davemar

It seems I just can't get to get my car running properly at the moment!

After I fixed my oil leak caused by a wonky camshaft seal, I was hoping everything would be fine. But now it has developed a really strange rattling noise when applying power. I've attached an mp3 file to show what it sounds like (sorry only mono, my second mic failed). I can't make it make the sound when revving when the engine is not under load, so can't check it when observing the engine with the car parked. The rattling appears only when applying power, and usually starts around 2.5k rpm.

I did initially suspect the exhaust manifold, as I removed that when fixing the oil seal. So I removed that, and refitted it again doubly checking everything was done up properly, but it made no difference. The only other things that I refitted for the camshaft seal fix was the cambelt and the radiator. Neither of those should change sound when power is applied.

So any ideas would be welcome!

BTW, it's a 2005 Blobeye WRX EJ205.

JDM_Stig

iTrader: (3)

If its starts around 2500 rpm and stops just after 3200 rpm its normally the start if the death knock.

ALi-B

iTrader: (1)

Weird! If that was a BMW I'd say it sounds like Vanos was goosed! (variable valve timing).

Check your oil pressure stability....are the oil pickups prone to cracking on these and sucking air?

davemar

It didn't make this noise before I fixed the leaking camshaft seals, so I feel its something I've done in the process of fixing that.

davemar

I decided to have a look at the turbo as the noise is load related. I've removed and dismantled the turbo to get the cartridge out for a closer look. As you'll see in the video there's a bit of play in it, so this might explain the noise.

1509joe

iTrader: (2)

Doesn't look too bad it's longitudinal play you should be looking for is it a TD turbo or a VF one.

Don Clark

As above the bearings are plain bearings so needs some clearance to build up the oil film to float the shaft. Longitudinal play is the killer
Blade leading edges look pretty chewed up - has it been used without a filter ??

ALi-B

iTrader: (1)

Not sure if that's the root of the noise, but that turbo has seen better days. The FOD damage on the compressor wheel is a bit concerning.

davemar

Yes, I was a bit concerned about the leading edges on the blades. Is the filter usually found in the banjo bolt for the oil supply? If so, then there didn't appear to be one in there.
I had the cartridge out a couple of months ago when I was doing some other work and the lateral play has certainly increased since then, and seems more on the end shown than the other end. The longitudinal play seems OK though. The turbo is a TD04 as standard.

The other problem I found was that the PCV valve didn't sound too good, with the bit inside not very free. The breather hoses are also completely rock hard with the short fat one split a bit too. So that doesn't help the breathing side of things.

ALi-B

iTrader: (1)

I don't think there is a filter. Worth checking the oil flow through the banjo incase of blockage...should throw out a pint of oil in a few seconds of engine idling (don't ask how I know this ).

davemar

OK, I've done some tinkering to try and get to the bottom of this...
- Replaced the little hose that connects between the block and the 3-way plastic connector that goes to the PCV valve. The hose had split (completely brittle) so was leaking air.
- Replaced the PCV valve as it wasn't as free as it could have been.
- Replaced the intercooler Y-pipe as that was brittle and a total nightmare to deal with. So replaced with a Mishimoto silicone one which is a lot more pliable and easy to fit.
- Removed and refitted the turbo as I decided the play in in was acceptable.

However, after all this the noise is still there. I've now done a better recording by placing a pair of mics under the bonnet, each one on top of the each suspension turret. So this gives a good stereo image to try and locate the sound. If you listen to this (either on headphones or decently spread stereo speakers) you'll hear that the squawking sound is over to the right, so around the turbo area. As before it only happens when applying gas under load. The recording makes the engine sound a bit more clattery than it really is as the bonnet is down as the mics are close to the engine.

Could a badly sealing gasket between the uppipe and turbo, or turbo and downpipe cause this sort of noise?

ALi-B

iTrader: (1)

Can you replicate the noise whilst revving when stationary. As then you can use a automotive stethoscope (or long screwdriver to the ear) to locate the area the noise is comming from.

davemar

No, that's the difficulty with this noise, it only happens when the engine is under load when driven. It doesn't happen no matter how much I rev the engine when stationary. If I had my own rolling road, then I might be able to load the engine up while stationary. I don't trust my driveway (bit of a slope) and angle stands enough to get the whole car in the air and drive the wheels.

Shane

iTrader: (6)

Somehow you've posted the solution to this post on a completely different thread from 2014.

https://www.scoobynet.com/scoobynet-...ine-noise.html

Gambit

iTrader: (6)

Thatll be due to davemar having infinite scroll enabled (it is by default)
https://www.scoobynet.com/news-and-a...d-threads.html

i advise everyone to disable it! its the worst feature ever on this board if enabled

davemar

Sorry about somehow replying to some prehistoric thread! Anyway, to ensure my reply doesn't get lost in that, here it is again....

I have appeared to have fixed it!

Firstly, I found one of the nuts on the manifold to up-pipe join had worked itself clean off. So that was obviously leaking a load of exhaust and making noises. Given that it did it twice, I must have bolted the exhaust sections in a bad order, so I removed the turbo (coming on to that in sec...), and downpipe, and then tightened everything back up starting as the bottom of the up-pipe then onto the turbo to up-pipe, then onto the turbo to down-pipe. Hopefully this ensures the pipes and turbo are stressing each other and the nuts stay tight. I popped some new gaskets on for good measure.

Secondly, when checking the turbo I noticed that the wastegate flap wasn't tightly closed. So when it was shut, the circular flap still could be wobbled and rotated. So this was probably causing the high-pitched rattling sound. So I just applied half a turn to the arm and the flap could shut properly. This has got rid of the high pitched sound.

So the engine sound back to normal now at last! Just in time for the MOT in a few days. So I expect the brakes to fail, the headlights to explode and the floor to rust out tomorrow.