OK, so for the sake of discussion...

over in that thread on MYG37, in post #148 ( http://www.myg37.com/forums/3773774-post148.html ), a poster, who has just had the 'full' repair service work done, mentions reasons why the dealership has a policy that they won't replace JUST the oil galley cover gaskets, and instead require the full replacement of the entire rear timing cover assy. with the gaskets already intact. One of the reasons given by their service tech is that Infiniti will not provide any torque specs for the screws securing the oil galley covers, so they can't be sure they will not just fail again.

So, while it doesn't seem like it should be rocket science to figure out, it does present a credible 'concern' as to what the correct procedure should be for R&R of the dreaded gaskets, especially considering that the rear timing cover is aluminum and the oil galley cover plate it steel. As we all know, dissimilar metals will expand and contract differently when subjected to heat cycles in an engine, with the poor little gasket between them bearing the brunt of maintaining a pressurized seal (as in head gasket issues with aluminum heads on an iron block).

Additionally, in other parts of that same thread, there are several mentions of the replacement gasket material NOT being anything different than the original (i.e. still just paper ). Infinitidude mentioned in some of his posts here that he believed that was not the case, and that he "thinks" they are different. He also refers to practical issues regarding R&R of the screws in concern, but no mention of a specific torque spec.


Infinitidude, for the sake of clarity, could you speak specifically as to whether you are absolutely certain the gaskets currently available are indeed of an improved material such that these issues should never return once they are replaced? Also, can you share what torque spec you are using when reinstalling the cover plates and any thoughts/reasoning behind how and why you came to them. Given the extreme costs in both time and labor involved to gain access to the damn screws and gaskets, I think it would be of great reassurance to know the abbreviated repair efforts would realistically not be short lived and that a repeat procedure is never even a conceivable outcome. (And thank you so much for addressing this!)

 

Just loctite the screws. And what does it matter if the gasket is improved or not, repair needs done either way? Worst case you replace with the same gaskets and get another 70k miles on 'em..

 

I'm sorry, but Loctite does not address the issue completely; it only means the screws shouldn't back out.

If the screws are torqued too tight, regardless of whether they use thread lock, it could possibly over-compress the gasket (at least around the screws) and potentially lead to a premature blowout of the gasket again. If the screws are torqued too little, again regardless of whether thread lock is used, they may not maintain enough clamping force on the gasket to hold up against oil pressure over time and likewise lead to a premature blowout. There is undoubtedly a sweet spot, one most likely relative to the composition of the particular gasket material used, that should be sought out.

If the gasket material is the same as the original, I think I'd want to seriously pursue an alternative, because for me, and I'm sure the vast majority of owners, the worst case you mention is totally unacceptable.

 

This thread I think answers my question but regardless thank you for the post. The question of why synthetic oil doesn't feel right in my car. On a higher mileage engine such as mine at 85000 miles, you're suggesting the gaskets are worn out and are allowing for nonuniform seal causing some oil pressure loss, in my case what sounds like a raspier engine tone when using motor oils that are more viscous and thinner such as full synthetic. No codes or CEL as maybe the pressure hasn't dropped far enough yet.

This raises another question and that is: could overfilling your oil on an oil change about 1/2 to a full quart increase oil pressure at all? A shop did this with regular oil and I could swear the engine felt and sounded healthier afterwards.

As the engine warms to operating temperature is it safe to say this seal could tighten up? after a recent full synthetic change, and a long drive on a hot day today, the raspiness seemed to go away after a while.


This is not good.

 

Hey man how's it going?? Was reading your information about the codes with the gasket...just bought a 2008 g35 sedan, no codes yet but should I just go ahead and replace those gaskets??? Also what other preventative measures should I be concerned about??

 

Don't replace them unless you actually have a problem. I have a 2007 Infiniti G35x sedan with none of these codes and no oil loss.

This doesn't happen to every car with the older gaskets. Only some cars are affected. You can be sure if this happens to many cars that Infiniti will probably issue a recall. The last generation Lexus ES models had an oil hose issue where it burst and leaked oil everywhere and Lexus promptly recalled all the cars.

 

I am still trying to learn about this... ( my car does not have any issues) So, basically this is an internal oil leak, and or oil pressure leak?? right?

 

Ehh, I highly doubt Infiniti will issue any recall for this. That case with the Lexus ES sounds like it's actually quite a different thing. Fundamentally, a hose that could burst and leak hot oil around an engine compartment is an outright safety (fire) hazard. With the VQ engines, the leak is still contained within the outer timing cover and does not pose such a safety hazard; just an expensive (and profitable) repair job. Hence, no recall.

That is correct.

 

Hmm interesting you say that. I did not realize that recalls were only for safety hazards. I thought recalls are usually for premature issues that happen in a majority of the same model vehicle. Infiniti would benefit from such a recall because it promotes brand loyalty and not leave a big distate to its customers.

Infiniti just recently recalled the JX for fuel gauge issues. It shouldn't be a safety hazard; just an inconvenience that people cannot get the right reading of their fuel levels. NHTSA says that running out of fuel on the road is dangerous and can lead to a crash. I would argue that a drop in oil pressure could lead to engine failures on the road and possibly cause a crash too.

 

Hey brother, the gaskets are indeed a different material as I just pulled one from the bag and it is definitley not a cheap paper gasket. You can tell that it is a tough durable gasket with a metal material inide of it. I can tell you from experience that we have never gone by a torque spec when tightening them down. If anyone has ever worked on engines they know when it is tight enough. They generally aren't going to give you a torque spec on something held down with phillips head screws. Hope this helps guys.

 

This has been a very useful thread, thanks to everybody for all the info in it. Just got a new to me 07 G35S with those 2 dreaded codes 2 weeks ago, tried the lucas oil trick with no success so in the process of getting my oil pressure tested, although I am sure it will be low as I had the low oil pressure light flicker every once in a while (full oil level). Hopefully get some pictures of the condition of these gaskets as I won't do this job myself (although I like to wrench every once in a while)

 

I just got a quote from the Infiniti Dealer her in Oregon quoting me 21.8 labor hours for this job plus replacing the water pump...to a whopping $3300! I am so glad I found this thread and honeslty cannot believe Infiniti will not recall this product. I have a 07 G35 at 68,000 miles...so precise exactly what you have been saying for year and mileage range of car of this to happen. I am actually goint to take the time to contact Infiniti Corporate regarding this issue. It has been my learning that recalls such as this don't happen unless there are enough complaints directly to Infiniti by customers, it seems alot of people just get it repaired..Thank you for all the info.

 

Good luck. I raised cane wi the dealer (pointlessly), but didn't contact Corporate - or NHTSA. Perhaps I should have. Please let us know the results of your efforts.

$3,300 & 22 hrs labor seems a bit high for this job (like 2X). Did they give any details as to why so much? Oddly, my local dealer actually refused to do the job because I had cleared the P0021 code before I dropped by. Far as they were concerned - no codes; car seems to run OK; there's no problem to fix. They said come back when there's a code set & we'll talk. So I axed them what they would charge to simply change those gaskets on the rear timing cover per my description, and they estimated $1,700 (not including $20 for the gaskets ).

 

I called consumer affairs this morning and they say it's a 17 hour labor job with the water pump. (dealer told me that needs to be replaced as well) consumer affairs pretty much backs up the dealer...when they first told me the price I asked them to hold off on the repairs as I had been considering trading up to a newer G37XS Coupe a month ago at the time of my oil change, decided to go back in and look at just going forward with that rather than pay for the repairs and the sales guy told me they would now only give me 4K for my car rather than the 15K they first quoted me because of the needed repairs...I am now at a complete loss of trust in my dealer and don't want to deal with them at all...I feel they are being shady, opportunists in this situation...years ago I had a Nissan Stanza manual tranny and the firewall caved in under the pressure of the clutch plate, I wrote a letter to corporate Nissan and the local dealer as I had found out from the repair shop that they had seen this often and only in the stanza. had to threaten to "go public nationwide" with it to get them to do anything and after that threat they finally repaired it free of charge. this is back in the early 90's mind you..I am sure it would be much harder to get results such as that now but I am certainly going to blast this on social media and as I own my own business I can spread the word through clients and friends.....thanks for this thread, it has empowered me atleast to not feel I have to go with the quote from the dealer.

 

Wait..... You get offered 15K, then the dealer finds out your engine is fuked, and you don't understand why they won't honor the first offer? Am I missing something?

Don't get me wrong I would NEVER get work done, other than warranty work, at a dealer ship. I have saved more than half over dealer prices by going private mechanics for repairs out of warranty.