Santa left drum playing Elf under my hood

[Ross-N-Chicago]

Weird thump sound under the hood...

Happy New Year,

Thanks to the many postings I was able to retorque the lower manifold bolts and stop my disappearing oil and coolant. A big thank you to all.

After doing this as well as replace plugs/wires, clean IAC, replace PCV, TPS, when I am in OD and at a stop light or sign, or just after killing it, I hear all kinds of wumps and thumps under the hood

I burped it once, is air still trapped in there? It is a weird sound but I think fixable. I certainly welcome suggestions.

 

[drnaline]

BigBurp

Does it sound like its diesiling?

 

[Blaine122300]

I know this one!!

It is your heater core!!

Put your hand on it once while its doing it. you will feel the whump whump whump sound. Mine does it all the time after running the heater. I took it to Ford and they told me there is nothing that can be done with it. It doesn't hurt anything just to let it whump whump once and a while. I just live with mine, and pretend that its just my trucks little way of talking to me, and telling me every thing is gonna be alright.

My advise, don't wory about it.

Andy

 

[Ross-N-Chicago]

no dieseling but it will definitely go for 15 secs or so after engine off. if it's the heater core, is that why i can feel it in my feet as it vibrates down the fire wall?

 

[Blaine122300]

yup, I feel mine when stopped at a red light, or when I turn the truck off. I have just dealt with mine for the last year and a half since it started. It's annoying, but I don't feel like redoing my whole heating system to get rid of a little gremlin.
I think that it is something specific to '91's. I have only heard of it in '91's.

Andy