Starting my Knock Sensor replacement today......

[Meaux]

I can allready see this is going to take awhile...

So far I've removed the deco plates, MAF, plenum, and 2 metal lines on top of the "valley". I only broke 2 hoses, a small vacuum hose and the one on top to Brake Booster.

Next up seems to be the Fuel Rails w/injectors. I'm assuming I won't have to pull injectors. Do the fuel rails just pop out of the intake runners once unbolted?

I'll check back later and hopefully not with bad news....

Haven't cut myself or dropped any blood...yet...:-)

Advice or words of encouragment will be appreciated...:-)

[DAEDALUS]

The fuel rail is pretty much just sitting on rubber donuts on the runners. You have to remove the fuel hoses at the rear to remove the rail completly.

[Meaux]

Hey thanks for the pictures!!! Thats alot better than the FSM drawings.

This job would be alot easier with the coolant ports offset, but then I guess it would be a Chevy!!!

Back in the heat.....

[elwesso]

Robert, who's engine is that???

[DAEDALUS]

Whose do you think bro?

[elwesso]

You puttin in a new engine into the Q??? Nice......!

[DAEDALUS]

I really don't know yet. The work's stagnating. I'm low on time and I'm still waiting for parts I ordered 3 weeks ago. I need to get my hands on some REALLY nice measuring tools before I can make a decision about what to do.

[elwesso]

I sense an engine teardown..... with pics!

I cant wait!!

[RobertsnewQ]

What do you need? I've got micrometers and bore gauges and stuff.

[DAEDALUS]

I'll need bore gauges that can read to .0001". Since I have no machinist experience, I think it would be wise for me to pick up an electronic one that records the smallest measurement so I can just rock the gauge back and forth in the bore.

[RobertsnewQ]

Sure thing - I've got standard Starrett internal expanding micrometers with .001 graduations.

[Q451990]

Removing the runners looks like it would make the job a lot easier... seems like I checked back when I did mine, but the runner gaskets were pretty expensive...

Nice pics!

Heath

[elwesso]

Removing the runners looks like it would make the job a lot easier... seems like I checked back when I did mine, but the runner gaskets were pretty expensive...

Nice pics!

Heath

I seem to remember asking Joe for whatever reason or another and they were only like $10 each..

Next time I do the plenum id like to remove my runners.....

[Meaux]

Is it possible to remove the bottom belly pan without jackin the car up?

Q451990 says, "Removing the runners looks like it would make the job a lot easier... seems like I checked back when I did mine, but the runner gaskets were pretty expensive...

Is it possible to replace the Knock Sensors without removing the Lower Intake (runner) Manifolds? The less I take apart, the better.

My lower intake runner gaskets cost $16.98ea., but they are not 8 round on each side, they have an oval like shape...I guess they changed em'....Hopefully for the better...

[elwesso]

1. Is it possible to remove the bottom belly pan without jackin the car up?

Q451990 says, "Removing the runners looks like it would make the job a lot easier... seems like I checked back when I did mine, but the runner gaskets were pretty expensive...

2. Is it possible to replace the Knock Sensors without removing the Lower Intake (runner) Manifolds? The less I take apart, the better.

3. My lower intake runner gaskets cost $16.98ea., but they are not 8 round on each side, they have an oval like shape...I guess they changed em'....Hopefully for the better...

1. Possibly. You may have to "go,go, gadget arm" to get some of them off

2. Yes, very possible. It is hard to get that Y coolant thing back in there though..

3. Yeah they changed the design for 94s.

[FarFetched]

DAMN it is spooky looking engine ...

[maxnix]

The fuel rail is pretty much just sitting on rubber donuts on the runners. You have to remove the fuel hoses at the rear to remove the rail completly.

Man, can you all say race engine? As close as you can get in anything not an exotic.

[Meaux]

DAMN it is spooky looking engine ...

Yep, gettin spooker everyday......:-)

I see now I'm gonna have to pull the runners because, I know I can get half the RTV Sealant inside the motor without even trying...:-)

Hell, I've gone this far anyway...Dang thing looks like an 8.0L instead of a 4.5L...

Belly pan came off without jackin her up, might as well find that Power steering leak...:-)

[3Q Jay]

I see now I'm gonna have to pull the runners because, I know I can get half the RTV Sealant inside the motor without even trying...:-)

maybe. are you planning [good idea] to change that 3 inch stub of water hose between the heads? that is the only reason that i know of to pull the y-pipe. i didn't do the ks on my car, they were done at dealer about 1500 mi before i bought it. they did the harness too. i'm quite certain that they did not remove the 'y' to do the ks.i do wish they had, and changed that hose. i'm going to have to go in in a few weeks mostly just for that.

one other thought on pulling the runners: you might be able to do the y hose just removing the passenger side rail and runners. don't undo the 2 bolts on the driver's side head, but just slip the hose out, do the ks, new hose in and put the pass side of the y in.of course, i don't know this from experience, yet---just musing.I would also like to hear from others who have done this. i wasn't wanting to pull the runners when i go in....

[Meaux]

Speaking of that hose, this happened to me about 4 years ago...I started seeing coolant in the valley, checked the "Radiator Cap" and found it bad, rubber was gone. Went to the one of the usual auto parts stores and they sold me a cap (Slant) that was supposed to go on that car...but it leaked also, and the coolant gets blown into the valley by the wind I guess. I looks as though a hose in the valley is leaking...coulda fooled me... If the dealer had told me I had a hose leak, I would have believed it....$$$$$....Got a new genuine Infiniti Cap. Problem solved.

Just something to look at.....

[3rd Q]

maybe. are you planning [good idea] to change that 3 inch stub of water hose between the heads? that is the only reason that i know of to pull the y-pipe. i didn't do the ks on my car, they were done at dealer about 1500 mi before i bought it. they did the harness too. i'm quite certain that they did not remove the 'y' to do the ks.i do wish they had, and changed that hose. i'm going to have to go in in a few weeks mostly just for that.

one other thought on pulling the runners: you might be able to do the y hose just removing the passenger side rail and runners. don't undo the 2 bolts on the driver's side head, but just slip the hose out, do the ks, new hose in and put the pass side of the y in.of course, i don't know this from experience, yet---just musing.I would also like to hear from others who have done this. i wasn't wanting to pull the runners when i go in....

Didn't pull the runners when I did mine. Y-pipe is a pain but not to difficult. When you connect up the coolant hoses to it just don't tighten the hose clamps down til the ends that connect to the heads are bolted in place. You will need to rotate one of them- the one that goes to the driver's side bank (I think) to get it snaked through without smearing the RTV off. Remember to torqe these bolts to specs, especially the KS ones- critical for the KS's to work properly. Always replace harness while there, not a bad idea to do injector harness as well (cheap insurance) and ohm injectors (replace if needed since you don't want to pull plenum again, I'm sure .

[Q45tech]

Unless you replace ABSOLUTELY EVERTHING RUBBER or plastic the odds of under plenum rework are high every 5-6 years [75-90k] anyway.....especially in hot areas of US.....................80k, 180k, 280k on mine.

2.5 months away from 300,000 miles.

[elwesso]

3rd Q is right.... You HAVE to remove the Y thing to get to the KS, its impossible otherwise.. And like he said you have to rotate the one part to get it in there and then rotate it back....

In order to remove the Y, you have to cut the hoses on the Y shaped thing in order to get it out....

[maxnix]

Unless you replace ABSOLUTELY EVERTHING RUBBER or plastic the odds of under plenum rework are high every 5-6 years [75-90k] anyway.....especially in hot areas of US.....................80k, 180k, 280k on mine.

2.5 months away from 300,000 miles.

Slowly, I am learning there is no cheap way unless one wants to endlessly repeat labor.
Modified by maxnix at 4:19 PM 8/13/2005

[RobertsnewQ]

I didn't have to cut mine to get it out. Just unbolt it and it comes out (with some wriggling, of course).

When you reinstall, assemble on the bench with the clamps not tightened and then rotate into place as others have said.

It's a pain, but it's not that bad.

On mine the PO replaced all the injectors, fuel lines and harness, but he didn't do the air/coolant hoses. Of course they started leaking vacuum a couple of years later....

So I checked the KS & harness and they are fine.

[911/Q45]

I was able to replace my knock sensors without pulling the coolant Y.

[Meaux]

Sounds like a trick I'd like to hear more about....What did you do, just pull the metal coolant inlets to the head?

I've gotten as far as pullin the left side runners...and loosening the left side inlet coolant fitting...Takin a break till Monday...

[911/Q45]

I didn't unbolt anything, just used a 1/4" drive socket and long extension to reach the KS bolts. Perhaps the 94 is slightly different than the 90?

[elwesso]

I was able to replace my knock sensors without pulling the coolant Y.

How!!!!?!?!??!

[3Q Jay]

I was able to replace my knock sensors without pulling the coolant Y.

i do not know how. but, i'm sure on a '94 it *can* be done this way, because the light blue RTV is still around my water outlets, even though the ks and ks harness were done on mine at costa mesa infiniti.

btw, the RTV has the same patina of dust and grime as the rest, so i'm quite sure it was not done in the last year, even though ks were.