Possible manifold leak

Tiny
LEANNHASTE
  • MEMBER
  • 1998 DODGE RAM
  • 5.9L
  • V8
  • 4WD
  • AUTOMATIC
  • 228 MILES
(1500 model)When I fire it up it sounds like it sucks in a whole lot of air in the throttle body. Then if we hold the gas down and it clears up after it warms up then it does not do it any more until it sits and gets cold again. Not sure what is wrong with it. Any ideas?
Thursday, November 9th, 2017 AT 5:33 PM

5 Replies

Tiny
HARRY P
  • MECHANIC
  • 2,292 POSTS
I would bet on a leaking intake manifold gasket or throttle body base gasket. Basically, extra unmetered air is getting in through one of those gaskets. Get a spray bottle of water and spray it around those areas liberally while the engine is idling. If the sound of the engine changes, or the engine dies or nearly shuts off, then you have found where the leak is.

Let us know what you find.
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Thursday, November 9th, 2017 AT 7:34 PM
Tiny
STEVE W.
  • MECHANIC
  • 13,576 POSTS
The 5.9 is known for manifold leaks, they like to suck the valley gasket under the intake in and cause problems. Start it and let it idle. Then spray a bit of carburetor cleaner around the intake gasket surface. If the engine suddenly changes in speed you have a leak.
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Friday, November 10th, 2017 AT 5:16 AM
Tiny
LEANNHASTE
  • MEMBER
  • 2 POSTS
We where thinking of a mass air flow sensor, but it does not come with one it comes with a MAP sensor. Also, the truck I got the people from put a throttle body spacer on it.
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Friday, November 10th, 2017 AT 6:00 AM
Tiny
STEVE W.
  • MECHANIC
  • 13,576 POSTS
Nope, no Chrysler product has a MAF. They all use a variant of the MAP based speed density system. Spacer should not cause an issue other than being a gimmick. If it was properly installed. Also, these engines will run up to 1000 rpm on initial start and stay there for a couple minutes if cold.
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Friday, November 10th, 2017 AT 7:54 AM
Tiny
HARRY P
  • MECHANIC
  • 2,292 POSTS
If I were a betting man I'd put money on a leaking intake gasket. Go ahead and get that test done. Let us know what you find.
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Saturday, November 11th, 2017 AT 5:00 AM

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