whistling/blowing sound from a 4.2 turbo 100!

Klaufi · 06-05-09, 12:12 PM

Hello every1..
My dads cruiser makes a pretty loud whistling sound under acceleration.
More when the turbo starts to spool.
And i feel like (might me improvising) that it's losing power and getting very low mpg (as if it would need oxygen)..

Only things ive checked is exhaust pipe (fixed 2 holes and nothing changed)
And the piping from the turbo -intercooler- the pipe that conects to the manifold so i only checked the plastic and rubber hoses nothing thats made from cast!

Any ideas before i start ripping apart and checking the turbo?

Also, anyone know how theese work?
ToyoDIY.com
ToyoDIY.com

Sorry if this text is confusing, wrote in one minute before leaving work

Thanks, Klaufi.

anthonycds · 06-05-09, 12:37 PM

sounds like a boost leak perhaps? I'd check the turbo intake/outlet pipes, as well as any hoses attached to the manifold, like EGR, boost sensor, and anything that may measure vacuum. Good luck!

cruiser100 · 06-05-09, 12:58 PM

Turbo's always make a "whislting" sound, some just more than others.

Questions:
- Has the sound gotten louder lately?
- Has there been any recent work under the hood?
- Any exhaust work lately?

Try this: block the vehicle (tires) and set the p-brake so the vehicle won't move. Start the engine, put the trans in "N". Have someone gently rev the engine up while you listen under the hood to try to pinpoint the sound. The turbo gets VERY hot, so don't touch it until it cools off and please don't toss water on it while its hot... yes, i've seen it done, not pretty.

If it is coming from the turbo itself, you'll want to check gaskets and bolts on the downpipe, intake and exhaust manifold connection. A lot of intakes have just a pipe and a clamp, make sure the clamp is tight and the intake pipe doesn't have a hole in it.

Also, remove the intake pipe and turn the impeller with your hand; it should spin freely. Also look for oil deposits while you have the pipe off.

If the impeller doesn't spin freely, you may have a bearing issue.

If you see oil, the oil seal may be leaking; it'll need to be replaced.

If it's not the turbo, come back and post where the noise is coming from and I'll try to give you some pointers.

Klaufi · 06-05-09, 01:38 PM

Cruiser100 i know that all turbos make a sound, but this sounds lika the boost is leaking, just thinking if u new of any common places to look at.. No echaust work or under the hood work, except bulbs changtes ^^

MC92MR2 · 06-05-09, 02:36 PM

check for a exhaust manifold leak, I had a warped exhaust manifold on my 92 MR2 turbo and it made a whistling sound under acceleration due to exhaust escaping between the manifold and the engine. good luck.

hks3sgte · 06-05-09, 02:38 PM

x2...

cruiser100 · 06-05-09, 03:13 PM

Quote:

Originally Posted by Klaufi

Cruiser100 i know that all turbos make a sound, but this sounds lika the boost is leaking, just thinking if u new of any common places to look at.. No echaust work or under the hood work, except bulbs changtes ^^

Check what I mentioned in my previous response. If you find nothing let us know.

The basics are some of the items you already mentioned (hoses, clamps, etc.). It's rare to see an intercooler leak but I've seen one or two.

First find out where the noise is coming from...