Fumes in Cab

[CatfishJoe]

Hey all, 

 

This is my first post here, so I figured I'd do a bit of an introduction as well. I'm located in western BC and I've got myself a '90 base Comanche 4.0, 5-speed, rwd for $800CAD, looking to do a lot of cool stuff with it, but need to get the main issues sorted first. I've fixed my tail light wiring, and done the headlight relay mod, which fixed my flickering headlights. I've noticed in the right lighting I can see smoke/fumes entering the cab from what seems to be low on the passenger side (below the dash) and possibly the ripped shift boot. After a bit of reading I went ahead and replaced the exhaust manifold, and added a flex joint in a new downpipe, with new gaskets all around. I noticed a stud had been snapped in the head, so I went ahead and drilled and tapped the hole larger. Also, the cat has been removed at some point.

 

After this, nothing has changed. I'm still seeing and smelling fumes leaking into the cab. I noticed that I have a filter on top of the valve cover that leaks oil out onto the cover. Could this possibly be a source of the smoke? Everyone I've taken along to check it out has said the smoke smells more like oil than exhaust.

 

The weird thing is, it only smokes under load. If I'm sitting in neutral at a light, I can rev it all day and not have any fumes come in, same with going downhill in gear. Going up hill is another story, it's at it's worst when on the gas in 3rd - 5th gears, especially going up hill. I'm at a loss here, as I've checked the whole exhaust system and can't find any leaks. The underside is a bit oily, but its nothing crazy, could I have possibly blown a seal that shoots oil onto the exhaust under load? Downpipe still looks clean too. Another thing I should note, I have almost no floor on the passenger side, which is on the list of things to fix. I've thought about repairing the floor and hoping for the best, but would rather fix the source of the problem instead of putting a band aid on it.

 

Any input you might have would be GREATLY appreciated, as I love this lil truck and want to fix it up the way it deserves. Also, it makes first dates a bit embarrassing when the smoke starts rolling in lol

 

Thanks!

[yxmj]

....?....you have no passenger floor pan.....you have exhaust entering your cab.....?....sort of like saying I have no roof.....and I can't figure out why my hair gets wet when it rains....

[Pete M]

welcome!  

 

any evidence of oil burning on the crossover exhaust pipe right behind the engine?  

[CatfishJoe]

Thanks everyone for the suggestions. I changed out my valve cover gasket, re-did my pcv/ccv lines and then my clutch blew so I've had her parked for the last few days while I work on my other Comanche. As I swapped the fuel rail from this one onto the other, I noticed a small amount of gas leaking out of the rear fuel line where it connects to the manifold. I'm guessing this is caused by the clip there not sealing properly, and  would also explain the smoke I'd been getting in the cab while on the throttle earlier. Hoping the rest of the work goes well and I get one of these on the road in time for the weekend.

[coolwind57]

On 5/26/2018 at 4:57 PM, CatfishJoe said:

Everyone I've taken along to check it out has said the smoke smells more like oil than exhaust.

 

On 5/26/2018 at 4:57 PM, CatfishJoe said:

I noticed that I have a filter on top of the valve cover that leaks oil out onto the cover.

 

On 5/26/2018 at 4:57 PM, CatfishJoe said:

it only smokes under load

 

I'd like to see a pic of your engine bay.  A filter on top of the valve cover is something I'd correct by getting the correct parts installled (vacuum harnesses, grommet/tubes, etc).  Some guys have fabricated oil catchers devices on these lines coming out of the valve cover.  Consider doing Cruiser54's valve cover mod (#25 at www.cruiser54.com) to cut down on the pulling of oil from the valve cover.  

 

Perhaps you found your issue with that fuel leak, but I'd still consider performing the above.

 

 

[CatfishJoe]

Quick update:

 

Sorry for disappearing for a while there. Thanks for your suggestion Coolwind, I noticed the smoke was still there after changing out fuel rail parts and did as you suggested. I replaced the lines and grommet coming out of the valve cover, added an oil catch can, and did the valve cover mod. No more smoke in the cabin! Looks like it's time to rebuild the engine over the winter, got a LOT of blow-by.