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/content.php?198-A-few-tricks-for-removing-broken-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!!!!:thmbup:

[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 :LOL2:

[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 :LOL2:

[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...

5158
5159

[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.
5164

[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 :LOL2:

[Carbonized]

mistersshmi, weird, your last post just showed up as I posted :cnfsd:. I see you got it :thmbup: 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

[spacecruisers]

thanks for your knowledge on o2 sensors. mine is a manual. the o2 sensor i just replaced, its on the pipe near the battery. i must have some parts from another van. i do know the PO had a parts van he swapped the motor from. you would think he'd have bothered to at least replace some components like the head gasket before doing all that work. the more i work on it the more i realize that 1. this van was incredibly neglected and 2. the work he did do on it was extremely sloppy shoddy work.

now i get to go back and fix all his mistakes! :dance2:

[NWVanner]

On my 87 4WD has the broken stud on the back of the manifold. I could smell exhaust in the van when I had the drivers window open and it was coming through the battery cover as it didn't seal well because some of the weatherstripping was old/missing. Installed new weatherstrip and all good now...also less road noise! :)

Both vans (87 and 85) had a strong (running rich) exhaust smell. Replacing and setting the Throttle position sensor helped a huge amount. Now the vans don't smell like they're running rich. Might help?

Brent

[spacecruisers]

you know, i have the same problem, I'm planning on turning out the tailpipe to the side as others have suggested, but I'm going to double check the seal on the battery cover as well. I actually don't get fumes in the cabin until i roll the windows down. I just bought a new TPS though thanks to your suggestion. My guess is the old one is shot just like every other part on this van :LOL2:

ill update when i get it in there.

[mrgrackle]

I get quite a bit of exhaust fumes in the van when driving. I'm guessing the rubber seal/gasket under the driver's seat is failing. What's this part called and where do I find it? Has anyone else had this issue, am I barking up the right tree?

Thanks in advance y'all!

[JPERL]

Sounds like you have an exhaust leak from the exhaust manifold if you are getting fumes in the cab and that's really more of the issue. It is a very common flaw with the van where one of the studs on the exhaust manifold are broken off. The rubber for the engine cover seal is no longer available and so you would have to get some weatherstrip and fashion your own seal also the rubber grommets where the parking brake cable and shift linkages pass through the floor are letting any fumes pass as well.

These seals were never air tight to begin with and so even if you had brand new seals an exhaust leak will still make its way into the cab and so really the repair to the exhaust needs to be addressed

[tennesseetoyota]

Would an exhaust leak make the van smell like gasoline? I've been having bad gas fumes in my cockpit for a while now. Was driving it on a road trip and it started sputtering real bad. Had to get a mechanic to look at it since I was on the road and it ended up being plugs, wires, distributor cap, and one (?) fuel injector. But that didn't seem to fix the issue completely.

Someone said something to me about a fuel rail, could this also be the source of gasoline smells or would it more likely be an exhaust leak? And how do I go about finding out what it is?

I did the test where you put your hand over the exhaust and listen for a leak but heard nothing (and got real good pressure). Mechanic said it also had real good compression (if that helps, I don't know, I'm still learning!).

[trestlehed]

Would an exhaust leak make the van smell like gasoline? I've been having bad gas fumes in my cockpit for a while now.

Unless you want to be driving a mobile barbeque, stop driving that thing until you find the source of the fuel leak. Places to check are the fuel rail, injectors, fuel pressure regulator and fuel filter. My guess is that if you already replaced 1 injector, then 1 of the remaining 3 injectors is leaking. Also replace the fuel injector connectors while you're at it (they get heat-baked and crumble to dust eventually). Use the search function or Google.
I got my new injector connectors from Amazon.com.

I found this thread with good advice and pics:
https://www.toyotavantech.com/forum/showthread.php?522-Other-parts-to-replace-while-replacing-Head-Gasket&highlight=fuel+injector+connectors

Good luck and let us know what you find.

[JPERL]

If you smell raw gasoline, this is a potential immediate fire hazard. Many a Van has died this way. The fuel pulsation damper on the fuel rail can leak as can injectors however the pulsation damper is more common failure point.

Are you getting poor gasoline mileage? If you smell gasoline your engine can be running rich which can be caused by air restrictions, ie dirty air filter. A bad 02 sensor , EFI temp sensor can cause the vehicle to run rich.

Mechanical reasons for running rich can be poor compression due to valves and or piston rings not sealing.

Did you get the compression readings ? "Good Compression" is subject to interpretation. The spec range is 128 to 178 PSI, but that does not necessarily mean that if you are in the low end of that range that you will be free of performance issues. Another factor in compression readings is that you want no greater than a 10% differential between cylinders so if you have 150PSI it is ideal to have 150 in all cylinders so the most you should be off on the low side is 15PSI and this you would feel as the engine would feel a little rough so while its not good for performance to have low compression but if you do, it is better that all cylinders preferably be within 5 to 10 PSI of each other.

The point is the better the compression, more of the fuel mixture will be burned so that there is no fumes left to smell meaning raw or partially ignited fuel is not getting dumped into the exhaust which in turns kills the catalytic converter.

More commonly I have seen lean misfires which means there is more air than fuel which is caused by a vacuum leak or a leaky intake manifold gasket . When you hear random put puts in the exhaust that's a lean misfire

[tennesseetoyota]

My gas mileage seems to have gone down I would say, but I largely chalked it up to driving in the city.

I didn't get any of the readings but can ask for those tomorrow when the mechanic opens back up. He said the other three injectors were find, which I trusted him on (perhaps too blindly).

I do hear occasional put puts in the exhaust when it's idling, and notice that it has a really hard time starting now (like it never did before, I have to crank it to get it going whereas it would turn without a single turn of the starter motor before).

I recently replaced the air filter, so I would assume it's not that (unless I managed to mess that up, which seems unlikely since the enclosure for it likely wouldn't shut unless it isn't snuggled in there just right).

When driving, it runs just as smooth as ever. It's just at idle and start that I'm having problems.

Also noticed that the mechanic turned the idle WAAAAAY up (perhaps to get it to start since it's struggling), so I'm wondering if something's been hidden there...

Any thoughts?

[boogieman]

when you replaced the air filter its likely you disturbed the intake boot and have an air leak between the maf and throttle body, make sure the t fitting on the underside is all hooked up and look for possible cracks in the rubber tube..

[tennesseetoyota]

I will look for sure my suspicion leads me to think this is unlikely. I drove around 4000 miles after changing the air filter before this problem started.

I suppose there's always the chance the mechanic messed with it and messed something up. I'll check it haha.

UPDATE: The mechanic said when he tested the compression they were all within the acceptable range and were all about the same, although he didn't have the numbers on them. He also said the other three injectors that he didn't replace were all "hitting" so there was no reason to replace them.

[llamavan]

Check the Fuel Pressure Regulator (https://www.toyotavantech.com/forum/showthread.php?589-Testing-fuel-system-replacing-fuel-pressure-regulator) and Fuel Pulsation Damper (https://www.toyotavantech.com/forum/showthread.php?231-Replacing-your-fuel-pulsation-damper).

Failure of either will cause the raw gas smell; failure of either is a significant fire hazard. Make sure both are sound or replace before driving the van!

Gwen

[tennesseetoyota]

So I think the cause of my issues may be the fuel pulsation damper. Looking at the other posts, mine doesn't quite look the same.

It honestly appears to be some sort of bolt that's stuck in there as opposed to the actual fuel pulsation damper (unless the bottom of certain fuel pulsation dampers was flat like that of a bolt). What do y'all think?

I've got the fuel pulsation damper and related gaskets on order.

7226

[JPERL]

you have no damper installed. that is just a bolt. Get that fixed ASAP, that is a fire hazard waiting to happen

[tennesseetoyota]

So I got the fuel pulsation dampener and replaced the bolt that was in there. Had some trouble getting the dampener in there but after putting some grease on it successfully got it to go in. Started it up and let it warm up to operating temperature and smelled no gasoline, so I would assume I am OK.

There is still a bit of a burble in the exhaust note, so I'm not sure if I've totally solved the problem. It just sputters on occasion, maybe every two or three seconds.

UPDATE: I drove it around about 20 miles or so with the windows up for a good bit, stopped, and let it sit for a few minutes. I came back out and opened the door to see if I smelled any fumes (like I had before) and didn't so I would assume I'm OK at this point (though if I go to the passenger side and smell beneath the door at the wheel well I can still smell a little bit of gasoline fumes). Just a little curious about the exhaust burble. Starting it hot after letting it cool down a bit makes it sputter almost as if it was misfiring (but it smooths out over time). It's also been making a lot of whooshing sounds when I give it the beans.

Any thoughts?

[Burntboot]

Fuel filter mounts near the RF wheel, maybe make sure that you have no leaks there, reusing banjo bolt gaskets is the No. 1 cause of filter leaks.
The rubber lines can get damaged/deteriorated, but hopefully its just gaskets.

[tennesseetoyota]

I for sure replaced the gaskets around the pulsation dampener (copper one and the one next to the dampener). It doesn't smell nearly as much as gas (I really don't think i smell any, I'm just having rough starts when cold and when I've let it cool a bit).

What is the "RF wheel"?

[llamavan]

What is the "RF wheel"?

Right front.

Gwen