Hi guys. Bit of a mystery here. Fairlady Z TT 1991 J reg.

 

I've just had my passenger side front wheel bearing replaced and then gearbox oil and coolant changed. Was checking the gearbox oil level when I got it back from the garage and noticed a disconnected black rubber hose, prob just under an inch in diameter, sitting on top of the engine in front of the battery. It has the remains of some black tape around the end, but is clean. No marks on it, no jubilee clip or any other sign of it being attached to anything. Now I don't know what all the bits of my engine are for, but I have spent long enough looking at it over the last 15 years to know that it has never had a disconnected hose sitting on top!!

 

Took it back round the garage and they've just spent an hour scratching their heads as to what it can be. Got it up on the ramps and the hose is fixed at the other end to something underneath the passenger side front wing. Mechanic says it's not oil, it's not water because the hose is clean. It has no pressure when blown into, either when the engine is running, or when it's not. It's about 3' long. There isn't a similar one on the other side. Was told it's not affecting the running of the engine, but I'm not happy to drive the car until I know what it is.

 

Neither of the mechanics have any idea what it is for or where it has come from :glare:. They've told me to take it back tomorrow so they can strip off the front wheel splash guard and find out what it's attached to.

 

Bit of a long shot, but any ideas please? :blink:

Theres aiv valves and clutch booster tanks under the arch linners maybe be its from a old delete .

any pics ?

could be prvr, aivs etc as mentioned

I should've taken pics while it was up on the ramp this morning. Didn't have a camera with me as I mistakenly thought the mechanic would know what it was :blink:

 

I know very little about mechanics but I've looked up AIV delete and know that nothing has ever been changed from its original set up as it was an (almost) new Jap import when I got it 15 years ago and have done nothing to it at all.

 

If these bits and pieces live under the wheel arch liners, might they have been disturbed when the mechanic changed the wheel bearing? Would they have to take the wheel arch liners off to replace the wheel bearing? Sorry to be dumb, all new to me :huh:

I know for sure this hose wasn't disconnected when it went into garage, so it's definitely something they've done

what garage did you go to?

I had a similar issue when I bought mine. It had a cutting out problem that turned out to be a faulty Mass Air Flow meter. During me mauling about under the bonnet, on the passenger side/plenum/battery area I too found a 'mystery pipe' that had come away from something and disappeared into the wheel arch somewhere at the other end. Took me about 2 days to eventually find where it had come off. Have a look at this pic, the orange arrow is pointing to where it fits/came away......hope this might help

Steve J

I should've taken pics while it was up on the ramp this morning. Didn't have a camera with me as I mistakenly thought the mechanic would know what it was :blink:

 

I know very little about mechanics but I've looked up AIV delete and know that nothing has ever been changed from its original set up as it was an (almost) new Jap import when I got it 15 years ago and have done nothing to it at all.

 

If these bits and pieces live under the wheel arch liners, might they have been disturbed when the mechanic changed the wheel bearing? Would they have to take the wheel arch liners off to replace the wheel bearing? Sorry to be dumb, all new to me :huh:

I know for sure this hose wasn't disconnected when it went into garage, so it's definitely something they've done

 

You wouldn't. the bearing sits in the hub which is easily accessed by simply removing the wheel. get a photo and we will soon work out what it is.

.....it's difficult to see cos it's under one of the thicker pipes.....

Here is a link to the AIV delete, which will show you what is under the arch liners on both sides.

 

http://www.300zx.co.uk/forums/showthread.php?99851-Full-AIV-Removal-For-JapSpec-Non-Turbos-by-DJ_Party_Favor

 

 

Passenger side AIV

 

Drivers arch liner removes to see AIV

 

If you were checking the gearbox level , then you have an autobox, which would have had the oil refilled via the dipstick tube, so if there is a hose off, it could be a vac pipe, possibly from the AIV solenoid.

 

Would be easier for us to diagnose with pics lol, but hopefully print off some of the pics in the link and it may help your garage.

If the hose is off near the battery it could be the pvr solenoid pipe, located on the plenum bracket, which then runs to the carbon canister under the front bumper, so if the hose is off the plenum as in Steves pic, it will aslo affect the running of the engine due to a vac leak.

Many thanks as always for your help guys - you're brilliant :) Have emailed all the info over to the garage and will be taking the car round there shortly. I'll let you know what they say and if they can't find what it is I'll get them to take some pics.

 

Wes, it's just my local garage I took it to, but the mechanic there has owned two Zs. Couldn't drive it any further with the wheel bearing gone. Since you are relatively local, could you recommend anyone for future work?

Think it's the passenger side AIV as shown in Groover's first photo. Where does the other end of this hose go? Is it connected to anything or is it left open to air? And where should it be routed under normal operation? Thanks a lot :)

Do you still have your cats? if you have no cats, then the Aiv system is not required and often the AIV tubes are left open, although the vac pipe on the AIV solenoid needs capping to prevent unnecessary vac leaks.

 

Which hose are you talking about, vac hose or the larger metal tube?

Hi Groover - car is exactly as it was built, I've never had anything done to it. The hose it looks like is the big (non ridged) black rubber one in your Passenger Side AIV photo above

Big hose goes to the air tank in the wing

 

 

Vac line diagram

 

check out this link for all the numbered parts on the engine

http://www.300zx.co.uk/forums/showthread.php?26120-Engine-by-numbers

Hi again guys

 

Thanks Groover, but after looking at your helpful pics, we don't think this is the pipe in question now. It's much longer than that - nearer 4' long. I've taken some pics (see below), but be aware that the garage have tucked a load of this pipe up under the car. Hope they might help :)

 

To recap, save reading all the post, this was found disconnected after auto gearbox oil change. Tape round one end, no sign of any jubilee clips or it being fixed anywhere

 

 

 

Daft test but have you tried blowing down it ?

 

Might give you a fair idea if its connected to anything else if you can feel pressure building up !

I have never seen that hose before lol.

Yes, have tried blowing down it. There's no pressure at all, whether the engine is running or not. It's completely clean inside, never had oil or water in it. Also pretty clean on the outside so must've been well tucked away somewhere

how about getting a bit of cable, say like coax and pushing it down, when it stops going any further pull it out,

 

gives you an idea of how far it goes.

Ive never seen that hose before either lol, must be something someone knocked up in the past for something.

 

I think rather than trying to locate where the pipe might go, you need to see where its coming from under the battery tray, it could be plugged into the air box inside the wing, but i dont remember seeing a hose that long or diameter for it to plumb into on the engine side, slao where mine has been deleted i cant check either.

If anyone reading this post can have a quick look under the bonnet to see if they have anything close, may help.

That wasn't the answer I wanted to hear Z32bolt :laugh:

 

It's about 3' long. Anyone any ideas or have my photos put you off?

I remember nothing of the sort under my battery tray.

Mines a 91 jap tt as well, I'll go have a look asap.

It may well not have been under the battery tray at all - that's just where the mechanic has put it up out of the way. The other end is connected high up under the passenger side wing.

If the hose is connected to the airbox in the top of the wing i would imagine it would join to pipework leading to the front of the car to the air intake piping for clean air to make its way into the aiv box, as its designed to cool the cats i would imagine this is where it should be heading.

Im still searching lol, so when i find the definite answer i will post up.