Another 2013 Head Gasket

[linuxgod]

This problem exists across many of Toyota’s engines including the GR V6, as they all use the 105.5mm bore spacing with cross drillings. The 3UR just seems to be the worst of them due to the cooling jackets. The system doesn’t run hotter overall, it runs hotter around the cylinder block walls, in certain areas, due to the coolant jacket insulating design used for the V8. The intake side is very restricted, especially when compared to other Toyota engines, and that is where the passages are that feed coolant between the cylinders, that’s where the head gasket blows. It also blows in the same spot on the GR V6, it’s just not as restricted in the coolant jacket area, so we hear of it less. That’s the best I can come up with with the info we have.

The GX 1UR is lower power, so perhaps that allows it to sneak by with less failures? All the UR Series engines use the same coolant jacket spacer, but I suspect other differences in the various vehicles cooling systems (example, many Lexus cars with the UR have degas/expansion tanks) and overall vehicle designs limit the failures here, too.

If you had to pull the heads to replace the HG, would you modify the coolant jacket spacer somehow?

 

[bjowett]

Yes, I would, at a minimum, trim some of the upper portion away. How much needs to be determined. There is a line molded in to the spacer that matches the opposite open exhaust side. It also aligns with the entry height of the of the blocked off cross drill holes. Perhaps, we should make a thread outside of @Wolvie head gasket failure and get all the info contained in one place?

 

[sdnative]

If you had to pull the heads to replace the HG, would you modify the coolant jacket spacer somehow?

I was going to ask the same question

 

[Wolvie]

I'll have to look for that thread. HG failure definitely isn't acidity alone but it is a big factor. I'd like to hear more from OP regarding if he is the original owner and the cooling system maintenance.

There are many variables that can bring light to main causes. We're you the original owner and did you do the radiator replacement during your ownership? Did you often have your vehicle under heavy load or just leisure cruising?

FWIW - I got my 2013 with 83k, did a coolant change before 100k. Ended up needing radiator replacement at around 130k, so new coolant then. Now I'm at 148k and the HG went bye bye.

*Edit - would be interesting to know the % of HG failures that also had prior radiator replacements. No idea how they would correlate, but it's coolant related and the rad is a known failure point.

 

[04UZJ100]

FWIW - I got my 2013 with 83k, did a coolant change before 100k. Ended up needing radiator replacement at around 130k, so new coolant then. Now I'm at 148k and the HG went bye bye.

*Edit - would be interesting to know the % of HG failures that also had prior radiator replacements. No idea how they would correlate, but it's coolant related and the rad is a known failure point.

Radiator doesn’t fail due to coolant chemistry. It fails due to stress risers developing and cracking from thermal-cycling around a poorly designed initial injection mold.

 

[bloc]

Now I'm wishing I had the forethought to modify the cooling jacket liners while I had the heads off.

This problem exists across many of Toyota’s engines including the GR V6, as they all use the 105.5mm bore spacing with cross drillings. The 3UR just seems to be the worst of them due to the cooling jackets. The system doesn’t run hotter overall, it runs hotter around the cylinder block walls, in certain areas, due to the coolant jacket insulating design used for the V8. The intake side is very restricted, especially when compared to other Toyota engines, and that is where the passages are that feed coolant between the cylinders, that’s where the head gasket blows. It also blows in the same spot on the GR V6, it’s just not as restricted in the coolant jacket area, so we hear of it less. That’s the best I can come up with with the info we have.

The GX 1UR is lower power, so perhaps that allows it to sneak by with less failures? All the UR Series engines use the same coolant jacket spacer, but I suspect other differences in the various vehicles cooling systems (example, many Lexus cars with the UR have degas/expansion tanks) and overall vehicle designs limit the failures here, too.

IIRC you retrofitted an expansion tank to at least one of your vehicles.. would you consider this a worthwhile investment for those people really hoping to avoid this fate?

 

[bjowett]

Yes, IMO the ability of the VDJ expansion tank to degas the coolant is worthwhile here. All good cooling systems should have one.