[Padilla]

What was GM thinking when they designed this car! Getting to those back spark plugs is not going to be an easy feat. The front bay was a price of cake but now I have to deal with a AIR shut-off valve and on top of that a tight area. Any ideas that would make this easier is appreciated. :banghead:

Secondly the parts house gave me NGK platinum spark plugs because they were out of AC delco. Are these good plugs?

 

[Submariner409]

Take the NGK's back. Based on experience, the engine will tell you they taste bad.

Lie over the engine and remove the two 10mm nuts from the flange on the AIR valve - DO NOT try to bend that pipe.

FWIW I use NGK's in several other engine build configurations but NOT in a Northstar.

AC Delco #41-987 Platinum Professional.

 

[ben.gators]

Return back those plugs and stick to Ac Delco... And yeah, installing the back plugs is really hard...

 

[00 Deville]

Secondly the parts house gave me NGK platinum spark plugs because they were out of AC delco. Are these good plugs?

NGK's are good plugs... but N*'s don't like them... do yourself a favor and take them back and get the AC Delco's before you do the rear bank or you may be doing the rear bank over again.

 

[curtc]

Good thing you asked, all of what have heard is correct. And no, it is not fun getting to those rear plugs....I remember that afternoon very well, lots of chosen words were thrown around that's for sure.

 

[98eldorado-lee]

call me stupid, but I paid 700 for a full tune up

 

[Submariner409]

If, and only if, the "full tune-up" included OEM plugs, wires, air filter, throttlebody and EGR cleaning, fuel injector cleaning and fuel pressure checks, oil and filter change and a full diagnostic readout with a paper copy to you, then that's a market price. Anything less and you got scammed.

 

[cadi509]

Yea the rear bank is hard but still not as hard a 4.9, also I have 8 plugs that I installed in my old 99 sts about 6months prior to me totaling it, would those be ok to put in my 03 now? Or are they already too worn down? I think I put about 7k on those plugs. Sorry to jack the thread...

 

[Submariner409]

Yea the rear bank is hard but still not as hard a 4.9, also I have 8 plugs that I installed in my old 99 sts about 6months prior to me totaling it, would those be ok to put in my 03 now? Or are they already too worn down? I think I put about 7k on those plugs. Sorry to jack the thread...

Different years, different engines, different plugs. The 99 used #41-950 plugs, the '03 uses #41-987 plugs. Same thread and reach, different heat ranges.

 

[curtc]

If you only put 7k on the plugs in your old car before you crashed it I would say they are fine, too bad they won't work for the newer N*. I have had my OEM plugs in since about 150k I think, the car is on its 3rd set now. Factory installed, then I put new ones in when I got it at 84k, replaced again around 150k.

 

[Skiller.]

If anyone can share their experience with me about the rear plugs, that would be great! I have the AIR shut-off valve out of the car, but now, the pipe that runs from the valve to the front air intake is restricting the cassette from coming out...Am I missing something here, or does that pipe have to be taken out?? And how is that possible? I tried to get a ratchet, a wrench, anything I could find on that 10mm nut holding it in place, but it's impossible to turn...

 

[mike5514]

Maybe Im nuts! but I have a gut feeling that nkg makes delco plugs now (also have this weird feeling that gm owns apiece of nkg.) SAYING that! rock autos delcos plugs are priced lower than the nkgs. Buy delcos. Mike

 

[Submariner409]

The original plugs in Northstars were DENSO. The new AC Delco 41-950 and 41-987 plugs are physically identical to the DENSO equivalent - and they're branded "Made in Japan" - not that most NGK product isn't made there also.............

 

[Submariner409]

the pipe that runs from the valve to the front air intake is restricting the cassette from coming out

Something's very fishy here..............Picture ???

 

[Skiller.]

Something's very fishy here..............Picture ???

My fault..I didn't remove the electrical connection on the coil cassette. It's off now.