Soarer Central: Stock turbos, harsh rattle under boost ??

Soarer Central Mechanical - TT Turbo Talk Stock turbos, harsh rattle under boost ??

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David Watt
Tinkerer
Qld
TT

Posts: 67
Reg: 09-2007

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Monday, January 28, 2008 - 02:23 pm, by: David Watt (David_w)

Hey guys. Damn hot day outside today, 33C plus the added temp from the car being in the sun all morning, so I'm not sure if that has anything to do with it.

The car drove fine on the way to work this morning but on the way home I noticed a harsh rattle coming on under boost which gets louder as boost goes up (naturally I babied it after I realised what was going on). Kind of sounds like sticking a small twig into bike spokes, then like shaking a can of spray paint as it gets louder but a very irregular rattle.

The car is cooling off but what can I look for once I pop the bonnet? I checked nothing was in the intake, but I'm guessing somethings seriously f**ked in one of the turbos. Or the cat.

Chris Prak
TryHard
WA
Soarer GTT-L

Posts: 195
Reg: 12-2006

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Tuesday, January 29, 2008 - 06:44 pm, by: Chris Prak (Carizma)

Check the manifold, dump, turbo bolts. They may have come loose and the rattle is the gasket or any vibration.

Otherwise you have a serious problem...

Does it boost still?

Luke Burt
TryHard
Queensland
Soarer TT

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Tuesday, January 29, 2008 - 08:15 pm, by: Luke Burt (Burt)

Yeah, is it still boosting as normal? Checked that nothing is actually stuck in your fan? lol

Give the car a couple of rev's in park, see if you can hear exactly where the noise is coming from. If you hear no noise while revving in park, its probably turbo related, revving the motor with no load on it won't produce enough exhaust to get much boost happening.. unless you keep revving it.. then the turbo's will start to spool and slowly get faster. but yeah.
Give that a try.
Try the old 'stethoscope' aka screwdriver and place it on your turbo housing while revving (if the noise is present) to locate which turbo is doing it etc.

Edward Salem
TryHard
SA
Aristo 3.0V TT

Posts: 309
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Wednesday, January 30, 2008 - 09:21 pm, by: Edward Salem (Sydeward)

hate to be the bearer of bad news but going by what your saying i think the sound is more likely coming from your engine than the turbos itself... especially if the noise grows louder consistently with the engines acceleration...

im not really an expert so theses nothing I can recommend over what the other members have suggested.

If theres anything I can suggest try observing the engine while its idle...
does it shake around a lot? are you noticing any vibrations? any clicking noises? or only when its being revved?

if your lucky your timing may be out, if your not it could be serious. either way take your car into a workshop and have it looked at asap

Chris Prak
TryHard
WA
Soarer GTT-L

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Thursday, January 31, 2008 - 09:46 pm, by: Chris Prak (Carizma)

Yes, thats right Edward, I forgot about that. When my main bearing blew, it made that rattle when rev'd while parked. However, it only did it in 2nd gear whilst driving.

Good luck with it anyway.

Dave Cazes
Tinkerer
sa
tt

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Wednesday, February 06, 2008 - 07:18 pm, by: Dave Cazes (Cazman)

man is everyone retarded on this forum

THE CAR IS PINGING- quite often sounds like rattling glass, get your car into a dyno centre, get the timing adjusted, and stop putting cheap 91 octane fuel in

David Watt
Tinkerer
Qld
TT

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Saturday, February 09, 2008 - 01:54 am, by: David Watt (David_w)

Thanks for assuming I run my performance turbo import on unleaded.

I haven't narrowed down the problem but I also have not experienced it since. It was certainly a temperature issue. That was definitely the hottest day this year, with the car sitting in the sun until I drove it home at around 1-2pm. It's running fine now but I will still be getting it looked at before the ECU goes in.

PS 98 octane only, kids.

Daniel Clarke
Goo Roo
NSW
TT 2.5L 6 cylinder

Posts: 2979
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Saturday, February 09, 2008 - 07:10 pm, by: Daniel Clarke (Dieseltrain)

Dave Cazes wrote on Wednesday, February 06, 2008 - 07:18 pm:
man is everyone retarded on this forum

Haha, How about you bugger off and stop using all of our knowledge then!!! Seeing as " we are all retarded "...

Good one Champ, your such a legend yourself...

Dave Cazes wrote on Wednesday, February 06, 2008 - 07:18 pm:
get your car into a dyno centre, get the timing adjusted, and stop putting cheap 91 octane fuel in

ANother great assumption. Get the timing adjusted??? Its a TT and cannot have its ignition changed, only checked. And great to see you also assumed he was running 91 fuel.

There is a difference between offering help and outright being an idiot with comments like these! I hope Peter has a word with you on this one.

Dave Cazes
Tinkerer
sa
tt

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Saturday, February 09, 2008 - 08:19 pm, by: Dave Cazes (Cazman)

yeah i dodnt realise that ya cant change the timing till now, pretty gay. time to buy some cam gears off ben then.
whose peter? is he single?

Charlie Ters
TryHard
nsw
TT

Posts: 167
Reg: 01-2007

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Saturday, February 09, 2008 - 09:36 pm, by: Charlie Ters (Ul05st)

....sms speak.....calling people retarded....and that comment about peter.... let me say things look pretty cloudy for you ...

Ben Socratous
Goo Roo
SA
I am the fibreglass/kevlar/carbonfibre king!

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Sunday, February 10, 2008 - 10:01 am, by: Ben Socratous (Socrates)

Settle down lads, I've now explained to Dave how things work around here.

Blake Gloyn
TryHard
manawatu
soarer JZZ30 TT

Posts: 232
Reg: 02-2006

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Sunday, February 10, 2008 - 03:32 pm, by: Blake Gloyn (Blakenz)

Dave,the 'timing' that you can adjust with cam gears is not the same as ignition timing.(perhaps i misunderstood your inference)

Dave Cazes
Tinkerer
sa
tt

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Monday, February 11, 2008 - 01:01 pm, by: Dave Cazes (Cazman)

blake, how is it different? not being rude. im pretty sure if you spark is say sparking at 12 o clock say, and you retard the timing on in/ex to 1 oclock, that mean you will have changed your timing regardless, the end result will be retarded regardless.

by the way this is an example only

Matthew Sharpe
Goo Roo
North Island
JZZ31

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Monday, February 11, 2008 - 01:46 pm, by: Matthew Sharpe (Madmatt)

Dave, I could be wrong as I'm by no means an expert, but I don't think changing cam timing in the way you infer is general practice as I can't see it leading to any performance gains. Essentially all you would end up doing is changing when fuel mixture enters and exhaust gasses leave during the combustion cycle. Generally this would have a very negative effect on performance, as you would notice if say, your cam timing was out by a notch or two on the cogs.

More commonly you would change the lift and/or dwell on the valves by modifying the camshaft profile - this will give performance gains by increasing gas exchange efficiency (provided your inlet and exhaust are up to it)

Blake Gloyn
TryHard
manawatu
soarer JZZ30 TT

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Monday, February 11, 2008 - 05:13 pm, by: Blake Gloyn (Blakenz)

I think it has to be different, because altering ignition timing via an aftermarket ecu is altering the timing compared to each piston stroke position,whereas altering cam timing -while it does marginally alter the timing of the filling and emptying of the cylinder - doesn't alter the firing of the spark plug relative to the position of the piston in its stroke. This is my opinion,I am no expert on motors. But i AM SURE that putting an adjustable cam gear on a 1jz motor will NOT give you the ability to control and alter base ignition timing in the same way you can on a RB25 motor. Someone please correct me if i am wrong.

Dave Cazes
Tinkerer
sa
tt

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Monday, February 11, 2008 - 11:39 pm, by: Dave Cazes (Cazman)

the reason you put cam gears on is so you can alter inlet and ex independently, and in doing so you can change where your power delivery comes in, as in move power like cams do, but small scale

1 example
http://my.is/forums/f62/exhaust-cam-gear-definition-analysis-243053/

now ther are many write ups, that is just the first one i googled

and it doesnt matter how you change you timing, whether your delaying you spark, of delaying when you cams reach "top dead" etc, if you were to adjust both the same degrees, it would do the same thing

but i believe ben says you cant od the inlet on autos, spewing for the auto boys

Matthew Sharpe
Goo Roo
North Island
JZZ31

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Tuesday, February 12, 2008 - 06:12 am, by: Matthew Sharpe (Madmatt)

Thats a great writeup.

Peter Nitschke
Junk Filterer
South Australia
GT4.0 V8

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Tuesday, February 12, 2008 - 06:49 am, by: Peter Nitschke (Pen)

Dave Cazes wrote on Monday, February 11, 2008 - 11:39 pm:
and it doesnt matter how you change you timing, whether your delaying you spark, of delaying when you cams reach "top dead" etc, if you were to adjust both the same degrees, it would do the same thing

Totally not true.