4.3L Oil Filter Bypass?

BlazerLT · #1 04-09-2005, 08:34 PM

Just gathering information.

Does the filter itself we use have the bypass in it or does the filter assembly whether on the block or in the remote setup with 4x4s have the bypass assembly in it?

I think the oil filter has the bypass but others are stating differently.

Anyone know for sure?

GrandmaGold · #2 04-10-2005, 02:55 PM

I believe, the bypass should be in the aluminum housing that is bolted to where the oil filter would be on a normal application...on the block.

BlazerLT · #3 04-10-2005, 07:37 PM

Quote:

Originally Posted by GrandmaGold

I believe, the bypass should be in the aluminum housing that is bolted to where the oil filter would be on a normal application...on the block.

Thanks bro, yea, I found out that it is.

Thanks for getting back to me though, I really appreciate it.

herkyhawki · #4 04-11-2005, 09:06 AM

Mine has bypass in the block where the adapter bolts to the block.
95Jimmy 4x4

BlazerLT · #5 04-11-2005, 02:45 PM

Quote:

Originally Posted by herkyhawki

Mine has bypass in the block where the adapter bolts to the block.
95Jimmy 4x4

Actually, it is in the remote oil filter housing itself.

muzzy1maniac · #6 04-11-2005, 07:24 PM

I'm a little new to this truck and engine. What is the "by-pass"?

BlazerLT · #7 04-11-2005, 07:29 PM

Quote:

Originally Posted by muzzy1maniac

I'm a little new to this truck and engine. What is the "by-pass"?

It is a pressure relief valve that when the pressure difference between the inlet and the oulet is too much, it will open to allow oil to bypass the filter element so the engine will not be starved of oil due to the oil being too thick because it is dirty, too cold , or the oil filter is plugged.

It is more of a safety thing so your engine has oil at all times even if it is unfiltered.

herkyhawki · #8 04-11-2005, 08:32 PM

Quote:

Originally Posted by BlazerLT

Actually, it is in the remote oil filter housing itself.

There is definitely a bypass in the block, above the adaptor. The bypass in the remote housing bypasses the filter element only. If you have a remote oil cooler, and a plugged filter, this bypass will open and send the oil on to the cooler. Think about what happens when both the filter and the cooler are plugged ( or full of sub-zero temperature oil).
The remote bypass opens to send oil to cooler and BAM ** it all blows. But don't worry, it won't go BAM because the bypass in the block opens to save your ass.

BlazerLT · #9 04-11-2005, 11:21 PM

Quote:

Originally Posted by herkyhawki

There is definitely a bypass in the block, above the adaptor. The bypass in the remote housing bypasses the filter element only. If you have a remote oil cooler, and a plugged filter, this bypass will open and send the oil on to the cooler. Think about what happens when both the filter and the cooler are plugged ( or full of sub-zero temperature oil).
The remote bypass opens to send oil to cooler and BAM ** it all blows. But don't worry, it won't go BAM because the bypass in the block opens to save your ass.

Sorry bro, but no, there is only one bypass and that is through the remote oil filter assembly. There isn't two sets of oil lines, one the ones that go to and from the remote filter assembly to the block, and one set that go to and from the oil filter assembly to the oil cooler in the rad.

The oil cooler lines run through the remote oil filter assembly so when the bypass opens, the oil will bypass the filter element and go straight to the cooler and back to the engine.

This was also confirmed by a ASE certified GM mechanic at a GM dealer I talked to today.

herkyhawki · #10 04-12-2005, 10:59 AM

BLT, Your GM dealer source is incorrect. If you want to really understand this , then keep asking around.
Talk to a machine shop that rebuilds these motors, or go there and look at one. You could also remove the adaptor at your next oil change and see the bypass in the block. You can press the center of it with a small screw driver to see how it opens against the spring pressure. I have one disassembled in my garage right now so I am sure.
Please re-read your own description of how it works and think about what happens if the cooler becomes plugged. If the cooler was plugged, the oil can't flow back to the engine.
There is a bypass in the block, and even if you don't believe it, it will save your engine.

BlazerLT · #11 04-12-2005, 10:22 PM

There is the remote oil filter setup clearly showing the bypass in the remote filter assembly and none in the block.

herkyhawki · #12 04-13-2005, 08:41 AM

Nice documentation. Now if you get a similar exploded view of the Block assembly, you will see the other bypass there. The bypass in the block is not part of the remote kit, it is part of the block ass'y. - so it would not be expected to be shown in the document you posted.

If you really want the complete answer to your question, I have given you a way to prove it. "go to machine shop and examine a 4.3 block, OR remove your adaptor and see it on your own engine". This would be a good oportunity to change the seals on the adaptor. Sorry I don't have camera or scanner to be able to post pictures to make it more clear for you.

blazee · #13 04-13-2005, 08:48 AM

Just throwing my two cents in:

The oil filter itself also has a bypass.

I don't know if the block has a bypass, but even if it did, it would not be shown in BlazerLT's picture. The picture doesn't show anything inside the block. Using that logic...I could use this pic to claim that an engine doesn't have a crank.

BlazerLT · #14 04-13-2005, 07:10 PM

Quote:

Originally Posted by blazee

Just throwing my two cents in:

The oil filter itself also has a bypass.

I don't know if the block has a bypass, but even if it did, it would not be shown in BlazerLT's picture. The picture doesn't show anything inside the block. Using that logic...I could use this pic to claim that an engine doesn't have a crank.

The block will have a bypass on a 2wd truck without the remote oil filter assembly.

The 4x4's with the remote setup has the bypass in the filter assembly.

There is not bypass vlave in our filters, it is a full flow only.

blazee · #15 04-13-2005, 08:35 PM

Quote:

Originally Posted by BlazerLT

There is not bypass vlave in our filters, it is a full flow only.

The box that my NAPA Gold filters come in says they have by-pass valves, that's why I said that our's have the valves in the filters, too.

After reading your reply, I checked the box again. There is a little * right after where it describes the by-pass valve. The bottom of the box says "When Applicable"

After reading that, I checked the WIX website (they make NAPA Gold). You are right our filters don't have by-pass valves.

http://www.wixfilters.com/filterlook...asp?Part=51036

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