M1009 exhaust smell in the cab

[n8roro]

At first I thought it was "just an old diesel truck thing" when I took it home a month or so ago. Went on a half hour drive with the wife and she said the fumes bothered her and she got a headache. There was oil all over the engine compartment that I thought could be getting hot and smoking so I cleaned bit all off and I thought the smell was better. Wife says no.

Then I thought maybe a fuel leak or an exhaust leak. There are no visible fuel leaks or drips after parking. The exhaust line looks ok and I was thinking I would wait for cold weather to find the leak, but my other passengers have complained. Upon examination I think the smell is stronger on the passenger side and could be the manifold gasket. But I also read on forums that a gasket is not needed. The manifold and exhaust line is rusry, but does not look shot. I will look into this more closely later this evening.

Is some odor in the cab normal? Are manifold gaskets needed? I know it is hard to diagnose over the internet, but I appreciate your imput.

Side note:. There is a fuel smell inside at all times which I also thought was normal. It could be I'm dealing with a fuel and exhaust leak.

Thanks,
Nate

 

[dependable]

No, it is not normal to have fuel fumes or exhaust smoke in the cab. Fuel from leaky return lines, or oil smoke from leaky valve cover gasket, burning off exhaust manifold will make fumes. Leaky exhaust with holes in floor would let another type of fumes in. Neither one is OK, so please fix it, and keep the windows down until you do.

 

[Recovry4x4]

If you're driving with the back wndow down, you will get fumes.

 

[ranchhopper]

Take a flashlight and check and see if the valley is wet under the intake manifold the IP will start leaking and fuel running down the top of a warm engine really smells. It will leak and run down toward the back of the block where there is a drain hole then runs down the trans bell housing it may not be leaking enough yet to puddle under the truck.

 

[n8roro]

Thanks for your reply. I am looking for the cause and will get it fixed. I brought it to my mechanic after my wife complained and he thought a seal on the transmission was bad and flinging oil around the engine bay which was hitting the exhaust and smoking and causing the smell. There also appeared to be a coolant leak which he said could drop on the engine and smoke. I cleaned off all the oil and it has not returned, but the smell remains. I did remove the 24V battery cables to the rear along with the grommet in the floor so I suppose exhaust could be coming in there. I will plug that hole, but I think the culprit lies elsewhere. I will look into your suggestions of possible causes and if I come up with nothing I'll take it in to the mechanic again. Thanks for the tips.

 

[n8roro]

Near the IP was dry. I'll check towards the back of the block. Thanks for the heads up

 

[beltfedonly]

I had the same problem, replace the window seal around the rear roll down window. LMC truck has it. Cured my exhaust smell problem.

 

[n8roro]

I'll put tape around all the seals on the tailgate and window to check if that solves the issue. That's for the suggestion.

 

[n8roro]

Noob question: Can I use permatex ultra black for the valve cover gasket, intake manifold, and the exhaust manifold gaskets? What would you guys use?

 

[sneekyeye]

You can use it for the intake and valve cover. If you want a gasket for the exhaust manifold, you're better off with a real gasket. That stuff isn't rated for that kind of heat.

 

[n8roro]

Is a gasket not needed for the exhaust manifold?

 

[Evil Dr. Porkchop]

A gasket is not used, at least not on the manifolds I've removed from CUCVs.

 

[n8roro]

Ok thanks I'll leave the manifold alone. I'll check the floor for holes, and replace the valve cover gaskets. I'll trace the fuel lines and look for small leaks as well. The smell seems to be coming from the front passenger side seems is worse with the passenger window open.

 

[n8roro]

I have not found an exhaust leak, but lots of other fluid seepage leaks. Here is what I found so far:

The only soot having to do with the exhaust line I could find was around the intake manifold. It was even all around so no obvious culprit:



There was little oil residue under the air filter (not sure if this is normal?)



The seal on the transfer case is bad so fluid from the driveshaft is flung everywhere including on the exhaust lines. This would smoke and could be the issue. The odor seems to stem from the front end though.



Where the oil hose enters looks like it has a bad seal, but I don's see how it would cause smoke.



This could be the culprit. There was lots of caked on oil in this area under the oil fill, and I think it could get hot enough to smoke. I cleaned it off so I hope this solves it. I will watch for an active leak as well.

There was also some fluid around the starter, but I guess I did not take a pic. No leaks near the IP or in the valley.Both comments and advice are appreciated.

 

[cucvrus]

This is a quick observation and experience. I had been trail riding Terminus M1009 on Saturday at Rausch Creek. We were in a very rocky area. Talking huge boulders. Crawling along and I heard a few axle hits and some rear end scrapping on the skid plate. I started driving down the flat areas and was over come with exhaust a couple times. Terminus has a new exhaust front to back. The exhaust was coming out from under the dash. I am driving and picturing in my head. What the heck could be leaking. The engine sounds normal no loud exhaust no leaks when I stopped at the cross roads. I drove back to a lot and the exhaust was getting me a head ache. i stopped and got out the exhaust seemed to dissipate away. I looked under the hood all normal. As normal as could be. the engine was covered in mud and water. Nothing unusual. I looked under the front and when I looked back the left tailpipe was bent up under the left 1/4 panel. I opened the door and raised the idle. I could see the exhaust exiting the area under the left dash. So I went back and my Son had bent the pipe back down. I gunned the engine again. No exhaust under the dash inside. I suspect. I say suspect. Without a sawzall I can not confirm. The exhaust was traveling up the 1/4 panel thru the B pillar and exiting the hollow part of the A pillar under the dash. So if you have bad tailpipes it is possible you have the same issue. Sort of makes sense. i have cut these apart and they are hollow shells. And being a 1984 that is 33 years of rust and corrosion inside the B pillar and it could allow the exhaust to rise upward and thru the roof and down the A pillar. I promise I was not smoking any weed or drinking any alcohol. It did happen and I firmy believe my diagnosis is correct on this matter. I wheeled again and smelled no exhaust. I clearly seen exhaust under the dash. Have a great day.

 

[n8roro]

Thanks I'll look into that as a possibility.

 

[dependable]

And being a 1984 that is 33 years of rust and corrosion

"We will sell no wine before its time" Just joshing on your new avatar. Is that the same guy? (Orson Wells)

Anyway, if that seems out of line, have been working on my kid's Volvo today, my apologies.

 

[n8roro]

Ok. The issue is somehow related to the heat/blower. No smell when driving without the blower on, but when I turn it on there is a smell. I put a CO2 detector in and it does no go off. I sealed around the blower housing and the heater core but that did not help. Any ideas what could be going on?

 

[cucvrus]

I think you have oil cooler lines leaking onto the exhaust pipes. You are getting the smell thru the heater because it is going up the cowl and into the inside. Just an idea. I have just changed 3 sets of oil cooler lines in the past 30 days. I have 2 more sets to change on plow trucks. Report back. I looked at you picture of the engine and the oil cooler lines are wetter then I would be comfortable with. Good Luck. Dorman replacements get my vote for fit and ease of installation.

 

[n8roro]

Your right! I have those lines and was going to try to hold off until spring when I swapped out the oil. If that is the root of the smell I guess I need to do it sooner if I want my wife to ride anywhere with me.

Thanks so much!