'98 Q45 with a bunch 'o codes.

[Dodgeyaussie]

Got the Mother in Law's Q45, and with a scan reader i got the following 7 codes in this order..

P0325 - Knock Sensor (Left Bank)P0110 - Air Intake Temp SensorP0304 - Misfire #4P0330 - Knock Sensor (Right Bank)

And the following "pending codes"

P0325P0110P0330

She also mentioned she lost a bunch of coolant (noticed a trail of evidence running down the driveway onto the road) however after filling it up, i can't find any obvious evidence of a leak anywhere.

So, it looks like it needs both knock sensors replaced, which looks like a bunch of fun based on the threads i have read on doing that job here.

I am a bit thrown by the "Air intake temp sensor" code though.

Would the misfire code be a result of the dud KS's or is that likely to be something completely different? Coil pack? I know she has had some coil packs replaced, i guess i better find out exactly which ones.

Is there a consolidated parts list for this job anywhere?

Is there a particular brand of KS that is more reliable than another?

I have read a couple of paranoidjack's threads so the job itself doesn't look "too" bad. Not looking forward to it in any case.

This sonofab**** made a racket when i started it up this morning too.



Modified by Dodgeyaussie at 1:32 PM 12/8/2009

Modified by Dodgeyaussie at 3:18 AM 12/9/2009
Modified by Dodgeyaussie at 5:52 PM 2/13/2010

[loystock]

The KS codes indicate they failed the ECM test and are out of spec (550 K-ohm). Better replace them at the same time. Discounted price from IoS - infinitipartsUSA.com is @ $142 each. You can try buying from eBay but at least 3 members in the forum have had no luck with them. Besides, replacing KS is not easy.

"paranoidjack" has an excellent writeup about plenum removal, including KS sensors. "bullittandy" had done it w/o removing the plenum. According to him, it's a 2-hour job and there is no need to replace the KS harness (unlike in the G50). Below is procedure from "bullittandy."

This certainly applies to a 97 and likely through 01. Sorry no pics (see farfetched writeup)Items to be removed:-Engine cover-Engine fan-Alternator (lower mounting nut had to be taped to case to hold it on during assembly)-Upper radiator hose-Aluminum radiator neck/hose (attached to above)-4 inch rubber hose under plenum (attached to Y-fitting) This hose likely has to be cut off, I purchased it from the dealer, $13 but it could be matched at autoparts store-Knock sensors-obviously, they look difficult to get to but came out with a 1/4 socket wrench-wiring harnessThe new knock sensors are difficult to get in (starting the bolts) but truthfully it could be done in 2 hours the second time around

Moral of the story:97+ Q owners with a minimum of mechanical ability (brake job ability) can make this repair, saving $500-800 in labor.

Yes, it's possible that the KS code triggered the misfire code. But it could also be due to coils, plugs, injectors, timing, etc. Just wait and see after replacement of KS.

The air intake code may just be due to loose connection to the sensor. The sensor is located at the air intake, just before the air filter box. Check the connection and clean the contacts..

The part in the picture is the Idler Pulley. It makes a loud screeching noise when the bearing inside goes bad. That part is also available from IoS. Other forum members have just replaced the bearing (machine press required).

[Dodgeyaussie]

What's IoS?

Oh, and i found the coolant leak. Just a small matter of a cracked top radiator tank, which leads one to wonder what caused excessive cooling system pressure to cause it to rupture.

[qship96]

Radiator cracks can be caused by more than just over-pressure.....old brittle plastic stressed by normal road shock,heat/cold cycling , mechanic or owner leaning on it while working under hood,etc- much more likely than any "over pressure" condition!

[paranoidjack]

The new knock sensors are difficult to get in (starting the bolts) but truthfully it could be done in 2 hours the second time around

The hardest part I had with the frontal KS removal attempt wasn't threading the bolts - I've read this twice now, but that took about 3 minutes. I could thread and even torque them. The hard part was mounting the small metal clip retainers for the harness connection! Had I had the correct width pliers it was feasible, but VERY cramped conditions.

[Dodgeyaussie]

So i figure the crack in the radiator tank is only a few inches long, i'll get me one of them thar Permatex Radiator repair kits.



Which is basically a small fiberglass kit with black resin. To do it properly, i took the top radiator hose off, and this happened...



"Great", i thought, this car ain't going anywhere now without a whole new radiator. But i messed around with the hose a bit, and decided that i could get enough of it on there to hold, temporarily at least, with a good hose clamp. I managed to get one of the broken bits back on the outlet as well, so hopefully it'll be good to go, until a more permanent fix is made.

It ain't pretty, but it should be effective..

[BadQ45t]

IOS is Infiniti of Scotsdale, AZ. They sell parts at good discounts over the Internet and on the phone as long as they are shipping, if you pull into their parts department if your a local you pay full price. But I got mats, brake pads, spark plugs, etc from them 25-40% cheaper then the local stealership.

the best brand of KS is Infiniti/Nissan, go OEM on this car for EVERYTHNIG except shocks/struts and springs.

[paranoidjack]

It ain't pretty, but it should be effective..

That's scary - fix that ASAP. Keep in mind, the cooling system is at a higher pressure at WOT and high rpm's than it is at the low idle at which you undoubtedly checked for leaks (unless you had a friend hold the gas to 6500rpm while you watched).

I wouldn't drive that. Not more than 1/8 mile to operating temperature.

[qship96]

Radiator cracks can be caused by more than just over-pressure.....old brittle plastic stressed by normal road shock,heat/cold cycling , mechanic or owner leaning on it while working under hood,etc- much more likely than any "over pressure" condition!

See above.....hardened old brittle plastic due in part to cheap materials chosen by nissan and tremendous underhood heat of the Q.....same with knock sensors and fuel injectors cracking and then ethanol attacking them

[Dodgeyaussie]

IOS is Infiniti of Scotsdale, AZ. They sell parts at good discounts over the Internet and on the phone as long as they are shipping, if you pull into their parts department if your a local you pay full price. But I got mats, brake pads, spark plugs, etc from them 25-40% cheaper then the local stealership.

the best brand of KS is Infiniti/Nissan, go OEM on this car for EVERYTHNIG except shocks/struts and springs.

Thanks for the info.

I found a supplier of radiator tanks and although they usually only wholesale, i am working with a guy there who i think will sell me a top tank, and at the price he quoted me, i'll probably do the bottom tank as well.

That's scary - fix that ASAP. Keep in mind, the cooling system is at a higher pressure at WOT and high rpm's than it is at the low idle at which you undoubtedly checked for leaks (unless you had a friend hold the gas to 6500rpm while you watched).

I wouldn't drive that. Not more than 1/8 mile to operating temperature.

Yeah an ASAP fix is going to happen. She only drives about 3 miles to work and back, so it should be ok for that.

[qship96]

Replace the WHOLE radiator, not just the end tanks!!!!!!!!!!!!!!!!!!!!!!!!

A brand new $200 radiator is better than a old OEM radiator.

[Dodgeyaussie]

So this thread details the plenum/KS procedure for a 2000 Q, is this any different to a '98?

zerothread?id=420801

[paranoidjack]

Don't think so, no. If so, very minor differences.

Also qship is right, replace the whole radiator. FORGET the bugs blocking the fins that you'll have to meticulously clean out with a radiator comb, the important part is the inevitably worn corroded interior of the radiator. Replace the whole thing, work an extra 8 hours at work if you have to - it is a better solution.

Then again, you DID say mother in law right? hehe

180k on mine on original radiator - I'm ready any day for it (maybe not my wallet though).


Modified by paranoidjack at 12:02 AM 12/10/2009

[Dodgeyaussie]

Well, on the good side, i have a new top tank on the way.

On the infuriating side, after driving it for a couple of days without the MIL on, (after having disconnected the battery for seat removal) i clean the MAF tonight, and pull a spark plug to see exactly what plugs it has in it, i fire it up, and instantly get the MIL back, along with TCS and SLIP lights on as an added bonus. It also now wants to idle at around 1200 rpm.

P0304 is gone, but has been replaced by P0100 (Mass Air Flow sensor) so in cleaning it, i have obviously screwed it somehow. I used the dedicated MAF cleaner on it. Eh...
Modified by Dodgeyaussie at 10:16 PM 12/14/2009

[Dodgeyaussie]

Well then, pulled the MAF sensor out and adjusted the contact prongs, idle problem fixed and TCS/SLIP lights now off.

[Dodgeyaussie]

Well.. a quick update and new issues.

As mentioned in another thread, i have replace the knock sensors (without removing the plenum) and cleared the codes. I've driven it around for a couple of days before the CEL came back on accompanied by hesitation under light acceleration and a miss at idle.

Pulled the codes and got 0301 (misfire on cylinder one) and 0161 (O2 sensor, right bank) which i never had before.

So tonight i pulled #1 and #3 coils and swapped them over and cleared the codes again to try and prove/disprove whether the coil pack is faulty. I did check the resistance as per the FSM and it checked out ok, so i'm not really expecting this to be the problem. I took it for a drive and the miss/hesitation is still there, but as yet, no CEL.

This being my mother-in-laws car, she needs to get it smogged so she can renew the tags on it. I am wondering if the car would pass smog if i were to clear the codes and immediately get it smogged as they won't even look at it when there is a CEL. In the past, it has taken a couple of days for the CEL to come back on.

My plan now is to go through the "Symptom Matrix Chart" (EC89) in the FSM to try an look for other causes.

This thing is becoming uber frustrating.

[bullittandy]

You can't clear codes and then get it smogged because the computer has to expereince a certain number of drive cycles before it can be smogged-at least thats what GA requires and I'm sure CA is similar.

Replace O2 sensors-check my recent post-its easy on a 99+. Buy one new coil and replace the bad one-you got lucky getting a specific cylinder code-don't jinx it.

Good luck!

[Dodgeyaussie]

You can't clear codes and then get it smogged because the computer has to expereince a certain number of drive cycles before it can be smogged-at least thats what GA requires and I'm sure CA is similar.

Replace O2 sensors-check my recent post-its easy on a 99+. Buy one new coil and replace the bad one-you got lucky getting a specific cylinder code-don't jinx it.

Good luck!

Is it ok to replace just one O2 sensor or do they have to be done in pairs?

Still not convinced it's the coil that is at fault. I ohmed #1 coil and then ohmed another and they both checked out ok. Is there another test to see if a coil is faulty?

[Infinitiguy19]

Replaced in pairs to: Save money on labor, Save your time from going back to the shop and to not confuse the ECU.

[Dodgeyaussie]

What is this...



And is it meant to make this ticking noise? It's a rythmic 3 ticks at a time noise, that speed up with rpm's.

http://www.youtube.com/watch?v=alFrE9YZ_y0

[Dodgeyaussie]

Sorry for all these obscure questions, but i'm clutching at straws here.

Is there meant to be a little hole in the exhaust here?



Compared to the other side, this doesn't look OEM.

[Infinitiguy19]

My best guess is thats a drain hole for water accumulated in the exhaust. But those holes are usually on the muffler if I am correct at all.

[Dodgeyaussie]

Another thought just popped into my head.

The MIL was running regular gas in it for some time, (against my advice) would that have done any particular damage that would cause the car to now have an occasional miss?

[bullittandy]

Replace the coil.

You got a code from a specific cylinder which is very rare so cinsider yourself blessed and replace that coil.

You can replace just one O2 sensor but they are all wearing out. Kinda like tires, you could replace one or two but even if the other two are in good shape it still makes sens to replace all four tires (or O2 sensors).

Just noticed that you have a 98, not sure where the O2 sensors are on a 98, my 97 has them orientated one way and my 99 another so my previous advice that its "easy" may not hold on your 98.

Good luck