...and then the Engine (VG30E) work 1992 Pathfinder SE info, details, advice.

[92SEPathFindr]

What's good ya'll?  Aside from the Axle and Suspension repairs my Pathfinder needs and a from a different post: 

 

The 1992 Pathfinder SE 4WD 5 Speed Manual probably (sooner or later) need engine work, valve/lifter/rings, ...not sure??

There is a noisy tick and a irregular "pop" exhaust "backfire".  I suppose I can post a video to youtube and a link if you think this may help considerably? 

An experienced mechanic at the local wrecking yard recently listened to the noise(s) with a stethoscope tool and concluded "it was in the top end" of the engine. 

So, maybe this could be fixed with a valve job?  Maybe a replacement "Head" unit?  I just don't know... rather than a REBUILD or REPLACE?  

 

I asked them about the "low milage" Japanese import replacement engines and they think those are actual crap unless you're really, really lucky...    

This engine will probably need a rebuilder/machine shop and I know of three or four in my area (Riverside County, CA) that seem highly qualified with great reviews and I plan to take the Nissan to in the real near future.  Any recommended shop(s) or machine shops you know? San Diego, Riverside, San Bernardino County, CA?

 

At first thought, it makes more sense to me to have my engine rebuilt, valves, head, lifters, crankshaft???  Or purchase a reman/rebuilt engine with a warranty $2-4K.  I asked fraserengineco dot com and they don't do the VG30E nor have the "tools" for it.  There's another company possible powertrainproducts dot net that may be a source.  And another, ATK Engines Remanufactured Crate Engine for 1987-1992 Nissan & Infinity with 3.0L V6 VG30E. 

Anyone know a good company to buy a rebuilt/reman engine who ship to a nearby shop for install/core, etc?  Anyone have other recommended options, possibilities, etc, advice.    

Side note: I don't think going to a different size (VG33) will work with the goddamn California smog rules. 

Thanks for you input and take care out there.  Aaron 

 

https://imgur.com/gallery/QcdhZQz engine photos post here on imgur

 

 

 

 

[92SEPathFindr]

Hey friends, I made a YouTube video featuring the current VG30E Engine noises on my 1992 Pathfinder SE 4WD.  These noises may indicate something in particular to the trained ear and I'm trying to determine what 1) may be the cause(s), 2) how serious is this, and 3) what type of mechanic shop job would fix this?  The Nissan dealer estimated close to 5K to have this engine rebuilt or replaced with a "low miles (180K)" used engine.  Maybe I can wait years for this job and save up money until then or maybe in the meantime have a rebuilt engine ordered (estimated 3-4.5K).  Thanks for your advice.  I continue to look for a quality mechanic with fair pricing in Riverside County CA and or a quality machine shop/ engine builder in San Diego, San Bernardino, or Riverside Counties, CA.  If and when I do this work, I want it to be the last time. 

Thanks and best regards, Aaron  

 

[Frenchy]

So from listening to the sound on the video I am wondering if this is actually rod knock or an exhaust leak at the manifolds due to manifold bolts breaking off(yes the VG30's had this happen quite often). Best way to check the manifold studs is to remove the heat shields and inspect. Spray a penatrating lube and let it soak before removing the bolts so they dont break.

Edited April 24, 2023 by Frenchy

[92SEPathFindr]

11 hours ago, Frenchy said:

So from listening to the sound on the video I am wondering if this is actually rod knock or an exhaust leak at the manifolds due to manifold bolts breaking off(yes the VG30's had this happen quite often). Best way to check the manifold studs is to remove the heat shields and inspect. Spray a penatrating lube and let it soak before removing the bolts so they dont break.

Thanks Frenchy, a couple of mechanics listening in person recently were also thinking about exhaust leak or leaks along with the knocking, tapping noise.  The tapping does seem legit inside the engine.  The main noise problem is separate from exhaust I'm nearly certain.  Last year or maybe 1.5 yrs ago the clutch was replaced and the shop removed and replaced the exhaust manifolds.  This doesn't mean they fixed a leak though, lol.  When the engine get's hotter than in the video there is also a single random pop/ backfire noise that happens maybe every 30-45 seconds.  IIRC, Nissan dealer near me was suggesting that the main issue may be a crankshaft bearing and about $4500 is needed for them to correct it.  I appreciate your input, ...thanks!    

[Strato_54]

That sounds pretty metallic. I don't think that would be coming from the manifold. The sound has a really solid ring to it, manifold leaks don't have that type of ring. How does your oil filter look?

 

edit: it seems louder on the driver side, maybe its head related?

Edited April 24, 2023 by Strato_54

[Slartibartfast]

Is it losing oil or coolant? Is the noise louder under load, right after startup, or when the engine is cold?

 

The exhaust popping has me thinking you might have a valvetrain issue, possibly a valve hanging up. I would be tempted to try a Berryman's or Seafoam intake treatment on it, see if that cleans up some crud from the offending valve stem and gets it moving properly again. Maybe add a little ATF to the oil to clean it out from the inside, without the risk of dislodging an oil-passage-clogging glob of schmoo with a harsher crankcase flush. You could also remove the valve cover and dig around for anything obviously visually wrong, but that's a bit of an undertaking on the driver's side because of how the plenum lays over the driver's side head.

 

These are known for exhaust studs snapping and causing leaks at the manifold. Mine's got at least one busted stud and has leaked there for at least as long as I've had it. It mostly makes noise when it's cold and/or under load. If your noise is consistent regardless of engine temp or load, then I doubt it's an exhaust leak. And, yeah, hopefully the last guys who had it apart last used better-quality studs than Nissan did. That said, exhaust leaks can be deceptive. My friend installed an exhaust manifold gasket backwards in his Blazer once, and it sounded like a much more expensive problem than it ended up being. I thought it had a collapsed lifter until I noticed the gasket was sticking out where it shouldn't have been. 

 

I also doubt it's the bottom end, but you can test that by unplugging each spark plug lead, one at a time, with the engine running. No spark means no fire, which means much less load on the bottom end. So if you pull a plug lead, and the noise stops, then you know it's bottom end, and you know which cylinder has the problem. This helped my dad diagnose a bottom end issue in his friend's Triumph (which turned out to be a bad small-end conrod bearing). This is also an easy way to zap yourself on the ignition system, so, fair warning there.

 

If you track the noise to one cylinder head, and the snake oil doesn't clear it up, you could just pull the one bad head and either swap it for a used/reman head, or take the old head to a machine shop to see if they can sort it out. Rockauto lists reman heads, looks like they only have the passenger's side in stock though. Swapping a head is a fairly major engine surgery, but I'd expect it to be cheaper and easier than replacing the whole engine.

[92SEPathFindr]

On 4/24/2023 at 4:52 PM, Strato_54 said:

That sounds pretty metallic. I don't think that would be coming from the manifold. The sound has a really solid ring to it, manifold leaks don't have that type of ring. How does your oil filter look?  It seems louder on the driver side, maybe its head related?  

Thanks for your feedback Strato_54! Really sounds metallic to me too, like a couple tiny hammers in there clanking along the wall of the block and YES more noticeable on the driver's side.  It's been suggested that it may be a camshaft bearing?  if it's a camshaft bearing, i'm wondering if that entails a full rebuild or a rebuilt head unit?  I don't know obviously yet it's been like this for getting close to 2 years (and 2 years of me driving the Pathfinder very little).  I'm adding a new video which is a Cold Start and more info.  Thank you again, cheers.  Aaron  

[92SEPathFindr]

On 4/24/2023 at 9:32 PM, Slartibartfast said:

Is it losing oil or coolant? Is the noise louder under load, right after startup, or when the engine is cold?

 

The exhaust popping has me thinking you might have a valvetrain issue, possibly a valve hanging up. I would be tempted to try a Berryman's or Seafoam intake treatment on it, see if that cleans up some crud from the offending valve stem and gets it moving properly again. Maybe add a little ATF to the oil to clean it out from the inside, without the risk of dislodging an oil-passage-clogging glob of schmoo with a harsher crankcase flush. You could also remove the valve cover and dig around for anything obviously visually wrong, but that's a bit of an undertaking on the driver's side because of how the plenum lays over the driver's side head.

 

These are known for exhaust studs snapping and causing leaks at the manifold. Mine's got at least one busted stud and has leaked there for at least as long as I've had it. It mostly makes noise when it's cold and/or under load. If your noise is consistent regardless of engine temp or load, then I doubt it's an exhaust leak. And, yeah, hopefully the last guys who had it apart last used better-quality studs than Nissan did. That said, exhaust leaks can be deceptive. My friend installed an exhaust manifold gasket backwards in his Blazer once, and it sounded like a much more expensive problem than it ended up being. I thought it had a collapsed lifter until I noticed the gasket was sticking out where it shouldn't have been. 

 

I also doubt it's the bottom end, but you can test that by unplugging each spark plug lead, one at a time, with the engine running. No spark means no fire, which means much less load on the bottom end. So if you pull a plug lead, and the noise stops, then you know it's bottom end, and you know which cylinder has the problem. This helped my dad diagnose a bottom end issue in his friend's Triumph (which turned out to be a bad small-end conrod bearing). This is also an easy way to zap yourself on the ignition system, so, fair warning there.

 

If you track the noise to one cylinder head, and the snake oil doesn't clear it up, you could just pull the one bad head and either swap it for a used/reman head, or take the old head to a machine shop to see if they can sort it out. Rockauto lists reman heads, looks like they only have the passenger's side in stock though. Swapping a head is a fairly major engine surgery, but I'd expect it to be cheaper and easier than replacing the whole engine.

Thanks so much Slartibartfast, I'm adding another video in I'm answered some of your questions...  I'm going to look over your messages more thoroughly next.  Much appreciate your feedback, your help.  Thanks again!!  

 

[92SEPathFindr]

On 4/24/2023 at 9:32 PM, Slartibartfast said:

Is it losing oil or coolant? No water loss whatsoever and good antifreeze h20 mix.  Oil loss is minimal, just a very small seep on the driver's side valve cover, no noteable loss. Is the noise louder under load?  Seems the same under load, right after startup, and when the engine is cold?  After the engine is hottest and been running quite a while, the popping starts infrequently.  Every so often ...pop, just one, pop.  

 

The exhaust popping has me thinking you might have a valvetrain issue, possibly a valve hanging up. I would be tempted to try a Berryman's or Seafoam intake treatment on it, see if that cleans up some crud from the offending valve stem and gets it moving properly again. Maybe add a little ATF to the oil to clean it out from the inside, without the risk of dislodging an oil-passage-clogging glob of schmoo with a harsher crankcase flush. You could also remove the valve cover and dig around for anything obviously visually wrong, but that's a bit of an undertaking on the driver's side because of how the plenum lays over the driver's side head. 

 

I believe I have run about every recommended crud buster protocol, including Seafoam, BG EPR & MOA, heavier grade Lucas Oil, repeated oil filter changes, Marvel Magic Mystery oil to oil and fuel, and Lucas Oil fuel system deep cleaner, others.  I always went back to change filter and fill oil with what I use now, Castrol Edge 5W-30, full synthetic.  Maybe the new video will be informative, let me know.   

 

These are known for exhaust studs snapping and causing leaks at the manifold. Mine's got at least one busted stud and has leaked there for at least as long as I've had it. It mostly makes noise when it's cold and/or under load. If your noise is consistent regardless of engine temp or load, then I doubt it's an exhaust leak. And, yeah, hopefully the last guys who had it apart last used better-quality studs than Nissan did. That said, exhaust leaks can be deceptive. My friend installed an exhaust manifold gasket backwards in his Blazer once, and it sounded like a much more expensive problem than it ended up being. I thought it had a collapsed lifter until I noticed the gasket was sticking out where it shouldn't have been. 

When the last shop did the clutch, I believe they had to work on the studs and put a new gasket although it still sounds like there may be a issue there.  Or maybe the catalytic converter has loose inner pieces.  It has past smog so I'm not bitchin about that.  A new CA approved CAT is $900+/- plus install...  ugh... 

 

I also doubt it's the bottom end, but you can test that by unplugging each spark plug lead, one at a time, with the engine running. No spark means no fire, which means much less load on the bottom end. So if you pull a plug lead, and the noise stops, then you know it's bottom end, and you know which cylinder has the problem. This helped my dad diagnose a bottom end issue in his friend's Triumph (which turned out to be a bad small-end conrod bearing). This is also an easy way to zap yourself on the ignition system, so, fair warning there. 

 

Haha,  oh okay interesting.  Yeah, any thoughts on the fuel injectors being faulty or getting old?  I see replacement (aftermarkets sets) for about $70, probably unrelated I imagine though.     

 

If you track the noise to one cylinder head, and the snake oil doesn't clear it up, you could just pull the one bad head and either swap it for a used/reman head, or take the old head to a machine shop to see if they can sort it out. Rockauto lists reman heads, looks like they only have the passenger's side in stock though. Swapping a head is a fairly major engine surgery, but I'd expect it to be cheaper and easier than replacing the whole engine.  

 

There are three reputable Engine Builder companies with about 1/2hr from me and I haven't gone to them yet to get an idea from them.  I think that's the next drive.  The Nissan has basically been a driveway queen for almost two years since the clutch was redone because of this noise, engine issue, and because i haven't been able to just throw a bunch of money at it at once.  I've been saving though to get it done and I need to soon.  Hey, thanks again for all the help, cheers  Aaron 

 

[Slartibartfast]

In Mr. 510's VG34 build thread, he found that a camshaft retainer bolt had somehow backed out and allowed the cam to walk forward, which he figured was the cause of the weird tick he'd been hearing. Something to look for when you get the valve cover off. I don't know that this would explain the popping, but if the cam journal is gnawing on the lifter, maybe that could be hanging up the valve and intermittently preventing it from closing properly, causing what I assume is a backfire.

 

Only popping when it's heat soaked still has me thinking it's got a sticky valve, but that's not a failure I've chased before so I don't know how common/likely it would be, and I don't know that it would explain the racket in the video. Too bad the snake oil didn't help. If you suspect the injectors, check the spark plugs, see if they're all about the same color on the business end. (The #6 plug is a notorious PITA, but is possible to remove with the right combination of extension/U joint/swearing, or the factory tool kit that may still be under your back seat. Blow out around them first if you can, dirt and mouse crap tend to settle in there.) If they all look about the same, I doubt it's the injectors. Wouldn't explain the tapping, either. If you do need an injector, avoid the cheap ones. Cuong Nguyen tried some and wasn't impressed. Black soot could be leaky injectors, but it could also be a bad temp sensor telling the computer it's colder outside than it is. Condensation on cold starts is normal.

 

I doubt it's the cat. The cat on my friend's Blazer failed and all it did was rattle. We cut it open after replacing it and found that the honeycomb had broken free of the can, bounced around inside, and gradually beat itself smaller so it rattled more and more. I don't think it ever threw a code, it just sounded like something was gonna fall off.

 

Long shot, when it's running, try pressing on that heat shield over the exhaust manifold with a long screwdriver or prybar. If the noise suddenly stops, the heat shield is loose. It doesn't sound like a heat shield to me, but they can make a hell of a racket when they break loose. I once drove back from the coast convinced that something in the drivetrain was about to fail, only to discover that I had a loose exhaust clamp. Wasn't nearly as regular as your noise, though, and didn't match engine RPM like yours is doing.

 

Long shot, have you tried running it with the drive belts off? Not for long (it'll overheat if run too long with no water pump), but if you crank it up and the noise is gone, could be a bearing going. My alt sounded pretty ominous when it started to go. Your noise sure does sound like it's in the engine, but it doesn't hurt to rule out the cheap stuff first.

[92SEPathFindr]

7 hours ago, Slartibartfast said:

In Mr. 510's VG34 build thread, he found that a camshaft retainer bolt had somehow backed out and allowed the cam to walk forward, which he figured was the cause of the weird tick he'd been hearing. Something to look for when you get the valve cover off. I don't know that this would explain the popping, but if the cam journal is gnawing on the lifter, maybe that could be hanging up the valve and intermittently preventing it from closing properly, causing what I assume is a backfire.

 

Only popping when it's heat soaked still has me thinking it's got a sticky valve, but that's not a failure I've chased before so I don't know how common/likely it would be, and I don't know that it would explain the racket in the video. Too bad the snake oil didn't help. If you suspect the injectors, check the spark plugs, see if they're all about the same color on the business end. (The #6 plug is a notorious PITA, but is possible to remove with the right combination of extension/U joint/swearing, or the factory tool kit that may still be under your back seat. Blow out around them first if you can, dirt and mouse crap tend to settle in there.) If they all look about the same, I doubt it's the injectors. Wouldn't explain the tapping, either. If you do need an injector, avoid the cheap ones. Cuong Nguyen tried some and wasn't impressed. Black soot could be leaky injectors, but it could also be a bad temp sensor telling the computer it's colder outside than it is. Condensation on cold starts is normal.

 

I doubt it's the cat. The cat on my friend's Blazer failed and all it did was rattle. We cut it open after replacing it and found that the honeycomb had broken free of the can, bounced around inside, and gradually beat itself smaller so it rattled more and more. I don't think it ever threw a code, it just sounded like something was gonna fall off.

 

Long shot, when it's running, try pressing on that heat shield over the exhaust manifold with a long screwdriver or prybar. If the noise suddenly stops, the heat shield is loose. It doesn't sound like a heat shield to me, but they can make a hell of a racket when they break loose. I once drove back from the coast convinced that something in the drivetrain was about to fail, only to discover that I had a loose exhaust clamp. Wasn't nearly as regular as your noise, though, and didn't match engine RPM like yours is doing.

 

Long shot, have you tried running it with the drive belts off? Not for long (it'll overheat if run too long with no water pump), but if you crank it up and the noise is gone, could be a bearing going. My alt sounded pretty ominous when it started to go. Your noise sure does sound like it's in the engine, but it doesn't hurt to rule out the cheap stuff first.

Hey Startibartfast, camshaft retainer sounds like it could be it ...time will tell indeed.  "The #6 plug is a notorious PITA, but is possible to remove with the right combination of extension/U joint/swearing, or the factory tool kit that may still be under your back seat?"  Haha, I'm going to check that kit!!  I had a shop not to long ago do the plugs, wires, distributor cap and they then also ran the smog check and it passed then.  These last years have really BLOWN past so this may have been in late 2020.  AS far as I know and I would guess the injectors are factory issue.  I have heard from another mechanic that, yeah, the cheap injectors are hit or miss....sucks! 

I appreciate the links, very interesting. 

I'll try the prybar on the heat shield.  Regarding deeper diagnosing like removing the drive belts, I think that will hopefully be done by the shop that swaps in a rebuilt motor or if they do the rebuilding...  I'll probably drive the Nissan to these three local Engine builder companies and see what they agree on.  Doing the Axles and Suspension work type repairs are within my level of comfortable work.  I'll update the posts with what I learn and as things go along.  Thanks so much for your ideas and experience.  

Best regards, Aaron

[92SEPathFindr]

8 hours ago, Slartibartfast said:

In Mr. 510's VG34 build thread, he found that a camshaft retainer bolt had somehow backed out and allowed the cam to walk forward, which he figured was the cause of the weird tick he'd been hearing.

Oh snap, Mr. 510's work is so impressive!!  Crazy skillful!  Thanks Slartibartfast.  

[Slartibartfast]

No worries! And yeah, that's a hell of a writeup.

[gamellott]

My rig would occasionally make that exact sound on start up. When I replaced the head gaskets, I found one lifter had a cleaved face on it, so I replaced it. Since then, the sound has not recurred. 

 

My bet, if you tear it down to the valve covers, you'll find a smoking gun there with the noise. A bad rod bearing is more of a knock

 

As far as backfiring, it would make sense to me that you probably have an injector issue. I had a slight misfire for the longest time, mostly audible at the tailpipe more than anywhere else. Eventually, the culprits outright failed. After replacing the failed injectors, the misfire completely went away and some amount of power was gained in the process. 

 

If you can identify a possible single failed/failing injector, the perfect time to replace it would be when the upper intake is off. 

[92SEPathFindr]

(Copied from my axle post) Well friends, I have really appreciated all your feedback and tips and advice. Yet the bad news is my 92SE still sits without any of the work being done.  Even with your encouragement and tips, I haven’t made the jump to do what I can handle and so nothing has been worked on yet.  I took the pathfinder up to a big local shop and they looked it over.  My need was to have the front axles replaced and then I added that any suspension/bushings that needed to be replaced would also be good to have.  There must be a fun phrase in the mechanic’s world for, “yeah, we’ll do it and you’ll REALLY pay a pretty penny too or you can take it somewhere else!!”  The shop quoted $5600 for axles, control arms, ball joints, steering gear, valve cover gasket, tie rods, idler arm, and center link parts and labor.  None of this would touch the VG30E engine knock/ probably bearing issue.  So, for now the 1992 sits again…. Maybe I’ll sell it, maybe I’ll find a way to do most of the work I can when we move to a larger yard.  Not sure about the future for the 92..  in the meantime at an auction I picked up a 2004 Nissan R50 which also needs an axle boot and some suspension work but pretty much everything else is working and in good repair.  So thank y’all again very much and here’s to the new and old pathfinders out there surviving!  
best regards, Aaron