Hello,
I have a Nissan Pulsar 1.5 (A QQ without the big wheels).
I have noticed when turning the car off after a run, long or short, there is a high pitch squeal sounding like a pump for about 10 seconds after turn off.
I seen a reference to a noise on the Duke forum but it never stated what it was just that it was "well known".
Would it be an oil pump? Or has anyone else got the same issue.
Thanks,
Jamie
1.5DCI - Squeal for 10 seconds when engine turned off.
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Deleted User 1571
I believe it to be an electric water pump that continues to cool the turbo bearing housing after shut-down.
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Deleted User 2899
If this is the same noise as mine then I have been told its normal (the garage said its part of the engine "purging itself", however mine (14 reg) has been at the dealers for 3 weeks and they loaned me a 65 reg (same spec as my 1.5 Tekna) and this was TOTALLY silent after turning the engine off and locking the door.
I live in a very quiet cul-de-sac so I can hear mine very loudly.
I live in a very quiet cul-de-sac so I can hear mine very loudly.
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ThreeSixty
- Posts: 100
- Joined: Mon Oct 19, 2015 3:56 pm
Thought the 1.5 had an oil cooled turbo!! If its water cooled as you mentioned above, that's a load of my chest when the stop/start is activated after a mildly hard run. Any leads to the technical specs of this turbo?Quacker wrote:I believe it to be an electric water pump that continues to cool the turbo bearing housing after shut-down.
1.5 dCi 360. Ink Blue; Mud Flaps and Internal rubber mats & after market door sill plates.
water cooled ???Quacker wrote:I believe it to be an electric water pump that continues to cool the turbo bearing housing after shut-down.
so where does this water come from ???
Qashqai acenta 1.2 petrol xtronic jan2016 - flame red - no bells and whistles.
previous , now departed , Primera 2l petrol cvt 2001 147000 faultless miles.
previous , now departed , Primera 2l petrol cvt 2001 147000 faultless miles.
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ThreeSixty
- Posts: 100
- Joined: Mon Oct 19, 2015 3:56 pm
On referring the owner's manual under Starting & Driving - it clearly states oil cooled turbo. It also states idle the engine if operated under high RPM levels over long periods of time.
As an aside, I think the start/stop is'nt intelligent enough to sense that the turbo needs a cool down. I was in the mountains and after a spirited climb, I expected the start/stop to not shut off the engine but it did!!!. Hence, start/stop is going to be switched off on highway runs and mountain climbs.
But this doesnt seem to be an issue with only the QQ, many brands and even BMW forums are debating the combination of start/stop & turbo cool down. Wish manufacturers could put in a few guidelines about what needs to be done, as the operation seems to be contrary to what's in the owner manual.
As an aside, I think the start/stop is'nt intelligent enough to sense that the turbo needs a cool down. I was in the mountains and after a spirited climb, I expected the start/stop to not shut off the engine but it did!!!. Hence, start/stop is going to be switched off on highway runs and mountain climbs.
But this doesnt seem to be an issue with only the QQ, many brands and even BMW forums are debating the combination of start/stop & turbo cool down. Wish manufacturers could put in a few guidelines about what needs to be done, as the operation seems to be contrary to what's in the owner manual.
1.5 dCi 360. Ink Blue; Mud Flaps and Internal rubber mats & after market door sill plates.
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Deleted User 759
most factory fit turbo's these days are water cooled.... your mileage may vary however and I don't have a DCI to check!
I am sure I read somewhere that the stop/start system had a thermocouple on the turbo which prevented stop/start operating if it was above a certain threshold. But either which way, although turbos get hot, with the size of the turbo's fitted to factory cars and the little stress that they are under is not that great compared to much bigger, or highly tuned beasts. Turbo's also don't take a huge amount of time to cool down to a reasonable temp even after a hard slog, maybe a minute or 2, so by the time you have exited the motorway up the slip road, gone around the roundabout, it should be cooled enough to kill the engine without to much worry. It isn't going to get much cooler than that to be fair!
If they are indeed water cooled, then they will take even less time to cool and will tend to have a less high heat peak than non-water cooled turbo. The other benefit of water cooled is water continues to flow around the system even with the engine off through convection.
I wrote a FAQ about this, and yes whilst I state if you have given it a pounding, don't switch it straight off, but at the same time, as long as its had a couple of minutes to calm down, it will be fine!
IMHO, leaving an engine to idle is poor practice. It allows heat to build up in areas you don't want it to build up and you are much better driving calmly for a mile or 2 before shutting down. This allows air to flow around the engine and air to be pushed through the rad, much more efficient way of cooling an engine off.
Anyway back to the topic. All the Nissan's I have owned (Primeras, Micra's, 200sx, Almeras.... granted, all petrol) have all made some sort of start-up, or shutdown noise. Most of the time they are just little chirps, beeps and high pitched whines. It's electrical gubins either priming, or resetting.
I am not aware that any of the QQ/Pulsar/Juke engines had electrical water pumps though...... gvmdaddy - kind enough to show where you got this info?
I am sure I read somewhere that the stop/start system had a thermocouple on the turbo which prevented stop/start operating if it was above a certain threshold. But either which way, although turbos get hot, with the size of the turbo's fitted to factory cars and the little stress that they are under is not that great compared to much bigger, or highly tuned beasts. Turbo's also don't take a huge amount of time to cool down to a reasonable temp even after a hard slog, maybe a minute or 2, so by the time you have exited the motorway up the slip road, gone around the roundabout, it should be cooled enough to kill the engine without to much worry. It isn't going to get much cooler than that to be fair!
If they are indeed water cooled, then they will take even less time to cool and will tend to have a less high heat peak than non-water cooled turbo. The other benefit of water cooled is water continues to flow around the system even with the engine off through convection.
I wrote a FAQ about this, and yes whilst I state if you have given it a pounding, don't switch it straight off, but at the same time, as long as its had a couple of minutes to calm down, it will be fine!
IMHO, leaving an engine to idle is poor practice. It allows heat to build up in areas you don't want it to build up and you are much better driving calmly for a mile or 2 before shutting down. This allows air to flow around the engine and air to be pushed through the rad, much more efficient way of cooling an engine off.
Anyway back to the topic. All the Nissan's I have owned (Primeras, Micra's, 200sx, Almeras.... granted, all petrol) have all made some sort of start-up, or shutdown noise. Most of the time they are just little chirps, beeps and high pitched whines. It's electrical gubins either priming, or resetting.
I am not aware that any of the QQ/Pulsar/Juke engines had electrical water pumps though...... gvmdaddy - kind enough to show where you got this info?
Owners manual...chapter 5 section 10 'the turbocharger uses engine oil for lubrication and cooling of its rotating components......If the engine has been operating at high rpm for an extended period of time, let it idle for a few minutes prior to shutdown'.
