1999 Q45 Coil Pack Problem ?

[tomsroe]

I have been to four mechanics and no one can seem to diagnose the "skip" in the engine. The dealer service department wants to replace all eight coil packs at a cost of $2,600 and cannot assure me that this will solve the problem.

I think the problem is either ignition or fuel injecton in one of the eight cylinders (not all eight).

Is this a common problem with Q45s at 120,000 miles?

[maxnix]

Hey Tom, welcome to NICO.

Now check the trunk of your car and find the letter y in INFINITI.

Next, do a search on stumble. Probably one of your coil packs. A good OBD II scanner and switching coilpacks one at a time between codes should clue you in.

[Q45tech]

Many european and Japanese and domestics have had coil pack reliability problems.................usually after warranty and after the peak quality years of 94-96..............lots of compaies tried cost cutting to maintain prices and the results have never been good.

As far as Infiniti they just don't make them like they use to after the Q41 cost cuts and downsizing.

Be happy since this is one of the few engine problems.

[elwesso]

Welcome to NICO.

I would get yourself a scanner and do a power balance test (sometimes called a cylinder drop test) and see what cylinders are bad, and then just swap the iffy coil packs to another cylinder and make sure the bad cylinder goes to the one you moved it to..

You then should be able to pick up a few used ones pretty cheap. id pick up a few and have some spares, because it is kind of a common issue on those cars.

[tomsroe]

Thanks for the spelling correction.

In addition to the posting today, I called Infiniti customer service and they are contacting the dealer. What are the chances that all eight coils fail at the same time? I think unlikely but strange things happen to mechanical devices like automobile engines.

[elwesso]

Thats the sure fire way for them to get the problem take care of. Sometimes the coil packs go from intermittent to bad so this will keep you out of their hair for a long time. You could go there and a month later have another one go bad (unlikely) and then thatd give you something to complain about.

[maxnix]

Dealer mentality is to replace all at once. Why you have to go to a specialist like http://www.jerrytucker.net or at least find a senior Infiniti technician at a dealer.

[Q45tech]

Before individual coil on plugs [1900-1989], it was common to periodically change the 1-2 coils on engines at 60,000 miles, now with less individual stress the individual coils can last 100-300,000 miles +.

The LS400 is a great example until 1998 it had 2 coils one of which was constantly failing after 120-150,000 miles. The plug wires were arching etc and got changed also, along with dist caps and rotor buttons.

An engine always seems to have a maintenace item or two besides spark plugs. Be glad they didn't use 8 x 2 plugs per cylinder like Mercedes or a timing belt like Lexus...........8 coils are cheap compared to the 100k service on Lexus.

[renkema]

well I'm back and so is my problem (misfires). I posted on this same issue last November. As Q45tech said, the problem can be intermittent and my situation is living proof.

Q, Brian, and Wes seem to be leaning much more toward a total coil replacement with this current set of posts, so maybe that's the route I should have taken last year. I have a scanner but I'm not sure all are created equal. Although the cylinder drop test sounds spot on, I don't remember my scanner having that ability.

I guess a call to Joe before the Oct. 10% goes is in order and a search for the play by play coil replacement instructions is in order. I keep trying to finagle a trip to T3 for a good once over, but haven't been able to find the time (4 hour drive one way from Nashville).

Cheers to Q, Brian, and Wes. This continues to be a bottomless pit of vital Q45 info!!

[maxnix]

Well, T-3 will save you a lot of time, even with the 8 hours of driving.

Read the stumble threads in Q45 Forum. If you don't start with a pristine intake system, causes could be multiple and obscure each other.
Modified by maxnix at 7:24 PM 10/22/2007

[96Qowner]

The are a couple of companies producing software with most of the functions of Nissan Consult. Here's a thread about one:

Thread for Nissan OBD ScanTech Testers

Q451990 says this:

I just tested it a few minutes ago. Version 1.40 has the power balance test and it seems to work nicely with my truck!

I think the most effective way to approach this "syndrome" is with data - as much as you can get. With the right software and analysis, you may be able to pinpoint an offending cylinder. And if it's not specific to one cylinder, it means the problem isn't an injector or coil.

[Q45tech]

Unfortunately a Consult nor copy Consult Software won't help you much unless you are the best tech in US.

Misfires need $5,000 in extra test equipment and the Consult........why dealers just change all 8 knowing that they will usually solve theproblem.

[renkema]

You're right Brian. Everytime I start to tackle this issue, I know I need to deal with all the plenum cleaning issues, KSs AND harness, etc. and I lose momentum quickly. I just don't trust my local dealer anymore so I know a trip south is in order.

Dennis, I couldn't hit your site today. Can you send me an email that I can reply to so I can try and coordinate a trip down there? Thanks

[maxnix]

If you have a good torque wrench and can read the manuals, you should attempt the cleaning yourself as it is mostly just labor intensive, then take it to T-3. Have a machine shop clean the plenum and EGR tube within it.

Get your parts from Joe.
Modified by maxnix at 7:58 AM 10/30/2007

[96Qowner]

Dennis, I couldn't hit your site today. Can you send me an email that I can reply to so I can try and coordinate a trip down there? Thanks

The site works - I had to unblock t3auto.com from my flash blocker. The Smyrna phone # is 404-794-7700.

[renkema]

is the below too good to be true (FCP Groton LLC is the vendor)??

My thought is that although they may be inferior, it may be worth it. According to this thread, the only sure method to solve coil problems on a '97 (without a lot of knowledge and equipment) is full 8 coil replacement. That means that good coils would be discarded in the process. So, if these last only half as long, I'm still way ahead on cost. The cost of the Nissan's is really making me balk at this. What if that's not the problem!! Then I'm 2grand to the wind! Any experience with non true OEM coils?

New Infiniti Ignition Coils Condition: Brand New - Auction is for 8 Brand New Ignition Coils Guaranteed OEM Quality and Fitment OEM Reference 224483H000 List Price for a Set of 8 is $1855.84 - Save big through FCP 1 Year Full Warranty Manufactured by Hitachi - OEM Supplier for Infiniti and Nissan

Fits the following models:

Fits Infiniti Q45 Models from 7/1996 to 1/2001

[maxnix]

You can get 8 OEM (shouldn't need them all) from Joe for less.

Read Q45tech's post:

We have had problems with generic I35 coils purchased by customer from chain store..............we pulled and replaced with oem and problems dissappeared?

As long as they have unconditional 12 month warranty on defects?

zerothread/289148

[renkema]

I just noticed I left out the most important component of my last post. The coils I referred to are $550 for all eight from an ebay vendor with over 23k posts (99%). Even Joe's price is close to triple that. That's why I said "too good to be true". I know Joe is the best price on the OEM but I'm still on the fence about quantity. You're right, I'm confident I don't need all eight (maybe only 1!), but as Q45tech said, it's very difficult on this model year to pinpoint the offender. In fact, it looks like his quote on the i35 coils suggested he replaced them all. Maybe that's the only way.

[maxnix]

You're right, I'm confident I don't need all eight (maybe only 1!), but as Q45tech said, it's very difficult on this model year to pinpoint the offender. In fact, it looks like his quote on the i35 coils suggested he replaced them all. Maybe that's the only way.

It's very difficult without a shop and an OBD II reader. Well, not really if you pay attention to procedure and start with a known good baseline (clean intake and working as new fuel system). With these, it becomes much easier.

Don't confuse a general statement about VQ coilpacks as a solid diagnosis of VH41DE coilpacks. Let them look after you have done the prelimnary intake restoration.

[Q45tech]

There is no ZERO excuse for a 1995+ owner to not have an inexpensive OBD2 scanner since it works on every brand and model until at 2012 when it's scheduled to be updated. OBD3

[renkema]

okay. My scanner (a $60 Topeak) gets an error when retrieving DTCs (engine off/power on).

The MIL light is continuously illuminated in the on/not started position. The Q's MIL light also comes on very briefly when I start the engine (scanner not connected). So I'm assuming my inexpensive scanner is too inexpensive OR my Q's computer is malfunctioning/not working.

Other than going to the dealer for the Consult II test, is there a way to test the Q's computer for malfunction? I've reviewed the EC section of my FSM and cannot find any reference to testing the ECM. I'm concerned that the ECM is NOT working (eventhough I get the MIL light) because the stumble is fairly regular and I would think it should have thrown at least 2 DTCs to make the MIL light come on permanently.

I did a homemade test of the ECM of my own. I disconnected the air temp sensor. I started the engine for the first time after disconnetion (MIL does not light). Turned off and started again, bing! the MIL comes on (2nd DTC error rule). This test would indicate to me that the ECM and it's function is okay?. I have to believe the ECM either works or does not. I can't imagine that it works for some monitors and not for others.

So now I'm stumped. Maybe there is such a thing as a TOO inexpensive scanner. Any suggestions about a good scanner (brand, functionality, especially one to try and diagnose the stumble). I've got a high end Windows based laptop. Maybe I'm not using the cheapo scanner correctly. However, it seems like a pretty simple operation: turn engine off, connect scanner, turn engine to ON (not started), read codes (this is where I get the "connection error"). The fact that this scanner appears to be dsigned to work ONLY with the engine off is another sign to me that I've got the wrong tool.

Any thoughts?