem in Jamaica), so hooray for increased capacity (this rad core is 42mm vs the stock toyota 28mm).
Anyway, I've been breaking in the engine and driving around for the past month or so, and i've seen no sign of any leaks or overheats.
I changed the noname cap that came with the rad for the equivalent Sankei (made in Japan) and kept the one it came with in the car as a spare. I can't risk my VERY expensive rebuild for the sake of a 8US rad cap.

I also installed the much spoken about 71 degree thermostat, more for peace of mind than anything else, as well as a new GMB water pump, new hoses

The engine seems to take a bit longer to get up to temperature on a cold start, which isn't ideal, but i'll take that tradeoff for extra cooling when things are hot.

I even installed and set up a basic (stage 1) water injection system (see the extra washer bottle on the right) which I can turn on only when needed (long hill climbs) for extra protection.

I'm still deciding if to catalog my long list of problems during the rebuild here, or if to start another thread. I think some of my experiences, particularly with using high sulphur diesel could be helpful.

View attachment 2458734

Ever find out exactly what was causing the outer leak? Mine has some staining on the outside, but doesn't look moist.. wondering if it was from previous owner and now fixed. But I did flush my system about a month or so ago and still have to refill my reservoir every few days as it gets low. Had an 80 series that did the same thing for about 3 months and then finally stayed full. But in curiosity I saw this thread and figured I'd ask in case I need to get ahead of something that might be serious!