Revs surging/hunting while cruising

[nedm1989]

Hey guys, I've upgraded from my old turboed QD32 D22 and now have a 550 and am loving it, although one of the only concerns I've had is when driving on a flat road at any speed under about maybe 90 but might have to confirm that the revs always seem to surge up around 250/300 rpm and then come back down to where they should be.

This pretty much happens all the time and wanted to know if anyone else has experienced this as other threads don't seem to describe it the same, it doesn't feel like it's changing gear but more so that the gearbox is letting itself slip.

Just wanted to know your thoughts?

And by the way to anyone that needs a what appears to be a full nissan workshop owners manual that covers all spain D40's including all info required on the v9x, PM me and I'll see what i can do

 

[Old.Tony]

Haven't heard of many issues with the V9X's SCV, but hunting is a common SCV symptom with the YD25 engine.

First thing I'd do (because it works so bloody well on my YD25) is throw a can of Liqui Moly Fuel System Treatment in the tank. Has worked for me every time.

I must also observe that changing fuel also affects this. When the Shell at Hexham (on my way home) had its diesel 20 cents per litre cheaper than the rest of town, I was buying fuel there as often as needed. After 4-5 tanks my car began hunting at idle, and happened to be away and had to resort to BP Ultimate Diesel (I'm actually a fan of that fuel, don't read that the wrong way). The hunting went away very quickly.

So I'm purely on BP Ultimate now ... car purrs like a kitten.

 

[nedm1989]

Thanks Tony, sorry I should have not used the word hunting, its only when driving rather than idleing. I always use BP Ultimate diesel in my 550

 

[Old.Tony]

From about 90km/h onwards our cars lock their torque converters, fully engaging the drive line. Could that be a factor?

 

[Kakol junior]

Surge

Hi nedm did you work out the problem?

 

[Hansie]

Problem solved?

Sent from my SM-G935F using Tapatalk

 

[zebra]

I've had this happen to mine this week the torque converter isn't locking up which in mine was caused by water in transmission after completing rebuild problems persisted and was solved by replacing torque converter clutch solenoid.

 

[Kakol junior]

Hi mate was yours doing this ? https://youtu.be/wq-icH8J9nk if so did you change out that solenoid yourself..part number be great..cheers

I've had this happen to mine this week the torque converter isn't locking up which in mine was caused by water in transmission after completing rebuild problems persisted and was solved by replacing torque converter clutch solenoid.

 

[skullbone]

http://www.sonnax.com/parts/2290-tcc-control-valve-kit-low-brake-switch-boost-valve-kit

i dont think this is the right control vavle nor solenoid. but i found this info

 

[nedm1989]

I had a look through the entire manual trying to find where the T/C clutch solenoid is located and didn't see it in the entire rebuild process, is it within the control module/valve body?

Also I think I think our gearboxes are slipping on purpose and I'll take some snap shots from the official nissan manual I have for our model ute tomorrow for you guys.

 

[Old.Tony]

I don't think we're supposed to know (and our manuals are the dealer service department's manuals). Nissan just replaced the entire TC to resolve the vibration problems, because (for the calibre of mechanic they know to have in dealer workshops) trying to diagnose and repair the components within the TC is not a simple task compared to removing and replacing the TC.

 

[nedm1989]

On a side note Tony was yours shuddering when the revs would drop to idle when coasting at around 40ish kms?

 

[Old.Tony]

Only when the transfer case bearing went.

 

[Kakol junior]

Any luck fixing this annoying problem?

 

[nedm1989]

from what I've now found in the nissan manual it is actually apart of the gearbox design to have variable slip in order to smooth engine output and increase fuel economy, which is probably why that gearbox will only take nissan matic S because of what ever kind of spec friction modifiers that use in it.

 

[aquanaut]

Hey guys
When i first drove my stx with v9x diesel was told to drive it in sports mode around town to prevent it from hunting gears!Seems to solve the problem.

 

[Kakol junior]

It helps a little but not completely...