knocking/rattling after intake manifold install

**ZForce1** · 04-09-2012, 02:49 PM

I removed my intake manifold, swapped out a knock sensor and re-installed the intake. Now I have a loud rattling/knocking sound coming from both cylinder banks. Like really loud valve clatter or worse. How could I screw up installing an intake manifold to cause something like this?

**transamtom** · 04-09-2012, 04:59 PM

How much dirt and crud was under the manifold?

Did you put socks down the ports when you cleaned it?

Are you missing any tools or the clips off the KS harness?

Was the old sensors plastic all hard and cracked? where did the pieces go if it was?

**blackSS01** · 04-09-2012, 05:47 PM

Sounds like something could have fallen down into the motor. I wouldn't run it and pull the manifold again. Don't want to damage anything major

**az gt eater** · 04-09-2012, 07:19 PM

Open it back up, get a shop vac down in the cylinder air ports. Start with a clean shop vac, and see if anything comes back out.

***SMWS6TA*** · 04-10-2012, 12:55 PM

Originally Posted by transamtom

How much dirt and crud was under the manifold?

Did you put socks down the ports when you cleaned it?

Are you missing any tools or the clips off the KS harness?

Was the old sensors plastic all hard and cracked? where did the pieces go if it was?

Originally Posted by blackSS01

Sounds like something could have fallen down into the motor. I wouldn't run it and pull the manifold again. Don't want to damage anything major

Originally Posted by az gt eater

Open it back up, get a shop vac down in the cylinder air ports. Start with a clean shop vac, and see if anything comes back out.

All of this.

Whenever the intake is off I will always use masking tape to keep everything out.

**ZForce1** · 04-10-2012, 02:18 PM

I'm afraid you may be right. I pulled the intake back off because I missed a small vacuum line on the back of the intake manifold. Looked everything over, put it all back together and it still does it. Runs REAL BAD. I guess there is nothing else it could be, huh? I did not drop any tools or hardware during the job. However, I did break the oil pressure sending unit, because I did not know the brake bleed line ran around it. I thought I got it all, but a piece must have fallen in that I never saw.

**FinZ28** · 04-10-2012, 04:34 PM

My guess after reading a couple of posts was something happened with the OPSU.

Do you have any part of it left to maybe figure out what's missing?

**ZForce1** · 04-11-2012, 12:53 PM

I'm not sure about all the internal parts of the opsu, but it did break in half and there was a yellow plastic thing about 1/2" diameter with a metal tab on it and two prongs about an inch or so long that think fell out from the inside of it when it broke. the top that broke off was all in one piece and it made it's way out of the engine in one piece. The bottom piece I removed with a special socket. It looked like I had it all, but I would have to buy another one for $50 and take it apart and compare it to the old one to be sure.