Amazing that they figured it out if this is the issue before Nissan engineers did

 

Wouldn't surprise me if nissan knew at some point a ways back, but financially in their best interest to keep denying engine failure warranty due to "sludge" (caused by the coolant in the oil) instead of acknowledging that there is an inherent design flaw. Foresee a kia or GM L87 style lifetime warranty coming from this eventually...

And btw isn't Nissan supposed to run out of money to even support basic operations this fall lol?

 

OK, so that is the WHAT of the problem. Didn't answer the WHY part of the issue.

Casting defect?

Too much torque applied to the headbolts during assembly?

Poor design?

 

They said all the coolant passages around the exhaust ports lead to thin walls in that area and the sharp edge creates a stress riser so an inherent flaw. Someone probably messed up their nastran FEA model lol or they did a "minor" change after the modelling had been done. Maybe exacerbated by a tq issue on the head bolt / manufacturing issue since they say it is more common on the one head than the other, but has been seen on both.

 

No wonder they're going under. Having to replace these motors under warranty at $30k a pop isn't a good business model.

 

Not to mention, which we all should know, they have to replace the turbos too.
I'm waiting on a backorder for a block and second set of turbos for over 115 days.

 

this is epic!, and I am a new AMS fan, i guess if you want a new engine get one from them ?? $15.5k stage 1 (no turbos included)

 

but whats interesting is this OEM engine is discontinued , so are we all just the last survivors...

 

Really? What's going into the Z's? Did they just completely give up on this engine entirely?

 

I think the 400Z VR30 would have been revised, but I don't know if the part numbers have changed, considering its fairly new in the game now.

 

Maybe so few people bought the new Z that it won't be a big issue lol. I seriously think I have seen like two ever on the road.

 

This is interesting development, we (the private techs I know) knew that it wasn't porous, glad to see somebody with the resources like AMS does investigate it. Infiniti has refused to investigate it, and techs are told to just immediately replace block so none of it is ever truly investigated. Not to mention the time and tools required.

I still am extremely curious as to what they have found with the galley plugs, I will send an email and hope for the best. The galley plugs and washer replacement had helped dozens of independent people so I'm not sure what the verdict on that is.

The plugs showed varnish almost exclusively on the driverside bank 1, and as ams mentions the cracks are on bank1, after re-watching the video im assuming then the crack is just moving aggressively to those plugs.

"We have found that there is an updated part number that we have not found this issue in yet. That is not to say the issue has been solved, just that we have not encountered it yet in our testing."

Let's find the part number

It makes sense it was so hard to find, techs arent literally sawing the head in half like ams, and surely no independent is haha.

 

part number as in a different block?

 

Shame the emissions required them to have that cooling jacket around the exhaust port. Must get quite hot there with all three cylinders using that common opening, so relatively close from source.

Only thinking out loud here: Shame it can't be structurally filled and that area bypassed (so rest is normal cooling operation)...probably not worth the effort though.

Also, wonder if it's simply the 'design' and not the casting quality on some. There is consistency but also differences in mass-produced items, even say 3% of total produced can seem like a lot of cases, even though small percentage.

 

They said that there is a newer part # that they have yet to see issues on, they didn't specify the change or the #. They also said that its affected 40% of the engines they have opened that is extreme for a factory machined block/design.

 

Interesting. I am glad a legitimate company has begun looking further into this as all there currently is, are mostly first-hand experiences with this issue. Their testing seems extensive and legitimate.

This problem seems to range from the water pump, to radiator cap, coolant lines, reservoir tank being warped, to the final porous block being an issue; which even then it varies.

I had coolant issues, particularly an external leak. I too was doubtful that the casting itself was porous, as like many mentioned, a porous block would show wear much earlier on into a cars life as opposed to the mile ranges we see by reported users, which is all across the board. I changed my thermostat and reservoirs but had a continued leak. Based off of Depanda's q50 thread here about galley gaskets, I decided to look into them. He informed me that similar to what AMS has reported here, that while the galleys stopped his leak, he actually had a cracked head bolt where it continued to leak. In a Hail Mary attempt, I had my galley gaskets replaced and that stopped the leaking coolant for me. For any users interested, I have a thread on my journey trying to resolve my coolant loss.

For any users trying to resolve their coolant loss: 1) Doing an oil test to check if your oil is mixing. This will show any external leaks (Either through Blackstone or just pour coolant UV dye into your reservoir. Using a blacklight, you can open your oil cap and see if the UV activates. If it does, you know your coolant and oil is mixing. You can also just check for milk substance). 2) UV dye or oil test will let you know how to proceed. Galley gaskets are super cheap, the labor is what will get you.

 

Have a question. Maybe I should ask AMS, but thought one might know the answer.
I understand how AMS can pressure check and guarantee that the engine they supply, block fine, and heads will not have the crack(s), but how can they guarantee they won't crack in the future when in use, especially if there is a design problem?

I know the Kia/Hyundai engine problem that now has a lifetime warranty and has surpassed a million replacements, they know the problem, but they do the replacement with the same engine, no changes in design, and some have needed it replaced three times. They don't correct the problem, they just use a new long block and hope the engine will last until the car has died of old age, but if not, just replace it once again.

Just curious.

 

When they say they can guarantee they are talking about their fully built long blocks.
As of today's video, No oem head is safe. They said there is an updated part # with no issues but didnt say updated what or # GRRR. I'm assuming 2023+ (nissan z included) heads.

 

OK, so that is the WHAT of the problem. Didn't answer the WHY part of the issue.

Casting defect?

Too much torque applied to the headbolts during assembly?

Poor design?

Poor design is the root cause, but multiple things can actually cause the problem as they didn't leave enough material around the coolant channels and head bolts, so there is very little margin for error during casting and being slightly over on the torque spec means its easier to over torque the head-bolts and cause a crack.

This is interesting development, we (the private techs I know) knew that it wasn't porous, glad to see somebody with the resources like AMS does investigate it. Infiniti has refused to investigate it, and techs are told to just immediately replace block so none of it is ever truly investigated. Not to mention the time and tools required.

I still am extremely curious as to what they have found with the galley plugs, I will send an email and hope for the best. The galley plugs and washer replacement had helped dozens of independent people so I'm not sure what the verdict on that is.

The plugs showed varnish almost exclusively on the driverside bank 1, and as ams mentions the cracks are on bank1, after re-watching the video im assuming then the crack is just moving aggressively to those plugs.

"We have found that there is an updated part number that we have not found this issue in yet. That is not to say the issue has been solved, just that we have not encountered it yet in our testing."

Let's find the part number

It makes sense it was so hard to find, techs arent literally sawing the head in half like ams, and surely no independent is haha.

They spoke about the plugs very briefly in the video, the crush washers used for the gallery plugs (while not impossible ) never came up in their testing it is the head bolts right next too the gallery plugs. So its possibly a misdiagnosis and the gallery plugs are just the low point and coolant is pooling there after cracks develop or as you said the cracks are traveling towards the plugs.

 

Poor design is the root cause, but multiple things can actually cause the problem as they didn't leave enough material around the coolant channels and head bolts, so there is very little margin for error during casting and being slightly over on the torque spec means its easier to over torque the head-bolts and cause a crack.

Also throw the temperature gradient that exists across that small cross-section (exhaust gas temp vs coolant temp) during operation. Different thermal expansion rates due to temp differences within the Aluminum casting can cause crack propogation.

It's all additive.

 

So can we replace a Q50 VR30 engine with a Nissan 400z VR30? Assuming you had a failure this might be a good way to go

 

You can but only with a manual z motor. The 9 speed has something different on the crank that makes the engine incompatible with any 7 speed.

 

I wonder if AMS is more likely to get failed engines sent in than healthy ones? Cause that’s 2x the rate of coolant contaminated oil engines that blackstone saw.

Guessing dealer doesn’t see a LOT of these as it seems to be failing past warranty on a lot of cars, and they dismiss a lot of failures because of “sludge”. So the probably low % failure rate is the 2% I think realfake has quoted seeing in dealer, and then the 20-40% from blackstone and AMS on the (very) high side.

 

….regardless at this point there is likely enough data that someone with an out of warranty failure could probably contact a lawyer because I think that’s likely how most warranty extensions end up coming about.

Or just takes an engine or two grenading in traffic reported to NHTSA and they will probably start the investigation themselves

 

Some Japanese executive needs to fall on his sword.

 

Some Japanese executive needs to fall on his sword.

Seppuku

 

I can attest that coolant leaking into the VR30 oil has potentially explosive results getting on to a highway.🥴

 

Yeah but you feed your VR30 beans, is it any shock that it shat itself on the highway one day? I kid, I kid.

 

I'm referring to the situation of the VR30. I haven't heard of any of these results occurring with the VR30 (though I understand anything is possible). Most VR30 failures from this issue were identified the loss of heating in the cabin, rising / overheating of the engine, engine noises, flashing mil light, reduced performance, etc....

By the way, I'm not arguing against you or anyone else. I'm just sharing what my understanding is of how NHTSA approaches situations like this.

I can attest that coolant leaking into the VR30 oil has potentially explosive results getting on to a highway.🥴

Did you make a report to NHTSA? It was literally only like 5 or 6 GM L87 reports of grenading on the highway that got it deemed a safety defect IIRC

 

Oh - I most certainly knew (as did Infiniti thanks to Blackstone oil reports) that we had coolant in the oil. The engine was ticking just before it gave way - we all heard the ticking post OCI at the dealership. My tech and service advisor all knew the engine was on its last leg due to the contaminated oil.

 

I found this from a question and answer via AMS:
"Did Nissan ever update this? Does a 2024 still when the same head as a 2016?"
AMS: "Actually, yes. To your first question, which would then be a no to your second. There is an updated part number where we have not yet seen the issue. But that does not definitively mean the issue is rectified, just that we have not seen it yet in our testing."

I still don't know why they wont say the part or part number, I'm assuming it's just updated RH Bank1 Cylinder but need to know the exact year. Not sure why its being gatekept, I understand they say its not full-proof but if they go from 40% of RH cylinders' cracked to 0% in new Rev. thats something. I'm going to call up my parts guy. If anybody finds the part# again please post it

 

I suspect AMS just doesn't want to confirm the part number and potentially push people into buying the new heads when they aren't sure if its an actual fix to the problem.

Based on the parts catalogue for online resources the new heads should be 110904HK0E and were changed around 2020 MY as its listed as replacements for 2016-19, this is also somewhat backed up by our own thread tracking the issue and there is pretty much zero Q50's from after 2020 that report the issue.

The Q50/Q60 sales fell off massively after 2020 so the sample size and number of people who could report on issues like that are much, much smaller so it may be why we simply don't see the issue on later model year cars.

@Phagan90 - Think you could confirm what the newest Part number is for the VR30 cylinder heads per chance?

 

I guess I don’t have to worry yet. 🤣🤣🤣

 

Design flaw, I believe it's something we all knew inside... Also I do believe 2020+ q50s/q60s still have coolant issues, so I don't believe infiniti's revised heads have solved the issue.

So will aftermarket heads fix the issue?

 

Ostensibly, yes aftermarket heads would fix the issue, assuming proper engineering and finite element analysis are done on the stressed areas of the cylinder heads and throughout. The problem is that nobody makes aftermarket heads for the VR30. It's possible that AMS will make some, but that's going to be a sh!t ton of R&D work, and they're not gonna be cheap. I don't think AMS has manufactured heads for any car. A bare VR38 cast aluminum stock block will run ≈ $8,650.

They did make their own VR38 block though. It's CNC machined from billet aluminum, but it costs $25,000. So rough estimate, maybe take the factory head price and triple it...if they decide to build them. And if you're going to that extent, you're probably doing higher lift cams, bigger valves, etc. I dunno, maybe they'll pull a rabbit out of the hat for the community-- never know.

 

Can confirm, ‘20 puked coolant internally at 82,000. Probably plummeting sales and lower mileage on the 20’s just mean there aren’t as many victims yet

 

oh damn, no warranty with that mileage im guessing? what did you do again? (i have seen your posts around here but apologies can't remember)

 

Yeah I don’t think I would ever buy a high mileage Q50, guessing like 90% are on deaths door lol