Infiniti Q50 Forum banner
61 - 80 of 95 Posts

· Registered
St. Louis, MO
Joined
·
1,706 Posts
I want to update that the exact source of the coolant mixture was due to bad core (freeze) plugs on both cylinder heads.
Whoa...is this what the porous block issue is in all cases? The issue never made sense to me...how if the block was truly flawed in casting that it wouldn't drink it's own coolant from day 1. This would explain it...that these plugs (which I never knew existed until now) are substandard and are failing after years and tens of thousands of miles.
 
  • Like
Reactions: Batell

· Premium Member
2016 Infiniti Q50 Red Sport AWD
Joined
·
16 Posts
Did you have 3rd party extended warranty? @Mikeymike11
Yes, however, I did have infiniti certified (used car) warranty until that ended when I hit 75k (4yr/75k). What sucks, when i decided to take it in, I hit 79k(long commute for work for 2yrs) and I just purchased warranty from Fidelity a few months prior (i know there are better ones, was cheap for what they offered). So, that made me look sus. However, the warranty inspector worked with my service advisor in the past, so was told it was a quick conversation and obviously the issue was not caused from neglect/abuse. I gathered all my receipts of purchasing regular maintenance items that I do myself, parts, etc. all ready to go, but was told no need.

Bad news is, Fidelity took me off their warranty, but since I had to pay 8k, as a "deductible", (contract was $100 deductible, but circumstances made it difficult), Infiniti hooked me up w/ a contract for a 2yr/45k warranty on the entire motor including components, w/ free parts/labor. I worked for Nissan in my younger days, I know how much Infiniti made off that 28k, so I knew they had no problem saying yes when I asked if I could purchase warranty from them when the advisor told me Fidelity cut me off.
 
  • Like
Reactions: nickdaria

· Premium Member
2016 Infiniti Q50 Red Sport AWD
Joined
·
16 Posts
Whoa...is this what the porous block issue is in all cases? The issue never made sense to me...how if the block was truly flawed in casting that it wouldn't drink it's own coolant from day 1. This would explain it...that these plugs (which I never knew existed until now) are substandard and are failing after years and tens of thousands of miles.
You know, maybe it could. I did a little research and asked some older car buddies and my brother who is a machinist for Boeing and has metal casting experience. It sums up that that it could involve those plugs, the surrounding surfaces where they are pressed in, the quality of them, and/or something with the water jackets having porosity (created during casting and/or later developed due to quality). I watched some videos on engine casting to learn more and doing a little more research. Hopefully this gets solved some day, to know how it started. I just hope this doesn't happen again. I will be doing an oil analysis twice a year now, incase it happens again, can catch it early before it gets worse.
 

· Super Moderator
Joined
·
4,224 Posts
So has the porous block issue been addressed by Infiniti?
They'll never tell. A good gage will be any reports from 400Z owners, which may take awhile.

A porous block is much about manufacturing and introducing defects into the Aluminum casting, which is inevitable, and then not having effective methods to screen out the bad actors.
 

· Registered
Joined
·
738 Posts
They'll never tell. A good gage will be any reports from 400Z owners, which may take awhile.

A porous block is much about manufacturing and introducing defects into the Aluminum casting, which is inevitable, and then not having effective methods to screen out the bad actors.
You'd think they would x-ray the blocks after they come out of casting to make sure they're good to go. That's a pretty standard practice in say, casting aluminum wheels.
 

· Super Moderator
Joined
·
4,224 Posts
You'd think they would x-ray the blocks after they come out of casting to make sure they're good to go. That's a pretty standard practice in say, casting aluminum wheels.
Well, thinking about my industry, when a modern gas turbine engine spits out a fan, compressor, or turbine blade in-service (which is very, very rare these days), due to a process flaw, it may not be the inspection method that's been the root cause, because the detection technology has improved immensely since the modern jet era started in the 60s, - it could easily be the human factor, i.e., inexperienced inspectors, lack of training, etc.

It's entirely possible the same human factors are playing a role in regards to QC on the manufacture of the VR30 engine blocks.
 

· Administrator
Newport, Oregon
Joined
·
18,363 Posts
You'd think they would x-ray the blocks after they come out of casting to make sure they're good to go. That's a pretty standard practice in say, casting aluminum wheels.
Blocks aren't typically X-rayed. The usual method for identifying cracks is mag particle testing (which doesn't work on aluminum blocks) or penetrating, florescent dyes. Pressure or vacuum testing is also used.
 
  • Like
Reactions: twin_snails

· Registered
Joined
·
31 Posts
2017 RS400
80,000
Low coolant
Infiniti mufflers, only mod

Blackstone lab oil analysis confirmed coolant in engine oil. Low coolant was an on going issue that was never properly diagnosed by multiple dealerships and should have been replaced at no cost under factory powertrain warranty. New engine installed under extended warranty that I purchased I also paid to diagnose it. Tech said they have seen issues with cylinder head plugs leaking into crankcase.

Advice - If you are under 70k/6 years, check your coolant levels... If low, get an oil analysis and press the dealer to do leak down and compression test so replacing the engine doesn't become your problem.
 

· Premium Member
'17 AWD Q50SS
Joined
·
810 Posts
Discussion Starter · #71 ·
2017 RS400
80,000
Low coolant
Infiniti mufflers, only mod

Blackstone lab oil analysis confirmed coolant in engine oil. Low coolant was an on going issue that was never properly diagnosed by multiple dealerships and should have been replaced at no cost under factory powertrain warranty. New engine installed under extended warranty that I purchased I also paid to diagnose it. Tech said they have seen issues with cylinder head plugs leaking into crankcase.

Advice - If you are under 70k/6 years, check your coolant levels... If low, get an oil analysis and press the dealer to do leak down and compression test so replacing the engine doesn't become your problem.
Thanks, added
 

· Registered
Joined
·
1,562 Posts
Lower Downpipe,
13,000mi on engine

Coolant pressure test failed. Went in because I had the same white sweet smelling exhaust smoke as my first engine.

600 miles past engine warranty. They better hope it's approved because if not it's going to be hell for them.

Tired of this ****. Seriously considering a B58.
 
  • Sad
Reactions: Batell

· Registered
Joined
·
31 Posts
Lower Downpipe,
13,000mi on engine

Coolant pressure test failed. Went in because I had the same white sweet smelling exhaust smoke as my first engine.

600 miles past engine warranty. They better hope it's approved because if not it's going to be hell for them.

Tired of this ****. Seriously considering a B58.
So even new engines are failing, great. I will be testing before the 12mo/12k mile new engine warranty is up for sure.

And it seems like, for an engine that has been out since 2016 model, they cant fix it and probably wont since they will focus on electrification.
 

· Registered
Joined
·
1,562 Posts
So even new engines are failing, great. I will be testing before the 12mo/12k mile new engine warranty is up for sure.

And it seems like, for an engine that has been out since 2016 model, they cant fix it and probably wont since they will focus on electrification.
From what I can tell, my car got old stock of the original 2016 engines because of the part number,
 

· Registered
St. Louis, MO
Joined
·
1,706 Posts
2017 RS400
80,000
Low coolant
Infiniti mufflers, only mod

Blackstone lab oil analysis confirmed coolant in engine oil. Low coolant was an on going issue that was never properly diagnosed by multiple dealerships and should have been replaced at no cost under factory powertrain warranty. New engine installed under extended warranty that I purchased I also paid to diagnose it. Tech said they have seen issues with cylinder head plugs leaking into crankcase.

Advice - If you are under 70k/6 years, check your coolant levels... If low, get an oil analysis and press the dealer to do leak down and compression test so replacing the engine doesn't become your problem.
Would you mind posting your Blackstone analysis? Curious how it compares to mine.
 

· Registered
St. Louis, MO
Joined
·
1,706 Posts
Lower Downpipe,
13,000mi on engine
Coolant pressure test failed. Went in because I had the same white sweet smelling exhaust smoke as my first engine.
600 miles past engine warranty. They better hope it's approved because if not it's going to be hell for them.
Tired of this ****. Seriously considering a B58.
Just - WOW! Really sorry to hear Nick! You deserve better and what a great advocate and continued contributor you could have been for this platform!
 

· Registered
Joined
·
1,562 Posts
Just - WOW! Really sorry to hear Nick! You deserve better and what a great advocate and continued contributor you could have been for this platform!
Thanks man. I'm just hoping INFINITI just does me right even though I was 150mi past engine warranty. I do still love this platform and this car. It seems like I've just been dealt a bad hand - which I assume is because of 2016 engines being used in my replacement.
 

· Registered
Joined
·
1,562 Posts
My dealer didn't do an oil analysis. They did a coolant system pressure test. Pressurized the system and it fell out of spec after 30 min. I also believe my advisor mentioned that he checked the cylinders as well.
 
61 - 80 of 95 Posts
Top