Another strange noise
Discussion
A shot in the dark, but thought I'd run it past you guys. When high revving my engine (under load)I get a noise like splinters coming off a spinning wheel, its not stones or tyres, sounds like its coming from the engine bay area directly behind my head. As soon as I'm off the power it stops. Note, it did this before with the old turbos. Could it be tappets ???? Oil etc just been changed and level fine. Any ideas??
This does not sound good. It was remapped on Wednesday by Trevor and passed with flying colours. How do I find out the detonation, and how do I put this right?? It happens around 4500-5000rpm. As for the ignition advance, I have no idea. The engine has been set up to M400 spec.
Edited by wessexrfc on Sunday 19th June 00:54
Could still be detonation - engines run differently on a dyno vs. on the road. So, if all the mapping was done on the dyno, without a road test to verify the tune, it could still detonate. Also, has anything changed since it was mapped, like brand/grade of fuel, etc? Is the weather drastically different from when it was mapped? You haven't filled up with a lower octane or changed from oxygenated to non-oxygenated (or vice-versa), have you? Could also be something non-map related, like fuel starvation under load, causing the engine to run lean and detonate. You might want to pull the spark plugs and inspect them for signs of detonation, and take a peek inside the cylinders...
Could it be something hitting the frame, like the exhaust or a heat shield? How about something like a loose spark plug?
Could it be something hitting the frame, like the exhaust or a heat shield? How about something like a loose spark plug?
Think your right, on low boost I think it didn't do it, will check. The car has been mapped on 95 octane and thats all I put into it. The weather is the same, spark plugs were cleaned and refitted. I've read this: http://www.misterfixit.com/deton.htm
But the sound I'm getting sounds like a crackel, as if a tyre was clearing fine gravel off it at high speed.
I take it my first step is to get it to run on low boost and see what happens if it stops would this suggest we have detonation, one way it suggests to stop this is to run on a higher Octane fuel, is this worth a go?? Then to the garage if it persists, how do they check for Detonation?? Lots of questions, sorry!!
But the sound I'm getting sounds like a crackel, as if a tyre was clearing fine gravel off it at high speed.
I take it my first step is to get it to run on low boost and see what happens if it stops would this suggest we have detonation, one way it suggests to stop this is to run on a higher Octane fuel, is this worth a go?? Then to the garage if it persists, how do they check for Detonation?? Lots of questions, sorry!!
Just noticed you said it also did it before with the old turbos, but yet the same fault did not show up on the rolling road during tuning, so it must be an intermittent fault, i assume you got the uprated actuators when you changed the turbos? Could it be a faulty electronic boost controller? i think a vacuum leak on the boost line would have shown up during tuning.
Running on higher octane will help reduce the chances of detonation whilst you find the problem, get some good quality fuel in there, clean out the fuel system/injectors, fuel filter, check the actuators are not sticking.
Are you using hot plugs? take one of the plugs out for inspection, take a photo and post it for us to have a look at, as for electronic boost control i suppose only a diagostics or replacement.
I am not really clued up on things like this but i just thought i would put forward some ideas
Running on higher octane will help reduce the chances of detonation whilst you find the problem, get some good quality fuel in there, clean out the fuel system/injectors, fuel filter, check the actuators are not sticking.
Are you using hot plugs? take one of the plugs out for inspection, take a photo and post it for us to have a look at, as for electronic boost control i suppose only a diagostics or replacement.
I am not really clued up on things like this but i just thought i would put forward some ideas
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