Hi all

After all this talk about engine failures with the M56 I think it’s best to sell while the car works great.

I don’t want to do this, I truly enjoy the car but I think it’s best to do it sooner than later.

I’ll let you know how it goes

Andy

Good luck Andy!

Apparently the 5.6 L V8 fuel pump/timing chain problem is common, with replacement of he fuel pump recommended at 50 to 60 k miles. It appears in the worst case the fuel pump seas fail, the the "lifter" that dives the f/p is doused with raw fuel--this causes it to bind stretching the chain because of the added load, and chewing away at the lifter and the cam lobe that drives it.

Eventually it seizes and things stop working, swarf in the oil and other bad things.

If I had one I' make damned sure that fuel pump got replaced each 50 to 60 k...

Thanks

Do you think that doing the fuel pump is almost a solid chance that the car will be fine?

I really don't want to sell but I might be needing to do a disability retirement and can't have a possible 13-15000 bill that kills my financial wellbeing.

I might go see the master mechanic at my Infiniti dealer and see if he can shed some light on this issue for us.

What my reserch on the web has revealed is that the leaking fuel pump seals precede the sort of catastrophic failure that was recently reported here--as this all takes place internally their is no "easy" observational check to determine the pump's status, if I had an M56 with 50-60k on it I'd change out the pump.

The progression of the cataclysmic failure, from pump seals leaking, to it's lifter seizing up, to the timing chain stretching out, to the **it hitting the fan is quite logical...

That does make total sense.
For the guys or anyone that can add to this was there an odor of had prior to the cats going out.

Did everyone that had a motor go have a cat issue prior to the engine failure. Maybe we can do some preventative maintenance and replace the pump and do from there.

I don't know what I would get off I sold the car, maybe a Lexus, not sure.

cliffyk wrote: ↑

Sat Oct 26, 2019 3:04 pm

What my reserch on the web has revealed is that the leaking fuel pump seals precede the sort of catastrophic failure that was recently reported here--as this all takes place internally their is no "easy" observational check to determine the pump's status, if I had an M56 with 50-60k on it I'd change out the pump.

The progression of the cataclysmic failure, from pump seals leaking, to it's lifter seizing up, to the timing chain stretching out, to the **it hitting the fan is quite logical...

CliffyK, thanks for the additional info. It lines up exactly with what Biggie says about his motor and what I suspect is wrong with mine. A leaking fuel pump is probably why I was getting 220 miles to the tank when I first got the car in 2012 to less than 190 miles to the tank. Your research makes perfect sense.

What does it cost or involve to replace the fuel pump? I wish it was still in the rear of the car like in older cars.

So I was looking online a bit.
It looks like the fuel pump is a relatively easy repair.
The cost comes from what they want for the fuel pump from the factory.
I might consider purchasing one then take it to my mechanic and have them replace it.

Has anyone done this repair on your own?

Andy

A question I have is are you catching the issue in time to preserve the motor?

There is a recall on the M56 fuel pressure sensor
I wonder if this was done to any of our cars.

I will ask my Infiniti dealer tomorrow.

Recall info
ITB15-017 April 21, 2015

I'm not having any issues to this point I'm just very alarmed as to how many people are having this issue.

I'm just trying to get ahead of the problem.

Don't want to sell but if it is a crap shoot I want our before it happens to me.

If replacing the main fuel pump will prevent this from happening I'll do it.

There are two fuel pumps not sure which one or both require replacement

Malbec 56 Beast wrote: ↑

Sun Oct 27, 2019 10:19 am

I'm not having any issues to this point I'm just very alarmed as to how many people are having this issue.

I'm just trying to get ahead of the problem.

Don't want to sell but if it is a crap shoot I want our before it happens to me.

If replacing the main fuel pump will prevent this from happening I'll do it.

There are two fuel pumps not sure which one or both require replacement

I understand. I mean, if I had the insight I have now 6 months ago, I would have sold. Hindsight is always 20/20. The only issue I see is there is no way to tell what damage has already been done internally to your motor. At this point you may be putting ketchup on a burnt steak. Remember, I had no warning signs of engine failure until about six months ago when the engine started tapping lightly. At that point I thought it was the heat shield or something else muffler related.

As far as the fuel pump issue - I don't know man. I feel that if the problem was as simple as the fuel pump Infiniti would have fixed it too with the timing chain recall. They had every chance to get the recall right after examining the failed Titan's and Qx56's that failed first. I'd like to know what a failed motor looks like on the inside post-timing chain recall. I wonder if the same parts began to fail again. I read somewhere that an Infiniti tech said he was starting to see stretching of the 2014+ timing chains, which were not impacted by the recall.

To add some info; the v8 has 2 fuel pumps
1. The conventional in-tank pump at the back of the car, on top of the fuel tank under the rear seats
2. The high pressure fuel pump which is located at the front of the engine.

Following Biggie's thread, I'm going to pay attention to that area when I do my engine teardown. The part is quite accessible, btw, although intake manifold removal is required as one of the HPFP removal steps.

I just want to give a shout out to all toy guys that are willing to lend a hand and to EdBway a very special thanks to answering all m I new and others stupid questions privately and publicly in a always curious way.

Let's keep supporting these guys in any way we can.
If it wasn't for you all is be screwed.

Andy

SO IF I sell my M56xS

What should I get.
I had a 2010 G37xS, the only reason why I sold it was the seats were very narrow, I'm not a small guy but my son has a 2015 Q50S and the seats are not bad at all.

Not sure if they have webbing issues with the 3.0T and y think the 3.7 is fairy bullet proof. What do you guys think.

I've live Subaru for a long time but I'm not a fan of the cvt trans.

I've been thinking of a red sport but they might be more than I want to spend. Oh, I buy used so nothing brand new for me.

Your opinions will be appreciated.

Thanks
Andy

Great information! I really like my M56S and don't want to sell but also don't want to replace the engine either. I'm anxious to hear more about the fuel pump replacement, it sounds like an easy fix but I have to ask - How many folks out there have higher mileage cars and have not replaced the fuel pump? The cars that I've heard about seem to have engine failure around 100k-120k but are there many out there that did not experience this?

I'm at 124kmi and didn't even know the fuel pump(s) were a replacement item. I thought the one in the tank is 'sealed' and didn't know there was one in the engine. But if it's not a hard job and not terribly expensive, I'll do it as part of my maintenance. Better to spend $100-200 than $3,000, IMO.

For what it's worth, I have seen an M56 with rather high miles. It had 2-3 prior owners and a declared 293,791 miles at the time it was listed for sale.

I can't seem to locate its carfax ATM, but from what I could see the maintenance history was very normal, save for the timing chain work.

Seems to me that as long as your mileage is tracking normal then the fuel pump is doing its job, so I don't see replacing it unless there is a noticeable drop in performance and/or mileage. I get 300 miles to the tank if I let it go to the 1/8 mark on my M56x no problem, but I do mostly highway driving. I am curious as to which bank drives the fuel pump. If it is bank 1, and it is leaking by, and everyone seems to get the P0420 and never the P0430, it makes me wonder if that has anything to do with the fuel pump issue.

It is physically located on bank 2. For anyone curious to see, here is a video.

Are we saying that replacing the fuel pump as indicated in the video might reduce the likelihood of an engine failure or does both fuel pumps need to be changed?

madmanpauly wrote: ↑

Mon Oct 28, 2019 1:09 pm

Are we saying that replacing the fuel pump as indicated in the video might reduce the likelihood of an engine failure or does both fuel pumps need to be changed?

It is the High Pressure fuel pump that seems to be the weak link, and as far as my research shows this is not a uniquely infiniti 5.6 L issue. Many other brands with direct fuel injection have experienced similar failures as well. 2500 psi is a LOT of pressure. THe seals on the M56 HPFP seem to be poorly engineered--'twas me I'd try to link it to an emissions failure (8 years/80k miles per the Clean Air Act of 1970)...

When the high pressure pump begins to fail does it also start to lose pressure? If so, you can put in a pressure sensor with a warning light to come on when it dips below required levels? I am into diesel performance (have a '04 Dodge with Cummins in it...and some goodies added to it....550hp/1000ftlbs at the wheels) and that's a pretty common thing done to many Diesel rigs. Their high pressure fuel pumps put out pressures up to 30,000psi.

Either way, this sucks that it's such a common issue for these engines.

I'm still suspicious of a possible cause / effect relationship that starts with significant oil burn and ends with timing chain trouble. Lots of different engines burn oil and it's not necessarily a cause for concern. However ... When timing chains start to stretch or loosen, they result in oil burn and if the chain is not replaced, it can continue to loosen and eventually fail. I can't prove it, but I just have this suspicion that the timing chain recall is the result of poor design of the timing chain and THAT explains why some 5.6 engines burn lots of oil. It might be interesting to compare oil burn before and after the timing chain recall is performed. If the the oil loss decreases after the recall, that supports my suspicion.
a** far as what to buy if you sell your M56? The only choice that comes close to the level of performance, quality, and reliability would be Lexus. Specifically, the 430 or 460 years. The LS models can be pricey for maintenance, but they very rarely need actual repairs. They also have a higher resale than Infiniti, so it might be slightly harder to get a used one at bargain prices, but my service rep came from Lexus and he says it was not unusual for LS 430/460's come in for oil changes with 200k miles and they almost never came in for anything but maintenance items. He actually drives a 460L with 160k miles and he has never done anything but fluid changes.

Larz

I'm hoping that the light that was put on this issue have me a little hope and I may keep the car.

I have it up for sale in a local online site so I'm not 100% wanting to sell. I will continue to monitor the fuel pump and go from there.

I was thinking of Lexus myself but they are pricey so I was thinking about the Infiniti Q50 3.0T or a red sport but I don't know much about either one so I'll jump on their forum and do some looking around.

My concern with my car is how quick the oil becomes dirty. The dealer is using Mobil one full syn but it is way dirty or more than what I experienced with the G37xS I owned.

Let me know if you all have the same issue with the oil becoming dirty with a full syn.

I do my oil changes at Infiniti about every 4-5kmi.
It doesn't seem to go down a lot but maybe between the full and add lines, sometimes closet to the ad.

Thanks
Andy

AS a former Mustang owner, a highly modified 525 HP 2003 Cobra and an '03 GT) I had been lusting (a bit) for that V8 sound; and sort of looking for an M56, however my researching of same has killed that fervour. You may want to look into a low milage M37--at 330 HP the motor feels as torquey as a small V8 (the EELV intake is amazing) and the 7-speed tranny lets you take advantage of it.

Additionally the engine is proving to be somewhat "bulletproof" with a million kids out there beating the crap out of their 370Zs. Try one, you might like it. You could supercharge it and get more juice than the M56...

does the ticking increase in speed as you put more gas?

To be clear on not having any symptoms so I'm not sure but I would say yes, but it being a high pressure pump maybe it stays steady.

Yoda
Are you having this issue now if yes is so the pump asap

The ticking for my car started a couple months ago. It is usually from a cold start and goes away after warming up so I never thought anything of it. Not everyday though.