Performed P0401 EGR cleaning TSB; now have high pitched noise emanating TB/IM

FIXED: there was a loose bolt on the throttle body; tightened it properly and no longer have high pitched noise.

Hi,

First time on these forums; and first time I've taken up a project of this skill.

I performed the P0401 TSB maintenance for EGR port cleaning, and followed this illustrated guide which didn't include replacing the intake manifold (as opposed to the P0401 TSB which suggests to replace it.)

So I performed pretty much everything as specified in the P0401 TSB except:

• Replace intake manifold gasket
• Insert the bolts in the Intake Manifold in the correct sequence (also known as torque sequence)

The torque sequence I can remedy (I just don't have the tools with me at the moment).

After performing the maintenance, and reassembling the intake manifold and throttle body, the car started after a couple of starts (we needed to burn the carbon choke in the egr ports). After driving a little bit, a high pitched whining noise began to emanate from around the throttle body/intake manifold area. It's difficult to say whether it's from the intake, TB, EGR valve, or something nearby that vicinity.

I'm considering replacing the intake manifold gasket (which would be a pain), and will also require replacing the intake manifold to throttle body gasket. I was hoping someone could point out other conditions for such a noise. Is it a leak?

More importantly: the car operates fine, but the noise concerns me. Is this something that will ruin the engine if not taken care of promptly; so far I've driven 75 miles without issue, but this is highly concerning to me.

Any assistance would be much appreciated.

Thanks.

sounds like an air leak. replace the gaskets. never reuse them. ruin the engine? im not sure but decrease in performance is more likely.

opps talk about reviving a dead thread.

It was exactly that due to a loose bolt connecting the throttle body to the intake manifold. I had 3 out of 4 tight, but this one was a bit loose. So problem solved, and thanks for the reply .

snappy said:

It was exactly that due to a loose bolt connecting the throttle body to the intake manifold. I had 3 out of 4 tight, but this one was a bit loose. So problem solved, and thanks for the reply .

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i was going to edit my thread to suggest that but i guess you got it already