Hey everyone,

I have a 1998 Dodge Ram, 5.9L with 167,000 miles.

I have a weird problem. I have tried to search on the forum, but it’s hard because I don’t know how to accurately describe of the problem.

I have a weird “hissing” or “shhhh” noise coming from the engine area. I can only hear it in the cab, when I step on the gas. Trying to track the noise down outside is hard because of the engine noise.

I suspect a vacuum leak, it sounds as though it is coming from the brake booster. I did do a vacuum test on the crank case to see if my plenum was leaking. There was no vacuum in the crank case (nor a pressure build up).

Seems to be running good, except horrible gas millage lol

Thoughts?
Thanks in advance.

 

if you have a stock air box then its probably either cracked, has a hole in it, the crank case vent hose is unhooked or broken (it runs from the valve cover to the air box), the gasket between the air box and throttle body is broken or missing, the band that holds the air box to the throttle body is loose, the pcv valve is loose/broken/unplugged/ or has a hole in the hose that goes to the intake manifold, or the air filter doesn't have good contact between the top and bottom half of the air box.

if it is not the air box then it could be a vacuum leak or a loose/unplugged IAC but it is more than likely related to the air box. if it is the IAC then your idle would be craptastic.

 

Pretty much the exact same issue I am having. I haven't had time to mess around with it because my job wants us to work 12 on and 12 off 6 days a week. Being a Deputy in Houston sucks. Let me know what you find!

 

I had the same problem, Sheriff420 suggested i use two gaskets on top of the Tb and it worked so it's worth a try, the gaskets only like 3 bucks, also when i was checking the hose to the pcv valve i inspected the valve and it looked like crap(literally) so i changed it as well, it's also one of the cheapest parts in the parts store.

 

i'm glad the 2 gaskets worked. on my cai i could see a gap so i had to use two and after a few months they got stuck together pretty good. then when i put my 14x3 air filter on i gave my dad one of them because his was dry and hard and mine were still pretty new squishy rubber.

 

I als noticed some play where the air box sits on the stud in the front, i thought air might be escaping there but it's working now and the turbo sound is gone.lol.

 

the stud in front is just a rubber plug that keeps it from rocking back and forth and twisting on the throttle body. there isn't a hole there for air to escape from.

 

What are the gaskets called so I don't look like a douche bag when I go into advanced auto parts?

 

i got mine from the dealer. i think the gaskets at advance are a rubber impregnated paper and the dealer has solid rubber. its should be called the throttle body gasket or the air cleaner gasket. just tell them you need the gasket that goes between the air box and the throttle body.

 

Are they still as cheap through the dealer