Engine Rattling Sound

[peadya100]

My car has started making a rattling sound under load at around the 1500-2500rpm mark.. loud enough for me to hear it. This is not good

I was worried it was pinging, but ive since learnt that the ECU pulls timing to prevent that so it shouldnt be pinging. Plus the car doesnt seem to be performing any worse.

[bass_straitener]

Have you contacted MSR and sought his advice on what to do?

That's the first thing to do. Contact your tuner.

[peadya100]

Have you contacted MSR and sought his advice on what to do?

That's the first thing to do. Contact your tuner.

Yep emailed msr and haven't heard back yet. Hes so busy and not very chatty.

Thats why I want to save time and check a few ideas myself and email him the logs.

[bass_straitener]

Not sure how far you are away from Somersby, but perhaps arranging a time to see him would be be the quickest way to resolve this issue.

The most I've had to wait for a response from him is 24 hours. He should get back to you soon.

[peadya100]

Yeah he just emailed me. He wants to see the car asap. He says it shouldnt be knocking as the ecu stops it happening. Might take it up this weekend to see him.

[bass_straitener]

Good to hear.

He's very good in getting back to people and the best way to resolve the issue is put it on the dyno.

I've checked his tunes and the knock correction is solid so I'd be surprised if knocking continuously.

Keep us posted on the outcome.

[<GB>]

Bad patch of fuel?

[peadya100]

Definitely not the fuel. Ive had two tanks do it and both from different servos. Im going in to see MSR on Saturday so fingers crossed it will be an easy fix!!

[alexeiwoody]

Taken an LV?

Vac hoses on?

EDIT: Dont need to log car - just use Leraning view to check if it has been knocking. Takes 30 secs with the tactrix cable and laptop and LV software.

It is not wastegate chatter - it would only happen to a very badly tuned car. And it would have shown up on the dyno. Also wastegate chatter is almost never the case *read - impossible.

One of your lines may have popped off and is causing things to malfuntion? Needs a good look and a feel of the hoses

[<GB>]

Definitely not the fuel. Ive had two tanks do it and both from different servos. Im going in to see MSR on Saturday so fingers crossed it will be an easy fix!!

different brand fuels?

If its only doing it on boost I would stay off boost

[peadya100]

Yeah different brand fuels.

Nah its not happening on boost, its happening at 1500-2000rpm.

[Robbks]

Nah its not happening on boost, its happening at 1500-2000rpm.

at the point right before boost come one.. like 0-1psi on medium throttle..?

If so i had two causes of this noise on my GT Fozz.
1) Wastegate chatter.
-with a big dump pipe and factory boost control (that still allows some boost pressure to get to the WG actuator at all times) there is very little exhaust restriction compared to the stock dump which allows the wastegate to just creep open a tiny bit and chatter against the exhaust housing, very common problem on TD04 equipped cars. solution was just to pre-tension the WG actuator arm a turn or two

2) Compressor Surge
-this is the turbo being able to produce more airflow than the engine can consume with only a partially opened throttle.
Common on just about every factory turbo'd subie, but you usually don;t hear it with a stock intake and exhaust.
if you de-restrict the intake and exhaust, it makes the problem worse, doesn't usually cause any drivability or mechanical issues, just a funny nose as teh turbo reaches 0-2 psi
pssssss chchchchch psssss

otherwise it could just be a rattling heat shield.

[Newbie GT]

What actually is knocking in easy terms ? Sorry but I'm interested to know what to look hear for

[Robbks]

"knocking" or "detonantion" generally refers to pre-ignition or explosive ignition of the air/ fuel mix in your engine.
fuel should normally ignite and burn a a fast by controlled rate
Knocking is where the fuel basically explodes, which creates huge cylinder pressures and excessive heat which can ruin bearings, pistons, etc due to the excessive forces causing metal on metal contact.
usually sounds like rattling a ball bearing in a tin can.

Causes are generally too much ignition timing, too lean fuel mixture, excessive in-cylinder temperatures, fuel without a high enough RON rating, etc.

[peadya100]

Nah its not happening on boost, its happening at 1500-2000rpm.

at the point right before boost come one.. like 0-1psi on medium throttle..?

If so i had two causes of this noise on my GT Fozz.
1) Wastegate chatter.
-with a big dump pipe and factory boost control (that still allows some boost pressure to get to the WG actuator at all times) there is very little exhaust restriction compared to the stock dump which allows the wastegate to just creep open a tiny bit and chatter against the exhaust housing, very common problem on TD04 equipped cars. solution was just to pre-tension the WG actuator arm a turn or two

2) Compressor Surge
-this is the turbo being able to produce more airflow than the engine can consume with only a partially opened throttle.
Common on just about every factory turbo'd subie, but you usually don;t hear it with a stock intake and exhaust.
if you de-restrict the intake and exhaust, it makes the problem worse, doesn't usually cause any drivability or mechanical issues, just a funny nose as teh turbo reaches 0-2 psi
pssssss chchchchch psssss

otherwise it could just be a rattling heat shield.

Thanks for this advice!! I think youll be on the money with one of those. The car doesnt seem to be performing worse.. but im far from an engine expert

MSR has said the car will pull timing at the rpms im experiencing the noise so pinging shouldnt be happening, but i guess ill find out on the weekend. There is definitely some of that compressor surge noise i can hear now with the intake, but its a separate noise im hearing as the rattling sound.

Fingers crossed its an easy fix like the wastegate chatter or something rattling. I really dont want this to be one of these never ending stories where i spend thousands of dollars replacing parts to try and fix it.