cham

This! Usually it’s the most pronounced when moving up a slight grade at neighborhood speeds (wind noise at a minimum and I’m in 1st or 2nd gear). That was how I discovered it in the first place was if obstructions were close to the edge of the road, I could hear the rattle sound bouncing off the obstruction. Now it’s obviously gotten loud enough to be heard otherwise. Why I initially was worried it could be timing components is that it basically goes away when everything is warm, I would think a heat shield rattle would happen all the time with the same intensity; apparently not the case. Like I said earlier, sometimes when starting a cold engine I’ll get a rattle in park for a split second and it’ll come and go but not frequently enough for me to be able to catch it quick enough. Hopefully the two rattles are related and it’ll get worse enough for me to pinpoint. Wish there was a way to determine it’s not timing components for certain though. Thanks for the insight everyone, I’ll definitely keep this thread posted when I find the source. If not I might take a trip to a mechanic. Should I expect them to be able to find it any better than I can?

I'll check the rocking of the engine when I shift into to Drive and Reverse but I don't believe it is anything out of the ordinary. I guess if it does seem to be the issue that'll solve the engine mount heat shielding issue because I can replace them at the same time. Any idea the kind of project it is to replace the mounts? Something interesting to note is the rattle can be heard while driving in 1st or 2nd at around 1750rpms when the vehicle is warming up but once its warmed up to operating temperature it seems to go away almost completely. If I shut it off and it sits for 5-10 minutes, then start the car again (already warmed up basically), it will start rattling again at 1750rpm for the next couple minutes of driving then stop again. I have not tried power-braking, little worried about the torque of the vehicle overcoming the brakes if I tried this; no trailer hitch so no dice. Is there any difference in revving the engine in neutral vs park? I should note when I tried revving in Park I only really went to 2000rpms as that is where the rattle is while driving; since there is no load applied, maybe the rattle wouldn't be evident until its higher in the revs possibly?

So I discovered or I should say realized the rattle about a year ago right before a trip to Colorado. I replaced my airbox filter a couple times during the trip just because of dusty conditions and did in fact clean my mass-air-flow sensor while I was out there with mass airflow cleaner. I noticed the rattling before the trip so it was not a consequence of the dusty conditions out there. I have since tried using Premium (Usually used Mid-grade or Regular) to see if that halted any rattle/knock since the other forum thread I mentioned earlier did suggest this. No change in the rattle, although I only tried this for one tank and I'm not sure if I need to try this for an extended period of time like a few weeks or so to let the ECM relearn. If it is engine knock and premium were to fix it; would the problem then be a failing knock sensor? Also I actually have a BlueDriver I bought to monitor coolant temps on long trips. It shows live fuel trim and timing advance data and I'm curious if I could just use that to see if it is in fact engine knock. The problem is I'm just not exactly sure how to conclude much from the data; I do realize the fuel trim percentages never get too far away from 0% when at a constant load or idle which I think means I'm not likely to have a vacuum leak or other ailment.

It seems that the only rattling I can find is just very slight rattles from my flicking on the shielding. Its unfortunate because the one in particular on the passenger side is the large shield between the exhaust and chassis/uni-body so I cannot wrap a hose clamp around that either. Thought for a second steel wool could be a good damper for the sound but realized quickly that it can catch fire fairly easily. Anyone know of some sort of material to wedge between the exhaust plates that will dampen rattle while being non-flammable? Maybe exhaust wrap would be the ticket. On top of that the engine mount exhaust shields rattle if I strike them but holding some sort of object against it, and then striking again nullifies the rattle. Just don't know how to stop something like that permanently not to mention how hard it is to reach them. Beyond that the catalytic shields seem fine and the manifold shields don't seem to rattle. I do get a slight rattle when idling from a cold engine that just seems to come and go randomly until the vehicle is fully warmed up, but the sound is no doubt a heat shielding rattle (not as bad as the rattle under load). I think I'll try starting the car and probing if I can induce any sort of continuous rattle from striking the shielding.

When you say engine mounts do you mean the literal bushings themselves rattling or the heat shielding covering the engine mounts?

I've been dealing with this nasty front end clattering for some time now and it's definitely in my best interest to start narrowing things down here in case it is the worst possibility. The realm of possibilities of course include; broken timing chain guides, accessory belt pulley bearings, exhaust shield rattle, and rattling honeycomb within cats. I guess you could include transmission but to me it sounds like its coming from the front of the vehicle and since its started, nothing has changed with the condition of my trans. It is a definite metallic clanking/rattling that happens between 1750 and 2000 rpm in 1st and 2nd for sure; by 3rd and 4th I'm going too fast to be able to hear if it happens then as well (so only under load; does not produce noise in Park). Now the heat shielding covering my engine mounts on both sides definitely rattle significantly when I strike them, not sure if they are the culprit but I guess it's possible. How might I go about securing them as hose clamps don't really work in this situation. Yes I have checked exhaust shielding underneath the car and the shielding between my passenger side resonator and the chassis is the only thing that rattles at all, and I have to hit it to rattle. Any ideas how I could narrow this down further; I saw another post with a similar situation but there was never a post on the discovered source. I'm thinking if this goes on too much longer I might just bring it by a dealership for a diagnosis but in some ways I'm not sure if I trust them to be thorough enough, I could see how it would be easy for them to recommend the most expensive job as I guess it's kind of subjective what is producing the sound.

In my personal opinion I find 31x10.5x15s to be the ideal tire size for our rigs. The sidewall ratio is more ideal for airing down offroad, not to mention proportionally it just looks better with 15s. Any bigger in tire size and in my opinion its a negative return of investment with the amount of supporting mods needed to accommodate. My factory wheels are of course hub centric and lug centric so I was actually going to use some WD21 15x7 lego wheels since they have the same hub bore and some hub-centric/lug-centric Bora spacers to get them to clear the caliper. I've since changed my mind simply because of the amount of moving parts needed to make it work. In addition I think I will be changing platforms here sometime soon so no sense in doing trimming to a factory rig. For anyone interested in the future, there was another user "bushnut" who did this exact setup. He used hardbody lego wheels with 31x10.5x5 tires and 1.25" wheel spacers to clear his 2000 facelift Calipers. Not sure if there was another alteration of caliper size between 2000 and onward but personally I think 1.5" or 1.75" spacers would look a little better anyway. For reference, that would get you in the realm of 4.5"-4.25" of backspacing with a regular 15x8 steel wheel.

Anyone know if you can use Mag Shank nut wheels on an originally Acorn/conical vehicle? Are the nuts for the Lego wheels M12x1.25? Pretty sure the torque specs are the same at 100ft/lbs.

Curious if anyone has got a set of the 15x7 tri-spoke Lego wheels they’d be willing to part with. I’m on the east coast, cheers.

For anyone interested I'll share my current situation and experience for any others who happen across this thread. I picked up the wheels I had been looking into; unfortunately the buyer did not know the brand or backspacing/offset. Turns out they were 4" backspacing 15x8 black D hole steel wheels. The more I looked into it I found that CT&W was inscribed on the wheel which is the manufacturer for Cragar wheels. I called up Cragar and confirmed these were in fact theirs but their D hole design is essentially identical to other brands. After test fitting the wheel, it very narrowly missed the front calipers. I mean very narrowly. I'd guess it has a clearance of 2mm at best and this is with three year old pads. New pads would definitely rub; in my opinion it's not worth it. I'll more than likely be going a different route now as 3.75" backspacing will probably create to much fender rub in the front and the look is not quite my taste. I mention this because I figure most all D-hole steel 15x8 wheels will run into this issue and I'm assuming the similarly designed Soft 8 wheels. If you're thinking about going this route in the future; stick to 3.75" backspacing for 15x8 steelies or go up to 16s and have fun with the backspacing. If you found aluminum wheels in a 15x8 with a semi-large offset they'll actually probably work because it's the recess in the steel wheel around its circumference that causes the issue; most alloy wheels don't incorporate this into the design.

I think that is a fair statement, especially since I do take my vehicle on trails in the backcountry. If it has 4" of backspacing or less I'll probably take them since I've seen success from people with those numbers. Also I'll check fitment and if it rubs at all, then I'll probably move on. If it doesn't that's a plus and in combination with grinding a little more material off the caliper I'm guessing that sort of clearance is acceptable. I did read on another post what you mention about caliper pads altering clearance; 15" wheels just look ideal with 31" tires ugh.

I'm looking at a set of 15x8 D-hole steel wheels but the seller doesn't remember the backspacing. I could not find any definitive answers on what offset/backspacing would prevent the wheel from rubbing the calipers of a facelift Pathfinder. I'm curious if anyone knows the limit of offset that will work for my 2002. Sounds like for 8" wheels, 3.75" backspacing has always worked. It also seems that 4" should work as well. What about 4.25" or 4.5", anyone tried it? I'll try to measure it while I'm there. I think I'm going to bring a floor jack too and check fitment at the sellers place before I leave. I know you can grind the caliper down a little so how much rubbing is okay?

The go to aftermarket stance is an 8" width wheel with 3.75" backspacing or -19mm offset and a 10.5" wide tire. That will give you some poke for sure though. If you want the very edge of the tire flush with the top of the fender flares; an 8" wide wheel with a 4.25" backspacing (-6 offset) is perfect for a 10.5" wide tire. For that backspacing you will need a 16" or larger wheel otherwise the wheel will likely rub on the calipers of a facelift Pathy. My opinion is that an 8" wide wheel with 4" backspacing (-12 offset) is the best looking for a 10.5" tire (very slight poke). You'll be able to run 15" wheels for that setup too. Your tires will probably tuck better offroad though with the 4.25" backspacing setup, but since you will be using spacers I wouldn't worry about that too much.

Just thought I'd update this post again for any future sleuthers who come across the same problem. Two and a half years later and the issue was never resolved. I actually had a shop go ahead and replace the bearings and races again with no improvement. Took a look at the axle spindle one day and I'm 99% sure the spindle itself is worn to the point of increasing tolerances and allowing clearance even with a seated bearing. I wouldn't be surprised if the internal mating surfaces between the hub and bearing race are also slightly warped. My guess is riding on the original failed wheel bearing for two long created enough excess heat to warp/damage and wear into the spindle. Either that or there was considerable play for a long time causing wear. At this point replacing the spindles and hub assembly is not realistic for this vehicle and its age.

Was sitting in a drive through today when randomly my RPMs started to surge and held a constant 1000RPM (vehicle in Drive and foot on brake); shifted it into park and the RPMs went up to a constant 1500RPM. This lasted about 5-8 minutes and then randomly they just decided to come back down to normal conditions. I literally was planning on replacing the IACV gaskets and coolant hoses tomorrow as preventative maintenance, and I've never had any problems with idle so this was new to me. If anyone can weigh in here, does this sound like a soon to be failing IACV? No codes to speak of. I will say the temperatures here in VA shot up today comparatively to previous weeks.

@Mr_Reverse Are the red and blue circled hoses in the attached photo the correct rubber hoses you are referring to that leak? Yes I do have the drive by cable operated throttle body. Edit: Just realized I do not have that hose circled in blue, just the red hose since mine is a 2002 and not a 2001 like in the video. Should I also go ahead and replace the hoses going to the IACV body at the green and yellow circled locations? Lastly, is there any chance the throttle-body/intake gasket (16293M) might leak coolant onto the solenoid? I’m assuming coolant doesn’t come into contact there but just to clarify I’m curious. @lookingatyou2013 When you mention the preformed O-ring type gasket that you replaced are you referring to (16076M) or (16076MA) from the diagram above in my past replies? Sent from my iPhone using Tapatalk

This'll be a quick inquiry. Installed the 2922 OME springs in the rear of my Pathfinder recently and noticed the bottom side of the coil doesn't rest directly on the lower perch of the axle. There is a very slight gap I'm assuming because the coil end is ground flat instead of being round like the original factory coils. I rotated the coils on both sides of the vehicle so that the closed cut ends face the front of the vehicle. Am I missing some positioning step to prevent this from happening; is it a problem that will worsen if gone unaddressed? In the pictures you can see the slight gap between the bottom flat side of the coil and the surface of the perch where they should be mating flush (what a pain to get these photos attached).

I’ve got a 2002 that needs replacement rear coils as it’s sagging. I imagine with my addition of a roof basket and bed platform system in the back, the medium duty springs won’t add too much height over stock which is my goal. Curious if anyone has any spares lying around for whatever reason. Let me know if you’d be interested in shipping to Virginia depending where you’re based, cheers!

Based on this guy's video, a seal fails internally it sounds like and shorts the motor out. From what he says this comes from the coolant passage flowing through the IACV, but you seem to think that is not the case. So you are saying it comes from an external leak that drips onto the motor itself? Can you identify the culprit hoses within the video? Are they visible within the video? Based on this schematic I would guess the guy in the video is referencing that o-ring seal (16076MA) between the IACV motor and the rest of the part body. I always thought, and maybe others as well, it was the gasket connecting the entire IACV unit to the throttle-body that failed (16076M). If anyone can confirm or deny any of my assumptions, that would be greatly appreciated. I'm also trying to prevent this from happening in the first place as I can find myself in some pretty desolate places where peace of mind is a beautiful thing.

I cannot seem to find a definitive answer for the exact cause of this and how to prevent it. There is mention of bypassing coolant passageways near the throttle-body which I cannot seem to follow. It's hard to tell based on posts whether the consensus is a seal internally failing within the IACV, the gasket mating the IACV unit to the throttle-body failing, or external coolant lines above the IACV motor that leak and drip coolant onto the motor itself. What would be a sound attempt at preventing this engineering wonder from happening? Replacing the IACV main gasket and unit? I'll be changing sparkplugs soon so this would be something to do while I'm in there.

Finally got around to replacing the front shaft u joints with those 5-3218x spicer joints. With the joints finally in, the caps in the yoke closest to the engine side were the only caps still semi-stiff when the shaft was put back into the vehicle. The rest I was able to bang into submission (meaning the other 6 out of 8 caps). Now there is a noticeable driveline rumble that starts around 55 or 60 mph and increases all the way to about 70 or 75. Still have not done enough driving to see yet but this kind of sucks since my trip coming up will be at those speeds exclusively. I’m wondering if it’s from those semi-stiff caps on the yoke or if I ever so slightly bent the yoke ears when banging on them. The driveshaft itself seemed to be in great condition with no missing balancing weights. I put the shaft back in exactly how it came out (can’t say that for the driveshaft bolts though). Marked everything prior to disassembly. So my question then is, at what point is a driveline vibration bad enough that it will rapidly damage the components it’s attached to? Also it’s only been a couple days and I’m wondering if driving on them will loosen the caps and help them settle over time, causing the vibration to settle as well. Is that a possibility? Sent from my iPhone using Tapatalk

I can certainly understand the thinking behind increased tolerances and its ability to fill that clearance. I guess because of the greater film thickness and shorter temporary shear the higher weight makes sense. What you mention about synthetic oil kind of makes sense as I previously mentioned that I can trace the worsening of the gasket back to when I switched to a Valvoline Synthetic Blend 5w-30. I was always told that its kind of a myth that synthetic fluids cause leaks but I think what is really going on is they expose leaks and seals being held together by sludge. Regardless, if/when I switch to 10w-40, should I continue to use a synthetic blend or switch back to conventional would you think? Also would there be any difference in leak rate between 5w-30 and 10w-30? Because it seems that most of the leak occurs during driving when things are already hot, 10w-30 would act the same or am I missing on a molecular level?

I'm a little apprehensive about changing the oil weight on an older vehicle that's worn with the factory weight all these years. I do see that the manual actually does mention 10W-40 as a possible option if the ambient temp is over 0 degF. Maybe something to try; should I be worried about causing any damage by switch weights at basically 200k? Something to note is I do smell burning oil after almost every drive, even some shorter ones. Never smell it in the cab though and I never see smoke either so I'm guessing its on its way to being a larger issue but not currently.

Thanks for the info, I thought as much. Should I not expect a “low oil pressure” light anytime soon? Is that pretty much only when the gaskets totally give way and provide no resistance? Would taking off just the upper plenum give me a larger amount of room to work with in getting at that PCV valve? I am currently using high mileage oil as well. I wonder if using a gasket swelling agent (stop-oil leak) in tandem with snugging the valve cover fasteners would be a good attempt. I’ve heard though its a 50-50 chance at causing a worse leak or helping. I have also heard about those sources of oil consumption as well. The bore taper would make sense and I’ve also heard something about the cats as well. I think if I remember correctly they are too close to the manifold; don’t quote me on that. I think naturally due to the engine being new for those model years, the kinks no doubt had not been ironed out. Is that oil cooler seal just behind the steering rack above the front axle? I think I’ve heard of that one before.

I'm gearing up for a long trip and have been slowly getting things in order in terms of maintenance. I made a recent post about my front drive-shaft and still have yet to get that sorted; of course I find another issue that seems to be more of a priority now. My valve covers have been leaking for quite some time but within the past year I've noticed it getting worse. I actually might be able to trace it back to when I switched from 10w-30 to a 5w-30 synthetic blend. More recently it has increased in frequency. Regardless, it's gotten to the point that I'm loosing about a quart every two weeks at best. Now this is somewhat manageable but my biggest concern is that both banks are leaking on either exhaust manifold. In a 24 hour period there isn't really much accumulation at all on the ground though when parked (few drops). I can certainly smell the burning rubber stench after most drives. This makes me think the system being pressurized when driving is what's pushing most of the oil out. So my main question is at what point does a valve cover leak of this nature become a fire hazard? Does there have to be large quantities over a very short period of time, or is any burning smell a huge concern? The shop I frequent knew about this and didn't sound too concerned over it. In addition I definitely don't see any smoke coming from the engine bay or behind me in the rear view mirror. I'm afraid that on a 1,500 mile drive though from everything getting hot, this would only be exacerbated. Is it as simple as carrying a fire extinguisher but I shouldn't have to use it, or is it more of a toss up situation? Lastly, I've looked into the fix and it seemingly is quite the endeavor. Since my pathy has the plastic valve covers, everyone on here seems to have the consensus that if you're replacing the gasket, replace the valve covers as well (as we all know their tube seals are not serviceable). There is also mention of warping at older age as another reason to replace. That also doesn't include the "while you're in there" cost as well. Sparkplugs, pcv, plethora of hoses and gaskets, knock sensor; I've heard people saying to not only replace the IACV gasket but also the IACV itself. The problem is I just don't see myself keeping this vehicle much longer and this couldn't happen at a more inconvenient time of course. My options it seems are pretty limited and I'm curious if anyone has tried those oil-stop leak snake oil products to any effect. I'm also worried my pcv valve could be stuck in an almost closed position creating this newfound loss of oil. Otherwise, any other fix besides replacing it is an exercise in futility. It's funny, I find myself dreaming about having the older pre-facelift models with the 3.3 now probably because of their better reliability. They tend to catch my eye more often on the road now as well. Let me know of your experience and if I'm overlooking any other possibilities, thanks a bunch.