94 Q plenum job.

[ThatsMyQ2Go]

I am getting ready to do my valve cover gaskets on my 94 Q Base, and my professional helper advised me that it would probably be a good time to knock out the knock sensors/harness/hoses/etc. I am inclined to agree. The car has at least 200k miles (speedometer/odometer stopped working over a year ago, though the car was parked til 2 months ago incidentally the power steering failed at the exact same time). At one point there was an under plenum kit mentioned on this forum but everything Infiniti now redirects to InfinitiPartsUSA. I checked the website and to be honest it's not incredibly user friendly. I called the 800 number, but the rep could only tell me that at one time they had the kit. So 2 questions here 1) Is the kit available elsewhere? 2) Does anyone know the part numbers for the hoses? My understanding is that the knock sensors are more or less generic to most Nissan/Infinity models of that time period.

The car has been great to me for 4 years with only a starter and blower motor being replaced. It has never left me stranded and its time to give this gem some live and unleash her beast. Thanks in advance.

[qship96]

Not sure on part numbers,but there is about 40 hoses under there including water,vacuum,and fuel- most of them are custom molded {shaped to fit perfectly} and generic from autozone,etc wont cut it! The downside is the whole kit of them was about $1000 several years ago,and from what I understand,some of them are no longer available anywhere.Very frustrating for all of us wishing to keep these old cars on the road {I currently have a bad knock sensor,and due to hose unavailability,am not willing to lift the plenum to replace it in fear of the hose that cracks or splits will be impossible to replace}. Good luck with your repair- but I would suggest not touching the plenum unless you can somehow source every single hose under there,aS the hose you skip will likely be the one that fails.

[elwesso]

You don't need to go under the plenum for the valve covers. there's no overlap there, so I would suggest that you keep those jobs separate.. The valve covers are difficult enough by themselves, you'll want to take the car to the scrap yard if you attempt both at the same time.

[ThatsMyQ2Go]

OK so then the next question is knock sensors first (this is what I'm thinking logically), or valve cover gaskets? I'm only losing a quarter quart an oil change (3k miles on Valvoline MaxLife SynPower 5w30).

Also I understand there was a kit available, I did a search and followed a link, unfortunately that company no longer has the kit with the sensors, hoses and harness. Does anyone know if an internet source that carries a similar kit, or can someone point me to the part numbers of the hoses. I want to go into this fully prepared, this isn't going to break the bank but its definitely going to be felt in my back pocket so I want to budget this appropriately, but not at the expense of doing the job right and certainly not the convenience of preparedness (I'd prefer to spare myself trips to the parts warehouse mid job.)

[94Q45Beast]

well if your serious about it then you could go to the stealership and pay extra bucks for them to make a kit. it'll definitely be over a thousand.

you could get any part you want from the dealership but it'll be expensive since it will be "special order" (as I was told) and come straight from the factory.

[ThatsMyQ2Go]

Ouch, I was hoping to avoid being raped at the stealership, though $1000 isn't much more than the kit I saw mentioned in the post from about 5 years ago.

Also how many of these hoses are actually custom?

[94Q45Beast]

I wana say all the plenum hoses are custom because I've used cheap autozone hoses on the fuel and coolant lines and its just not holding up as well meaning the clamps with the Phillips head on it always comes loose...all my specialty hoses are in good condition except for my pcv valve hose that was torn while removing the plenum.

[qship96]

OK so then the next question is knock sensors first (this is what I'm thinking logically), or valve cover gaskets? I'm only losing a quarter quart an oil change (3k miles on Valvoline MaxLife SynPower 5w30).

Also I understand there was a kit available, I did a search and followed a link, unfortunately that company no longer has the kit with the sensors, hoses and harness. Does anyone know if an internet source that carries a similar kit, or can someone point me to the part numbers of the hoses. I want to go into this fully prepared, this isn't going to break the bank but its definitely going to be felt in my back pocket so I want to budget this appropriately, but not at the expense of doing the job right and certainly not the convenience of preparedness (I'd prefer to spare myself trips to the parts warehouse mid job.)

Well, you cant reliably do the knock sensors until you have every hose that goes under the plenum......which may prove difficult to impossible to get {Nissan no longer has a few needed ones available new} so why not tackle the valve cover gaskets and sparkplugs first while you try to acquire all needed hoses for the plenum job?

[elwesso]

I agree with Q-ship. Get the VC gaskets done.

Compared to the 90-93 Q's, the 94-96's seem to have better quality hoses that don't rot so easily compared to the older ones. The really expensive hoses are the air hoses on the back of the plenum (the Y shaped hose going to the IAC and this other tiny one that's like $40 by itself). The PCV and coolant hoses are usually pretty cheap. Overall the coolant and the PCV hoses are the really weird shaped ones (they obviously had to custom mold a lot of them for really tight bends).

Since you're doing the KS, you won't be able to save the big coolant hoses under the plenum so be sure to replace those. Otherwise squeeze a few of the hoses around the plenum (I like the one going from the plenum to the passenger side valve cover) and if it's somewhat pliable, you should be able to save most of them. Difficult part is you won't know which ones you destroy until it's too late, so I'd probably suggest getting everything and then just sending back what you don't need.

Here's a parts list for the plenum job...

http://infiniti.home.insightbb.com/part ... points.htm

You can give those part numbers to Dan at Infiniti of Scottsdale [email protected], tell him Wes sent you. He was around during the time they had the under-plenum hose kits.

Don't get the KS from them though, you can pick up brand new ones on ebay wicked cheap.. You can find them for $30-$40 each on ebay (OEM nissan) versus they will be $140 each from Dan.

[ThatsMyQ2Go]

Ok so VC gaskets first while locating parts sounds like a plan. I planned on getting the KS on eBay, I'd seen the prices for OEM KS and harness was much better than the stealership prices.

[94Q45Beast]

those cheap KS on ebay don't last as long....I did a KS job with 30 dollar each "OEM" Nissan badged and they only lasted roughly 10K miles. oh and since your doing the VC job first, now would be a good time to do the spark plugs if you haven't already.

and I haven't seen a KS harness on ebay that can be used on the Q directly

[elwesso]

If they're genuine Nissan parts then it shouldn't matter where they come from.

[3Q Jay]

....and from what I understand,some of them are no longer available anywhere.Very frustrating for all of us wishing to keep these old cars on the road {I currently have a bad knock sensor,and due to hose unavailability,am not willing to lift the plenum to replace it in fear of the hose that cracks or splits will be impossible to replace}.

don't even get me started on the lack of Nissan product support for these old gems.
But Qship, didn't you have T3 replace all your hoses 7-8 years ago? I am with Wes that the quality of the 94+ rubber is much better than the early G50 rubber. the only hoses I actually broke were the power brake booster (easy to access). in any case, while certainly safe if you have full set of replacements on hand, i wouldn't sweat the hoses to get at the KS.

[Lou Jones]

I replaced the KS and fuel injectors on my '92 about 4 or 5 years ago. Also changed spark plugs and replaced a couple of the coils at the same time.
You'll never get the plenum off and back on without breaking at least several of the hoses, some of which are right up against the firewall and impossible to reach once the plenum is back in place. I replaced all of mine (once I figured out that I never wanted to go back under the plenum again for any reason) and the hose kit cost about $800.00 then. As stated above, you might not even be able to find some of them now.
Valve cover and spark plugs are easy on the passenger side, not so much on the driver's side. In fact, I don't see how you could get to the driver's side with the plenum on but I will yield to the experts above when they say it can be done as I'm not a professional.

[94Q45Beast]

I'm working on the hose kit, just need a little more time.

[3Q Jay]

I replaced the KS and fuel injectors on my '92 about 4 or 5 years ago. Also changed spark plugs and replaced a couple of the coils at the same time.
You'll never get the plenum off and back on without breaking at least several of the hoses, some of which are right up against the firewall and impossible to reach once the plenum is back in place. I replaced all of mine (once I figured out that I never wanted to go back under the plenum again for any reason) and the hose kit cost about $800.00 then. As stated above, you might not even be able to find some of them now.
Valve cover and spark plugs are easy on the passenger side, not so much on the driver's side. In fact, I don't see how you could get to the driver's side with the plenum on but I will yield to the experts above when they say it can be done as I'm not a professional.

Driver side VC quite easy (well relatively anyway) once the throttle body is removed from the plenum.
You will still need to position the EGR tube toward the back. hit the seat of the tube where it goes into the exhaust mani with PB blaster to loosen up.