Exhaust in cabin (after doing spark plugs)
 

HELP!

Engine was running rough and I removed the intake to access the rear coils/plugs. Now the cabin smells like fumes at a red light, lesser so if recirculate is selected on HVAC.

I tried to locate an exhaust leak with soapy water and pressure from a shop van in the tailpipe but couldn't find any leaks!

The EGR valve is my suspect because I really had a hard time getting the pipe off the bottom and the whole unit was twisting a bit. Still, spraying with soapy water didn't reveal anything on the valve or the downpipe.

Also before I throw $$$ at an EGR valve I'm wondering if the plastic upper intake it mounts to could have cracked.

Vehicle runs fine, no CEL light, just a fume smell. Thoughts???

If you suspect the intake may be cracked, just spray a little brake cleaner or starting fluid in that area and watch for an RPM change.

Hmm, that sounds like a good trick. Would a crack that sucks in a combustible also be able to spit out exhaust?

An EGR valve which leaks will not cause a problem with fumes without negatively affecting the way the engine idles. I know you used a shop vac. but holding a rag tightly at the tailpipe works better for finding leaks. You will need someone to hold the rag while you look for a leak. The leak would have to be upstream from the EGR if the engine still idles good. Manifold vacuum will be at its highest at idle and the EGR should be closed during idle so any leak at the intake manifold or downstream from the EGR would present itself as a suction and draw in any fumes into the engine and likely would affect idle quality.I still believe you have an exhaust leak somewhere upstream from the EGR. If you have a capable scan tool, a vacuum leak would show up as a highly positive reading of your fuel trims.

I do have a nice Bluetooth scan tool and Torque app, I'll check that out. It drives and idles just fine. It was driving like garbage with a cyl 1 misfire for a few weeks before I swapped the plugs and coils, but since then, not rough at all.

Ive also tried looking for the leak on cold mornings when the exhaust is visible out the tail pipe, nothing. Last night I tried in the dark with a flashlight to see if maybe it revealed anything. Nope. I haven't tried blocking the exhaust when I do that...

I think time to take this one in to the pros at least for diagnostic as much as I hate to give up. "The nose knows"... There's a leak.

https://cimg2.ibsrv.net/gimg/www.for...99f4cebc59.jpg
MIght be unrelated but that whole area is all wet from something (was before I removed the intake). Is this the PCV valve? Could that be the culprit?

If the PCV system is not functioning, pressure will build up in the crankcase which can emit a burning oil smell. Somewhat different from an exhaust odor.There is accumulated oil in that area you point out. A split or poorly fitting hose or grommet can do that too.

Well the shop looked at it today. And found... Nothing. Can't determine any exhaust leaks after fogging. Didn't smell the smell (then again it only really hits you at red lights, sometimes more than others).

Said maybe if the EGR pipe flange was cracked it might leak when hot vs cold but didn't seem confident that was the issue.

I guess I'll try try again at another shop.

I'm also thinking clean that whole area up and see what's what in terms of maybe identifying the oil leak.

Sometimes you can use an old technique for locating exhaust leaks.
You must be careful when doing this, take a length of something like a 3 foot length of garden hose place one end close to your ear and use the other end of the hose to place near exhaust pipe/manifold joints. If there is any kind of leak ,you will hear it as if it was right next to your ear.. Works 99.9% of the time, unless your wife is calling you to do something,then that last percent gets lost.

Going to bump my old thread here... Because I'm still sucking fumes at red lights.

Went to another trusted shop today that couldn't find any leak. He said he does smell a tiny bit of exhaust in the cabin... But searched the vehicle top to bottom and can't find the leak.

Man... This really stinks. Literally. I drive with the windows open or at least cracked all the time now.

Two reputable shops can't find it! But I smell it.