SR20 Forum banner
1 - 13 of 13 Posts

·
GT2835R
Joined
·
7,609 Posts
Didnt search did you? Kinda sounds like shaking beads in a can or something. Check you plugs. Symptoms can be from really lean a/f ratios, cheap gas, hot plugs etc. You probably wanna search.

btw - nobody gets flamed around here anymore for not searching. Thats a good thing, I guess we are all nice.
 

·
Bitter Old Man
Joined
·
2,637 Posts
btw - nobody gets flamed around here anymore for not searching. Thats a good thing, I guess we are all nice.
No, I've been busy elsewhere. Duck and cover, guys.

Detonation sounds like rattling from under the hood/bonnet/engine cover. It gets louder as you open throttle at low rpm and gets quieter as you close the throttle or rev higher.

Sabre's 93 octane (Süd Afrika, nicht wahr?) is not the same as ours; they use Research method only, so it's more like our 89 pump octane. 17 ºBTDC should be fine if his engine has less than 10:1 compression ratio. Lots of miles (possible carbon build-up) or less than advertised octane grade would cause problems. Also, you have to follow the factory service manual procedure for setting timing, otherwise you have no real clue as to actual base timing.
 

·
Registered
Joined
·
2,122 Posts
Oh wow. I'm happy this topic was discussed. I'm having a similar issue. I get a crazy rattly sound when I lug the engine around in a gear that is too high for the actual speed the car is traveling. I"ve heard it around 1500 rpm to about 3k rpm. It fades away as i go agressive with the throttle. Best way i can think of describing it is as if when your shaking up a spray paint can. If you can picture the sound the paint ball makes but with a frequency thats about 20 times faster.

Maybe i am getting detonation.
 

·
sleeper
Joined
·
5,445 Posts
Very good possibility. The fact that it goes away at higher rpms is another indicator. Denotation occurs more easily at lower rpms. Pull you spark plugs and have a look; you can often tell by checking the plugs. Also, either back off the timing and/or put in higher octane gas to see if the problem goes away.
 

·
Registered
Joined
·
945 Posts
Also fitting the 300TT radiator cap MAY help, only if you have some hot spots in the head. It is available from Nissan at the same price as the std 0.9Bar rad cap, but it is 1.2 Bar, the Nismo is 1.3 Bar for reference.

Mike
 

·
Registered
Joined
·
2,122 Posts
I think i fixed my problem. I adjusted the timing a couple of weeks ago. Problem was that I used the timing gun the wrong way. I'm thinking my timing was at 30 degrees at idle. So today i took the timing down to 15 degrees at idle. Hopefully this solved my detonation. Funny when you think of detonation you think of pinging. I thought it would sound metallic. The sound the car made was not like that at all.

I'll post up again in a week when my gas tank gets refilled. I put in some 91 octane just to be cautious. Hopefully it was just a advanced timing problem..
 
1 - 13 of 13 Posts
Top