TripleG

I have a 91 GT that recently developed this loud annoying sound on startup. I have searched the net and some people have mentioned a Camshaft Position Sensor...but none specifically for a foxbody 5.0. The sound is similar to videos posted on the CPS, however I have uploaded 3 videos in an effort to solve this quick since it is related to the engine and it is my daily driver.

The noise is definitely not pulley or belt related as it is coming from the driver side of the engine near the firewall. Descriptions of videos will pertain to the stage.

Here's to hoping its not something major...

Video 1

Video 2

Video 3

TripleG

In video 1, when the car gets close to dying, that was me pushing on the throttle housing in the opposite direction...

mattdel

Its mechanical in nature, and goes away with throttle, so its a moving part, possibly oiled. Broken valve spring/seat ?

Maxwelhse

Under the hood it sounds like a heinous exhaust leak to me....

You still have your EGR cross over tube?

89StangGTConvertible

sounds like a valvetrain related issue to me... possibly lifters...?? sounds awful... hope you get it figured out quickly... I wouldn't run it too much...

holyshift

Definitely a valve train issue. Pop that intake off and valve covers....time to get dirty.

pedalhappy

yep under the valve covers

tinman

I'd go with valve-train here too.
Look real careful at pushrod/rocker arm...........

TripleG

Got the valve cover off and the rocker arms and push rods look ok. Any specific way to inspect these besides visual and checking the security of the components?

TripleG

found a great video on the youtube about lifter noise. Going to try the engine flush technique and see if that alleviates the problem. Thanks for the direction.