What is wrong with routing the return oil from a bypass filter down the oil dipstick tube? Yes, I lose my dipstick, but it seems to be a lot better than drilling my cast aluminium oil pan on my BMW 325I. Are there usually "snags" with using the dipstick tube as the return path? I have read that using the oil pour cap on the valve cover can lead to problems with oil getting sucked into the PCV.
Oil Dipstick Return Line?
- Thread starter carock
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The bypass has a certain amount of pressure and I don't think you could just place a return line down the dip stick tube without issues.
I have a return line to the valve cover. Just use one of the Amsoil hollow tap bolts or swivel fitting near the back/firewall part of the valve cover. Hollow bolt is the easy one to do. See the Franz install on this bypass post page for pics. Just don't place the return line near the pvc side, place it on the opposite end of the valve cover.
I have a return line to the valve cover. Just use one of the Amsoil hollow tap bolts or swivel fitting near the back/firewall part of the valve cover. Hollow bolt is the easy one to do. See the Franz install on this bypass post page for pics. Just don't place the return line near the pvc side, place it on the opposite end of the valve cover.
There have been cases where oil entering the valve cover was sucked up into the intake. It can be dangerous in a diesel engine. I once returned the oil to the valve cover on my Peugeot diesel using a self tapping hollow bolt in the valve cover. The engine ran very well on motor oil. You can also return the oil too close to the valves and get oil sucked past a valve stem seal. It is common on heavy duty diesel engines to find an extra dip stick hole. On some engines you can braze a fitting on the dip stick. You can sometimes use a compression tee fitting. On over head cam engines there is so much oil around the cam a little more doesn't hurt. If the fill cap is in a place where there is a easy path for the oil to drain back to the oil pan you are probably OK. Looking back I probably returned the oil to the wrong side of the baffle on the Peugeot. The old 78 Peugeot had a spin on filter. I installed a two port sandwich adapter and solved that problem.
Ralph
Ralph
As long as the line is attached securely to the dipstick tube it should work OK. My only concern would be that the returning oil might be getting dumped onto the crankshaft causing extra drag. You'd have to find a good picture or diagram online of where the dipstick tube enters the crankcase to know for sure.
How big is the dip stick tube?
I would want to make absolutely certain that once the oil warmed it would not try to creep back up the dip stick tube because it couldn't drain fast enough.
I myself have routed the oil back through the oil fill cap. I have had no problems that I can detect, and it is a diesel... I guess it is all in the build of the engine. The oil pumps on the cummins 5.9 push a LOT of oil (40 gpm I beleive) so there is a ton of oil in the valve cover already. I don't have to worry about a PCV system, and I have not noticed excessive blow-by out of the breather tube. Only time will tell, I suppose.
I would have no problem going to either the dip stick tube (if it can handle the flow) or the valve cover in your situation.
I would want to make absolutely certain that once the oil warmed it would not try to creep back up the dip stick tube because it couldn't drain fast enough.
I myself have routed the oil back through the oil fill cap. I have had no problems that I can detect, and it is a diesel... I guess it is all in the build of the engine. The oil pumps on the cummins 5.9 push a LOT of oil (40 gpm I beleive) so there is a ton of oil in the valve cover already. I don't have to worry about a PCV system, and I have not noticed excessive blow-by out of the breather tube. Only time will tell, I suppose.
I would have no problem going to either the dip stick tube (if it can handle the flow) or the valve cover in your situation.
I have a 91 vw jetta with a 1.6 turbo diesel.
It is fitted with a frantz filter. 1st I returned the oil to the oil filler cap, but the oil was sucked into the intake. Then I moved it to the dipstick tube, used 3/8 hose and it worked great. Expect that is was a pain to check the oil.
Bron32
It is fitted with a frantz filter. 1st I returned the oil to the oil filler cap, but the oil was sucked into the intake. Then I moved it to the dipstick tube, used 3/8 hose and it worked great. Expect that is was a pain to check the oil.
Bron32
Carock,
I too considered the dip stick route as the least invasive return option but couldn't "MacGyver" a satisfactory way to secure the line. I ended up buying the Amsoil oil fill cap swivel adapter that works out great. The PCV intake is far enough from the cap that I don't have an issue of oil being sucked in, which was my only initial concern.
If you can think of a good way to secure the return line to the dipstick tube, I’d like to hear about it.
I too considered the dip stick route as the least invasive return option but couldn't "MacGyver" a satisfactory way to secure the line. I ended up buying the Amsoil oil fill cap swivel adapter that works out great. The PCV intake is far enough from the cap that I don't have an issue of oil being sucked in, which was my only initial concern.
If you can think of a good way to secure the return line to the dipstick tube, I’d like to hear about it.
The 3/8 hose fit over the dipstick tube. It was secured with 2 hose clamps. Never leaked. I have since moved the return hose again. I found a small inspection plate on the side of the block, drilled/tapped a 3/8 fitting into it. That's where I return the oil now.
bron32
bron32
I had considered a return to the dipstick tube at one time. What I had sketched:
Get a premade flared steel brake line and push the flare up into your rubber hose ABOUT 3". Clamp the two together near the flare.
You can now insert the steel line into the dipstick tube and can obviously adust the length. Because of where the flare is clamped, you can put the rubber hose over the dipstick tube as well and clamp the hose to the dipstick tube. This 2nd clamp mechanically holds this assembly in place. The first clamp seals your oil flow.
I had also considered buyng a dipstick tube from the dealer since most have one bolt and an o-ring sealing them. Take this new tube and braze, weld, etc a fitting onto it that could easily be removed to insert a dipsitick. (Olympic had actually added a "Y" so the dipstick and the return could be connected at smae time).
I actually ended up creating a "T" fitting in place of my oil plug and returned bypassed oil to the oil pan. One end of the "T" has a plug so I can drain my oil without disconnecting the oil line. I can email photos if you like but plan on posting eventually...
Tim
Get a premade flared steel brake line and push the flare up into your rubber hose ABOUT 3". Clamp the two together near the flare.
You can now insert the steel line into the dipstick tube and can obviously adust the length. Because of where the flare is clamped, you can put the rubber hose over the dipstick tube as well and clamp the hose to the dipstick tube. This 2nd clamp mechanically holds this assembly in place. The first clamp seals your oil flow.
I had also considered buyng a dipstick tube from the dealer since most have one bolt and an o-ring sealing them. Take this new tube and braze, weld, etc a fitting onto it that could easily be removed to insert a dipsitick. (Olympic had actually added a "Y" so the dipstick and the return could be connected at smae time).
I actually ended up creating a "T" fitting in place of my oil plug and returned bypassed oil to the oil pan. One end of the "T" has a plug so I can drain my oil without disconnecting the oil line. I can email photos if you like but plan on posting eventually...
Tim
In some cases wouldn't you be putting the return oil right on a spinning crankshaft? Could you go to a shop that rebuilds your type of engine and do some looking around on a bare block? There has to be some reasonable place to tap into.
It's for fear of something happening to the fitting or hose to allow the oil drain unbeknown, especially during operation. I would rather not for this very reason, but I'm going to install a pre-oiling pump that essentially requires use of the drain plug as a supply, and so I will also return my bypass there as well.
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