Where to tap bypass feed for GM 3.4L V6?

[Bill Plock]

Razl’s recent Oil Guard EPS-10 install topic has revived my interest in adding a bypass filter to the 3.4L V6 in my wife’s 04 Impala ( I have an EPS-20 on my Duramax Diesel). I have been thinking about where to locate the filter and the best place to tap the feed (I would prefer not to use a sandwich adapter). I’m wondering if I can use the bypass valve service port located near the full flow filter. This is a plug that allows service access to the internal bypass valve. Looks like it would be an ideal place to tap pressurized oil to feed the bypass. For the return I would use an oil filler cap with an Amsoil swivel fitting

Anyone have any thoughts and/or experience on using the GM 3.1/3.4L bypass valve service port or alternatives? All thoughts & suggestions welcome …

 

[Gary Allan]

Hmm..I wonder

I would assume that the service port has access to both sides of the filter oil flow/pressure and seperates them via a spring and ball. So a fitting threaded into it would receive either pre-filter or post filter pressure depending on if the ball was unseated or normally biased.

I think it should work. It would eliminate the need to "T" the pressure sender (one less piece) ..but is in essentially the same location (assuming that your sender is there also) ..so you're not really saving much.

Hopefully someone with more a more intimate relationship with the V6 will chime in here.

 

[Bill Plock]

Gary,

Thanks for your input..

From what I can tell from the Helms factory service manual, the port is on the input side of the full-flow filter and as you said, it would eliminate the T needed when using the OE pressure sender port. It's also in a more convienent location and would allow me to more easily to add a second pressure sendor/aftermarket oil presure gauge (curently has just a warning light).

 

[Gary Allan]

Well, let's think about it a little more. The port must have access to both sides of the filter. The piston or ball beyond or in front of the spring seperates them. By your description, I'll venture to say that if you unthread the plug, you'll pull out a spring and then a piston or ball. That would mean that the port itself (assuming the ball/piston is intact) is open to the engine/outlet side of the filter and that on the other side of the ball/piston is the oil pump/inlet side of the filter.

If it's a piston, there is the possibilty that the length of the piston blocks a side port until it is back seated while compressing the spring during excessive pressure. If it's a ball ..then no worries. There is no way a ball can cover two ports on two planes.

One probable way to tell is if you encounter oil when you remove the plug.

 

[Bill Plock]

Thanks Gary.. I'll take a closer look before proceeding and report back in about a week - headed out for a vaction with the family this morning

 

[Gary Allan]

Well, safe trip and enjoy the fun with the family

 

[Bill Plock]

Vacation was good and summer is just about over. .. So, I finally had a little time to revisit using the bypass valve service port on the 3.4L V6 in my my wife’s Impala for a bypass feed.

Taking a closer look at the helms manual shows that the service port is on the outlet side of the filter (as Gary accurately predicted

). The bypass valve is an assembly that appears to fully captivate the valve … so it looks like the service port should function nicely as a bypass filter feed…

Here’s a picture that shows the service port on the full flow filter adapter …

Now…I just need to find some time to install one …