weird exhaust issue

[wally]

ok I'm at a loss here, I have a 98 with the 2.5L that if I have to make a quick stop I get exhaust pooring out of my hood and through my heater vents. I thought maybe it was my egr tube but I replaced that and it still does it. ( tube did have a small hole in it), now I'm thinking it may be coming back out through the air intake and I'm not sure why it would do this. timing belt is original to my knowledge and the truck does have 193k on it, truck runs great but thinking maybe the valves are out of timing? please help me.

 

[Mark_88]

There is a vent pipe on top of the valve cover that should run either to the air intake box on or the throttle body...check to see if that is connected properly...that and the actual exhaust system should be the only places where the exhaust should be going.

Did you inspect all the joints from the header through to the cat? If that was leaking there should also be an associated noise with it. The vent pipe doesn't make any loud noises, but it certainly smokes and blows foul smelling air...that's where mine was leaking...and I also had a few holes in the floor and firewall that allowed the exhaust into the cab...

Maybe pull back the carpet and check for holes too...

 

[wally]

yes no obvious exhaust leaks, I changed the egr tube because it was the only thing that was roached, and I replaced the the breather tube from the valve cover to the throttle body a year ago and it is intact. Only time it happens is when I come to a hard quick stop and it looks like my truck overheated but it is exhaust rolling out from under the hood which is then sucked through the heater vents into the cab.

 

[chilsam]

Valve cover leak?

sounds to be like an oil leak as u drive it pools up and when you hit the brakes its flowing onto your exhaust system somewhere or could b tranny fluid doing same ? IMHO

 

[Mark_88]

Ah, well, that is different...a rapid stop does sound like fluids hitting the hot exhaust and burning off...it could be oil from a valve cover leak or from the vent tube...that vent tube can actually suck oil up into the TB, but that is not the problem...it would be the lower end of the vent tube that may be leaking down into the valve cover...or the valve cover leaking oil into the plug well...

 

[chilsam]

Fluid levels

Ma b check oil and coolant level c if its a coolant or oiling system prob,u think it could b the heater core leaking and coolant pooling up inside the plenumn and running out the drain on the lower access cover when there is hard braking?

 

[wally]

changing the transmission dipstick tube tomorrow, it looks rusty and wet so I will try that first. no oil leaks that I can see, doesn't even burn oil at 193k on it

 

[chilsam]

Shtains

Look for stains or discoloring on exhaust that might help tell u were fluid is contacting the pipe if thats the problem

 

[wally]

changed the tranny dipstick tube and haven't had it happen since then, it did have some pin holes in it.

 

[chilsam]

Good