Jump to content
SAU Community

Recommended Posts

Hey all,

Need alot of help here. When the car is running in 4WD, at the begining when I start up the car (engine is cold), the 4WD works fine.

As the car heats up, in matter of 10 mins or so... the car is jolting during acceleration.

Ive changed the 4WD pump. and also changed 4WD computer. And still the same. WHAT IS GOING ON?

And this is defenetly the 4WD, cos I took the 4WD fuse out and ran it on RWD and it drives like a dream.

But i want it in 4WD to be the same. Has anyone come accross this? Will appreciate any advise.

Cheers Zac

Link to comment
https://www.sau.com.au/forums/topic/207699-unusual-4wd-problem/
Share on other sites

  • Replies 40
  • Created
  • Last Reply

Top Posters In This Topic

have you checked the attesa pump and fluid in your boot...i have a R32 GTS4 which is pretty much the samt awd system and when u start hitting boost the awd guage starts to go up. Therefor ur attesa pump is rooted or u may have low/no attesa fluid left.

hope this helps

vinnie

have you checked the attesa pump and fluid in your boot...i have a R32 GTS4 which is pretty much the samt awd system and when u start hitting boost the awd guage starts to go up. Therefor ur attesa pump is rooted or u may have low/no attesa fluid left.

hope this helps

vinnie

Yea I actually replace the Attesa pump and bleed it and all that. The fluid in my boot is in level. I will double check.

Too right! I have lost count of how many times this point has been made - AWD NISSANS MUST HAVE THE SAME ROLLING DIAMETER ON ALL 4 CORNERS.

I never thought about that. So are you saying that this could be the reason for my car jolting when accellerating???

Could it having anything to do with the oil in my gear box or transfer case? I have red line oil in there. Could the grade of the oil make a difference?

I never thought about that. So are you saying that this could be the reason for my car jolting when accellerating???

No he is saying that it IS the reason.

Could it having anything to do with the oil in my gear box or transfer case? I have red line oil in there. Could the grade of the oil make a difference?

No.

Thanks alot for all your help guys. Im gona get the tyres changed immediately.. And will let you know the outcome. Cheers Zac.

Hi Guys,

Just went to the car and double checked the tyre size for fronts and back..

Fronts - 245/40/18

Rears - 265/35/18

Can you guys just confirm again that it is defenetly the tyres that causing this stupid jolting problem for me. And can you explain to me why and how this is happening.

Appreciate your help guys .Cheers

Pull the fuse on the 4WD system & go for a drive. If the problem has gone then it is your tyres.

Much of the input for the system is differential wheel speed front to rear. If the system detects it it thinks wheelspin & pushes torque forward. This is almost certainly the cause of the jolting as the locked up system & differential wheel speeds need to somehow get back to normal - hence the car jolts.

What is your front torque gauge reading when you drive around normally?

Pull the fuse on the 4WD system & go for a drive. If the problem has gone then it is your tyres.

Much of the input for the system is differential wheel speed front to rear. If the system detects it it thinks wheelspin & pushes torque forward. This is almost certainly the cause of the jolting as the locked up system & differential wheel speeds need to somehow get back to normal - hence the car jolts.

What is your front torque gauge reading when you drive around normally?

Thanks Guys.

It's definitely the tyres

Fronts - 245/40/18
sidewall = 98mm
Rears - 265/35/18
sidewall = 92.75mm

So, rear tyre has a smaller rolling diameter. This means that the rears turn faster than the fronts. ATTESSA sees this as "wheel spin", and sends some drive to the fronts.

It's definitely the tyres

sidewall = 98mm

sidewall = 92.75mm

So, rear tyre has a smaller rolling diameter. This means that the rears turn faster than the fronts. ATTESSA sees this as "wheel spin", and sends some drive to the fronts.

I replaced the tyres at the back...to be the same as the front tyres. And wahlahhh... the jolting had ended. BUT when I was boosting it up ....there was still quite a slighhhht jolt...i guess im noticing it cos I know it. But it was still there. I want it to be smoooth ass...What needs to be done???

im gettin brand new tyres put all around.... 265/35/18 front and back this week.

Appreciate the help.

The diameters are obviously the same. The offset is probably not so important (at least in a straight line).

The tyre fitter should be able to measure the widths (although that info is usually cast on the inside of the rim). I'm only guessing here, but if you are already running different width tyres front and rear, then it is likely the rims are different widths front and rear.

The rims really need to be the same all round, otherwise you can spend hours working out what combination of tyres (makes / models / sizes) will give the desired equal rolling diameters.

This is what happens when you go for "the look" without regard to the technology underlying the performance.

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



  • Similar Content

  • Latest Posts

    • I have been being VERY quiet about what you're alluding to, as it is something that ticks me off... The number of cars from factory that run coil overs is HUGE! Most of them these days do... The other part that annoys me, is people saying "Well all the incabin adjustable suspension is illegal by blah blah blah"... If that's the case, then why can I buy a car brand new that can do it if, FULL STOP in cabin adjustable suspension is illegal...   Also, I could just chuck some aftermarket shocks in my car, throw the stock springs on, after my blue slip, dump my super low springs back in. Same shock and spring style setup... Hell, they could also be the same colour springs etc.     I'm voting, BlueSlipper didn't want to touch the above car for some reason. Whether it be some sort of bias against the car, the owner, them maybe having previously done dodgy shit and now they're being super careful in case they get slapped in the face by the Gumbyment again... Find a new blueslip place.   And can confirm as you had said, yes there are holy bibles of vehicle heights, and all sorts of other suspension stuff. Heck your run of the mill mechanic, and tyre shop has access to all of that stuff. It's how they do wheel alignments...
    • Funny story Heading to Sydney this morning on the HWY there was some slow traffic, so I gave it the beans and midway through my overtaking "power run" I lost all power It seems that I missed a hose clamp,  and the MAF and filter went WiFi To make this more problematic, the little tool kit that lives in the boot, is sitting in the sun room at Goulburn......LOL Luckily for me I found a bit of steel on the side of the road that could be used like a rusty and bent flat head screw driver to tighten it up enough that it got me into Sydney, it is now all tight like a tiger with the aid of a 8mm socket Note to self: Use my brain and double check stuff, and always keep that little tool kit in the car for when I have a brain fart
    • Oh, and as for everyone with their fuel economy changes, I switch between E10 and 98 in the company car. Even do when I had personal cars that could run on E10. You know what changed my fuel economy in any noticeable way? How I drove, and where I drove. Otherwise, say on full tanks of just back and forth from work only (So same trips, same sort of traffic), couldn't notice a difference that I can correlate to the type of fuel in use. In the current vehicle, that's over 42L of USABLE fuel. While 98 is all "more energy dense", it also has higher knock resistance as it takes more energy to get it to ignite too. The longer hydrocarbons, typically more tightly bound. So running the same ignition map, can also produce less power, if there isn't enough time to get it all burnt through properly, as yep, the flame propagation speed is different from lower octane fuel to higher (Higher has a lower flame propagation, due to the more tightly bound and harder to self ignite funs. This is also typically where, a vehicle that is designed purely to run on 91 (Whether it be E10 or normal 91) usually sees absolutely no real world difference in fuel economy for the normal man, woman, or dog.
    • We've got some servos around me that have 91 with E10, 91 (no E10), 95, and 98. At those stations the change from 91 E10 to 91, is typically around 8c/L.   But lets not get started on the price of fuel in Oz. It's ridiculous. All the service stations around me, bar one, the price of fuel has been over the $2 mark per litre for the cheapest, 98 being around $2.45. That one service station is a CostCo, fuel from it comes from the same refineries, and makes no pitstops, it runs great, including the 98. In fact, I've had no issues on CostCo fuel, but plenty of issues at other stations!. The CostCo fuel, was $1.65 roughly this week for 94 with E10. $1.88 for 98. Servos directly across from it, $2.10 for 91 E10, and $2.48 for 98. The part I had to laugh at? If I drive multiple HOURS away from Brisbane, say out near Nanango, or Kingaroy, or even out to Goondiwindi, the price of their fuel, is the same as what it is at the CostCo... Oh, and that BP servo at Goondiwindi is HUGE and goes through epic turnover of fuel, so it's not sitting there for weeks going to shit. And what blows me away, my mate is one of the people who drives the Fuel Tanker all around QLD, delivering to all those places. At the same company his previous role was doing the "local haul" deliveries... Same truck, same driver, same pickup point it all comes from. So you tell me, how the hell it is 60c/L CHEAPER for fuel, when nearly all else is equal, except they require a B-Double to drive half a day out of Brisbane, and half a day back, every second day, compared to the delivery that can be under 30 minutes drive from the fuel pickup point... Not to mention, go five blocks down the road, and Ampol to Ampol will vary 30c/L... And I've had this conversation with my mate... The way it's priced, is just typical, pure and utter rubbish... He also does runs from Brisbane, to all over QLD, down to Newcastle, Sydney, Nowra, Melbourne, Geelong, and even out to parts of the NT depending on the companies needs. His main stuff is all the longer distance away from home for a few days at a time, then when he's back, he loves to just pickup extra shifts wherever he can in whichever truck, hence all the weird different places.   Oh, as for getting E10 into all the fuels in Australia... It was very quickly highlighted, that we don't have enough biomass available to use to make E10 sustainably like they require, and it would dramatically cut into our, and the worlds food chain supply...   I vote we all just start running on liquid methane gas... Plenty of that just getting tapped off at tips from underground decay... (Note, this is pure just stupid commenting. I could very easily highlight the reasons its not a good idea especially on scale...)
    • Am I correct in assuming that the R35's are getting the classic skyline haircut off the odometer?  Quick search on carsales, there are 33 08 and 09 GTR's for sale, only 2 of them have more then 100,000km's on them (116,075 and 110,000 respectively).  And somehow there are about 25 for sale with around 60,000kms? Looks like the classic skyline haircut to me =/
×
×
  • Create New...