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Mike6

Vacuum lines - is this a problem?

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When I rebuilt my engine (carb turbo) I replaced all the vacuum lines, cold enrichment valve, non return valve, thermal ignition valve etc etc. Winter then hit and I have covered around 500 miles since rebuild.

 

I was checking it out yesterday, the engine oil is clean and at the level I topped it up to. Coolant is fine and no mayo and there are no leaks that I can find. I should add that I replaced the liners and pistons including new rings etc so oil pressure is at top of guage but drops back on tickover.

 

The vacuum lines appear oily and oil is seeping out a bit around the joints coming out from the carbs and around the non return valve going into the cold enrichment valve. It isnt pouring out but theres enough to show up and the silicon lines seem a bit sticky. I have noticed that also going into the cold enrichment valve is the crankcase breather valve pipe which is supposed to take oil back into the crankcase.

 

It might be that a small amount of oil is normal and its simply a case of the various connection points not being tight enough but can anyone confirm. About the only thing I didnt overhaul was the turbo so if this is spitting out a bit of oil could it find its way into the carbs and then out through those two vacuum connections.  

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Don't know how your 88 works, so not sure where the oil could be coming from, but for a time I tried some of that silicone vacuum hose for the various lines into my plenum and from the charcoal canister.  Not only did that cheap silicone hose get really dirty fast, but it also ruptured with the boost pressure in a very short amount of time (1 day, and while on the dyno)...  So I replaced it with proper pressure rated rubber hose!

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Thanks Travis, something to watch out for. I am beginning to think this could almost be related to the 'more crankcase breather problems' just posted. From the green crankcase breather valve (not a valve at all!) there is a small outlet going into the cold enrichment thermal valve. This is described as a bleed going into the carbs  via the enrichment valve and non return valve. If a bit of oil is being thrown out from the crankcase (i have very strong oil pressure on the quage) then that could be the reason why I am finding some oil in this area. I am still running the engine in so it has yet to settle in.

 

However I did fill the oil level up to the top notch on the dipstick and perhaps I should take out a small amount of oil. My oil pressure guage goes up to 5 before going into the red. The car currently runs at the 5 mark even when hot but drops backaround 3 on tickover so I presume everything is ok??

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