RB20DET Knocking.... Help Please

[5 litre eater]

Hey all,

I posted in another thread about this, but would like everyone's opinion on what could be wrong...

I'm not exactly a wizz at this whole mechanical side of life, so can anyone please explain to me what is wrong, if anything? I did an ECU fault test about 2 weeks ago on my R32 5sp RB20DET, and saw that the Knock Sensor code was coming up (from memory it's 3 long flashes, and 4 short flashes). When the car is cold, it is very hard to start (have to pump accelerator repeatedly) and the oil pressure sits under 4 on the dash nearly at all times... It never stalls when i push the clutch in, and never has yet. It also feels like the car isn't moving as quickly as it should. (EG, in every gear, second especially, it doesn't feel as free moving as it should...)

Does this mean i've done a main bearing, blown the bottom end or am i just paranoid?

Thanks. Matt.

[Roy]

Give it a basic service.

I suggest :

- clean AFM (and air filter/or change element whatever is applicable)

- Put in new spark plugs (read cheapies - copper)

- Change oil and filter

You dont actually state that you can hear a knock from the engine.

Im changing the oil in my car this weekend, i would expect as was the case with my old SR20, that once it gets a gut of fresh/thin oil if a knock is present then it will be more evident once i have done an oil change. Incidentally this will be the 3rd oil change since i first noticed noise 9,500kms ago.

Im now thinking its perhaps some ancillary noise or perhaps top end noise on startup in my case.

[5 litre eater]

Thanks again Roy for your advice... I've got it booked in at BMT on monday for a full service. Like i said earlier, i wouldn't know what the knocking noise sounded like, but thankfully i know what detonation sounds like.

Cheers again.

Matt

[WazR32GTSt]

matt,

i had htis code flash up when i did an ECU diagnostics and the reason it comes up is that there is some sort of fault with the ECU getting readings from the knock sensor

in my case one of the 2 knock sensor's was not plugged in!

it could aslo be that the sensor if faulty or just screwed.

it takes 2 minutes to check them: just stand over th battery looking towards the throttle body. If you hold a torch and look through the intake runners of cylinders 1 and 2 then you should see a little green sensor with a white plug plugged in. It is right under the intake plenum and attached to the block (may be hard to see). there is also another snesor between runners 5 and 6. have a look. in my case the plug's were hanging and not into the sensor... i had many of the symptoms you mention above of which most went away after i put the plug back in!

cheers,

Warren

[5 litre eater]

Thanks for the advice warren. I just went out to check, and the plugs are in. I just hope now it's a faulty sensor.....

[WazR32GTSt]

if you need anotehr sensor, i think there is a guy in the for sale section who is wrecking an rb20det so he might be looking to sell his 2 for cheap...

[5 litre eater]

I think Dr Drift has a spare one for me. The car's booked into BMT on Monday, so we'll see then. Fingers Crossed. It's in dire need of a full service, so hopefully with that and the new sensor, all will be well...

[WazR32GTSt]

good luck mate

keep us posted...

[5 litre eater]

Turned out to be a faulty knock sensor... Still haven't got around to fixing it tho. The service certainly helped aswell. It runs a lot smoother, but is still hard to start in the mornings.

[WazR32GTSt]

change it and the car will run even better!

hard starting. hmmmmm welcome to my world...

i've narrowed my problem to fuel and ignition

not plugs possible injectors blocked or coil pack screwed

[Dr_Drift]

Problem solved... broken wire on knock sensor plug at rear of inlet manifold...

ALL GOOD

[unwritten law]

Mine is suffering from pretty much the same symtoms - cold starts and a bit of ping (rattle sort of noise when at higher revs) - when its hot, i am running too much boost on a stock cooler for this sort of weather me thinks...

i am thinking the fuel pump is on its way out, is there anyway to check it? Can somebody send me the diagnostic codes and how to check it?

[email protected]

[Dr_Drift]

Mine is suffering from pretty much the same symtoms - cold starts and a bit of ping (rattle sort of noise when at higher revs) - when its hot, i am running too much boost on a stock cooler for this sort of weather me thinks...

i am thinking the fuel pump is on its way out, is there anyway to check it? Can somebody send me the diagnostic codes and how to check it?

[email protected]

call me on 0411 878 961 and I'll talk ya through it if you like./.

[MM2death]

My 32 has gradually been getting harder to start since i got it. I have to pump the accelerator and will only go on the second turn of the key.

Is there a simple explanation for this?

My oil and filter was changed not long ago. Plugs are around 7000km mark.

Regards,

Scott

[RaseR]

Hey my R32 is also beginning to get harder to start, it only happens in the morning when the car is dead cold, it starts first turn of the key but sits at 300rpm or less and almost stalls unless I tap the accelerator, at which point it roars into life...well not really - it just starts idling properly! Sticky AAC valve perhaps?

I'd love to know the actual cause of this as well, it's only a recent thing on mine, and as with MM2Death - mine has regular oil changes and I just checked the plugs.

thanx,

Dave.

[Dr_Drift]

RaceR - I can show you how to check your fault codes if you want to see me at work sometime?

MM2death - Might be a bit far for you to drive??

Doc.

[RaseR]

Hey Dr_Drift,

Thanx for that, if all goes to plan I should be bringing the car into BMT early next year to get some mods installed/car dynoed, so that'd be the best time to get you to check it.

BTW, you worked on my friends car - the purple DR30, I drove him down to pick it up. The car is running really well, I can't believe how quick it is! Once it's complied & on the road (soonish) it's definitely gonna scare some people!!! ;-)

cya!

[Dr_Drift]

RaseR - Small world I love FJ's they're quite an amazing motor.... The one i was chasing fell through so I'm sticking an SR20 in my Datto 1600!!!

Look forward to seeing that FJ for some mods soon

Doc.

[MM2death]

RaceR - I can show you how to check your fault codes if you want to see me at work sometime?

MM2death - Might be a bit far for you to drive??

Doc.

Yea you could say.

So i guess there is no one simple explanation for this?

Scott

[WazR32GTSt]

my similar symptoms turned out to be blocked injectors which cost $90 to clean (not including labour as they are piss easy to remove, just hard to put back in)

fixed cold starts and a slight miss i had at idle