Exhaust leak? Or fuel issue?

[69SCSS]

I've been having this issue with my truck for a bit, but thought it was just because the cab had lost of holes in it. I have since put a couple layers of sound deadener and plugs on all the holes (just about) in the cab. Definitely quieter, but the issue remains.

When I drive the truck I get a slight fumes smell and start to get a headache if I drive for too long (30 minutes or more). My headers (Heddman mid-length HED-69010) are noisy. It pretty much sounds like an exhaust leak, but the guy who did my exhaust said the collectors make that sound because they're thin headers. I've never had a set of headers sound like that before, but I took his word for it at the time.

At this point I don't know what to believe. The truck has good power, starts good, etc. Here's the only 2 possibilities I can think of:

1. The collectors ARE leaking. They are the ball in socket type and honestly don't know if they really are sealing. I've had issues with the bolts working loose to the point that I have lock bolts on the ends to make sure they don't work loose anymore!

2. I need to vent my gas tank. I have a Blazer tank, and I ran the fuel line along the passenger side frame rail to a fuel filter just before the cab (so I can get to it easier), then run the line forward to the fuel pump. I used a Blazer Fuel line for the full length. I have not found any leaks. I am using a filler neck from a Suburban, but it's the later (71-72) non vented cap. I was thinking of putting in a vent tube from the passenger side fitting on the top of the tank, up into the bed with a check valve.

Any thoughts? I was already on the verge of going with ramhorns, but if the headers are leaking, I'm going for it. Any thoughts? Anyone in the Portland / Vancouver area wanna take a ride with me and see what you think? I want to enjoy driving my truck, dammit!

Thanks, Al

[GASoline71]

You should be able to tell if it is a raw fuel smell or exhaust fumes. Either way... exhaust is carbon monoxide and will kill you. If you're getting a headache after only half an hour you need to get that exhaust fixed. I have Hedmann long tubes with the ball and socket flange. They are the easiest header flange I have ever used. All I can think of is that they are on crooked and the "socket" is not covering the "ball part completely.

Gary

[69SCSS]

Originally Posted by GASoline71

You should be able to tell if it is a raw fuel smell or exhaust fumes. Either way... exhaust is carbon monoxide and will kill you. If you're getting a headache after only half an hour you need to get that exhaust fixed. I have Hedmann long tubes with the ball and socket flange. They are the easiest header flange I have ever used. All I can think of is that they are on crooked and the "socket" is not covering the "ball part completely.

Gary

It's definitely exhaust fumes. I'm bringing the truck down to the guy who did the exhaust next week and seeing what my options are. I am trying not to hit the button and order the ramhorns.... that's another over $200 to spend on just the manifolds. Argh.

[Greasey Harley]

I have had good luck finding exhaust leaks on cold mornings.
Climb under the truck, have someone start it and look for where it's leaking. A cold start up, on a cold morning (cold enough to see your breath), any exhaust leaks will be obvious.

[69SCSS]

I got fed up with it yesterday and decided to pull all the nuts off the bolts and start over. I put it back together going around the flange with 1/2 turns until they snugged, then 1/4 turns until they were all tight. Then I put the lock nuts on. Finished both sides and took it for a drive. Seems like I got most of the leak taken care of, but the headers themselves are thin, so they're noisy. I'm going to go for the Speedway 2.5" collector ramhorns in a few weeks, because honestly the ticking sound from the collectors bugs me!!!
Plus I still think they are leaking a little, even though I didn't really smell anything last night driving it to the gig. Just SOUNDS like an exhaust leak and that makes me like driving it less.
Hopefully I can drive this to work without the headaches now!!

[MagmaJct]

I know it's been a couple week, but...

An effective way to find leaks is to get a length of hose, about 1/4", and use it as a probe. Hold one end to your ear, and, with the engine running, move the other end around suspect areas. You'll hear it!

Easier than finding a vacuum leak!