So out of no where my Pathfinder has begun to make this winding/rattle sound from under the carriage when I hite 1,500 rpm, in drive going at least 20 mph. Car has to be warmed up for it to happen. It only makes the sound at 1,500 rpm and goes away as you throttle to a higher rpm. If I hold the pedel at 1,500, I can keep the loud, annoying, embarrassing sound. It even makes the sound when decelerating and passing the 1,500 point.
Most likely the heat shields are rusted or loose and vibrating.
This car has very little rust underneath as it was stored indoors most of it's 65,000 miles. Is a heat shield something I can crawl uner and tighten myself? (I've got the Hayes Pathfinder manual).
Do you think it could be anything else (like really expensive to fix?)
The heat sheild is a plate they put on the catalytic converter to keep rocks and other debri from damaging the converter. It is usually welded to the converter ,(but in my diagram it looks like it uses bolts??? if your is that way then just tighen or replace the bolts) ,so if ithas rusted loose you either need to weld it back on, take it the rest of the way off or slide a piece of rubber hose on the sheild where the weld broke off to keep it from vibrating.In your haynes manual you can see it in the chapter for fuel and exhaust systems (for an 87-95 model itis on 4-29 but I don't have the book for the newer model). Look for a diagram titled typical exhaust system and find the catalytic conveter it is right below it in the diagram but not labeled. It really has no purpose except to try and protect the catalytic converter and to dissapate a little heat.
PS you can also see on the first page for the chapter on the maintence schedule, chapter 2 in mine , for a better idea of where it is and what it looks like.
The heat sheild is a plate they put on the catalytic converter to keep rocks and other debri from damaging the converter. It is usually welded to the converter ,(but in my diagram it looks like it uses bolts??? if your is that way then just tighen or replace the bolts) ,so if ithas rusted loose you either need to weld it back on, take it the rest of the way off or slide a piece of rubber hose on the sheild where the weld broke off to keep it from vibrating.In your haynes manual you can see it in the chapter for fuel and exhaust systems (for an 87-95 model itis on 4-29 but I don't have the book for the newer model). Look for a diagram titled typical exhaust system and find the catalytic conveter it is right below it in the diagram but not labeled. It really has no purpose except to try and protect the catalytic converter and to dissapate a little heat.
PS you can also see on the first page for the chapter on the maintence schedule, chapter 2 in mine , for a better idea of where it is and what it looks like.
thanks - page 6-29 in the 1996 - 2001 Haynes. I'll look for it and see if it is loose. Wont a pice of rubber hose melt/burn up and create a smell?
For your 98 you actually have heat shields attached to the exhaust running pretty much from the engine back to the center muffler, completely surrounding the exhaust pipe. Check towards the front pretty much below the front seats at both sides and I'm betting that's where they are starting to rust apart and make noise.
__________________
1997 Pathfinder XE
Air Lift Air Bags, Warn Hubs
Wont a pice of rubber hose melt/burn up and create a smell?
Sorry about the incomplete statement I should have said rubber heater hose that they use like on the heater core. But make sure you find the highest temp rated hose you can get ( a few hundred degress should be fine) it shouldn't cost but about $1 or less per foot at the zone. You could also try riveting the shield back together if possible in your situation and you don't mind a little challenge. PS if you rivet I'd use aluminum to prevent more rust.
well....after breaking off rusted nuts and tearing off pieces of the rusted heat shields, the solution has not been solved. I did remove the rusted section of the "full body" heat shields, and tapped on everything else under the carriage to replicate the winding/rattle that happens ONLY at 1,500 rpm. Nothing under there that I can touch sounds like the problem. So, I have some scrap metal and a cut on my finger from the rusted shield...and still the annoying, loud sound. I did enjoy doing the work though!
Option 1: Every time you reach 1,500 RPM turn up the radio loud .
Option 2: Buy a newer Nissan!
Option 3: Make a run to the Sam's club and buy a case of duct tape , then hysterically tape everything underneath your truck to everything else to prevent any possibility of rattle.
Option 4 Wear ear muff/plugs when you drive.
Option5: Tell everyone that you have a new anti theft device on your truck that your testing for its manufacturer and every time someone steals a car equipped with this that once they hit 1,500 rpm it gives off an audible signal when they ask how come its not loud just tell them "They're working the bugs out for that"
Option 6: Try to diagnose when it happens.... does it happen in reverse? If its a manual does it do it in all the gears or in an auto in N or park ? Does it do it on decelleration and accelleration or at a certain speed or time of day? Also try to find Technical Service Bullitens for you Pathfinder and is so do any pertain to a rattle?
Trying to root out the problem is hard and not fun you could try it but I like options 1 3 4 & 5 best!
PS no crap any info you can give me about the above "serious" questions would be real helpful in determining what is causing it.
BTW a cut and rust on your hand is nothing I am missing a small part of the tip of my thump from trying to loosen some bell housing bolts on a camaro with a slippery wrench and at the time I split my finger open 1/4 inch causing heavy blod loss but after some alcohol on the finger and a needle and thread with a homemade bandage of electrical tape and cotton it quit and back to the tranny I went. Just goes to show don't come in to hang out with your buddies working on cars and offer to help them out! I'm a :dumbass:
Sounds like a Catalytic Converter heat shield. Rock, broken weld, lost screw, etc... Be sure to check the manifold heat shields as well...
__________________
Aaron Ford
95 2WD Nissan PU E
2002 Oldsmobile Intrigue GX
"The hard part about playing chicken is knowing when to flinch" Scott Glenn in The Hunt for Red October
well...Nissan went ahead and removed all the heat shields. The mechanic was so sure this was the problem, I let 'em do it. Cost me 82.50 for the job - the car now rides nice and quiet (accept for the high pitch whirling/whistle sound from the baffle plates that only I can hear when driving). BTW, I had tested all heat-shield noise under all the diff. conditions and gears you asked and failed to mention that in my original post.
Hope I didn't really need those rusted heat shields!
Mike
(now on to baffle plates and if they are covered in my extended, after market warranty)
Nah you really don't need all of thos sheilds unless one of them was protecting a line/wire from the exhaust heat or the exhaust is close to something and in danger of bumpin against it on the road. The mechanic rpobly did think its was the problem because I'm sure he'd have much rather beeen doing something else other than getting rust and dirt from underneath all over him for $20-$30 labor.
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1,500 RPM rattle/winding sound
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