Alright this weekend I was at a local autocross(my first time autocrossing) and at the end of my second to last run my car threw both serpentine belts. I replaced both belts with gates about 10 months ago and this is the first time I have had issues with them. I checked both idler pulleys and the bearings spin freely and with no noise. I also took a ruler to them and all of the pulleys are in line. All of the grooves in all the pulleys look great as well. I checked everything on my car before starting the event and the belts had the same amount of tension the always have had. Any ideas as to why my car threw these belts and suggestions on how to keep it from happening again?

 

Twenty five years ago I had a 1988 Mazda 929 5 speed manual. At about 180,000 miles it needed a timing belt. Took it to a local shop that replaced the belt and a few idler pulleys.
Two days after picking up the vehicle it was barely running.
Took it back and was told it had jumped timing and they reset it.
Ran fine for two days and the same thing happened again.
After it happened the third time the shop refused to reset the timing again.
Fortunately I had paid by credit card and requested a charge back on my card for poor workmanship which I received.
Took the car to a Mazda dealer that put the correct belt on. The dealer told me the aftermarket belt that the previous shop used was not exactly the correct size.

Lesson learned

I never had any more work done on my vehicles except at the dealer.

You get what you pay for. Buy cheaper and you buy twice

Telcoman

 

Something must not have been tightened down.

Common mistake is after adjusting the tension bolt forgetting to tighten the bolt on the pulley itself.

I'd also look into the idler pulley delete for one less thing to fail. I have the OEM spacer you'll need if interested in that.

 

Did the pulley delete on both of my G35s at belt replacement. Well worth the extra 10 minutes to delete an idler.

 

My idler pulley is chromed so it's not going anywhere. Thanks Marcus!!

 

I've had the Gates belts on my car for nearly 50K miles. No issues at all with them.

HOWEVER, soo after installing a new belt, it stretches. Some cars have self-tensioners that adjust for the belt stretch, but on cars with tension pulleys you lock into place, the belt can stretch and become loose. SO after 5-6 months I had to go retighten the belts again. Since then, no issues at all. I never see it mentioned in belt change DIY's, but I would definitely recheck belt tension on the G35 after a few months simply because of the system these cars use to maintain tension. There is no self-adjustment for belt stretch.

My theory on what happened? The belts stretched and were loose. AutoXing stresses the power steering pump heavily and loading and unloading it would potentially cause the belt to slip, especially if loose. Since the PS belt is behind the AC belt, it's a matter of the loose belt getting caught in the pulley for the a/c belt and causing that to slip off.

I'd reinstall both belts and retighten them properly. After a few months, recheck the tension and adjust if needed.

I've run OEM, Gates and Gatorback belts on many cars i've owned or had to maintain. No issues with any of those brands.

 

hmm well you run 87 octane in a g37, you go to the dealer.... Im not judging you, just what you wrote.

Find a performance shop that specializes in the platform. The dealership rips people off far more than people who dont know the small things on our cars, which makes them appear less educated.

I dont even run regular gas in my 2004 Sentra that I paid $1500 bucks for! You are what you eat. Same applies to cars....run better gas, id put money on getting at least 2mpg better.

Add it up at .30 cents more per gallon, 15 gallons at most fill ups, is only like $5 bucks. If you get better gas mileage or not its irrelavent. Knowing the engine ingested cleaner fuel will save you tons in the long term. But Id put money on that G37 running better MPG on premium fuels.


I run the Gates HD GREEN belts on my vortech set up. They hold firm. When I did have belt issues, it was indeed a faulty pulley bearing. Also the AC or Alternator are known to have issues after 100K miles too. (their pulleys and resistance)

 

93 octane is not "better" than 87 octane. It's not cleaner. The only technical difference between 87 octane and 93 octane from the same gas station is it's resistance to ignition which helps hold off detonation in higher compression or boosted engines.

It's like saying 5W-30 is "better" than 10W-40. It just has a lower ignition point than higher octanes which may be desirable in certain situations. It's not cheap gas in the sense that dirt and crud is floating in it. Same additives, same cleanliness spec, etc. All that changes is the ratios of octane/heptane/etc. in the fuel to change it's resistance to detonation.

If a car is designed to run on 87 octane, running higher octanes won't make a difference. If anything, performance should decrease due to the fuel being harder to ignite. Generally you want to run the lowest octane possible without detonation for max performance and efficiency. Sometimes there are exceptions.


Older G35 sedans were "premium recommended" and could run lower octanes. They only required 91+ for max performance. I ran 93 octane for a long time in my sedan, but about 2 years ago I switched to 89 octane after partaking in a "what octane for my G35 sedan" thread. Charted my mileage over a long period of time and noticed no reduction in fuel economy at all. So i've kept on running 89 ever since. Unsure if i'll experiement with 87. Fuel economy hasn't changed, but it's possible HP has. Since my G35 is a beater to me, I don't really care about HP. I drive 30K miles per year in this car (and about 10K in my "nicer" car which is Premium required and gets 93)


EDIT: After all this i went and researched if the 09+ G37 sedan could also run 87-89 octane like the older models. Manual states they are premium required cars. Even given my experience with my sedan running lower octane and not noticing a difference in fuel economy, I would not run less than 91+ octane on an 09+ Sedan. Even states warranty can be voided due to damage caused by running a lower octane. I don't have the time or money to fight a dealer and/or Infiniti corporate that would claim that just to make a point that they are being overprotective, nor do i have the test equipment to back up any claims that running lower octane on a car requiring 91+ is perfectly safe. That extra 50 cents per fillup sounds cheap in this situation

 

Thanks Mustang!

you know what I meant. So literal.

Since you are so literal, why are you on a G35 site with a username saying mustang.

If you put 87 in your car, you are INDEED putting cheap, dirty 711, BS gas in it because you dont care. Yes there are quality gas stations with great 87 octane fuel. But if you run 87 you dont care where you get gas. Filling up at any Joe Blow gas station.

you said 89 not 87. Proving my point.

Im my situtation running a 2004 Nissan Sentra in which I have placed 60 Miles on the car since Mid November of last year. I drive up and down I95 fromo DC to Richmond, VA.

Running 89 octane (I will never use 87 in anything other than a lawn mower) I get on average about 360 miles per tank yeilding 29-31mpg on average.

Running 93 octane I get 400-410 miles per tank.

In both situations it was about 50/50 city vs highway. I punch it and drive it like I stole it, however on the drives to Richmond its nonstop traffic until the halfway point, then the speed limit is 70. I run 75-76mph from that point on. I consistently get about 32-34 mpg.


This is my experience and should be noted as MY experience and opinion. I notice significant change for the extra $3 per fill up. Even a 1 mile per gallon increase over 300 miles pays for the extra 3 bucks. Im getting 3-6 mpg differences.

Also when I was running 89 it was winter so I didnt run the AC
Since I switched to 93, its been summer, AC on full blast with my kids in the car, still got positive, significant increases.

Like all post (not to be menat as the Bible and so literal) take what you need or have learned from my experience and apply it to your specific situation.

MUSTANG, you also drive one of the HEAVIEST G35s on in the line up, behind the G37 Vert. Your gas mileage is going to suck regardless. The increases we see wont be as pronounced in a car that is 800 lbs heavier than my sentra. You also have the weaker motor having a 2006. So you have the weakest engine (unless its a manual RevUp) and the heaviest car, You results would be less obvious due to the weight issue, but yet preminum will yield better results, I dont care what you say.

I have owned over 17 cars, and there is a drastic difference in fuel economy running premium quality fuels.

There is a gas station right next to hills garage that sell CHEAP, CRAPPY, DIRTY gas, that without even asking the customer, Hills can tell within minutes on the dyno that they filled up at that gas station. Even the premiun fuel their.

Thanks for your informative post, but you come off negative. I share my experiences, positive or negative. Ive been boosted, not boosted, had engines replaced, ran multiple kinds of exhaust and the OEM exhaust didnt limit my power like one might assume. One must read through the marketing hype and make the best educated decision for themselves.

Higher octane fules offer a more controlled burn that higher compression engines can take advantage of....G35s are high compression, so is my little Sentra. Running high octane in a older low compression set up like um say a mustang might not make much sense. However the new mustangs have very high compression, uncommon in the past for V8s, just like the Z06, M5s, exotic V8s.

 

You should listen to Mustang, your mileage figures are laughable. It's sad that you refuse to learn and only defend your preconceived beliefs. I feel the need to comment this harshly because it makes me mad that people like you are spreading this misinformation. If you did a little research instead of being defensive you would change your thinking about octane ratings.

 

Whatever

Both my previous 06 G35 6sp that was traded in with 171796 miles and my current 2012 G37S run all the time on WaWA 87 octane gasoline






Telcoman

 

I tried running 87 octane then 89 octane in my G and even used the low octane map in Osiris. Engine pinged and knocked like a **** so I went right back to 93. Never again for my baby.

 

I agreee Blue Dream...there is a grave difference from G35/7 owers and G35/7 drivers. I use my cars, I dont just drive them to take granma to bingo!




Telecom, driving 45mph on the highway engines wont ping on 37 octane! LOL



Laughable is laughing at a weak 50-60 miles per tank difference. We arent talking hybrid numbers. A few mpg over a tank, but driving as much as I do, its adds up fast. I guess now you would agrue that driving my Sentra since November I have NOT saved about 9500 in gas? Because I dont get 12-14 MPG in my G? I get about 200 miles a tank in my G to inlcude Meth. Why? Because Im not driving it to bingo. lol I used to daily drive my G, because I effing love my car!

I love the experts on her with under 100 post, PHDeez, and all the knowledge in the world. Yall crack me up.



I respect you Sir for doing additional research. No hard feelings. I post what has happened to me. I dont expect the book to be thrown at me as if I applied my situation to every case. I have run performance cars for 20 years and like I said. Nothing regular goes into any of my cars. Mobile 1 wont go in my G (see oil analysis thread my350z, grab some popcorn is about 200,000 post long now. lol) The ECU can and will adjust, but I wont risk ping and detonnation to save a few pennies.

Running 93 will not hurt your car
Running 87 could.

tomaaaato
tomatto


Back to the SUBJECT!!! FOEMAN13

Did you look at the Gates Green HD belts? Boosted mine last twice as long as the OEM style.

 

Yes, your car needs that octane level. Gzilla thinks that higher octane gas is higher quality gas. FWIW I use 93 in my car for the extra power and because I run it hard.

 

You are not getting "50-60" more miles per tank in your sentra by using 93 octane, you're fooling yourself. That's about as believable as if you claimed a magnet attached to your fuel line was helping your mpg's.