13BT coolant leak: missing freeze plugs (tight plug Number 1) question

[Mardie]

Hello,

first time posting on the forum here, but have been a member for some time. I tried searching already, but didn't come up with any results. (Or maybe I'm not using the proper search term). I'm grateful for the amount of knowledge found here.

2 months ago bought a BJ74 with a 13BT engine and so happy with it. Recently I noticed coolant dripping on the floor and decided to check where the leak is coming from. I had to remove the turbo and exhaust manifold and found the leaks. In the picture below I circled in green where the coolant is leaking. Circled in purple, there is no coolant leaking. None of the 4 holes in the picture have freeze plugs. Not sure if they popped out some time ago.

The diameter of the holes are 12mm, so I purchased some generic 12 mm freeze plugs. However, no luck, as they are too small and just sit loose in the hole. I ordered the original plugs (Part No.: 96411-41200), waiting for them to arrive. I ordered it last week and the order is still being processed

My question: is it normal that coolant only leaks from the 2 holes, even with all the 4 freeze plugs missing? (I'm assuming all these holes need the plugs. I may be wrong)

Also posted a picture of the car. It's imported from South Africa by the previous owner. Now getting a new life in Suriname, South America.

thanks in advance!

 

[FJBen]

Hello,

first time posting on the forum here, but have been a member for some time. I tried searching already, but didn't come up with any results. (Or maybe I'm not using the proper search term). I'm grateful for the amount of knowledge found here.

2 months ago bought a BJ74 with a 13BT engine and so happy with it. Recently I noticed coolant dripping on the floor and decided to check where the leak is coming from. I had to remove the turbo and exhaust manifold and found the leaks. In the picture below I circled in green where the coolant is leaking. Circled in purple, there is no coolant leaking. None of the 4 holes in the picture have freeze plugs. Not sure if they popped out some time ago.

The diameter of the holes are 12mm, so I purchased some generic 12 mm freeze plugs. However, no luck, as they are too small and just sit loose in the hole. I ordered the original plugs (Part No.: 96411-41200), waiting for them to arrive. I ordered it last week and the order is still being processed

My question: is it normal that coolant only leaks from the 2 holes, even with all the 4 freeze plugs missing? (I'm assuming all these holes need the plugs. I may be wrong)

Also posted a picture of the car. It's imported from South Africa by the previous owner. Now getting a new life in Suriname, South America.

thanks in advance!

View attachment 4046928View attachment 4046931

Welcome to mud!

Nice 74!

Here’s my engine when I rebuilt it. There aren’t any plugs there. You can see thats for the headbolt that goes through to the block, but there aren’t any plugs per se on the holes.

And here after 5 years of driving on the rebuild. Fixing a few leaks.

There shouldn’t be any coolant coming from those holes. The turbo sits there so are the lines from the turbo leaking?

If coolant truly is coming out of those holes then your head would have to be cracked somewhere for coolant getting there.

 

[Mardie]

Thank you!

I was looking at the parts diagram, so I may have incorrectly assumed that a tight plug is needed (4 needed looking at the part details).

I can see the coolant dripping out of these two holes (stole your picture, as this is much clearer), for sure not leaking from turbo. So from the looks of it, it's a bad head? . Do you know if this can be fixed, or I should be on the lookout for a new head?

 

[FJBen]

Thank you!

I was looking at the parts diagram, so I may have incorrectly assumed that a tight plug is needed (4 needed looking at the part details).

View attachment 4046978


I can see the coolant dripping out of these two holes (stole your picture, as this is much clearer), for sure not leaking from turbo. So from the looks of it, it's a bad head? . Do you know if this can be fixed, or I should be on the lookout for a new head?

View attachment 4046988

Can you get a better picture of the leak?

It’s possible it’s the head gasket, especially if it’s the original, that leaking and getting to those bolt hole areas.

 

[Mardie]

Ok..cool...will snap a picture tomorrow at daylight. Let's hope it's the gasket. I already have the gasket kit, but waiting for the finances to do a full rebuild.

 

[Mardie]

Just a quick update: over the weekend I brought the car to my mechanic. Decided to go ahead with removing the head and see what's going on. Hopefully just the gasket. Will have the head checked as well by a machine shop. Will update as soon as the head returns.

 

[Mardie]

So the head was removed. Confirmed it was the gasket. The head bolts were also a bit loose . Tomorrow pressure testing, fingers crossed the head is ok.

 

[duncanrm]

Good luck with the pressure test!

 

[FJBen]

So the head was removed. Confirmed it was the gasket. The head bolts were also a bit loose . Tomorrow pressure testing, fingers crossed the head is ok.
View attachment 4048879

View attachment 4048888
View attachment 4048890View attachment 4048891

The 13bt heads are tough. I’m guessing it’s just your old composite head gasket failure causing the leaks.

Put an MLS gasket on, surface the head correctly, go over the head since you have it off. Replace valve seals, make sure valves/springs are all good and in spec, clean it all up, clean the block and it should be good to go.

 

[Mardie]

So here I am. Today finally got news on the pressure testing: the head has a crack. So now the search begins for a replacement head (or maybe a replacement engine). I may have some luck, a local part store has a 13B head in their inventory system, but they need to confirm if it's really in stock. Fingers crossed

Update: head is available, for USD 1600 (brand new). Will search for other options first

Update 2: Multiple cracks actually, as pictured below, between the valves

 

[Eurasiaoverland]

If that's a new genuine head, jump on it! Parts for the 13B-T are very rare, and a used head would not be much less (in the US or Europe etc).

A 14B or 15B engine would be a nice upgrade if you can fund a factory turbo version.

 

[Mardie]

If that's a new genuine head, jump on it! Parts for the 13B-T are very rare, and a used head would not be much less (in the US or Europe etc).

A 14B or 15B engine would be a nice upgrade if you can fund a factory turbo version.

Hmm, something to consider.

Is the 15B a direct fit? There's one available locally, however, with light blow-by according to the seller.

 

[wesintl]

3b and 13bt always crack between the valves. It might not be leaking into the cyl. If you weren’t losing coolant before you might be ok. Slap a hg in a run it.

 

[Eurasiaoverland]

Hmm, something to consider.

Is the 15B a direct fit? There's one available locally, however, with light blow-by according to the seller.

Yes, the 15B will fit straight to the transmission and engine mounts. There will be minor adjustments to intake piping, turbo coolant lines, heater hoses (if you have the heater connected there) etc. A 15B is an easier rebuild as parts are still available.

 

[Mardie]

3b and 13bt always crack between the valves. It might not be leaking into the cyl. If you weren’t losing coolant before you might be ok. Slap a hg in a run it.

Thanks for this info. Know anyone in the forum that has done this?
The coolant was leaking from (what I incorrectly thought) the freeze plug holes. Apparently the head gasket was blown and some of the head bolts were not torqued to spec (actually loose/finger tight). There was no coolant in the cylinders and no milky engine oil. The engine was running fine, without any issues or noticeable power loss (only very high vibrations at low RPM/idle).

 

[Mardie]

Yes, the 15B will fit straight to the transmission and engine mounts. There will be minor adjustments to intake piping, turbo coolant lines, heater hoses (if you have the heater connected there) etc. A 15B is an easier rebuild as parts are still available.

Good to hear. Let me do some research on this.

 

[Eurasiaoverland]

Thanks for this info. Know anyone in the forum that has done this?
The coolant was leaking from (what I incorrectly thought) the freeze plug holes. Apparently the head gasket was blown and some of the head bolts were not torqued to spec (actually loose/finger tight). There was no coolant in the cylinders and no milky engine oil. The engine was running fine, without any issues or noticeable power loss (only very high vibrations at low RPM/idle).

The 13Bs came from the factory with a composite head gasket that over time has been shown to fail. Toyota has replaced this with an MLS (multi-layered steel) head gasket that cures this issue.

I would guess that coolant has run low due to the leaking HG and then the head has cracked from low coolant/local overheating. I expect your block surface may have corrosion from the hot coolant, and might need machining.

I would not wase my time running a cracked head in any engine, and certainly not a turbocharged engine.

 

[Mardie]

The 13Bs came from the factory with a composite head gasket that over time has been shown to fail. Toyota has replaced this with an MLS (multi-layered steel) head gasket that cures this issue.

I would guess that coolant has run low due to the leaking HG and then the head has cracked from low coolant/local overheating. I expect your block surface may have corrosion from the hot coolant, and might need machining.

I would not wase my time running a cracked head in any engine, and certainly not a turbocharged engine.

Thinking of replacing the HG first and see how it goes (since I already have the gasket kit).
In the meantime, I can get the 15B engine, rebuild it and have it ready if the 13B decides to blow .