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Engine Knock (Repeatedly) on an unmodified completely standard 2017 R35

5K views 19 replies 7 participants last post by  gtr mart 
#1 ·
Has anyone had any issues with engine knock on a standard car before? Where it knocks almost every time I go to put my foot down!

This is my 4th R35 having had a 2009, 2013, 2016 and now this 2017 and all my previous cars I never had any problems with engine knock at all. I put 99 Octane in and have tried different petrol stations of Shell and Tesco to rule out any fuel quality issues but still I get engine knock almost every time I go to accelerate hard like for example joining the motorway on a long straight slip road and no traffic.

Its a pain because the car sort of goes in to a half limp mode and restricts boost to 10psi etc and any car you may of just overtaken is now going back past me looking at me wondering why I'm suddenly slowing down. Plus as soon as I turn my ignition off and back on again it goes back to normal however that's the last thing I would want to do is stop on the hard shoulder and do a reset so I just wait until I get off the motorway and stop safely. Unfortunately though it means I'm forever driving around in a GTR with half the power plus I'm concerned now that each time there is engine knock that the engine is getting damaged.

The car is still under warranty until October and so I'm keen to get this fixed by Nissan under warranty and before it runs out. So far when I took it in they only cleared the code and today I'm going back in because it happened 2 days ago and the technician is going to read the "Freeze Frame" data and send it to Nissan to see if they can establish what is causing the engine knock.

Is there anyone on here that can help answer a question I have please - I'd like to know if all these engine knocks I've been getting could of caused any internal engine damage? and if so should I be insisting on a full engine inspection / replacement or is engine knock not that bad?. I've read conflicting stories however just because Nissan actually fit a Knock Sensor then I would say it's not a good thing for an engine otherwise they wouldn't fit a sensor in the first place however if the sensor can act quick enough to stop any damage from happening then that's a good thing however I'm not a GTR Technician.

If anyone has any advice on whether my engine could of been damaged then I'd very much appreciate it.

Thanks
 
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#2 ·
Do you get any error messages on the screen? Do you have to restart the car to clear the issue every time?
Since it is under warranty I'd strongly push for Nissan to get it sorted. Otherwise I would have gotten a Ecutek license and bluetooth dongle and logged the issue happening and try to inspect it or send it to Litchfield or some other GT-R expert for advice.

A pure shot in the dark guess would be some sort of issue with the fueling system, i.e. failing pumps/dropping fuel pressure.
 
#8 ·
Thanks for your response. I get no error messages or warning lights. Nissan tell me they clear a knock sensor code however I don’t know the exact code. Every time it happens I normally continue to drive it with the reduced power and then when I next stop the car and restart again then the car is back to full power.. It will not clear without a restart even if I drive for several hours. With the boost limited at 10psi and probably the timing adjusted then I’d estimate I’m getting about 300bhp. So it’s not like a 30mph limo home mode however it’s a bit embarrassing when turbo diesels are flashing their lights to get you to move over! Lol

I think the fuel pumps are okay because I bring up on the display fuel, boost and accelerator pedal position and it looks okay on the fuel flow. Fuel quality is ruled out having used 2 different Shells and 2 Different Tesco’s, all 99 octane rating and hashappened from all stations.

I will certainly push Nissan on this and will update this post with findings etc. Hoping it’s just a faulty knock sensor or something line that, fingers crossed.
 
#3 ·
Hello,

To answer your questions and keep it simple, Nissan Engineers have decided to add knock sensors to their engines for timing and combustion management.

About the knocks you hear, it'll depends on its severity and an oil check will give you an idea if further inspection is needed in case of metallic residues are found.

The issues you have with your car are coming from a faulty knock sensor sending inaccurate signals to the ECU.

Once the result of the data check is back, I would request for a full service on top of whatever they replace (knock sensor, ignition coils and its wire harness etc..)
 
#10 ·
Thanks for your post. I live in Weston Super Mare and currently got Nissan Cribbs Causeway In Bristol involved to fix it. When I went in on Saturday the GTR Technician downloaded to their computer all the data of what was happening at the time of the knock sensor giving It’s warning and he was sending that to Nissan UK who would of only got that info today. He did say that there is only 1 person now at Nissan UK that oversees GTR’s so I’m hoping he can pin point it otherwise they’ll need to send it on to Japan.

The car warranty doesn’t expire until October and being that I’ve brought this up now then even if this did drag on being repaired then I’m sure it will be covered.

Have been looking at buying one of the EcuTek Dongles anyway however I can’t make my mind up on which one.As far as I can see the Bluetooth one is great for compatibility with phones or iPads etc but doesn’t let you install maps with it and the wired version that you can install maps with would need to be connected to a laptop and not quite so versatile.

Previous GTRs I’ve had done at Litchfields, however I quite like the thought of being able to (Via a Tuner, not myself) Map the car remotely without having to take it there. Do you have experience with the EcuTek connect / advise which one to go for?
 
#13 ·
Quite a lot of people have experienced knock or dulled performance due to degrading fuel quality. The tesco and shell 99 fuels make the octane through an additive pack which doesn't seem to do well when the fuel is sitting in the petrol stations for long periods.

I've supplied the klotz Higher Octane Booster to lots of skyline and R35 owners which has done the trick and made the car feel fast again each and every time.

Having read through your thread, it's possible you have an issue so good the car is back with Nissan. If its an inconclusive answer then you might want to consider a couple of bottles of good booster

 
#14 ·
Quite a lot of people have experienced knock or dulled performance due to degrading fuel quality. The tesco and shell 99 fuels make the octane through an additive pack which doesn't seem to do well when the fuel is sitting in the petrol stations for long periods.

I've supplied the klotz Higher Octane Booster to lots of skyline and R35 owners which has done the trick and made the car feel fast again each and every time.

Having read through your thread, it's possible you have an issue so good the car is back with Nissan. If its an inconclusive answer then you might want to consider a couple of bottles of good booster

Okay thanks for the info.

I thought it might be fuel at first however because this is my 4th R35 and never had this problem before and I’ve used 4 different petrol stations and get the problem from all of them then I think it’s something on the car. Also if I’m putting in the highest octane rating of fuel you can buy in the U.K. and still getting this problem then Nissan need to resolve this.

I know mapped cars can suffer more with knocking however even in my earlier mapped cars I never had any knocking

I’ll certainly bear your product in mind if I do a track day, thanks.
 
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