: N* plugs & wires: DIY or leave it for the pros?



Henrik
02-14-04, 07:51 PM
My 95 N* needs new plugs and wires. How difficult is it to perform yourself? How much would a garage charge for labor and parts? Are there any gotchas? Which parts are preferred: OEM or aftermarket. Thanks for any pointers or answers.

zonie77
02-14-04, 09:06 PM
There are a bunch of threads on this. Powerglide wrote up his tips a few weeks ago.
Also, bbobynski wrote up a great 100K service recently. Look for these, they'll answer all your questions.

I's easy, Use AC Delco plugs and wires.

Realtor1
02-17-04, 03:24 PM
I second that

BeelzeBob
02-17-04, 03:30 PM
Really, a 95 Northstar is one of the easiest engines to change the plugs and wires on in existence.... Just do them one at a time to keep them from getting mixed up...and they are even numbered and labeled to help if you do.


use the AC Delco OEM plugs (dual platinum) and the OEM wires to avoid any RFI/EMI problems that are common with aftermarket wires and plugs. The OEM plugs will provide the best performance as has been proven on the dyno.

Henrik
02-17-04, 06:29 PM
Thanks for the replies. As per your suggestion I ordered exactly what you indicated. Once I have received and installed it (hopefully without problems) I will post back. Thanks again, forums like this one really makes a difference.

Henrik
02-29-04, 11:42 PM
I ordered all my parts (AC Delco OEM) from Rockauto.com and did the following in one Sunday: replaced both belts, 8 plugs, all wires, 4 head lamp bulbs, air filter, PCV valve, 1 windshield wiper arm and both blades. The car runs like a dream! You were all right in that this is definitely doable for a non-pro like myself.

A couple a comments and questions: I noticed that the plugs I pulled appeared to be the original Dual Platinum plugs, the gap was up to 0.08 inch on some of them (after 70K miles)! I also noticed that the old plugs were of the so-called "new type" (no grooves in the porcelain insulator) whereas the ones I installed are of the "old type" with grooves. Is this something I should be worried about?

Also I found it to be a lot of work to install the (non-numbered and completely separate) wires. Basically I had to label all wires after figuring out the correct ones by looking at the old set. The set I bought was (AC Delco OEM) but I would have expected the set to be labeled and have guides and other plastic hardware attached.

Next weekend it is time to do all the brakes which appear to be a bit weak. I am pretty sure they were never done before. I am not sure I can fix all that in one day though. I also plan to flush the brake fluid while I am at it.

Thanks for all advise or pointers.

BeelzeBob
03-01-04, 03:34 PM
I ordered all my parts (AC Delco OEM) from Rockauto.com and did the following in one Sunday: replaced both belts, 8 plugs, all wires, 4 head lamp bulbs, air filter, PCV valve, 1 windshield wiper arm and both blades. The car runs like a dream! You were all right in that this is definitely doable for a non-pro like myself.

A couple a comments and questions: I noticed that the plugs I pulled appeared to be the original Dual Platinum plugs, the gap was up to 0.08 inch on some of them (after 70K miles)! I also noticed that the old plugs were of the so-called "new type" (no grooves in the porcelain insulator) whereas the ones I installed are of the "old type" with grooves. Is this something I should be worried about?

Also I found it to be a lot of work to install the (non-numbered and completely separate) wires. Basically I had to label all wires after figuring out the correct ones by looking at the old set. The set I bought was (AC Delco OEM) but I would have expected the set to be labeled and have guides and other plastic hardware attached.

Next weekend it is time to do all the brakes which appear to be a bit weak. I am pretty sure they were never done before. I am not sure I can fix all that in one day though. I also plan to flush the brake fluid while I am at it.

Thanks for all advise or pointers.

The wide spark plug gap indicates that the platinum pad must have come off at some point and the plug gap started to wear and open up as a result. "Normal" considering the age of the plugs and the model year for some of the pads to have fallen off.

The other maintenance you need to do if it hasn't been done is to drain the cooling system and refill with fresh 50/50 coolant/distilled water. Maintenance of the cooling sytem is extremely critical to the long term health of any all aluminum engine and the Northstar is no exception. Yours still used the green , conventional , sillicated coolant so it needs/needed to be replaced every 2-3 years/24-32 K miles.... If it hasn't been done then do it ASAP. Use the conventional green coolant and install the GM coolant supplement/BarsLeaks "golden seal" cooling system sealer into the radiator hose when you do the cooling system maintenance to guard against nuisance leaks of the cooling system. Search forum using "coolant supplement" and read up....

Henrik
03-01-04, 09:23 PM
Thx bbobynski! I will change the coolant fluid as per your suggestion! :)

Before you jump in, let me also add that I intend to replace the transmission fluid. Please allow me to ask three more questions:

Q1: Am I right that it is not possible to replace the transmission filter? :confused:

Q2: I would like to replace the somewhat rusty looking mufflers. I would like my new mufflers to be less restrictive both in terms of performance and sound. What are my best choices if I want stainless steel mufflers? :confused:

Q3: I would like to replace the 225/60/16 tires with 235/55/16 Michelin z-rated tires keeping my aluminum rims. Will this work and are there any gotchas? :confused:

BeelzeBob
03-01-04, 09:34 PM
Thx bbobynski! I will change the coolant fluid as per your suggestion! :)

Before you jump in, let me also add that I intend to replace the transmission fluid. Please allow me to ask three more questions:

Q1: Am I right that it is not possible to replace the transmission filter? :confused:

Q2: I would like to replace the somewhat rusty looking mufflers. I would like my new mufflers to be less restrictive both in terms of performance and sound. What are my best choices if I want stainless steel mufflers? :confused:

Q3: I would like to replace the 225/60/16 tires with 235/55/16 Michelin z-rated tires keeping my aluminum rims. Will this work and are there any gotchas? :confused:


Yes, you can replace the trans fluid. Your car has a 4T80E transmission that uses a dry sump lube system that stores most all the fluid in the side cover. A scavenge pump picks up the fluid and pumps it to the side cover where it is stored until picked up by the main pressure pump. To change the trans fluid, drop the bottom pan and drain what fluid is down there and clean the two pickup screens. No filter to change or service, just the screens. Underneath the bottom pan there is a "hidden" drain plug that will drain the side cover. It is directly under the side cover so it is pretty easy to find once the bottom pan is removed. Drain the side cover, replace the drain plug and bottom pan and refill with fresh fluid. Don't be tempted into a trans flush by a trans shop or anything like that. Just drain and refill with fresh.

You should also check the water pump drive belt and the small spring loaded tensioner on water pump drive belt to make sure it is free to move and is properly tensioning the water pump drive belt located at the rear of the engine off the left hand intake camshaft.

As far as tires and mufflers...I'll have to let others with experience with some of the aftermarket parts give you advice. I don't have any personal experience with those so I hate to steer you wrong.

Henrik
03-05-04, 12:01 PM
Thx for your suggestions,

I did change the water pump drive belt as per your suggestion. It was easy after I reached the conclusion to remove the small spring loaded tensioner to get the old belt off and the new one on.

With regards to the coolant fluid, I now bought the GM sealant pellets ($2 per box of 5). The GM parts service person was unsure what coolant I should use, he asked me to check the color of the fluid (on my 95 Eldorado etc). The cap is green and the coolant is green. Now, does this mean that I must replace it with new green coolant (mixed with distilled water) or can I actually use the (improved?) red coolant (Dex-cool?) used in 96 and up Cadillac vehicles. I am sorry for asking all these questions, but I want to get it right the first time around. This is a great forum, could not do my Cadillac service without it.

BeelzeBob
03-05-04, 01:42 PM
Thx for your suggestions,

I did change the water pump drive belt as per your suggestion. It was easy after I reached the conclusion to remove the small spring loaded tensioner to get the old belt off and the new one on.

With regards to the coolant fluid, I now bought the GM sealant pellets ($2 per box of 5). The GM parts service person was unsure what coolant I should use, he asked me to check the color of the fluid (on my 95 Eldorado etc). The cap is green and the coolant is green. Now, does this mean that I must replace it with new green coolant (mixed with distilled water) or can I actually use the (improved?) red coolant (Dex-cool?) used in 96 and up Cadillac vehicles. I am sorry for asking all these questions, but I want to get it right the first time around. This is a great forum, could not do my Cadillac service without it.

Use the green conventional coolant mixed 50/50 with distilled water. The 96 and later engines had the DexCool coolant. The DexCool is not "better" or "improved" ... it just has much longer life corrosion inhibitors in it. The green, conventional, silicated coolant offers the same level of corrosion protection and cooling capability...it just needs to be replaced more frequently. Unfortunately, once the system is run with the green silicated coolant the silicates will plate out onto the metal surfaces of the engine internally and render the "long life" feature of the DexCool coolant inert....so there is no reason to switch to it..it is more expensive, would have to be replaced frequently and offers no other advantage.