Is my intake manifold leaking?
#1
Is my intake manifold leaking?
1990 4Runner 3VZE rough idle, about 500 rpm. Stalls a lot. I cleaned the throttle body, replaced a few vacuum hoses, and went looking for other vacuum leaks. I hear the sucking sound on the left side of the engine from around the intake plenum and I'm thinking it might be a leaking intake manifold gasket.
This all started when the car backfired last week while starting up. Since then, it has run like total crap.
I'm not losing antifreeze. Is it possible to have a vacuum leak in the manifold gasket without a corresponding water leak? Is there something else under the plenum that I should be looking at? Is there a way I can test this to be certain it is the manifold gasket before I got to the trouble of replacing it?
I'm considering dynamite if I can't get this fixed.
This all started when the car backfired last week while starting up. Since then, it has run like total crap.
I'm not losing antifreeze. Is it possible to have a vacuum leak in the manifold gasket without a corresponding water leak? Is there something else under the plenum that I should be looking at? Is there a way I can test this to be certain it is the manifold gasket before I got to the trouble of replacing it?
I'm considering dynamite if I can't get this fixed.
#2
Registered User
Well If you use dynamite, you wont have to worry about vacuum leaks. Pretty loud and real messy. Before you set it off you might check the intake air hose from the filter box to the intake. Since you said it backfired it may have cracked the hose. If you can hear a vacuum leak but cant fine it, get someone else to look at it. Sometimes we look for something so hard we cant see it..
#7
It would seem I have no business under the hood at all. After failing to find anything with the carb cleaner, with the propane, and with another person looking at it, I was having my father-in-law (an old gearhead) listen to it, but he couldn't hear anything that he thought was a vacuum leak and my wife, just out of the blue, said, "check the timing." So I scoffed under my breath and did it to exclude it from consideration. So this thing was waaaaaay out of time. The mark was all the way at the bottom of the gauge, nowhere near the "10" that it should be. It hasn't run this good in a long time. I just got used to it being underpowered, so I guess I never thought it wasn't supposed to be driving like that.
Anyway, thanX for the ideas. For now, the dynamite will have to wait.
Anyway, thanX for the ideas. For now, the dynamite will have to wait.