Hi, I have a subaru sti 2007 and at 5500rpm it loses power and makes a loud rickety noise, I took it to a garage and they said its detonating! I have got it booked in at marlin motors on Tuesday and hopefully they will be able to fix it for me as they have a 4wheel drive rolling road, I use tesco 99 Ron and shell vpower. Has anyone else had this problem? Does anyone know what may of caused it? Thanks in advanced for your help

 

Rickety huh.
Have a read here and see how well you sleep tonight https://www.scoobynet.com/scoobynet-...-failures.html

 

Un oh 2.5 failure again

 

 

its highly unlikely you are hearing detonation as to get to this point you would have to be having massive general issues

could be many things but requires a proper check-over

 

The cars on the above link all seem to be 2008 onwards, anyway I will see what Marlin motors say

 

:

 

mines an 06 and failed, its all 2.5's.

 

Could just be a plug
You just don't know until it's been looked at

 

As above - could be anything tbh from an up-pipe gasket to a loose spark plug - hopefully nothing too drastic for the OP.

Mick

 

Yeh let's hope so, the garage did say that it was detonating at 5500rpm, this was when it was losing power and started making that loud rattling noise. If the car was detonating then would you only hear it at 5500rpm ? Are there any other symptoms to look for if it was detonating do you think ?

 

if it was det loud enough to hear you'd have no engine left

 

How did they diagnose it as detonating ??

 

I took it to the garage where I bought it from, I told them what the problem was (losing power at 5500rpm and making a loud racket noise when it gets to 5500rpm, 2 mechanics took it for a test drive with "live data" and they came back and said its detonating, hopefully it's not actually detonating and may just be a lose spark plug or something

 

what do they mean by live data?

 

I have a video clip of the noise but not sure if I can upload a video?

 

Not entirely sure to be honest as they said to wait in the waiting room while they test drove it

 

if you can heard it on a video then its not det mate. Det you need det cans to hear. Get it to a decent specialist for them to have a listen, API is down your way i think?

 

Chances are they had a device or laptop plugged in and were logging/watching things like timing and knock detection.

 

Oh that's good news, I'm glad it's not detonating, I have it booked in at marlin motors on Tuesday, they have a 4 wheel drive rolling road, I will let you know what the problem was

 

Thats not true. On the only 2 expeiances of det i have personally had, i can only descibe the sound as gravel being shaken in a can!

Incidentslly the first time it happened i was having a dice up with a classic scoob on the m4. 120mph ish and the result was nice hole in a valve.

The second time, different car and engine, same sound.

That also resulted in a burnt valve lol

 

Is the car bog standard? or has it been modded...at all?

 

The car is standard as far as I know, but the thing is it drives perfectly in 1st gear all the way to 7000rpm and also still drives normally until 5500rpm in second gear , so if it was detonation then would it still drive normally up until 5500rpm in second gear does anyone think?

 

The car is standard as far as I know, but the thing is it drives perfectly in 1st gear all the way to 7000rpm and also still drives normally until 5500rpm in second gear , so if it was detonation then would it still drive normally up until 5500rpm in second gear does anyone think?

 

read post 12

 

Ok thank, I will let you know what the problem was tomorrow, I'm sure it's not detonation as the car drives fine in 1st gear all the way to 7000rpm , the noise only happens at 5500rpm in second gear, hopefully it's just a lose spark plug or something

 

Det doesn't work like that .its down to load as well. If its a really loud noise it s probably not det though.

 

Any results?

 

Hi, its at the garage at the moment, fungures crossed its nothing major

 

Keep us informed this makes for good reading. Good luck hope all is well with the car