Cabin fumes with top up in a 70 lark

is this common, I have new floors and trunk?

 

I would bet its a shorter than usual tailpipe that's giving you trouble unless you have other bad exhaust problems. Almost like if you have a SUV and the rear window is open or tailgate. The fumes swirl around and come to the front. How far out from the bumper is the end of your tailpipes??

 

My exhuast tips stop just short of the bumper , maybe I will try a couple of chrome tips.

 

Not common. Check the exhaust system for any pinholes

 

Get the pipes past the bumper and you should not have a problem. Check out the rest of the system to make sure there are no other exhaust leaks under the car.

 

I agree with the previous posts - thoroughly check the exhaust system. After that I would remove the carpet and/or get up under the dash and look for missing rubber grommets and/or plugs in the firewall that could be allowing engine bay stink in to the cabin. I used black RTV on a lot of the firewall holes.

 

i did drill a 3/4" hole through the firewall to run my temp gauge and i never sealed it so small so didn't think it would matter i will get some duct seal and seal it up

 

Another possibility is the hood / cowl seal.
If it's gone or not sealing I think the engine fumes will be
sucked in through the cowl vent to the inside.o No:

 

My 65 does this too, and the exhaust is new/properly routed and there are no holes in the floor..I generaly dont notice unless it's running really lean. Never figured out why.

 

Strange thing is the fumes are worse with the windows down and thats when I am driving.

 

Only windows up for me - it has to be with the kinda vortex created when the car cuts through the air, maybe the swirl drags air back toward the side of the car..

 

As per one of George N's articles I got some black roof sealant in a caulk tube and sealed the trunk/wheel well seams. I was getting a lot of air infiltration in to the trunk. Just another area for you to investigate...

 

Trunk area could be the culprit as the floor was replaced but I spilled a bottle of cleaner into the fender cavity and it jus poured out over the driveway.

 

Keep those drains clear! A convertible is nothing but one big drain pipe, and you dont want that water sitting anywhere!

 

I think you located your trouble spot then..Get to looking up underneath and seal off the holes with sealer..

 

I think I used this...

http://www.homedepot.com/p/Loctite-...ashing-Sealant-1675273/203163733#.Ufly7NJkyAg