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VG30E Spark Plugs Stuck


Albeitt
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I was getting ready for a compression test so I can diagnose some issues with my VG30E when I came across an issue with the spark plugs.

 

Spark plugs 1, 3, and 5 (passenger side) were a breeze to remove (though it appears that #5 wasn't in all the way?).

 

I hit a wall with spark plugs 2, 4, and 6. They refuse to come out, so I'm thinking either the previous owner stripped them because they're a PITA to access, or they're just seized because of my coolant burning issue that I already know I have.

 

Any suggestions for removal? I've currently got WD40 (yes I know, but it's all I had) sitting on the threads as good as I can do considering the accessibility issues. I'll be trying again soon, but if that still doesn't work, what else can I do? They've loosened a bit, but are now stuck. 

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WD40's better than nothing. If they loosened a little, try tightening them again, see if working them back and forth (with plenty of WD) will loosen them up. Also blow out around them if you can, the plug wells like to fill up with crap.

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Most of the time I've found they weren't stuck, but there is a lot of crap in the plug wells preventing the socket from seating properly. Actually I'd say 100% of the time that's what it is. I've never had a seized plug in a VG.

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7 hours ago, Slartibartfast said:

WD40's better than nothing. If they loosened a little, try tightening them again, see if working them back and forth (with plenty of WD) will loosen them up. Also blow out around them if you can, the plug wells like to fill up with crap.

 

4 hours ago, adamzan said:

Most of the time I've found they weren't stuck, but there is a lot of crap in the plug wells preventing the socket from seating properly. Actually I'd say 100% of the time that's what it is. I've never had a seized plug in a VG.

Yup, it's definitely a bunch of crap and grease and stuff. WD40 is slowly working and I've also got some liquid wrench that I'll try. There's no way I would've been able to clean them out either. It's pretty grungy 

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  • 2 years later...

I was recently given a 1995 Pathfinder XE. Sat for 11 years, has 210K on a broken odometer. The free Pathfinder has cost me $1500.00 in parts, and at least 40 hours labor already. It drives good, but needs a ton of maintenance. I was replacing the timing belt ( on principal), came to find out it didnt need it. The L shaped water hose  behind it I replaced on principle. The aluminum housing it connects to had a hole corroded in it where hose attaches. I sprayed water into the wrong orifice when cleaning the cooling system.!!  Big mistake.  Filled a cylinder with water through an open valve which I discovered when trying to turn the engine over by hand.  ( By hand thank god. ) I removed the intake housing to access the three spark plugs from hell on the driver side of the engine. I dont see how anyone could change these plugs without getting grit in the spark plug holes and or cross threading the plugs. A hellish design when it comes to maintenance. I chose to remove this intake, which was  the most difficult job I have ever performed on any vehicle. More hoses and sensors than you can believe, and some of the hoses are damn near impossible to access. Putting it back together is not going to be any easier. After removal, I vaacumed around the plugs, blew dirt, vaacumed, blew, removed plugs, and blew the water out of all plug holes. I then put about 3 ounces of oil in each, and rotated the engine 2 x 360 degrees. I then blew out the oil of all 6 cylinders, rotated 90 degrees, blew out all 6, etc., until I had rotated 360 degrees. I then re inserted spark plugs. I then took a shower to get the oil out of my hair and face and entire body. The plugs were more worn than any I have ever seen. Car ran fine though! I may replace with irridium plugs because I will never touch another 95 V-6 spark plug again after I finish this job. I will eventually finish repair on this SOB, but I made a lot of mistakes, and learned a lot on this job.  A word of advice, if you replace the plugs on one of these, set aside  LOT of time to clean around the plugs, and to get the new ones in without cross threading. The "funnel" shape of the plug holes and the fact they are horizontal guarantees they are full of sand and dirt.  What a nightmare.

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The plug wells are supposed to drain into the area under the lower manifold, but the drain is usually blocked with casting flash that they couldn't be bothered to clean out. I cleaned mine up a bit when I had my intake out In hopes that it would make life easier if/when I was in there again.

 

You want real fun, try getting a compression tester with a bent hose to thread into #6, with the intake on. 

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  • 3 weeks later...

I recently went through the whole top end of my VG30 and I will agree that it was a giant pain. I can't imagine having to do it on some of the newer engines that really have a lot more sensors, plastic, and crap to control the engine. I have never had a real problem getting any of the spark plugs out of the heads. It's that damned vacuum line next to #6 that keeps getting knocked off and making it run rough. I credit my luck to this because it appears as though the previous owners did keep it pretty clean and appeared as though they only took it to Nissan Dealers. Belts, hoses, everything that I would have gotten at NAPA, or some other parts store, were OEM Nissan parts. 

 

Getting to the spark plugs on the drivers side is pretty much a straight shot unless you have debris, as mentioned, preventing you from getting a good bite on the plug. But ya... When I tore it down, I did find the holes filled with oil from leaking valve covers. So... the drains in mine, that I didn't know about until now, are likely blocked.

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  • 3 weeks later...

Are we talking about the same car? I removed the air intake which was a job from hell. More hoses in tight spots than any car I have ever worked on. Some of the hoses have tight turns, and difficult access. Cleaned plug holes, and installed new plugs. Am suprised at the gap, at least 100 thousand, though engine was running fine. I suspect, after 200K and 22 years, these are the origional plugs. Re-installed air intake and alll hoses.        Installing pass. side plug wires was pure hell. Installing driver side wires is not hell, it is impossible. Cant see plugs, cant get hands inside. How in the hell does anyone change these plugs? Do mechanics just charge for it and not change them? I can see no way to do this without removing the air intake and installing wires before plenum. This may be a good engine, but it had ZERO thought as to maintenance during the design. "Free" car is up to $1400.00 and 40 hours labor.  

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Yeah, it's a pain, but it is possible. The trick for the driver's side plug wires is getting the angle right. IIRC I found some angle to where I could see the plug between runners, or got a finger down in there and found it by braille, and went from there. It's not fun, but I've worked on worse.

 

That said, I intend to do everything but tension the belts on my VG33 before I put the engine in the truck.

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Well....Round I dont remember the number. This job started as  timing belt replacement. Due to the design and age of engine, and my fear of getting dirt in the plug holes  I removed the air intake. A hellish job removing at least 20 hoses and plugs. Removing the EGR pipe resulted in breaking the upper cast connection, and givig up on the lower connection after making one tool, and buying a set of clawfoot wrenches and still could not loosen the lower connection. After 18 years of use and 10 years of sitting, I dont think anyone could remove these nuts while engine is in the car. Water hose flange had a finger size hole in it, $125.00.  ( Should have used JB weld.) Broken cast EGR  flange, JB weld. When re installing the harmonic balancer, broke the bottom of the belt cast cover. ( You must tighten the lower cover bolt BEFORE installing the HB. More JB weld.     ( The front belt guide disk has a slot, but there is no corresponding keyway on the crankshaft.  ???)  People on youtube show adjusting the tension of the belt with a finger by the seat of the pants (which apalled me.) Try to push 22 lbs. on a bathroom scale with a finger.  In order to do it correctly, I bought a Browning belt tensioner off Ebay. Book calls for 22 lbs, and 1/2" deflection. The eccentric tensioner, at maximun tension will only provide 10 lbs. tension. 10lbs!!! Well, I guess my 100 bucks was a lesson learned, because at least I know I did the best I could. I used a Gates Belt. Cannot exceed 10 lbs at 1/2". Perhaps a Nissan Belt would have provided the proper tension.  I aint goin there.  This has been a really tough job for me. If anyone else has replaced a timing belt, I would love to hear about your experience, and to know how you tensioned it. On a positive note, I am taking a home course in classic car repair, and learning about the miracle of JB weld.    

 

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13 hours ago, Slartibartfast said:

Yeah, it's a pain, but it is possible. The trick for the driver's side plug wires is getting the angle right. IIRC I found some angle to where I could see the plug between runners, or got a finger down in there and found it by braille, and went from there. It's not fun, but I've worked on worse.

 

That said, I intend to do everything but tension the belts on my VG33 before I put the engine in the truck.

How do you plan on tensioning the timing belt?

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How did you tension the timing belt?

"The service manual has an elaborate method involving shims and weights. I used the method in this tutorial instead."  The Factory manual and the Haynes manual are crystal clear on the 1995 about using a tensioner to obtain a certain deflection at 22lbs pressure. It seems no one uses this method, ( the tutorial you used did not ), and no one on you tube does, probably because a tensioning tool is something no one owns and no one is going to buy for a one time use. I did buy one,, because a slipping or broken belt on an interfearence engine would cost about 25 times the price of a tension gage.  Anyway, the jokes on me because at maximum possible tension on my new Gates belt, I could only obtain 10 lbs pressure at 1/2" deflection.  I suspect most shade tree mechanics ( I am one ), cut corners on factory procedures to some degree, often without catastrophic results.  I am puzzled at my inability to obtain the required tension.  Is it another case of a once reputable Brand ( Gates ), now outsourcing to the cheapest slave labor supplier? ( The belt sure feels tight as hell!)    Hmmmmm......         How many miles have you put on your car since belt change?   

 

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I think I did the belt at around 230k miles, and it passed 250 recently with no issues. I did have the timing together and apart a few times before I was happy with it, both because I couldn't convince myself I hadn't set it too tight and because I didn't replace the crank seal the first time around and it started leaking as soon as I buttoned it back up. I wasn't impressed by the tutorial's 90° tension check, but I figured it would get me closer than I'd get screwing around with improvised shims and a fish scale. 

 

Not sure why your tension isn't meeting spec. It shouldn't need to be maxxed out on the tensioner, and you don't want to set the belt too tight. I think I used a Gates belt on mine too and found no fault with it. Do you have a link to the tester you're using, and have you checked it against a known weight to make sure it's reading right?

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I have done at least 20 timing belts on these engines, using the 90 degree twist trick each time, and have never had a problem.

 

As for the intake being hard to remove, I assume you're coming from carbed domestics lol. It's not that bad, certainly easier than the one I just did on my Volkswagen golf. The good thing is these engines run forever if you don't let the timing belt break. My last one I ran till just over 550k km (300k miles) and only retired it due to rust up here in the north.

 

As for the plugs, don't spend $ on the iridium ones, just use the V power copper or G power platinum, they're more than good enough and last a long time.

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On 9/19/2022 at 4:19 PM, Slartibartfast said:

I think I did the belt at around 230k miles, and it passed 250 recently with no issues. I did have the timing together and apart a few times before I was happy with it, both because I couldn't convince myself I hadn't set it too tight and because I didn't replace the crank seal the first time around and it started leaking as soon as I buttoned it back up. I wasn't impressed by the tutorial's 90° tension check, but I figured it would get me closer than I'd get screwing around with improvised shims and a fish scale. 

 

Not sure why your tension isn't meeting spec. It shouldn't need to be maxxed out on the tensioner, and you don't want to set the belt too tight. I think I used a Gates belt on mine too and found no fault with it. Do you have a link to the tester you're using, and have you checked it against a known weight to make sure it's reading right?

I used a "Browning Belt tension checker", which is easy to verify proper function by pressing it on a bathroom scale. A friend pointed out to me my failure to meet 22lbs was that the tension between the cams will not change until you rotate the engine a time or two. Ended up adjusting, rotating, measuring, repeat.....until getting 1/2" at 22lbs. I did not use a feeler gage at the tensioner like the book says.  I bought two of the tension checkers off ebay. ( cost for two was slightly more than one. ) Now I have two tools I will never use again instead of just one.  If you want one, let me know. It seems most just guestimate tension without disaster, but using the gauge and factory procedure gives me peace of mind.  ( I do feel that if you charge some else for doing a belt, and do not use a tensioner, you are a shiester. A broken or slipping belt would destroy an enging long enough down the road where the owner would be screwed. )  This job has worn me out. I made so many mistakes, broke parts, JB weld fixes, bought tools, made tools, etc. Oh well, some play golf or fish. I work on old cars. During the fix, I decided to flush the cooling system with a water hose. Was not paying attention and shot water into a valve cover! After replacing belt, plugs, hoses, etc. I started engine, and it looked like an industrial mosquito fogger. Scared me to death. Let it run for ten minutes, smoke cleared,and all was good.  Joke is on me.  Thanks for your input.

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On 9/19/2022 at 7:39 PM, adamzan said:

I have done at least 20 timing belts on these engines, using the 90 degree twist trick each time, and have never had a problem.

 

As for the intake being hard to remove, I assume you're coming from carbed domestics lol. It's not that bad, certainly easier than the one I just did on my Volkswagen golf. The good thing is these engines run forever if you don't let the timing belt break. My last one I ran till just over 550k km (300k miles) and only retired it due to rust up here in the north.

 

As for the plugs, don't spend $ on the iridium ones, just use the V power copper or G power platinum, they're more than good enough and last a long time.

If you did 20 of those without a tensioner, I wonder how many of them lasted another 100K miles without issue?

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6 minutes ago, Burco said:

If you did 20 of those without a tensioner, I wonder how many of them lasted another 100K miles without issue?

 

6 minutes ago, Burco said:

Glad to hear though, that they are good engines, This car was given to me. Looks like crap, inside and out, but drives fine and runs good. $ 1500.00 in parts, and 80 or so hours of labor later, I will have to drive it for a while to get my money back out of it.

 

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On 7/10/2020 at 9:59 PM, Albeitt said:

I was getting ready for a compression test so I can diagnose some issues with my VG30E when I came across an issue with the spark plugs.

 

Spark plugs 1, 3, and 5 (passenger side) were a breeze to remove (though it appears that #5 wasn't in all the way?).

 

I hit a wall with spark plugs 2, 4, and 6. They refuse to come out, so I'm thinking either the previous owner stripped them because they're a PITA to access, or they're just seized because of my coolant burning issue that I already know I have.

 

Any suggestions for removal? I've currently got WD40 (yes I know, but it's all I had) sitting on the threads as good as I can do considering the accessibility issues. I'll be trying again soon, but if that still doesn't work, what else can I do? They've loosened a bit, but are now stuck. 

I suggest removing the air intake. Yes it is an unpleasant time consuming job, but you then could clean around the plugs with air and degreaser, and if necessicary, helicoil the plug holes. Would also let you inspect hoses and vacuum lines.  Removing that intake was a hellish job for me. 

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  • 1 month later...

I did the injectors recently and just cut those two PITA coolant hose in the back of the intake for the TB.  I replaced them with some silicone lines with a clamp at the curve to keep it from kinking badly.  Works fine, if I was in a warm climate I would bypass those lines...taking the intake off and on would be a lot easier.

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