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View Full Version : HELP ! On full throttle my car literally screams like a girl in a horror movie???



Rudeyboy18
Saturday 6th April 2013, 19:16
Ummm Im a tad concerned about an unusual sound coming from my car when I floor it....

Its deffo coming from the engine bay somewhere, So today Ive replaced the remaining vac lines and Even the pipe work on the evap line, tightened all the hose clips on RIP kit etc. But still on full throttle she literally SCREEMS / LOUD whistle ........ Is this a sign of the turbo about to go or even the actuator ???
The car still boosts and holds BUT 1psi lower than before I think, doesn't seem noticeably slower, no engine lights..... JUST A LOUD WHISTLE /SCREAM when foot to the floor or when psi goes over 14 .

Anyone had the same problems?

So the car has been MOT'd for all of 3 days and I did say " hopefully 12months trouble free motoring ahead " now I can see why frankies reply to that was "pmsl "

1998 V70 R , Pre ME7

M-R-P
Saturday 6th April 2013, 19:28
Mine used to do that when I had the mbc fitted - running lean due to undersized injectors and the noise was the block "ringing" from multiple detonation. Sounds like a screaming whistle - almost like the turbo is leaking.

Check your afr if you can mate, it may be wrong (hope I am) but you dont want to melt a piston.

Rudeyboy18
Saturday 6th April 2013, 19:39
Shall I disconnect the MBC for now, or just crank it right down to minimum. I do get the code come up occasionally it does say running lean. . . So you might just be right. Im not used to the abbreviations .... What is AFR?

T5frankie
Saturday 6th April 2013, 19:40
Shall I disconnect the MBC for now, or just crank it right down to minimum. I do get the code come up occasionally it does say running lean. . . So you might just be right. Im not used to the abbreviations .... What is AFR?

take it off full stop if you want your engine to last, i'm sick of changing engines

Rudeyboy18
Saturday 6th April 2013, 19:41
Also Mr p , what did you actually do to resolve the problem?? Get bigger injectors and mapped again to suit? I think I have whites... but stained a nicotine colour

M-R-P
Saturday 6th April 2013, 19:44
Air Fuel Ratio. If you run lean too often you risc melting pistons, valves etc. this isn't a "slight chance" you will melt something eventually. Get that mbc off mate, while you can.

M-R-P
Saturday 6th April 2013, 19:47
I took the mbc off and and put a set of rebuilt blues in.
If yours is ME7, you should have blues too. Whites don't work as well at 3:8bar pressure.

T5frankie
Saturday 6th April 2013, 19:54
his aint me7

M-R-P
Saturday 6th April 2013, 20:06
Oh yeah - missed the "pre" and only saw ME7 lol

Still, that level of detonation ain't good. ME7 or not ;)

Rudeyboy18
Saturday 6th April 2013, 22:13
So, I should look at my air fuel ratio on torque app..... What should the levels be?? Will it fluctuate during driving etc or does the ecu keep it constant while running??

The mbc is off now and I floored it and the noise was still there at full throttle but the car was slower without the Mbc :-( -4psi.....

Im going to look into some injectors then.... shall I just get blues anyway or stick to standard whites??

Martin, did the noise literally go away once your car ran less lean?? Or did you need the Ecu reprogrammed to make the car run better?

M-R-P
Saturday 6th April 2013, 22:34
It whistled a bit but nowhere near as much. Now I fitted the blues (the ones it should have) its fine (and faster).

No ecu tinkering needed. How old is your fuel filter? Maybe there's something starving it of fuel?

Rudeyboy18
Sunday 7th April 2013, 14:18
No idea about fuel filter.... I guess its worth changing anyway. I tried to read my afr... but the torque app has the option.... but its not highlighted green for me to use the dial and read it. Ive done research and it says should be 14.7.... and about 11.5 Wide open throttle.....

But I cant get any readings. Its connected to ecu ok. Gives me the stautus, but no reading. GRRR.

Im the hunt for some blue now as I read on the bosch injectors that whiles are good for anything up for 279bhp (max flow ) Blues up for 312 and greens up 363 or something like that. So I must be maxing my old whites out...........??? as I was 259whp which I guess is around the 280mark bhp with no MBC and +4psi with it on.....

I did do a sound clip of what it sounded.......... but just realised this site, photobucket wont accept the file!!! Dam

smithson007
Sunday 7th April 2013, 18:37
Mine is doing the same at the min. I suspected my turbo was ready for a rebuild but after talking to somebody about it yesterday they suggested checking the intercooler isnt leaking.
He said it could just be a small split that will only show up under good boost pressure.
Mine only started doing this once i replaced my worn BCS for a good one so shes now boosting to around 1.2 bar at WOT.

Rudeyboy18
Sunday 7th April 2013, 20:13
Mine is doing the same at the min. I suspected my turbo was ready for a rebuild but after talking to somebody about it yesterday they suggested checking the intercooler isnt leaking.
He said it could just be a small split that will only show up under good boost pressure.
Mine only started doing this once i replaced my worn BCS for a good one so shes now boosting to around 1.2 bar at WOT.

Just seen this reply.... Hope we both get it sorted asap