Manual that thinks it's Automatic

Roadie · Post by **Roadie** » Wed Dec 02, 2015 7:47 pm

I have had a look around the forum for this but can not find anything, so here goes
I have a 1.5DCI, when i slow down without my feet on the clutch or accelerator the car will drive along in 1st, 2nd and 3rd and in 1st will still pull up a steep hill. I know diesels will pull in 1st on the flat but uphill? and i have never known them to drive along in 2nd and 3rd. It also picked up speed on a couple of occasions. The car is booked to go in next Wednesday for the dealer to have a look at it, but i wondered if anyone else had experienced this or had any ideas on what could be causing this. The last time i experienced anything like this was years ago when i had a choke jammed slightly open. One other thing the revs seem normal.

gvmdaddy · Post by **gvmdaddy** » Wed Dec 02, 2015 9:44 pm

Mine does the same. Its my first diesel in 30 years so I just see it as a characteristic ie higher torque. On the flat it will comfortably pull along in 5th and 6th gear with no foot on the pedal. Never had it increase in speed though. Im certainly no mechanic at all, but when did you last have an oil change and what mileage have you done? Could it possibly have anything to do with diesel having made its way into the sump oil?

Roadie · Post by **Roadie** » Wed Dec 02, 2015 10:08 pm

No oil change, it's only done 4000 miles and oil level has not moved. The dealer said it was strange. I put it down to the torque at first but to pull in 2nd and 3rd on the flat and uphill in first i have never heard of. None of my other diesels have acted like this apart from pulling in 1st.

duncho · Post by **duncho** » Thu Dec 03, 2015 8:43 am

Why do you want to have it inspected if it is exceeding your expectations? It's nothing wrong with it, you can see that the engine is capable to do the job, but it simply is not healthy to do so as certain engine parts as well as clutch are overloaded when you pulling out on higher gears.

Roadie · Post by **Roadie** » Thu Dec 03, 2015 6:26 pm

duncho wrote:Why do you want to have it inspected if it is exceeding your expectations? It's nothing wrong with it, you can see that the engine is capable to do the job, but it simply is not healthy to do so as certain engine parts as well as clutch are overloaded when you pulling out on higher gears.

Why do i want it inspected? well you answered that yourself...not healthy! even the dealer said it was strange, and i certainly don't like it when it picks up speed on it's own.

Deleted User 2899 · Post by **Deleted User 2899** » Tue Dec 22, 2015 9:47 am

Yup. Mine creeps along nicely in 1st and 2nd gear. Extremely useful when stuck in a line of slow moving traffic. Its like having an Automatic but without the cost

I don't think I have had any problems with it increasing in speed however my wife has a Skoda Octavia 1.6 diesel and I have noticed some fairly dramatic increases in speed on hers especially in 4th gear.

QQ013 · Post by **QQ013** » Wed Dec 23, 2015 2:03 pm

and i certainly don't like it when it picks up speed on it's own.

It does not.. Your the one who is using the gears.
I used to drive a Peugeot 407 diesel 2L that reached about 50 km/u in the fourth gear on idle. It's a sign of a lot of torque so just use it sensible.

F1 Bob · Post by **F1 Bob** » Wed Dec 23, 2015 3:36 pm

I seem to remember that there is also an anti-stall system which will not allow the engine to stall if you come off the throttle at low revs. I believe it will increase power to prevent stalling which could be why you feel the speed increasing?

bone_tone · Post by **bone_tone** » Thu Dec 24, 2015 12:01 pm

Lanstrom wrote:Yup. Mine creeps along nicely in 1st and 2nd gear. Extremely useful when stuck in a line of slow moving traffic. Its like having an Automatic but without the cost

I don't think I have had any problems with it increasing in speed however my wife has a Skoda Octavia 1.6 diesel and I have noticed some fairly dramatic increases in speed on hers especially in 4th gear.

Yes, I had exactly the same thing with a Skoda Superb 2.0 diesel - sounds like it's a very common feature of diesel engines.

Deleted User 1571 · Post by **Deleted User 1571** » Fri Dec 25, 2015 9:30 am

Diesel engines have governors. Nowadays they are electronic governors but no less governors that manage the revs of the engine. It tries to maintain a given engine speed even under varying load.
The extent to which it is able to maintain this is relative to the amount of torque available from the crankshaft. Diesels traditionally have abundant torque at relatively low revs compared to petrol engines.

As it happens the little 1.5 Renault diesel has quite unremarkable 'start-off' torque compared to many other larger diesel engines. It is far easier to stall than those others, although still significantly superior to most petrol engines in this respect.

The very latest versions of the K9K engine, as fitted to the current Qashqai, is much improved in this respect over even previous generations of the same engine family. Somehow the engineers have raised maximum torque and start-off torque significantly, although it is not class-leading in this respect. It is however, and has become a very competitive engine that is pleasant to drive, refined in the Qashqai installation, and economical. What more could one want from a budget price diesel engine?

Manual that thinks it's Automatic

Nissan Qashqai Forums

Follow Nissan QashQai Forums