Exhaust smell inside cabin, possible exhaust leak?

[spacecruisers]

Ive noticed since I bought this van I get the occasional exhaust smell inside the cabin. It seems to be worse under load, up hills, etc. Do I have an exhaust leak? The exhaust seems to be free of any holes so I'm thinking it might be up on the manifold - that might also explain how it comes on so strongly. My exhaust doesnt smoke at all but I think it might be running slightly rich, its a little fuel-ly smelling so its a little noxious, even with the windows down. Is there something I can do to pinpoint the leak? I'm thinking if i could get it to smoke somehow I could maybe see where its escaping?

[spacecruisers]

Its near impossible to see the exhaust manifold since its blocked by all the EFI stuff, I couldn't find any write ups on getting to/removing the exhaust manifold, anyone that could help me out it'd be greatly appreciated. Want to make sure the van is ready for my move

[JDM VANMAN]

I think its last exhaust stud that always breaks of due to it's location and the heat causing a leak that comes into the cabin area, take a look at this excellent thread in how to repair-

http://www.toyotavantech.com/forum/c...-exhaust-studs

Also you gotta check out Tims thread on his weekend project... it's mind blowing with pictures, details, part numbers and so much more!!!

Type in-

1) pictures of my weekend project
2) blew rear main oil seal

I used that when I was replacing a ton of parts on my 4WD to turn it into a daily driver.

have fun!!!!

[spacecruisers]

thanks! that helps! i bet its a pretty safe bet thats what my problem is. how to i get to the exhaust manifold? is there another post i can reference? looks like i have to remove quite a bit to get at it in the first place. i use tims weekend post as a part number reference all the time its so handy

[djshimon]

Also check your battery cover(and power steering and other ones) and make sure that's tightened down or exhaust comes in through there.

[spacecruisers]

Took the van to the mechanic today and he said it looked like all the studs were intact since he could see the nuts intact. He thinks it may just be the gasket. Problem is he said it's labor intensive since you have to remove the intake and all sorts of stuff. Quoted price was $495 plus additional if studs and other stuff breaks on his way in there. Yikes.

I would really like like to do this myself but I'm moving soon and don't have a lot of time. I havent when able to get a response from anyone how to do this. Is there a post somewhere that I haven't been able to find on replacing the manifold gasket, or even just some direction on getting the intake off? What all do I need to remove to do this job?

Any help would be a huge lifesaver. I just don't have the money but I need to fix this before I leave next week so I don't die from carbon monoxide poisoning

[trestlehed]

You might wanna check the driver's seat lid gasket seal. I had the leaky exhaust manifold AND a bad engine lid seal. If you end up fixing your exhaust manifold, that's also a good time to have your fuel injectors checked/cleaned/replaced (as needed).

[spacecruisers]

noticed this today when i was under the van. doesn't appear to be leaking when i put my hand up there - it appears the gasket is indeed the source of the leak after consulting with a mechanic. i wondered what this is though? I have an O2 sensor further downstream, but i saw what appears to be a second O2 sensor port up next to the manifold? Anyone know? I thought these vans only had a single sensor...

[Roger]

It has two O2 sensors... I had to replace both when I bought my 1988 van, to get the check engine light to shut off. Looks like you'll need to hunt around for the wires.

I've also had my exhaust manifold replaced, and the engine packing (lid seal) was still available from Toyota, a year or so back, when I replaced that. I keep a carbon monoxide meter with ppm readout in my van to be safe, and with the exhaust sealed up tight and the new engine seal, it sits at zero where you'd hope it would be. If you can smell the exhaust, it's probably something you want to fix sooner rather than later. And I regret not having the injectors checked out when the manifold was replaced... definitely the time to do it when you have everything apart.

[Surf5557]

I've had problems with exhaust entering via the rear door seal (lack there of). Its amazing that there is a vacuum created by your car moving, and the exhaust will suck through the door if it has a chance. I'd check that too!

[Cali Cruiser]

Your pictures are close-up and make it difficult to orientate where and what we are looking at...however I believe we are looking at a broken o2 sensor, which would make your van run less-than ideal. Simple fix and cheap. Definitely replace that, if that is indeed what you have pictured.

Here is a picture of the o2 sensor (the new/shiny thing in the pic)...as viewed from behind the driver-side front wheel. To my knowledge, this is the only o2 sensor.

[Roger]

I've had problems with exhaust entering via the rear door seal (lack there of).

Yeah, that's another issue I've read about, though it hasn't been a problem for me.

I can say that when I had new exhaust installed, I did what others on the forum have and rerouted the tailpipe out the side, behind the back tire, to maybe prevent the issue down the road. There's a thread about it somewhere on here. I also replaced the rear hatch seal with something out of a Ford minivan that gave me a real tight fit, because I had a water leak in the top of the original seal.

[originalkwyjibo]

Regarding the o2 sensor, not all vans have two o2 sensors. I may be wrong on the year and someone may correct me on that but I believe the dual sensors started in 87 with one before and one after the catalytic converter with both being mounted in the pipe. Prior to that there was a single sensor mounted in the manifold. Both my vans are 88s and both have one sensor near the battery and one near the rear axle. One has a block off plate mounted to the exhaust manifold o2 sensor port and the other has a broken sensor in the manifold. I assumed the manifold had been replaced with an older one. I also have an 86 engine in my garage with a single sensor in the manifold port. If you don't have any o2 sensor codes and/or have another sensor mounted after the cat then I wouldn't worry about the one in the manifold.

[Cali Cruiser]

84-87 have 1 sensor.
88-89 have 2 sensors.

[spacecruisers]

Cali Cruiser, sorry for the bad pic - had a hard time getting the phone oriented for a picture under there, but the picture you provided is exactly the O2 port I'm looking at.

My van is an 87, there are two O2 ports - the one pictured (by the manifold) and one closer to the battery compartment. The catalytic converter is further back near the muffler.

The seal on my tailgate is good. Planning on turning the tailpipe out though - read several threads about that on here in the past. If i open the windows it sucks the exhaust in. The seal under the seat is in good shape. Fumes generally stay out of the cabin unless i roll the windows down.

I believe i also have a bad head gasket since my exhaust smells particularly bad and the coolant overflow exposes some contamination occurring. Will probably end up doing the HG, injectors, and exhaust all at once. Big job ahead.

Looks like I'll probably be adding an O2 sensor soon as well - the van actually runs real well, though the MPGs are a bit low (16-17), we'll see if adding the second O2 makes any noticeable difference. I replaced the other one a couple months ago - i assume its the same part number.

[spacecruisers]

cali cruiser and originalkwyjibo thanks for the responses, after looking at it some more, i think the one pictured near the manifold was intentionally blocked off. it wouldn't make sense to have two o2 sensors before the cat, plus as i can tell i only have one 02 connector harness in the engine compartment. plus as you mentioned 87's only have one sensor. ill just leave it how it is! It's looking like i need a new head gasket so ill probably fix the exhaust gasket leak and check injectors all at the same time when its all apart.

[Carbonized]

I have reed somewhere here that the ECU changed between 87 and 89 and that may be why your van runs well on one sensor. Until then that sensor was ment for the regulation of the Air/Fuel ratio. Since then in addition to that, it also report to the ECU on the state of the Cat. converter by having a pre and post Cat. sensor. If you had an 88/89 van and only one sensor working, I bet you would have the check engine light on and a stored code. Van would still run well unless a Cat meltdown or exhaust restriction causing back pressure. Maybe the manifold is not original, or they all had the port but the sensor depended of geographic. If you do not have a wire there for it what are you going to plug the sensor into?
Any way if your ECU is playing nice.... don't F... with it

[Carbonized]

mistersshmi, weird, your last post just showed up as I posted . I see you got it sorry!

[spacecruisers]

no worries your post was still useful!

the van runs fine, MPG's are a little low, but i think thats mostly due to the old tired engine and the 4x4 mods (lift, tires, roof rack, etc.)

you would think if an 02 sensor was missing it would be running rough, which it isn't. for all its faults (a leaky head gasket for one) it runs great.

[JPERL]

Important Note.

The 1987 model Had only one sensor. The 02 port you are seeing on the exhaust manifold is where the 02 sensor would be mounted if you had a manual transmission. If you have an automatic, the 02 sensor is threaded into the exhaust pipe.

There should be a cover over the unused port. If there is an 02 sensor there it might have been put there in error or to cover up the hole if the cover got damaged

The 84-86 Van regardless of transmission has its single 02 sensor threaded into the exhaust manifold.

the 88-89 have (2) 02 sensors threaded into the exhaust pipe 1 upstream and the other downstream of the CAT