[SOLVED] Volvo 240 - identify my hose (intake manifold)

lasercowboy

As I was looking where best to fit the hose for the vacuum ("fuel economy") gauge, I came across this hose on the intake manifold. The spur it's connected to appears to be blocked (and oily) and the other end meets a curious sharp spur on another big oily pipe very nearby. The whole hose is only ~20 cm long.

It can't possibly be fulfilling its designed function as the end on the manifold is fully clogged with oily muck.

My questions for you wonderfully knowledgable folk:

1) What is it, and what does it do?
2) Should I clean it? Should I clean the things its connected to? And if so, how?

In this image, the hose is arrowed. For bearings, the firewall is on the left, and battery is top right corner.

The spur it connects to is clogged up like a constipated whassname

The other end goes to this vicious looking spur

lasercowboy

Forgot to mention: 89 model, B230F, M47, NA petrol.

BradC

Piccy no worky

lasercowboy

ok, should be working now!

volvodriverman

All part of the crankcase ventilation. Down below all that is the flame trap Pull out everything you can & clean it all. There will be a blocked little plastic filter screen in there I'd expect. I tend to soak it all in kero, scrape off gunge wherever possible & blow the rest out with compressed air. Remove the vac nipple on the intake & run a correctly sized drill bit through it. This is usually the cause of oil leaks.

lasercowboy

Awesome - thank you! So I have finally come across the dreaded flame trap...

Any tips on how to remove it easily? It's really tucked under the injector rail there.

lasercowboy

Update: i removed and cleaned the flame trap, hoses and nipple. The actual flame trap was mostly disintegrated, and there's no way it'll ever pull a sensible vacuum... not sure how the engine is running so well! I've taped it up as best I can for now, and a new one is on order.

I'm guessing this means i should probably also remove the oil separator box and clean that out too?

BradC

Absolutely

lasercowboy

Ok, so I took off the oil separator (breather) box. Contrary to internet wisdom, it can be done without removing anything else (neither the manifold nor accelerator cable bracket) if patient and in possession of a socket with extension and universal joint.

Great advice from @volvodriverman and @BradC - the box once removed sounded like a jar of rice... It was full of carbonised particles and in desperate need of cleaning. After much cleaning and scraping, it looks much better, and I've reinstalled (O-ring was still good).

The hose and flame trap housing were pretty disintegrated. I now understand why the car wasn't running rough - the blockages were stopping loss of vacuum! With all of the orifices cleaned out, I won't be going anywhere until the new flame trap and hose arrives. BUT, should be running a lot better once it does and is all installed.

Before:

and after:

BradC

Nice.

A rambling word of advice on the O-ring however.

Many years ago when I overhauled anything I'd make a judgement call on consumable parts and if they looked ok I'd leave them be. That might be an O-ring, bearing, gasket, seal.. you get the idea. Over the years experience showed me that not often, but often enough to note those parts would later fail.

A current example would be my bore pump. It's a 40 year old Aussie made pump with an Italian motor. last year I had to strip it down to replace the mechanical seal. I did an assessment at the time and the bearings felt and sounded great so I left them. 8 months later it started wailing like a banshee, and tomorrow it comes out for new bearings. Had I replaced them at the time, for the price of about $30, I'd not have to pull the bloody thing out again.

Similarly, when I pull the distrbutor out, it goes back with a new o-ring. The transmission? New rear main, torque converter seal and pump o-ring.

You'll be fuming if in 9 months you find a little oil weep from that box and have to pull it to replace the o-ring for the sake of an extra dollar now.

On the flame trap itself. I have a handful of plastic flame traps I ordered from fcp, but in the car I have a washable metal flame trap. Every service it comes out and gets a squirt of carby cleaner and it's good to go.

lasercowboy

You are of course correct - and now I know it's not too much of a bugger to remove, I'll replace the O-ring at the next opportunity once it arrives.

Very interesting to hear that you use the metal ones - the Haynes and even Volvo recommend replacing the metal ones with plastic. Do you find the metal wound one is just more robust/long-lived?

BradC

6 of one, half a dozen of the other. I chuck the plastic ones away and I wash the metal ones out. Since I switched from conventional oil to a full synthetic I find it gets dirty but not coked up like it used to with the cheaper oil. I put the metal one in as a bit of an experiment 4 years ago and its still working for me so I keep it.

lasercowboy

Ok thanks - just curious. Always more interesting to hear people's reasoning than just believing the 'because i say so' Haynes manual (which is actually kinda terrible for the 240, with lots of missing stuff and mistakes).

familyman

I have no experience with plastic ones - yet - but the 1970s models came with metal flame traps as original. I lost count how many times I pulled that thing out and degreased it. Why they recommend replacing it with plastic is beyond me!? The only cavet is - I don't know how the current metal ones are constructed - but the orginal metal ones, the metal is like a strip trimmed off a sheet of corrugated roofing iron, that is then coiled into a circle and stuffed into an outer ring. This is pretty obvious - and you'd have to push it out a LONG way to make this mistake, but you can push the centre out, so it looks cone-shaped. I imagine if you shoved it out far enough, it would come out, and/or be impossible to get it back into its outer shell. (Like trying to repair a bent slinky.)

familyman

Sorry - forgot my point... We had the original metal flame trap on our 1978 244DL - until three years ago when we scrapped the car. That's 35 years with the same flame trap - and no reason why it would ever need replacing that I can see.

familyman

Oh - and one more point...

I have often read about cleaning the flame trap on USA forums, causing oil leaks, etc. However, every time I removed it (once every year or two), it was far from blocked. And that includes the first time I ever did it - which was years after learning of it. I had no oil leaks on a 1976 & 78. (Unlike all the nearly-new Falcons/Commodores/etc. other people we knew owned.)

The plastic flame trap in our current car, 1991 240... I removed it recently. The car only has 40,000km on it. The flame trap was spotless and no gunk in the hoses...

SO - I think the reason it gunks up MIGHT be - regular oil changes!? (I change the oil at 3 month intervals.)