Need help ASAP PLEASE!!!!!!!

[bigred90gt]

I think I have a big problem. I was on the way to work thismorning, and all of a sudden I started hearing a pretty loud ticking, it was almost like an exhaust leak. The truck started riding pretty rough. When I exited the freeway and stopped at the red light, the truck would shake with every tick, and I could feel it in the stick. The stick was going back and forth about 1/2" with every tick. I got out a work and opened the hood, and I am pretty sure that it is not an exhaust leak.
BTW - The truck is a 93 F-150 4.9l I6. Any suggestions would be great. I'm hoping it is not a valve or a lifter or something. If it were a valve, would it still crank and run, or would you loose compression and not get anywhere?

Thanks for the help. This is my daily driver and I cannot afford for it to be down for more than a day or two.
Caymon

[PKRWUD]

You have to identify where it's coming from. I'll tell you now, that engine is famous for having the air injection tubing rusting through, creating an exhaust leak. I'd look there first.

Take care,
~Chris

[bigred90gt]

I listened and it almost sounded like it was coming from the back of the head. What exactly is the injection tubing? I hope it is an exhaust leak, but I usually can't catch a break like that. When it rains it pours. What would be a fix for the air injection tubing? Thanks for the reply.
Caymon

[PKRWUD]

Yup, it's the air injection tube. #6 is where it usually rusts through. Standing in front of the truck, looking at the engine, right on the passenger side of the valve cover, you'll see this metal tube. It branches into each cylinder at the head (see pic). The whole thing is gonna have to be replaced. Pull the upper intake off, and inspect it. It is possible that it's an exhaust gasket, but you'll have to take the intake off for that anyway, so check this first.

Take care,
~Chris

[bigred90gt]

Is that for the smog pump? If I take it out, for weight reduction, I'll clog my cats right? If that is the case, I'll just buy a new tube. Thanks for the help. It has seemed to have mellowed out a bit. I didn't hear it on the way home from work.

Caymon

[PKRWUD]

The smog system injects air into the cat and into the head. That tube is where it goes into the head. I would replace it if i were you, but expect to pay $100. Also check before you spend the money. like i said, it could also be a gasket, but i do think it's the tube.

[bigred90gt]

I don't have any idea what the hell it was, but it just quit making the noise. Oh well, I guess I can't complain.

Caymon

[bigred90gt]

The weirdest thing happened this morning. I've been driving the stang for fear that the noise was something serious and today I decided to drive the truck. In the same place on the freeway, within ~500', the truck stared making the same noise. I drove it around town last night and heard nothing. I get on the freeway this morning and it comes back. If it were the tubes, would it be comstant? I checked to see if I could pinpoint where the noise was coming from, and I couldn't. I'm lost and don't want to get stuck on the side of the road. So it looks like I'll be crusin the stang until I can figure it out. Thanks for the help Chris.

Caymon

[bigred90gt]

Hey Chris, you hiding? It hasn't done it in a couple of days, but that doesn't mean it won't start again. I changed the oil and tried some zMax and it seemed to have helped.

Caymon

[PKRWUD]

Hey. Sorry, I'm at RHC all the time. That place is getting busy, and is taking all my time.

It still could be the tube. I had that problem on and off for 3 years before i finally fixed it. It would come and go. In fact, I'd forget all about it, and then get on it at some point and hear it. Other times I could get on it, and not hear it at all. For me, it was the tube going to the head for the #6 cylinder.

[bigred90gt]

Thanks man. I tried to check out RHC the other day to join, but, when I typed in the adress and hit go, it told me that I did not have permission to access the site??? I guess I'll try another time.

Caymon