My truck has a horrible noise coming out of the intake. Someone that used to work on fords told me it was the smog pump. Will this hurt anything on my truck if i don't get it fixed for a while? How much is it to get one changed out?

Thanks,

 

Okay here is the deal. I have read threads on here and can't really decide what is making the noise. When idling it will make a whooping noise and the rpms will rev up and down. I have been told it is the IAC and I have been told it is the smog pump. I have also been told it might be the MAF sensor, but I have cleaned it and it will still make the noise when I unplug the MAF sensor. Can anyone help me?

When it first started making the noise, I sprayed intake cleaner in the throttle body and cleaned the IAC and it stopped for a few days. I have done this a few times and less time the noise stops. I don't know what to. I don't want to spend alot of money on something that might not be causing the problem.

Thanks in advance!!

 

Searching for idel sounds like a vacuum leak.


Have you cleaned the IAC besides spraying solvent into the TB?

 

Yes, I took the IAC off and cleaned the inside of it.

 

No such thing as a smog pump on our engines. I've heard of the EGR valve making noise before, but it's not very common, and typically signals a bad EGR valve. However, if the EGR valve is bad, the engine usually knows it and throws a code.

What, exactly, does it sound like? "horrible noise" could be a lot of things.

 

It is like a whooping noise. It is coming from the tube connected to the IAC and echoing back out through the intake tube.

 

What is the EGR valve? And I am not getting a check engine light or anything like that.

 

If there is being vacuum applied to the EGR at idle, the idle will be low and erratic. The EGR valve is the little flying-saucer looking piece to the right of the throttle body. There will be one vacuum hose attached to the top of it.


You could pull that off and mannually apply vacuum over the fitting(a shop vac will work). The engine should idle down and run rough while there is vacuum applied. If nothing changes, the EGR is probably stuck.

I think if this were the case, though, it would be more than just a strange noise. It would probably idle and run very rough. It is worth atry, though. It's easy to do.

 

It does idle rough, like I said earlier it makes a whooping noise and the engine will rev the rpms up and down. Is the IAC and the EGR the same thing or are they different?

 

If you cleaned the IAC and it fixed the problem than the IAC was the problem. Also the fact that the idle RPM moves up and down indicates a problem with the IAC. It is very common, according to posts I've read on this site, that cleaning the IAC results in a temporary fix. Buy a new IAC and swap it out.

Good Luck

 

Thanks I will try that.

If there are any other suggestions in case that isn't it, please let me have them!!

 

I agree, replace the IAC.

 

new iac

i sprayed silicone grease into mine and it seems to be working ok for now. i think i will get a new one soon.

 

Just now replying to this one. I fixed it along time ago. It was the IAC, I just bought another one from the ford dealership and replaced it myself.