Quick help needed, missing a pipe on back-side of inlet manifold

[Alecci]

Greetings,

I find myself in the need of some quick quality assistance. My car is due for MOT at 11:15 tomorrow, and it's the last available time around my area until the 14th of July so I don't want to miss it or there'll not be much of a car season for my part.

I just replaced a faulty knock-sensor and all went well until was basically finished putting it all back together. Now I'm missing one of the four push-on pipes/hoses on the back side of the inlet manifold. I tried looking about for just short of an hour but I cannot seem to find the last one!

Can someone with a 3200GT take a quick look and perhaps even a picture of these pipes/hoses and, as well as possible, where they originate from?

Any help would be very much appreciated!

 

[ledlights]

Alex,

When you're looking from the front of the car which side has a missing pipe..... If you let me know, I'll have a look.

Regards,

Steve

 

[Alecci]

It's the right side, the top "nipple". Think it's the top one as the lower one goes to the pop-off valves via Y-coupling and this one I have. I'm also sure of the ones on the left side.

 

[ledlights]

On my car both pipes on the RHS go off in the same bundle. They run along the back of the bulkhead under the fuse box and round toward the front of the car. If you can see both small bore pipes under the fuse box, one of them should be unattached! Good luck with finding it.

Regards,

Steve

 

[Alecci]

OK, this isn't going at all well. I've just spent another hour or so looking (not even slept tonight). Wherever I look, there are no unattached pipes/hoses anywhere!

I've copied some pictures from the workshop manual, specifically the chapter named Engine Fuel Supply and its subchapters.

Let's start off with the basics:

Figure 38 of page 48

The above picture tells us that pipes/hoses numbered 2, 4, 6 and 8 are our primary concern here. The relevant caption to the picture reads:

2: Pop-off Valves with Y-coupling
4: Absolute Pressure Sensor Downstream of Throttle (with "hump")
6: Carbon Filter Washing Solenoid Valve
8: Anti-Evaporation System Thermal Valve

Now, these are my findings:

2 - this is the easy one, after re-installing the intake manifold there was only one unattached pipe/hose that were connected to an Y-coupling. It sits to the right of the engine if looking down upon it when standing in front of the car.

4 - this one ought also to be somewhat easy, as I never disconnected the pipe/hose from the Pressure Sensor - and that one is quite easy to find above and to the left of the engine. The pipe/hose that was connected to the Pressure Sensor, however, was not the one with the "hump" as shown in the picture, but another one. I therefore opted to connect the pipe/hose with the "hump" to this "nipple" and instead attached the pipe/hose from the Pressure Sensor to "nipple" 8 instead. The other end of the hose/pipe with the hump is attached to the Thermal Valve, sitting on top of the engine at the far back and beneath the inlet manifold. On my car it's colored in some shade of green.

6 - This is the "nipple" without any hose/pipe currently attached, as I cannot find one.

8 - Following the above mentioned picture as opposed to the picture's caption, I connected the hose/pipe without the "hump" from the Pressure Sensor to this one.

Figure 58 - Page 65

This picture is not in complete harmony with the previous one, its caption reads:

3 - Activated Carbon Filter Canister
4 - Pneumatic Washing Valve (I assume this is the "Carbon Filter Washing Solenoid Valve" mentioned for point 6 above)
5 - Inlet Manifold
6 - Thermal Valve (I assume this is the "Anti-Evaporation System Thermal Valve" mentioned for point 8 above)

This picture does show a "hump" in the hose/pipe that I opted to connect to "nipple" 4 from the previous picture, and whose other end is indeed attached to the Thermal Valve. Seems I made the right choice then...

Now it get's really interesting though.

Figure 64 - page 70

The relevant caption to this image reads accordingly:

5 - Activated Carbon Filter Canister
6 - Solenoid Valve (this is present in previous pictures as well though not captioned by me, this is thus not the same as the Thermal Valve.
7 - Pneumatic Washing Valve (not shown attached to the Carbon Canister anymore, instead to the intake pipe between filter and turbocharger.
8 - Intake Manifold

It's all a little bit confusing to say the least, but I'm fairly sure that it's the pipe/hose for the Washing Valve that I'm lacking, but having spent a total of 2.5 hours looking for it without any progress I'm close to losing heart.

The workshop manual states that "Any overpressure created in the tank (due to malfunctioning of the washing valve or clogged pipes) is discharged outside through the safety valve in the cap which has been suitably set for this purpose." I interpret this in a way that I could, at least for the time being - and in order to reach my MOT time in a few hours - just plug the "nipple" on the intake manifold and drive the car nonetheless?

 

[conaero]

I had the same issue when I refitted my engine. I was scratching my head for days them I found it. The pipe that runs round the bulkhead I had tucked up under the pipe work to keep it out of the way. I did it so well you could not see it.

From memory the other left pipes go under the plenum to the Pierburg valve.

Good luck I hope this is if some assistance.

 

[Parisien]

Indeed Matt.....your mind plays tricks on you......hope you get it sorted in time Alex......but a 4 month wait is not acceptable.......please contact your local MP.......


P

 

[ledlights]

It took me a while to trace last night as both pipes (2 and 6) run together across the bulkhead on the rear right of the engine bay. If you look at the bulkhead fusebox both should be visible under it. One of them isn't connected, so if you pull it, it should come free and you'll be able to reconnect the end - I expect it's just become tucked up somewhere there. There 's so much going on in the engine bay that I wouldn't bother going back to its source, just start at the 2 small bore pipes in the bundle on the bulkhead and you'll find it eventually.

Good luck,

Steve

 

[Alecci]

I plugged the last "nipple" 6 in the first picture, supporting my decision on what's written in the workshop manual and cited above. Going now for the MOT, after which I will remove the intake manifold once again and continue my investigations.

Steve mate,

I'm so grateful for all the assistance you've provided me - both on this topic as well as your own regarding the diagnosing, you certainly are to be commended! I don't know if it's because of your car being RHD and mine being LHD, but the fuse boxes are on my passenger's side, which would translate to your driver's side, the left side if looking into the engine bay when standing at the front of the car and looking down upon the engine. There are only two large diameter hoses under or at all anywhere near the fuse box on my car. I have a bundle on the other side, however, and there I can find two small diameter hoses/pipes only (I took the clip apart to check it thoroughly) - one going from the Y-coupling to "nipple 2" and the other going from the corner of the engine bay (where the carbon canister is located acording to workshop schematics) to the Thermal Valve.

Matt:

I can see Pierburg valve sitting on the left side (your driver's side, my passenger's side), and I can trace it's two only hoses quite easily. They were never touched when removing and re-installing the intake manifold, and they are both attached in all ends.

 

[ledlights]

Alex,

You're very welcome.

I'm sure you'll be fine plugging the port for your MoT. The small bore pipes you mention are the ones the go to that side of the inlet, one goes to the T- valve and the other one is your missing one. Sorry about the misunderstanding regarding the fusebox, if the servo is on the RHS for a LHD car they would have had to switch it to the left.

Hope it passed,

Steve

 

[Alecci]

Good news - the car passed MOT with flying colors, no remarks whatsoever other than that they thought it was in excellent condition. This year's car season is thus saved.

Bad news - when I came back home I took off to a secluded road where there's no traffic or people and tried giving it some WOT. It's slow to build boost and doesn't boost as high as it should. I got to 0.5 bar on 2nd and 3rd gear, a little higher on 4th but not close to the 0.95 bar it's supposed to boost in standard condition.

Steve,

Look at the picture below of the engine bay (actual picture from my car). I have circled the origins of the three hoses/pipes I've managed to find and named them according to which "nipple" they're attached to from the picture in post #5. The horizontal arrow points to the hose/pipe between the Y-coupling and the intake manifold, the vertical arrow points to the hose/pipe from the corner of the engine bay to the Thermal Valve.

The Thermal Valve is named number 4 and sits below the intake manifold at the far back of the engine and to the right in the picture.

These four are all the small diameter hoses/pipes I can find at the back of the engine, and they're all connected to something. It's seems to be simply missing...

Guess I'll take the intake manifold off once again in order to check for air leaks - which may be the cause of the boost problems - anyway, and I'll try to look for the missing pipe/hose then. Not today though, as I worked with the car through the night and only got two hours sleep, but maybe tomorrow. At least the MOT is done now so at least there's no panic and need to rush things anymore.

 

[Parisien]

Good news mostly.....onwards and upwards

P

 

[ledlights]

Okay, the 2 small bore pipes for the ports travel along the bulkhead (where you have a 2 on your photo) and go straight onto the ports on the back of the inlet. It looks a little different to the arrangement on my car, even if you ignore the RHD to LHD conversion. The only thing I can think of is that another pipe from the thermal valve is lying under the inlet, so you can't see it and this is what you're missing.

On the boost issue, it could be that the pressure has caused a prolapse in the gasket in the inlet manifold. I managed to repair mine with silicone but the screws really need to thread locked in place.

Steve

 

[Alecci]

I took the intake manifold off again this morning, and I've spent just a little more than an hour looking for the fourth pipe. It's nowhere to be seen.

Regarding the boost issue, I found a damaged o-ring between the intake manifold and one of the intake ports in the head, guess this may be the culprit.

 

[ledlights]

The same o-ring issue caused my car to stall coming up to junctions, so you've done well to find it. As for the missing small bore pipe.......

Steve

 

[SteveM]

This seems to be a familiar story to mine. I think reading your notes and photos is that you are missing the pipe from a valve that sits between the power steering resevoir and the wing. In my case this is connected to nipple number 4. It is confusing as it is bundled together with a number of pipes including the pipe that drops behind the wheel arch to the carbon wash if I recall correctly(in my case to nipple number 8). The L shaped nipple (no 2) goes back under the manifold to the Y piece and pieperb valve and if you are nogetting boost then a split hose (as in my case) was the problem with boost. The final nipple is connected to teh bottom of the solenoid mounted on the bulkhead(Opposite side from your photo as RHD UK spec). Good luck. Another Steve!

 

[Alecci]

I finally managed to find the missing pipe. It's routed under the intake manifold and I've spotted it several times before. I've even pulled it gently to see if it's attached somewhere, but because it wouldn't move I just assumed it was connected to something else. This time I took apart all the cables and pipes at the rear end of the intake manifold and went through them one by one. It turned out the missing pipe was stuck and therefore wouldn't move. A note on this one though, I can now confirm that it is not connected to the Pierburg valve, but to another Y-coupling with one end going of to each side of the engine (I assume to the pop-off valves).

The Pierburg valve have three pipes, one going to the RHS compressor, the second going to an Y-coupling and thence on to the waste-gates and finally the third venting to the atmosphere.

I've yet to test-drive the car, but I will be back with a report shortly.

 

[Alecci]

Car now behaves as it should, a heartfelt thanks to all of those who have provided assistance and encouragement along the way - none mentioned and none forgotten.

 

[RSM Masser]

Interesting reading - I have replaced both knock sensors, however by not checking all the water hoses I had a small leak, resulting in the intake manifold having to come off again and missing my MoT slot as well! - I should have redeemed the tax as its been off the road since Feb 15th - the offending replacement hose arrived Friday, I wont get a chance to fit until the weekend.

I only had 3 small vacuum pipes on the rear of the inlet manifold - the top left (looking at the manifold as if it was fitted in the car, like the picture) was blanked off - there are two others about halfway down on each side, another under the cover plate to the throttle body.

I did test run the engine after putting all back together the first time - seemed to run okay - no misfire (as previously) I will follow the thread carefully to see ifmine is any different or I've got something wrong

I numbered and labelled mine but was still left with a long pipe with worn off paint that I cant undertstand where it went - so instead of a missing pipe I have an extra one.