1HDT Coolant into Overflow - What am I missing?

[crave reFleXion]

@perrobravo Did you block airflow to the radiator when you did the TeeKay test? It helps to bring it up to temperature quickly and sometimes you won't be pushing coolant until things get up to operating temperature and are under a bit of a load/stress. Your symptoms suggest combustion gas issue mate, which can be due to numerous reasons: head and block mating surfaces, improper head bolt torquing, using coolant instead of straight water for the first 1,000km, using any type of HG sealant Etc...

 

[cruisermatt]

You can't retorque TTY (torque to yield) head bolts.

sure you can.

does the book say you can? No. But it can be done

 

[cruisermatt]

Did this problem start as soon as you put it all back together after HG replacement? I just picked up an HDJ81 with the same problem and haven't dove in yet. Your setup sounds similar to mine - Gturbo badboy set at 28lbs, OEM HG and bolts.

My plan of attack is to re-torque every head bolt one at a time and see if that helps. If not, I'm going to take the head off and put on ARP studs and a new HG.

one at a time as opposed to multiple at a time?

 

[BiffS]

Adding to the list.

We currently have FOUR engines in shop with this same issue, although 3 of them are exhibiting a very specific knocking at around 2250 RPM. All have seen service (i.e. water pumps/ thermostats/ BEBs, fuel pumps at least checked, coolant system checked) and they all push coolant on loading. All are automatic. Clutch fans also checked. I've also taken a call from an owner with a 1HZ reporting the same coolant push issues.

#1 and #2 are OEM, and as far as can be told, not rebuilt. Fuel pump and injectors in one have been recently rebuilt by a very reputable shop. Pump time verified as spot on.

#3 was rebuilt to attempt to solve the knock/ coolant push issue (not by us), We replaced the head gasket after about 15,000 km logged on it and later broke the crank in two places on cylinders 5 and 6. It now has a new block and crank, and still exhibits the knock/ coolant push issue. Also had the pump rebuilt by a different reputable shop, and has new injectors and factory new radiator.

#4 is owned by a former Toyota business owner and the motor has been fastidiously maintained and serviced, including a recent rebuild, where everything was magnafluxed and done properly. Does not exhibit the 2200 rpm knock, but pushes coolant.

So the only real common denominator here is that they all have AISIN water pumps with the plastic impeller (3 verified, 1 probably). I'm wondering if it's a matter of insufficient flow due to cheaping out on the castings/ clearances, so they simply don't flow enough. We have verified that 2 of them continue to bubble when the engine has been shut off for a couple minutes, suggesting that head gaskets or block compression leakage is not a likely culprit.

Other considerations: Maybe the local fuel supply has some oddities going on with it? One has tried adding cetane booster/ modified pump ratios, etc without change.

We are Westcoast, Canada located.

 

[OGBeno]

Very interesting indeed.... This kind of data is super weird. I wonder if the Ozzies or others globally are having these issues with these old engines..

 

[crave reFleXion]

sure you can.

does the book say you can? No. But it can be done

And how would you go about doing that? The last time I rebuilt my 14BT I used a digital torque wrench and recorded the final two 90 degree torque measurements to see what the actual torque would be. Perhaps you could then retorque to those measurements, but I thought that once TTY bolts stretch you can't reuse them? So, pray tell 'how can it be done?'

 

[perrobravo]

Adding to the list.

We currently have FOUR engines in shop with this same issue, although 3 of them are exhibiting a very specific knocking at around 2250 RPM. All have seen service (i.e. water pumps/ thermostats/ BEBs, fuel pumps at least checked, coolant system checked) and they all push coolant on loading. All are automatic. Clutch fans also checked. I've also taken a call from an owner with a 1HZ reporting the same coolant push issues.

#1 and #2 are OEM, and as far as can be told, not rebuilt. Fuel pump and injectors in one have been recently rebuilt by a very reputable shop. Pump time verified as spot on.

#3 was rebuilt to attempt to solve the knock/ coolant push issue (not by us), We replaced the head gasket after about 15,000 km logged on it and later broke the crank in two places on cylinders 5 and 6. It now has a new block and crank, and still exhibits the knock/ coolant push issue. Also had the pump rebuilt by a different reputable shop, and has new injectors and factory new radiator.

#4 is owned by a former Toyota business owner and the motor has been fastidiously maintained and serviced, including a recent rebuild, where everything was magnafluxed and done properly. Does not exhibit the 2200 rpm knock, but pushes coolant.

So the only real common denominator here is that they all have AISIN water pumps with the plastic impeller (3 verified, 1 probably). I'm wondering if it's a matter of insufficient flow due to cheaping out on the castings/ clearances, so they simply don't flow enough. We have verified that 2 of them continue to bubble when the engine has been shut off for a couple minutes, suggesting that head gaskets or block compression leakage is not a likely culprit.

Other considerations: Maybe the local fuel supply has some oddities going on with it? One has tried adding cetane booster/ modified pump ratios, etc without change.

We are Westcoast, Canada located.

Thanks for the input, @BiffS !

I changed the water pump on mine around 35K kilometers ago in September 2017. I couldn't find pictures to confirm whether the new AISIN pump has a plastic impeller. Maybe someone who knows more about this (ahem... @Onur ) would know based on the dates? While I'm not excited about having to replace the water pump so soon, I'd be much happier to have that be the problem than a warped block, cracked head, etc. that @ToyotaMatt has me worried about!

By the way, @ToyotaMatt , here's another pic/T-TEN instructional aid from the same museum in Nagoya. I was tempted to harvest parts when I was there a few years ago, but realized that was probably a bad idea for a number of reasons. I didn't know it at the time, but I've used the pictures I took that day several times as reference when working on random stuff.

 

[cruisermatt]

And how would you go about doing that? The last time I rebuilt my 14BT I used a digital torque wrench and recorded the final two 90 degree torque measurements to see what the actual torque would be. Perhaps you could then retorque to those measurements, but I thought that once TTY bolts stretch you can't reuse them? So, pray tell 'how can it be done?'

torque wrench go “click”

 

[OGBeno]

All of the 16100-19235 water pumps in OEM or aftermarket Aisin form have plastic impellers.

 

[crave reFleXion]

torque wrench go “click”

Mine goes "beep" actually...

 

[ToyotaMatt]

Thanks for the input, @BiffS !

I changed the water pump on mine around 35K kilometers ago in September 2017. I couldn't find pictures to confirm whether the new AISIN pump has a plastic impeller. Maybe someone who knows more about this (ahem... @Onur ) would know based on the dates? While I'm not excited about having to replace the water pump so soon, I'd be much happier to have that be the problem than a warped block, cracked head, etc. that @ToyotaMatt has me worried about!

By the way, @ToyotaMatt , here's another pic/T-TEN instructional aid from the same museum in Nagoya. I was tempted to harvest parts when I was there a few years ago, but realized that was probably a bad idea for a number of reasons. I didn't know it at the time, but I've used the pictures I took that day several times as reference when working on random stuff.

HOLY COW

thats a keeper image thanks !

where did u dig this up ?

always a new day of learning new and exciting things here on MUD !

 

[BiffS]

HOLY COW

thats a keeper image thanks !

where did u dig this up ?

always a new day of learning new and exciting things here on MUD !

Umm.... I took it of my truck?

 

[roscoFJ73]

So the only real common denominator here is that they all have AISIN water pumps with the plastic impeller (3 verified, 1 probably). I'm wondering if it's a matter of insufficient flow due to cheaping out on the castings/ clearances,

You can easily verify its pumping by removing the upper radiator hose and observing the coolant flow, but I think they work well. Ive replaced 2 and the impeller was like new both times as I had a new OEM to compare them with. They were just weeping out the hole on the base

This kind of data is super weird. I wonder if the Ozzies or others globally are having these issues with these old engines..

The coolant level is supposed to rise and fall in the overflow bottle . But I haven't heard of any out of the ordinary issues. Most of them are 1HZ with turbo's .The 1HD T with direct injection is supposed to run cooler than the 1HZ.
The last pump I changed, I used an aftermarket pump with a metal impeller, it appeared to be good quality and and caused no problems. The impeller copied the plastic OEM design but I think it had an extra blade. There were some with metal impellers around a few years back and they looked crap, but a reputable dealer said they backed them.
I think it was a GMB like this . I used one of their clutch fans as well which worked ok. Its a Japanese brand that is also OEM on some vehicles

 

[ToyotaMatt]

Thanks for the input, @BiffS !

I changed the water pump on mine around 35K kilometers ago in September 2017. I couldn't find pictures to confirm whether the new AISIN pump has a plastic impeller. Maybe someone who knows more about this (ahem... @Onur ) would know based on the dates? While I'm not excited about having to replace the water pump so soon, I'd be much happier to have that be the problem than a warped block, cracked head, etc. that @ToyotaMatt has me worried about!

By the way, @ToyotaMatt , here's another pic/T-TEN instructional aid from the same museum in Nagoya. I was tempted to harvest parts when I was there a few years ago, but realized that was probably a bad idea for a number of reasons. I didn't know it at the time, but I've used the pictures I took that day several times as reference when working on random stuff.

to be clear not trying to worry you or make you fret in any way

just trying to help and share my related experience

sorry if the tech comes across harsh , its just a possible reality

 

[roscoFJ73]

We currently have FOUR engines in shop with this same issue,

Are these engines in vehicles or imported engines on stands?

 

[BiffS]

Are these engines in vehicles or imported engines on stands?

No worries at all. We're all adults here!

3 are in trucks, one is on a pallet presently.

All JDM trucks.

 

[roscoFJ73]

3 are in trucks, one is on a pallet presently.

All JDM trucks.

I often wonder of the problem existed when they were with their previous owners. Its like a few years back when all the 2LT variants were blowing up.

 

[BiffS]

I often wonder of the problem existed when they were with their previous owners. Its like a few years back when all the 2LT variants were blowing up.

As noted, #3 was fully rebuilt... twice. head magnafluxed, measured, checked, and by two different, but reputable machine shops. in the end, it had a completely new bottom end.

2LT trucks are the flawed design issues that we've all heard so much about, but they still fetch top dollar on BAT.

 

[roscoFJ73]

I know about the flaws in the 2LT, but I still suspect many were offloaded into export markets because the owner knew it had a problem.

Just how much coolant are they pushing out?

 

[roscoFJ73]

I have this one going on too. After a hard tow in a 30mph headwind this started, despite not overheating. I'm really hoping its a headgasket and not a cracked head. After about 3 hours of hard hilly driving, or even an hour sometimes, I'll have a completely full reservoir. It does pull it all back in to the engine however when it cools down, sometimes overnight, sometimes after a day driving around town and a full cool. If I'm just putting around town, even if it is very hot and the engine runs at a 85-90*C (normally I'd say it sticks between 80-85*C) it wont' fill the reservoir beyond a small bit of expansion and contraction. When the reservoir is full there is some bubbling from the radiator fill tube, which makes sense from the pressure and air that's displaced in to the radiator. I guess I'm just venting here... I hope I can get this sorted, and that it's not a cracked cylinder head.

Maybe you are overfilling it. Ive noticed on the 1HZ's they don't stay full in the top tank and are usually about 1/2 an inch above the core. Radiators tend to find their own level if everything is working ok. Ive gone 18 months without topping them up , even in hot weather.