Rattling coming from engine bay.

[li7in6]

I have a very high mileage 2.3 (just about to roll over to 200k). I keep getting intermittent moderately loud rattling noise coming from the engine bay. It varry's based on engine speed and typically goes away at higher rpm. Sometimes it will rattle a little at idle and just off to about 1500rpm. Other time's it wont rattle at all at idle but will rattle at around 1500rpm. Almost seems to have to do with the angle of incline the truck is on. So I don't think its internal. Sitting in the cab it sounds like its coming from the passenger side foot well near the trans. tunnel. but its hard to pinpoint. There will be weeks and even a month or longer that I wont hear it at all so i'll forget about it, then it'll come back and start driving me nuts. It never seems to want to rattle when I'm looking for it

I thought it was from the exhaust, either header to downpipe bolts coming loose or the exhaust partly rusted through. but after checking it several time, the bolts are tight, if rusted and the entire pipe is intact. I got under the truck and muscled the entire exhaust around and cant get any sort of clank or contact with anything. All the hangers are intact. I've also looked at anything else that might be causing it but cant find anything.

Any help would be appreciated.

 

[li7in6]

oh, the sound, more specifically, sounds like if you took an empty tin can on a string and tried to dangle it against a vibrating engine block.

 

[Mark_88]

Sounds like a heat shield is loose...or something else...take a screw driver and crawl under the truck and tap any pieces of shiny metal...if you hear a twang instead of a thud you've probably found your rattle...

The heat shield on the cat is usually the culprit, but I've had others such as the one for the pre heat tube that goes into the intake...and also a sheild for the brake lines on my suzuki...but Rangers don't usually have those ones...

 

[RobbieD]

I'd also take look at the heat shield on the cat. My upper half had broke all of the welds, and was just lying there on top of the cat.

 

[Mark_88]

I'd also take look at the heat shield on the cat. My upper half had broke all of the welds, and was just lying there on top of the cat.

I've had this happen on a nearly new Ford Tempo...drove me crazy at the drive through where you can hear the noise amplified by the proximity to the walls...probably wouldn't have noticed it if I didn't have an unhealthy diet (aka junk food)...

Rattles are usually not a problem...anything major that rattles usually falls apart or blows up before you hear too much noise....

 

[Byrd]

I've had this happen on a nearly new Ford Tempo...drove me crazy at the drive through where you can hear the noise amplified by the proximity to the walls...probably wouldn't have noticed it if I didn't have an unhealthy diet (aka junk food)...

Rattles are usually not a problem...anything major that rattles usually falls apart or blows up before you hear too much noise....

HAHAHA! Tooo True!

I 4th the motion for checking the upper heat shield on the cat. Ripped mine off last month. had to actually cut it off though because only two of the welds were gone and for some magical reason the other two were still perfect...

G'luck!

-Byrd