Jump to content
SAU Community

Excessive Slowing Down Without Using Brakes

Marteh

By Marteh,
in R Series (R30, R31, R32, R33, R34)

 Share

Recommended Posts

Marteh Rookie

Marteh

Posted
Posted

I have owned my N/A R34 4 door for approximately 11 months now and in the past 1 month I have seen a significant change in how my car is running.

I have noticed that when completely letting go of my accelerator on a flat road, the car begins to brake quite quickly without any coasting sensation you would expect.

Even when going down a hill, (for those of you on the north shore in Sydney, the big dipper on the F3 near Mount Colah) I need to have my foot on the accelerator to keep it from dropping below 110km/h (whilst having momentum GOING DOWN A STEEP HILL)

The only modifications which have been made over this time period (and or 2 months before noticing a problem) was the installation of a 2.5" catback exhaust, and replacement of coilpacks and spark plugs.

It is obviously a very uncomfortable feeling and uneconomic when my foot needs to be left on the accelerator when otherwise, I could simply have the foot off and be coasting. In the meantime I have been shifting to neutral (I should have noted the transmission is tiptronic) to attempt to save fuel.

The uncomfortable and annoying "self-braking-problem" seems to be due to the revs not dropping instantly when taking the foot off my accelerator, it will instead drop from whatever revs i was on to 2k slowly creep down from 2k - 1.1k and feel asif a great load is on the gear. When changing to neutral immediately after letting off the accelerator, the revs drop to ~1.1k, 1k and obviously not being in gear, I can coast comfortably.

the only reason I am posting is because I know that my car was performing differently with the ability to simply coast, without going from 60km-40km in 2 seconds on flat road and momentum.

I would REALLY appreciate any insight or help into what the problem may be!

lack of backpressure to the engine?

limp mode for some reason?

Marteh Rookie

Marteh

Posted
  • Author
Posted

Its actually funny that you mention that.

I'm not exactly sure what a seized calliper entails however..

my front left wheel squeeks about twice per rotation WITHOUT any brakes applied, this may be the problem area, this could be some point of contact?

Once i begin to brake the squeak dissapears (I assume its not a brake pad problem since squeeling you hear from the wheelswould occur WHILST braking, but this isn't the case for me)

Other unique feelings I have when lightly pressing my brake say at 60km/h is a subtle back and forth motion, maybe indicating that the brakes are grabbing/letting go, grabbing/letting go (case of warped disc brakes?) Once I apply more pressure to the brake the pads come into complete contact with the disc and the feeling of braking is smooth. I have NO vibration in my steering wheel while braking, just to clarify.

So I now might have two problems.

Do any of these symptoms sound familiar?

PM-R33 Grand Master

PM-R33

Posted
Posted

Jack up the car and rotate each wheel with your hand. Each wheel should rotate fairly smoothly and only just be touching the brake pads. If one or more wheels feels a lot tighter than the others than you know you have a brake caliper/brake rotor issue.

jiffo Mentor

jiffo

Posted
Posted

You say that you need to select neutral for the car to freewheel as it used to do.

If neutral fixes the problem, it's hardly going to be a brake issue is it.

Take the thing to an auto specialist. One quick test drive and they'll diagnose any transmission issues.

mad082 Grand Master

mad082

Posted
Posted

yeah if putting it into neutral makes the car coast just fine then it is more than likely a gearbox issue (won't be brakess). may be low on fluid, the fluid is in need of replacing, or the gearbox may have an issue.

Daleo Grand Master

Daleo

Posted
Posted

Putting your auto in neutral whilst doing 110km/h is one of the best ways to destroy it.

Oil pressure is what keeps the transmission alive, the faster you go the higher the pressure. So what you're doing is effectively running you auto at idle oil pressure, (the pump is on the converter side), but you're spinning the internals at 110km/h, because it is locked to the tailshaft. Low pressure equals failure.

Get it to an auto specialist before you damage it any further.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Dose Pipe Sutututu
      R32 GTST - 600KW+ RB28/CD009 Build

      By Dose Pipe Sutututu · Posted

      LOL.... a good amount of people (not all) on that continent seem to know everything and like to measure things in bananas, football fields, statue of liberties instead of the metric system lol.
    • dawhitehonky
      M35 Aftermarket Fuel Pump

      By dawhitehonky · Posted

      I assume the modules are similar enough, so if you've had no issues I don't see why I would. I have tried to find a wiring diagram for the FPCM / fuel pump circuit, but I can't find it anywhere. Otherwise, I would just do some wire cutting and joining at the FPCM and give the 12 V supplied to the FPCM directly to the pump instead. If you know anyone that could help with wiring diagrams, I'd be very happy  
    • GTSBoy
      M35 Aftermarket Fuel Pump

      By GTSBoy · Posted

      If it dies, then bypass. The task isn't difficult. I have one running on a standard R32 FPCM. That's after nearly 20 years of it running an 040, which pull substantially more current than the Walbro. They're not the same module, but I'd hope it indicates that the R33 one should be man enough for the job. I think people kill them when putting proper sized pumps on them, not these little toy pumps we're talking about here.
    • GTSBoy
      Rapid-fire squeaking/creaking from rear suspension

      By GTSBoy · Posted

      Silicone spray won't hurt anything. And if it does, that's an opportunity to put some solid steel spherical bushings in, so you can really learn what suspension noise sounds like, If you're going to try it, just spray one bush at a time, so you can work out which one is actually noisy. My best guess is that if the noise started only since putting the coilovers in, then it is just noise being transmitted up through the top mounts of the struts, and not necessarily "new" noise from bushes. But it's almost impossible to know.
    • GTSBoy
      Jacks that fit under GTR lips that can reach the subframe?

      By GTSBoy · Posted

      Are you saying the 34 is SUV height, and not that we're talking about an SUV here? (because if we're talking about an SUV, you don't fix them. You just replace them when something breaks. Not worth establishing sufficient emotional connection with an SUV to warrant doing any work on one). I wouldn't jack my car up on a short little loop of 10mm steel rod poking out through a hole in the bumper bar, front or rear end. I realise that we're probably not talking about that type of loop at the front, being the one under/behind the bar on a Skyline.... but even for that one, trying to jack up on what amounts to a thin piece of steel, designed purely for withstanding a horizontal tension force, not a vertical compressive force (and so would be prone to buckling/crushing) and, my most particular bitch about it - located RIGHT AT THE EXTREME FRONT OF THE CAR, applying a load up through the radiator support panel, etc, with almost the entire mass of the car cantilevered between there and the rear wheels? Nope. Not doing that. Not on the regular. That structure out there in front of the front crossmember is not designed to carry load in the vertical direction. Not really designed to carry any load at all, really. The chassis rail that the tow point is connected to would be fine loaded in tension, as per towing. Not intended to carry the mass of the whole car, especially loaded all on one rail, with twisting and all sorts of shitty load distribution going on. No, I will happily drive up on some pieces of wood, thanks. That can only happen on driven wheels, and they are at the other end of the car, and this problem does not exist at that end of the car. And even then, I have been known to drive up on at least 1x piece of 2x8 each side at the rear, simply to reduce the amount of jack pumping necessary to get the car up high enough for the jack stands. What really really shits me about Skylines is the lack of decent places for chassis stands at either end of the car. You'd think they'd be designed into the crossmembers.
×
×
  • Create New...