bartmk Posted January 3, 2007 Share Posted January 3, 2007 So, my good old '97 Pathfinder has a strange noise going on and I was hoping you guys could give it a listen and give me some input. First of all, my rig has 113k on it and is in very good condition. Within the past month the timing belt and water pump have been changed as well as a fresh oil change. The videos below are from a cold start. The sound your hearing seems to be coming from around the passenger side around the valve cover/exhaust area. Seems to idle and run perfect. After taking a short drive the sound quites down to a point where you can barely hear it. I had an old Ford that had some lifter issue that sounded very similar but it ran great for years and years. Take a look, tell me what you think. Thanks! Video 1: Reving the engine a bit (not under load) Video 2: At idle Link to comment Share on other sites More sharing options...
The Pimpness Monster Posted January 3, 2007 Share Posted January 3, 2007 Most definatly an exhaust leak at the manifold gasket. After warm up, gasket will become more pliable and expand, minimizing the actual leak. That's why it quiets down. From the info I'm gathering about our rigs, having newly aquired one myself...this seems to be an extremely common defect in design. Hope this was helpful, good luck. Link to comment Share on other sites More sharing options...
xkrewx Posted January 4, 2007 Share Posted January 4, 2007 yeah about that...how much damage can this kind of exhaust leak cause. you said that the gasket becomes more pliable and in effect seals the leak...how serious is this problem? Link to comment Share on other sites More sharing options...
bartmk Posted January 4, 2007 Author Share Posted January 4, 2007 I have also read that the exhaust manifold studs have a bad habit of breaking from time to time and the exhaust manifold itself can crack. To add to it, there isn't a single supplier of aftermarket headers for the '97 models. (Still don't know if that noise is accually an exhaust leak though, waiting on more feedback before I bring it into the shop) Link to comment Share on other sites More sharing options...
The Pimpness Monster Posted January 4, 2007 Share Posted January 4, 2007 Yeah, the stock exhaust pretty much blows donkey balls on all fronts. The severity of the exhaust leak of course determines the potential for harm to your engine. Ranges from nothing more than an annoyance all the way to major computer and/or mechanical failure. Bottom line...get it addressed ASAP if it is a direct engine leak. oh, and heat simply makes "things" expand, therefore reducing the "gap" between parts so to speak. This is only in reference to his syptoms minimizing after warm up, some get worse... A good custom shop could always build ya some headers if your willing to spend some $$ Link to comment Share on other sites More sharing options...
psugrd2b Posted January 4, 2007 Share Posted January 4, 2007 The exhaust manifold studs are a major design mistake on the part of Nissan. I just went through the joy of fixing the problem on my '95 pathy. I was hesitant to tackle the job myself, tapping out corroded studs on an aluminum head is not the easiest task, but it is possible with the right tools and patience. I actually had a local good ole' boy mechanic do it for me. He had done the job on a few other V6 Nissans. It is a good idea to get it fixed ASAP. That being said, I listened to the sound you had on your video and it didn't sound like an exhaust leak to me. I'm sure it's not quite the same as hearing it first hand, but it sounded like the valve tap of a V6 with 100K+ miles on it. (Which is to be expected, and not a major issue) I suggest removing the heat shileds around the exhaust manifold (start with the side you think the noise is coming from) and visually inspecting the studs. From what I understand the studs toward the front of the manifold are the most likely to go. I also suggest putting light torque on them even if they are there. I did this and the head of the stud came right off. You may see them there, but there might not be much left. I know that's a lot to digest, but like I said I just went through the whole process. Look around on this site as well, there used to be some great pictures of the manifold showing where all the studs are exactly. Good luck and let us know how it turns out. Link to comment Share on other sites More sharing options...
bartmk Posted January 7, 2007 Author Share Posted January 7, 2007 88pathoffroad wrote in the tech section: Pathfinders with the VG30i and VG30E engines were built with weak exhaust manifold studs that are prone to breaking because the exhaust manifolds tend to expand unevenly when warming up and cooling down. This causes the infamous "ticking" noise often heard from the front of Pathfinders which quiets down after the manifolds have heated up sufficiently. This applies to all Pathfinders from 1987 through 1996. Does that mean that this problem does not apply to my '97 with the 3.3L? Link to comment Share on other sites More sharing options...
88pathoffroad Posted January 7, 2007 Share Posted January 7, 2007 Hi. Firstly, I didn't write the FAQ section, it was copy/pasted from Jim's old forum. It contains a lot of accurate info and some inaccuracies that have really gone unfixed for a long time. Sorry about that. After watching the videos, it sounds to me like it has a lifter ticking. That's all I can say from over here in Oregon. I'm not next to the vehicle in question nor can I diagnose it's problems from over the internet. That said, some engines do have lifter noise problems and some do have manifold stud or collector gasket problems. The majority of the manifold stud problems are experienced in 87-95 WD21 Pathfinders. Exhaust noise tends to be harsher and snappier than the noise I observed in the videos, but then again it could just be a very very small leak. I have no way to tell from here. I would try to find some Seafoam, add some to the engine oil, the gas tank and then run some though the intake via the brake booster hose to see if that helps. After adding the Seafoam to the engine oil, I would run it for a bit to let it clean the system up internally, then change the oil and filter. I'd go with 5-30 or 5-20 oil for the wintertime and see how that affects the noise. It may be a "bad" lifter, or it may simply be crud built up in a single lifter that may come out after the Seafoam. The idea here is KISS: Keep It Simple, Stupid. (No, I didn't make that up, and no, it's not meant to disparage anyone in this thread.) Link to comment Share on other sites More sharing options...
Casey.T Posted January 7, 2007 Share Posted January 7, 2007 I sorry I did not get a chance to listen to this sooner... That sounds exactly like the motor in my 91... I have swapped out the lifters on both sides and Im running Thorleys that I have re torqued, they are not leaking.... I am still dumb founded on what is causing this noise.... Mine will lighten up a little after it warms up, but it is still very distictive when running... Started with 10-30 then went to 5-30... When I get the Subaru out of the Garage Ill try the seafoam.... Link to comment Share on other sites More sharing options...
Casey.T Posted January 15, 2007 Share Posted January 15, 2007 So I grabbed some SeaFoam last night... Ran some of it through the Vaccuum hose coming off of the Charcoal Canister.... Smoked like a mother... Had to rev the engine a bit to get it to suck in it... Need to add it to the oil when I know im going to be driving it a bit and ready for another oil change.... Link to comment Share on other sites More sharing options...
nissandoms47 Posted January 15, 2007 Share Posted January 15, 2007 ya all that smoke is the carbon crap getting thrown out of the engine, did your tick go away or is it still there? Link to comment Share on other sites More sharing options...
Casey.T Posted January 15, 2007 Share Posted January 15, 2007 Still have the tick/tap... but it is more throttle resposive... or it was just the fact the sun went down and everything was iced up I will play with it more tomorrow as the Tap is much more noticable when she starts up.. simple process of elimination with the SeaFoam... Link to comment Share on other sites More sharing options...
Casey.T Posted January 15, 2007 Share Posted January 15, 2007 When I had the engine apart, I had the upper and lower intakes washed in a parts washer... but it still had alot of smoke :o I may have to get another can it was only $5... and do the 95 as well.... Link to comment Share on other sites More sharing options...
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