oil vapour separator

[markko]

Hi everyone,

I am thinking about removing and cleaning the oil vapour separator in my 78. I don't know that it's ever been done, and the hoses don't look quite kosher. (The small hose is wrapped in what looks like electrical tape!) I have read elsewhere in this forum that this can be quite difficult. It seems that it's easier to attach the hoses with the separator removed. It's hard to believe that the separator can be removed without first removing the intake manifold, but it seems that it can. There is barely a finger's worth of clearance between the bolt that holds it in and the bottom of the manifold. I have read, however, that it doesn't take much to free the bolt, after which the separator will slide out, I assume away from the block rather than towards the radiator.

I plan to clean the separator and replace the hoses, gasket, and flame trap. It looks like removing the dipstick tube would ease access; does that seem right? Are there any other tips, tricks, or traps that I should be aware of?

Thanks

[18Fiatsandcounting]

A few thoughts:

- The separator can be removed without removing the intake manifold, but it is tricky. I seem to recall it was actually easier when working from underneath the car, at least some of the time. It also depends on what style intake manifold you have, and the 2L engine is easier as it is taller (not that this helps in your case).

- Definitely disconnect the battery before starting the work. All you need to do is drop a wrench or the like between the engine and that positive post on the starter motor (which is live all the time) to demonstrate the concept of arc welding. Could also start a fire given how close you are to fuel lines.

- If you're going to replace the two hoses (the small angled one and the longer curved one up to the carb, just cut them off with an x-acto knife or the like. Makes life easier, and you don't have to mess with loosening the hose clamps.

- The long bolt that holds the separator to the block takes a 13 mm wrench.

-Bryan

[Odoyle]

If you have a single plane manifold I am almost certain the intake manifold will have to be removed in order to take out the long bolt that keeps the separator bolted to the block. You will also have to drain coolant as there are ports through the manifold.

[markko]

Thanks for your help 18fiats and odoyle. Stupid question time: how do I tell which manifold I have?

[18Fiatsandcounting]

Stupid question time: how do I tell which manifold I have?

If you can get us the Fiat part number that is stamped on the manifold between the #2 and #3 cylinders, we can figure out what you have. For example, on my '71 Fiat (not a single plane manifold), the stamping numbers are:
"125BC.040 – C1 4248068 – AS.9"

-Bryan

[markko]

Hi Bryan,

This is what is stamped there:

FF 134 AS6C S62 4372291

Thanks for your help.

[18Fiatsandcounting]

I think that casting number is for your 1800 cylinder head, not the intake manifold. In a list I have, the 1800 cylinder head is listed as 134 AS 4372291. The other numbers are probably date codes, the casting factory, or US vs. European, etc.

Actually, now that I think about it, the casting number for the intake manifold may be on its underside, visible only from underneath or when you take the manifold off. I'm guessing that your intake might be a 4334448, which was used on some 1800 engines. Again, just a guess. If that is what you have, it's known as a "single plane manifold", and is considered pretty good in terms of performance.

I don't recall having removed the oil separator on an 1800 with the manifold on the engine, so I don't know if it can be done. As Odoyle noted above, it might be next to impossible. I know I have done this job on a 1438 cc and 2L engine without removing the manifold, but those are different.

-Bryan

[markko]

You're right. Those numbers are on the head. I don't see any numbers on the manifold, and I haven't crawled under the car. I don't want to take the manifold off, so I think I may just replace the hoses and clean the separator as well as I can without removing it. It looks awkward but possible. Any advice?

[manoa matt]

You do NOT have to remove the intake manifold to get the oil vapor separator out. Just did it last weekend.

[18Fiatsandcounting]

Here's how I would do it: Cut off the hoses to the oil separator with an X-acto knife. Get a 13 mm wrench on the long bolt that hold the separator on, and slowly work it off. From below or from on top; whatever works best. Once the bolt is loose, it should angle sideways, and you can then pull the separator off. Clean everything up, put the new gaskets in, put the new hoses on, put the long bolt back in the hole, and then curse and grunt until you get the bolt to grab the threads. Make sure your gasket and hoses are all lined up, and tighten up that bolt. When done, power down a beer. Maybe more.

-Bryan