EGR
- Thread starter tomdalrymple
- Start date
Here is the rest of the story.....I just built the engine, with aluminum ported heads, mild cam, and Fords tubular intake manifold. All sensors are new. The EGR goes thru a BBK 75mm spacer. When the engine idles below 900 it has a loud hi-pitched squeal that sounds like a bearing, or a vacuum leak. It is very hard to figure out where the sound is coming from After much effort I've isolated it to the EGR. If I unhook the vacuum line and apply vacuum to the EGR valve, the sound immediately goes away. I took the valve off, and it appears to be in good, clean shape. I resealed it, and no difference. Any suggestions?
So, with the EGR installed, and no lines hooked up to it at all, you're getting a squealing sound?
As far as real world net effect of it not being installed, your light throttle mpg will go down, and the emissions under the same condition will go up. Those are the only effects.
93lxtwin
New Member
I get the same noise from my engine around the same RPM. Goes away when I raise the RPM over a 1000. My EGR isn't hooked up though. I have a Trick Flow Track Heat setup and just put an EGR spacer in between my throttle body and intake. But I get the same noise as you describe. It isn't a vacuum leak in my case, not sure about yours but I doubt it if you have everything sealed up correctly. I've just attributed it to the intake setup, creating this whistling sound at that RPM, it isn't causing a running issue for me. Maybe something with the aluminum runners or something, just my guess.
Possibility is that opening the egr introduces flow into the manifold which changes the flow of air by the throttle body...which causes the whistling to stop
Bbks are notorious for whistling.
Joe and 5L5 should have nailed it right on the head. Reading through the post, I was waiting to see someones response like that. BBK and Prefessional Products TBs are very common culprits of this. It's the tolerance between the TB blade/housing or possibly the tiny bypass hole on the TB blade thst id causing the high pitch whistle. Try swapping the TB out and let us know. Then it's your option to live with it or replace it with an Edelbrock or Accufab, I haven't had issues with them.
larrym1961
5 Year Member
I had the very same annoying whistle at idle too with both A Ford Racing GT40 Intake and TFS Street Heat intake, I had both a Profesonal Products and TFS (witch seems to be an exact twin to the Proffesonal Product) 70mm throttle bodies. I just recently added the Motorcract idle adjuster plate to my Idle Bypass solonoid, and closed the the throttle plate per instructions and that annoying whistle went away, now all I hear is large amounts of air being drawn in through the Air Raid conical filter like it should. I too thought it was the EGR but in fact was the air going past the throttle plate the whole time!
Thanks for the great information. As an experiment, I backed off the idle set screw. The whistle is gone. The idle is now a bit slow. I has previously done a mod to the AIC (suggested on this web site) that allows a bit of air to bypass the throttle plate. I may do that a bit more aggressively to get the idle back up to 7-800. Any down side to the above?
