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Happy to report that we’re solved B) .
After I got the pipe clear, it occurred to me that I maybe didn’t have to cut it apart to get at the blockage – which turned out to be on the interior of that large iron part that connects to the big brass EGR tube. Or maybe it wouldn’t have cleared until I’d done all the work from the inside of the pipe, brushing it out and all that. In any case, it’s back in the car with the hose attached. It had been taken apart for so long that I forgot where 2 of the harness connectors went. Actually, I forgot that I even unhooked the ECT sensor connector and spent most of today just trying to find the damn thing. It’s kind of buried in this engine under some hoses.
Having sat for a year (more or less), the battery was obviously dead. I jumped it with my Honda and let it charge for a while. I had it idling for 25-30 minutes today and it was just purring along the entire time. It’s a good sound.
So now I just have to fix the front left caliper and replace the front pads, check the rear brakes, and get the muffler welded back onto the exhaust pipe and I’ll be good to sell her as I’ll be fairly confident she’ll pass inspection at that point. Feels good!
Yep, those are the tops of the spark plugs there. Oil doesn’t seem to be coming out of those however – I think it’s coming from those two bolts judging by the pattern. I’m just about out of daylight today so I’ll check tomorrow.
Would a larger picture help? I can get one of those too – I should have with this picture but wasn’t thinking.
OK… retitling because I think I may have gotten it. We’ll see… I ended up having to cut that tube in order to get at the blockage, but I’ve got it clear. I put the engine back together and thought I had purchased the correct vacuum hose to connect the EGR stuff to the now-shortened tube. Alas, I did not. So I placed an Amazon order for the proper tubing (1/4″ ID) and once it gets here I should have an update on whether this journey is complete.
I finally went out and looked at it again. I got this assembly off, which the EGR pipe connects into and you can see beginning at 7:48 in Eric’s video (https://www.youtube.com/watch?v=GKFJxnn4IIQ).
I started trying to get a 1″ steel pipe cleaner into the EGR pipe and got it stuck, but in order to do so I had to take this off. So I did, and promptly got my pipe cleaning brush stuck inside. I’ll need to get my pliers to get it out, so I decided to spray some carb cleaner into this assembly anyway since it was all black inside. The larger interior area, while dirty, is clear enough for air to flow – interesting. I wonder if this means the EGR pipe itself is the same (dirty, but not clogged). Anyway, I clean off the end of this narrow little tube which goes to the EGR valve stuff… and sure enough, I can’t blow through it. So I spray carb cleaner in there and it starts coming out brown and black, but it’s really not good enough. I’m going to need to really get this pipe cleaned out, I think, and then try putting it back together to see if the problem is fixed “good enough.”
Any ideas for this little pipe? If I get it out, should I just replace it (anyone know where I could buy one, and what it’s even called? heh)? Or could I perhaps cut it off and buy, and then bend into shape, a piece of steel tubing of the proper size? Welding or soldering it onto the cut-off section? Basically, I was wondering if I could cut it just above where the nut is, as it starts to curve, and clean it from there and then either clean and re-attach the cut off section that goes to the EGR, or simply replace it?
For the EGR pipe, would it be safe to spray carb cleaner in the top and see if it comes out the bottom? Or would that be a terrible idea (either the carb cleaner itself or the junk in the pipe being bad for the pre-cat)?
[quote=”Timothy S” post=164784]Can you unbolt the catalytic convertor from the exhaust manifold, just below the egr pipe connection? That might allow you to access the pipe. On the Altima I had in Texas, that was all one piece, with a support bracket bolted to the block at the bottom of the manifold/ downpipe assembly. Looks like you can go after 6 bolts connecting the pre cat to the exhaust manifold and possibly a support bolt and drop the pre cat out the bottom of the engine bay. It’s also got 3 nuts connecting it to a flexible exhaust line under the engine.[/quote]
Thanks for keeping up with the thread, I really appreciate it. It’s nice to have a second voice.
I can get to those bolts holding the pre-cat on, maybe. They are done from underneath, but now that I’m working in a driveway and not at the curb I can jack up the car and maybe get at them from underneath. I will try it sometime this week. I already know I can get the exhaust manifold off of the engine block, as I’ve taken those fasteners off before when I thought I could get the pre-cat out. I may need to take some more stuff out of the engine compartment if I go that route, as I may not be able to pull the pre-cat + EGR pipe assembly out given the shape of the pipe itself. Here’s a pic from before I took the heat shield off. I may have to take the distributor assembly out if I want to take the manifold + EGR pipe out.
If I 100% knew this was the problem, I would just replace the exhaust manifold (~$80) and EGR pipe (~$40) themselves. In this pic you can see that my exhaust manifold may have a crack all the way through it, right in the middle. :dry: You can also see the after effects of a cracked radiator from ~2012 on some of the things below the manifold (you can see that coolant looked into the engine bay). I’ll have to clean that up, too.
OK, I got to the EGR pipe itself. Eric’s video told me I needed a 30mm and 24mm wrench, so I got some more wrenches. The 30mm nut at the top of the pipe came right off – I think it must have been taken off in December 2014 when I had the intake manifold gasket repaired. Looked like there was some silicon on the threads. So that’s cool.
However, I took the exhaust manifold heat shield off (also requires taking out the radiator fans), and got to the 24mm nut at the bottom. It’s completely rust-frozen in, it seems. Here’s a pic before I used a brass wire brush and slow-sprayed some penetrating oil. As you can see, I started to round the 24mm nut off a little bit when I applied my rubber mallet to the wrench, so I stopped.
While getting the radiator fans out, I spilled some coolant. I’ll need to clean that up (I inherited a really messy engine compartment and have never bothered to clean it up… :blush: ).
Any advice? I have some 12-inch stainless steel tube cleaning brushes on the way, and I can get into the top end of the pipe, but I’ve read that the bottom end is the one more likely to be clogged and it’s not exactly a straight pipe. If I can’t get the nut off, could I hacksaw the pipe, clean it out from the break, and then solder on a “patch”, which I saw somebody else do?
You can also see into the warm-up three-way cat here. When I peer in through that O2 hole, it appears to be all white – so it’s fine, right?
I have a basic vacuum gauge but not really sure how to use it in this case.
I have the reverse problem, sort of – the worst of the problem is at idle. Under load, it runs fine (if really inefficiently).
I’m also not sure if I can loosen the bolts that go to the cat. Maybe. I’ve looked in that area before because I was thinking that if I took it off, and it ran fine, I’d have identified the cat as the problem. Unfortunately, my cat is welded on (I think it has been replaced once before) and the warm-up cat just after the exhaust manifold and O2 sensor is impossible for me to get off without lifting the car far enough off the ground that I can get sufficient torque on the rusty bolts attached from underneath. Something I could do in my backyard, but I’d have to build a couple of ramps. Not something I’m eager to do.
The pipe itself being clogged would explain why the EGR vacuum line being disconnected was only a temporary fix (for about 2 weeks), and why taking some of the screws out that hold the exhaust manifold heat shield on and also open up holes in the manifold itself (there is one on each side) seemed to improve the running, as that would let off some of the pressure ahead of the EGR pipe itself.
I have a torch, so maybe I can get the 24mm nut off of the exhaust manifold itself. We’ll see. The engine has run hot in the past on several occasion so it might be pretty well baked on there.
[quote=”Timothy S” post=164475]You have removed the egr pipe with the valve. It connects to the exhaust manifold and loops around the engine under the distributor. The cast in passage for the egr appears to exactly where you indicated on your picture of the intake manifold. If I remember from my ’98 Altima the plugs have a hex head, but I never needed to remove them. Maybe try a large hex bit for a 3/8 drive ratchet and pray the corroded aluminum plugs don’t strip or round off.[/quote]
I actually had to go outside again and check, as I didn’t remember my car having the pipe that Eric talks about and shows around 5:35 in that video. Sure enough, there it is and I can see that it’s connected to the manifold with a pair of 10mm bolts. I’ll take that off tomorrow. It’s not really anywhere near the EGR valve itself, at least not obviously so. Without that video showing me where it was, I never would have found it. Unfortunately, the big nut that attaches to the EGR pipe itself looks extremely rusted. I would not be surprised if I couldn’t get it off at all… but hopefully I can make progress by first detaching it from the manifold.
Thanks a ton for your helpful input.
[quote=”Timothy S” post=164471]The Altima intake manifold is very difficult to remove, though Eric makes it look manageable in a video on replacing the intake gasket.
If you got the egr pipe and valve off, you have your problem in hand. The valve gets clogged up and starts to leak or get stuck.
You cant gain easy access to the inside of the manifold, but truck/pathfinder/240sx owners can because they dont have the same clearance issues with the firewall and could easily access these plugs. As an Altima owner, if you want the manifold off, you need to remove it while still attached to the head. Plan on a head gasket, because there’s not enough clearance between the fire wall and the engine to get it past the intake manifold studs.
Given this level of difficulty, I’d try cleaning up the valve and egr pipe and testing the back pressure transducer (keeps the egr from opening when it’s not supposed to and looks a lot like the inverted saucer egr valve) as well as the egr solenoid mounted on the passenger end of the hard vacuum lines that run ontop of the intake manifold.[/quote]I don’t know how I never watched that video before, as I watched the precursor video to that one where he diagnosed the problem (which really helped me narrow it down to the EGR).
Unfortunately, the Altima doesn’t have an EGR pipe. If there’s anything like the pipe the Maxima has, it’s actually built into the structure of the intake manifold. After reading about the plug bolts, I went out and looked again (even though it’s late). I may have identified them? These are exactly in line with each other, and there may be a tube running between them. It’s also about the same level as what I think is the very bottom of the chamber that leads to the EGR valve itself. So I think the EGR air goes up into the valve, then down into this tube that distributes it to all 4 cylinder intakes. I’ve temporarily lifted the fuel rail with the injectors out of the way here for clarity.
I think I can get to these plugs, but I don’t currently have the hardware to undo them. Shouldn’t cost too much for something that fits, right? Then, if this is a big pipe for the EGR, I’ll need to get some loooooong brushes. To recap, I’ve actually already replaced the EGR valve itself as well as what I think you’re calling the transducer (it’s a disc- or saucer-looking thing that connects to the EGR valve, and is not the solenoid).
I’ve been doing a lot of googling the past few hours, and I just came across this thread:
http://www.nissanclub.com/forums/general-nissan-altima-discussion-1993-2001/323852-1998-altima-intake-manifold-gasket-replacement.htmlThe OP there says:
My problem area is the EGR passages. the two outers are open but the two inner ones are not. I noticed what appears to be pipe plugs threaded into the underside of the intake manifold at about the same area opisite the EGR passages. can I just remove these plugs to access the back side of the EGR passages?
I know the 1998 Altima engine is very similar to my 1997 (my roommate had one 3 years ago and we, well I, worked on it a bit), so the plugs should be in the same spot, yes? If I can locate them, perhaps I don’t need to get the manifold off after all? This is some journey…
Here is a screenshot from my repair manual. The diagram is obviously a concept diagram (I don’t know the technical term for it) of the system, and not actually what the engine looks like. The place I’ve circled corresponds, I believe, to what comes just after where the EGR valve attaches on my manifold (the spot with the black holes in my previous pictures). I do remember that I would get multiple cylinder misfire codes, as well as specific cylinder misfire codes, so there has to be a place where the EGR tubes split somewhere inside the manifold, right?
I need to get some pipe cleaners, yeah? I saw a YouTube where one guy was using throttle cable and a power drill… :ohmy:
Here’s one of the previous pics again with very poor mouse-drawn arrows on it. Does anyone know at what point it becomes 4 separate tubes?
Circled in these pics are some bolts/nuts I am going to have an awful time getting to in order to get this thing off. From the linked picture in question 2, it actually appears as if the thing that holds the throttle cables is not a separate piece of metal, as I had assumed, even though I’ve circled the bolts. To put it simply, here’s what I’m wondering right now:
1) Am I even in the right place? It’s my understanding that the EGR valve and solenoid do the whole EGR thing through these intakes, which are clearly for air.
2) I do need to take this thing off in order to clean it, right? This is the part (from a 2000 Altima) that I’ve been thinking I need to get off: http://images.hollandersolutions.com/I65/65E/4CW/3TI/U.jpg
3) You can see into the EGR holes in these pictures – am I mistaken in thinking that there are places deeper than this that I’d need to get at? You can see they’re pretty gunked up (although not clogged, at least at a glance).
Alright, I’ve been able to get back under the hood. I made sure I knew where everything went in order to put it back together first, and then went about figuring out how to get the fuel rail off and what I would need to do in order to get at the EGR passageways. Unfortunately, it looks to be a near-impossible job.
Why am I even doing this? Because if it’s the EGR passages being clogged, then all I need to do is clean those out, replace the front right caliper, and have the muffler welded back on… and then the car should pass MD inspection, meaning it would sell for $1100 or thereabouts. I’m looking at $48 from Autozone for the caliper and a few hours of labor on my part. I already have a set of front pads, as I know those are low. I don’t know what a welding/exhaust shop would charge me for the muffler work, but I’m hoping $200 or less. So that’s $250 plus my time, if it’s the EGR passageways… and without getting it to pass inspection, we’re looking at $300 or so to sell it. Maybe $500 if I’m lucky enough that someone who can fix it on their own springs for it, but in MD you can’t register a vehicle unless it passes inspection. So that’s why I want to fix it. I have until the end of June before it costs me another $65 in tags registration (which I’ve already paid, but would be refunded). Oh, and it needs a battery, so another $120 or so brings the estimated total to $370 plus time, against about $600-800 difference in sale price (there are a few ’97 Altimas on craigslist right now in my area for $500 that also need repairs, but they all run, allegedly…).
Going to upload a few pics here in a moment.
Thanks. It’s definitely possible that there’s an issue with the muffler being blocked, but even if so there’s definitely an issue farther up as well. I wouldn’t be surprised if the issue farther up caused a lot of buildup in the muffler, but I’ll get to that if/when I fix the other stuff.
This occurred to me on the way home today, but I could have just taken the O2 sensor out again when it started running rough a few weeks ago to determine if the problem was exhaust manifold and beyond, or pre-manifold. I might reassemble it and test that out first, because taking the engine apart to get to the EGR passages. It might be inconclusive, but it would give me another data point at least. When I was posting earlier, I forgot that I had actually done something similar to this before. On the exhaust manifold, there are mounting screws…and 2 of them actually plug up holes into the exhaust itself. When I opened those up, I think it ran better. I put them back in so I wouldn’t lose the bolts. There’s something weird about the manifold also – there are only 4 bolts holding it in, but holes for at least 6. Here’s what looks to be an OEM replacement for the manifold itself (not a bad price, if my problem is in here I wouldn’t be displeased):
http://www.amazon.com/Dorman-674-508-Exhaust-Manifold-Kit/dp/B000E35VRA/ref=sr_1_6In that picture you can see where there are placeholders in the heat shield for where bolts/screws would go. Towards the bottom (right) end is where the 2 bolts are that I took out and clearly felt exhaust leaving from the holes. I thought this was weird.
One thing that peeves me about this is that I paid several places several hundred bucks to fix various things, most notably an intake gasket leak (who knows if that actually existed… I’m not sure that shop is very good – they just told me it was the MAF sensor after the gasket “fix” didn’t fix it), and got nowhere. They basically had no idea, or it would happen to run fine while they had it. The last place I took it just unhooked the EGR valve hose which made it run fine, but I had to pay them for “diagnostic time” as they spent several hours fooling around with it. I wish places would just listen to me when I tell the guy who’s going to be working on my car, directly, exactly what I did and what I found. I didn’t plug the EGR hose, so there was a potential vacuum leak there, but it ran smoothly for a week or so and then began misfiring again.
So at this point I’m treating it as a learning experience/potential project car. Good point about the caliper – when I bought this car, the same caliper locked up about a week after I got it home. I noticed when checking this one out that there’s no way that’s a 4-year-old caliper on there now, so it was either rebuilt or it was the mounting pins that locked up rather than the caliper itself (I paid a guy to do it). When we moved, I priced out the caliper parts. I want to say it was $30 for a caliper WITH bracket at Advance.
I agree also that, if the engine were maintained properly, it would keep going for quite a while and be a good little car. It’s only got ~140K miles on it. I suppose I’ll keep posting as I investigate and learn things. Don’t have time tonight to put it back together and check it by taking the O2 sensor out. I actually have a vacuum gauge, but can’t seem to use it properly to test for back pressure at the manifold.
