HappyAndy HalfDork
5/5/10 9:36 p.m.

Happy Andy's back-ally, after-hours, underground economy stimulating repair shop has been kicked into high gear the past few weeks. It seems that every one within a twenty mile area that wants a quality repair done for less than pro shop prices has found my number. I turn away work that I'm not sure that I do perfectly on the first shot. This brings me to the Nissan question, I've been asked to do a tune up on a '98 infinity I30,( just a more expencive maxima), It seems obvious to me that the intake manifold needs to be removed to get to the plugs on the rear cyl head. Are there any tricks of the trade or proven short cuts to make this job easier? what parts will I need other than the intake plenum gasket? Are these engines known for having problems with siezed spark plugs? Last but not least, the check engine light is on for a miss-fire on at least one cyl; is it likely that the coil-on-plug coils are burnt out on the miss-firing cyls? I've already done some brake work on this car and its obviously been poorly maintained, so I'm not real eager to take on this job, but OTOH it doesn't look all that hard, and my experience with 4 cyl Nissan engines has been completly positive.

SO, what do the GRM Nissan experts say? Dive in or run away?

irish44j HalfDork
5/5/10 9:57 p.m.

In reply to HappyAndy:

Andy, the IM does not need to be removed. You can access the rear bank plugs using a universal joint on your rachet to your plug socket. (same to remove the coil pack screws down in there too) It's a pain in the ass, and easier with small hands, but can be done. As I recall, you may need to move a few of the vac lines or other small stuff on top, or at least detach the mount brackets to get to one of the plugs....

Also be careful not to drop the coil screws....they will fall into an area that makes it almost impossible to get them out!

The VQ30DE is not known for having any issues with seized plugs to my knowledge.

VQ30 coils are notorious for going bad. You can usually pick up used sets at a junkyard and chances are that at least one will be good. There is a resistance test that sometimes works - you need to compare all the readings between all six coils and a known good coil...you can find information on this test on Maxima.org....I'll see if I can find the link for you.

You can also get a new set for a VQ30 probably for $150 or so, last I checked. Call DAVE BURNETTE at South Point Nissan in Texas, and tell him that Josh/Irish44j from maxima.org referred you - he will likely give you "at-cost" pricing or close to it for parts :D

Maxima.org has a ton of info on these cars - just look in the "4th generation maxima" section for any mechanicals....it is more complete than the I30 section!

(btw, I am a long-time former moderator on Maxima.org...and as you note, the I30 is a maxima in infiniti clothing).

irish44j HalfDork
5/5/10 10:04 p.m.

Here you go on the coil test: it's for the 5th-generation maxima (VQ30DE-K), but it's essentially the same engine (different IM with VIAS) and it should work with 4th-gen/I30 coils as well.. Unfortunately, the photos/charts that he originally attached are now dead links, but you should be able to figure it out from the text...


let me know if you have any other questions....I had a heavily modified maxima ('00) and pretty much took apart and reassembled the entire car at various points (aside from engine internals)...

HappyAndy HalfDork
5/5/10 10:20 p.m.

In reply to irish44j: Thanks for the tips, unfortunatly, I have huge hands, but I'll try it any way. Siezed plugs are my biggest fear, but I've worked on thousands of Nissan industrial engines and can only recall a couple of siezed plugs.

irish44j HalfDork
5/5/10 10:24 p.m.

In reply to HappyAndy:

I changed mine at 120k for the first time and it wasn't a problem....

Also, my hands aren't small, but I do have thin fingers. I still don't think you'll have too much of a problem.

If anything, removing the IM isn't all that difficult either, especially in the non-VIAS cars (as yours, IIRC, is)

belteshazzar SuperDork
5/5/10 10:29 p.m.

iirc, most auto parts stores will have the coils on the shelf for fairly cheap. just replace the one the computer told you was bad.

never had a stuck plug in a VQ (or any other meaningful problem for that matter).

digdug18 Reader
5/5/10 10:31 p.m.

I 'd like to see a thread, including pictures on "Happy Andy's back-ally, after-hours, underground economy stimulating repair shop" If you have the time to post one mind you. As I'm considering doing such a thing in my neighborhood as well, off the books and under the radar.


spitfirebill Dork
5/6/10 9:16 a.m.

I had a 96 Maxima and +1 everything Irish said. I recall no big problems changing plugs. Never had one stick. I normally used NGK platinum plugs, but they are $12 a pop. Right before we sold the car, it started a miss, that may have been a coil. But replaced the plugs and it went away). I had put copper plugs in previously).

Maxima.org is a good source, but it can get testy at times. I think I got put in timeout once for no reason all. Don't recall if Irish did it or not. I don''t go there any more since we are now maximaless.

irish44j HalfDork
5/6/10 6:47 p.m.

In reply to spitfirebill:

lol.....if you hung out in the 4th gen forums, it probably wasn't me. I was the moderator of the 5th gen, road course/autocross, and "garage" forums and rarely went into others.

but yes, certain parts there get testy, especially as the cars have gotten older and cheaper and more kids get them and come on the forums....