Oil pump sump pickup tube

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05-21-2009, 08:31 AM
RedHeartbeat

Oil pump sump pickup tube

I've had low oil pressure ever since I started my 408 stroker engine, 20psi at idle and about 40 psi at WOT. When you put a stroker crank in you have to put washers under the windage tray to keep the throws from hitting it. I was told by Erik at HKE to be sure to have about 1/4" gap from the end of the pickup tube to the bottom of the pan. I've never really had good oil pressure so it finally bothered me enough that I pulled pan to check the gap that was there. When assembled, HKE had the 1/4" gap they speficied. I have a 4.8 completely stock on the engine stand so I pulled the pan on it and found that GM builds them with 1/2" gap to the bottom of the pan. My first attempt to fix my oil pressure issue is to change my gap to 1/2" like the 4.8L engine has. I also have purchased a new pickup tube to oil pump clamp that uses both bolt holes in the pump to center up the tube inside the pump bore. BRP Muscle Rods Your LS1 - LSX Conversion Kit Specialist I also noticed when I took the pump tube out that it had the thinner blue o-ring. I have a stock 2004 6L o-ring and its red and a whole lot thicker. I'll be replacing that while I'm in there. Hopefully this fixes the oil issue. What I'm thinking is that with the sump being too close to the floor of the pan the pump was cavitating and pulling lots of air up with the oil.

Wish me luck. :laugh:
05-21-2009, 08:42 AM
TurboMic

sounds like a good plan.
05-21-2009, 09:44 AM
SCIV

I thought 1/4" was the MINIMUM gap? I am betting it is the O-ring. My 408 saw 80 psi @ WOT.
05-21-2009, 09:47 AM
mean05

Man that sounds like a lot of work, but i have the same issue, the new motor idles at 25ish and cruises at 40ish
05-21-2009, 09:49 AM
PurpleMinivan

I had the blue o ring in my 418 and the same low oil pressure... Sending you a pm Greg!
05-21-2009, 09:50 AM
RedHeartbeat

I was just over on HotRod magazine's site and they had an article recommending 1/4" but it was on the old school gear drive pumps. Not sure if gerotor design would be different. I know what GM does works so I'm going to try it.
05-21-2009, 11:13 AM
SCIV

What oil pump you running?
05-21-2009, 11:18 AM
RedHeartbeat

Stock 2004 LQ4 pump, I think. I'm not sure since HKE put it in.
05-21-2009, 11:20 AM
SCIV

Triple post FTW! Drinking already Greg?
05-21-2009, 11:25 AM
RedHeartbeat

Weird. Fixed.
05-21-2009, 11:32 AM
PurpleMinivan

Quote:

Originally Posted by SCIV

Triple post FTW! Drinking already Greg?

I saw that too :lol:... must be nice to be a Mod:greg:
05-21-2009, 11:56 AM
RedHeartbeat

There are a couple perks but anyone can delete their own posts. :)
05-21-2009, 12:45 PM
George C

your issue was due to using the Fbody O ring. its a thinner O ring used for the cars pick up tube. the trucks run the fat Red Oring.

my 408 had 60psi at idle

http://i172.photobucket.com/albums/w...s/Oring004.jpg
http://i172.photobucket.com/albums/w...s/Oring003.jpg
http://i172.photobucket.com/albums/w...s/Oring002.jpg
http://i172.photobucket.com/albums/w...s/Oring001.jpg
05-21-2009, 06:01 PM
GasGuzzler

Just replaced a pump in a 06? 6.0 for low oil pressure (stuck regulator valve) and it had an orange/red oring. Check that valve while it's apart!
05-21-2009, 06:03 PM
PurpleMinivan

Great example pics George.... Sticky Thread with some cleaning up?
05-21-2009, 06:06 PM
SCIV

So since I am swapping to an f-body pan & pickup tube, I need to swap from my current red oring to the thinner blue one?
05-21-2009, 06:11 PM
PurpleMinivan

Quote:

Originally Posted by SCIV

So since I am swapping to an f-body pan & pickup tube, I need to swap from my current red oring to the thinner blue one?

I'd make the red one fit... blue O ring is flimsy. I have one if you really want to use a blue one.
05-21-2009, 07:46 PM
zeake

Great info in this thread. I want to know the end result.
05-21-2009, 07:51 PM
George C

Quote:

Originally Posted by DBTBSS

Great example pics George.... Sticky Thread with some cleaning up?

i learned the hard way. that was from the 408. fired it up got camera out and did my walk around. checked motor 2 minutes later and had no oil psi. i was freaking out. it had it on start up.. pulled it all apart and seen the O ring from the Fbody on there. orderd the big fatty and had great psi. what a pain it was
05-22-2009, 12:33 AM
RedHeartbeat

well, couldn't use the aluminum clamp I bought for the pump/pickup tube. The sump tube I have is the new design with the floating clamp, not brazed on the tube like in Quik's pics. I put the new red o-ring on and put it all together. Put new filter and oil in it and fired it up, NO OIL PRESSURE!!! It was better before. :laugh: Now I have to find out if I broke a wire or something in the OP sending unit. I pulled the oil return block off above the filter and oil poured out so there is oil flow. I am going to put a manual gauge on it tomorrow to verify there is pressure before going any further.
05-22-2009, 07:41 AM
Ramsey

Yeh ide like to know also .I used the red oring on mine and still idle at 30 and cruise 40-45 and my motor is new from gm.
05-22-2009, 09:36 AM
RedHeartbeat

I've often wondered why we just don't put two orings on the tube. Any ideas?
05-22-2009, 10:10 AM
SCIV

Quote:

Originally Posted by RedHeartbeat

I've often wondered why we just don't put two orings on the tube. Any ideas?

Theory sounds good. Nowhere for them to fall off to, and there is plenty of room for them??? I guess if the tube didn't seat all the way, it could bet sucked into the pump? No, that doesn't seem right or it could suck up the single just as easy.
05-22-2009, 08:00 PM
txarkitekt

Greg, how long did you let it idle before you shut it off? Usually you have to let it idle for a minute or give it a few revs before you see oil pressure on the dash gauge...when replacing a pickup tube o-ring.
05-22-2009, 09:12 PM
RedHeartbeat

it ran for a good long time. I put a manual gauge on it tonight at the block above the oil filter and the OP is low and comes up with RPM but not very high. I pulled it back apart tonight, going to check out the pump and see if the regulator spring/piston are stuck or something. This means tearing the whole front of the engine off. :sad: I hoped I could access it from the bottom/oil pan are but no luck. :grr: I sure didn't want to have to pull it all apart but sometime you just gotta do what you gotta do.

I saw a picture of a pro engine builder putting silicone from a tube onto the oring before putting the tube into the pump. I might give that a try too, just gotta be patient enough to give it time to set up before I start the engine.
05-22-2009, 10:46 PM
408.Luke

did u tear the O-ring? it happens alot. i had a 1/4 in gap between the pan and pick up tube on my 408 and i had the red oring had 55-60 psi at cruse. also did u put oil back in it? :lol: j/k but it might be something simple.
05-22-2009, 10:51 PM
GasGuzzler

From experience I know the cap comes off to get the regulator spring and valve out with only the pan off.

I thought I told you to double check that valve! :spit: Sorry for the trouble.
05-22-2009, 11:48 PM
RedHeartbeat

You can't get to the regulator spring with the front cover on with my type cover. Not sure where it came from, truck or fbody, but you cant get to the cap and then there would be no access to the spring or plunger.

Yes, there was oil. Took it back apart and the oring is in as good condition as when it went in. This thing has never had any good oil pressure numbers for some reason though its survived 30+ bottles of about 225 HP sprays of nitrous to it.
05-22-2009, 11:51 PM
GasGuzzler

Maybe the chassis is different or maybe the pump is. Mine might have been a tad newer and was factory installed in its engine and chassis. I know it would have come out because I pulled it to see what was the deal but then tore the front off anyway to go ahead and replace the pump to make sure and CMA.
05-23-2009, 01:21 AM
COWL327

I did the same thing Greg....I used 2 black orings.It was sunday morning and I wasnt going to find the correct oring...LOL I think there is room for improvement on the tube clamp itself,as well there are 2 holes in tyhe pump but mine only used one....kinda lop sided to me
05-23-2009, 02:20 AM
George C

maybe you just have loose tolerances in your bearings
05-23-2009, 03:11 PM
RedHeartbeat

Just got through watching today's HorsepowerTV where they are building up an LQ4 and they had an issue with the oring on their engine too. It's all about pickup tube alignment for them, they slotted the mount that goes on the tube, the one in the middle, to take some load off the oring. This is such a bad design that the problem is posted all over the internet. GM needs to reinvent this wheel. The show will be aired again tomorrow AM for those of you interested in seeing it. THey took a stock LQ4 with electric water pump and headers making 380s in HP on the engine to 411 with a cam and springs and a tune update. Next week they put on a FAST intake.
05-23-2009, 08:43 PM
DBRODS

Greg.....
http://www.ls1truck.com/forums/mecha...ow-volume.html
05-23-2009, 08:50 PM
Beatdown Z

Quote:

Originally Posted by RedHeartbeat

Just got through watching today's HorsepowerTV where they are building up an LQ4 and they had an issue with the oring on their engine too. It's all about pickup tube alignment for them, they slotted the mount that goes on the tube, the one in the middle, to take some load off the oring. This is such a bad design that the problem is posted all over the internet. GM needs to reinvent this wheel. The show will be aired again tomorrow AM for those of you interested in seeing it. THey took a stock LQ4 with electric water pump and headers making 380s in HP on the engine to 411 with a cam and springs and a tune update. Next week they put on a FAST intake.

They already aired that episode. With the FAST intake and a new tune (adding 10* timing) they ended up making 514 HP.
05-23-2009, 08:53 PM
408.Luke

they got 103hp out of a fast intake dang!! :lol:
05-23-2009, 10:27 PM
GasGuzzler

After my fone convo with you this topic update is more funnierest. :LOL:
05-24-2009, 12:03 AM
RedHeartbeat

I tried doing what you're talking about Jon but the weight of the pickup tube screws with everything. The truck style pickup tube actually has a retainer that floats on the tube rather than being brazed in a fixed position. If the retainer were brazed into a fixed position, the procedure you documented would work great. Now I have a fancy little aluminum oil pump clamp I can't use. :sad:

I'm afraid the pressure regulator spring is faulty. Anyone have a pump laying around they're willing to pull the spring out of and see what color the paint is on it and how long it is? My spring was white and only 2.000" long. Its appearantly not made of quality spring steel because if you compress it you can make it shorter, if you pull on it the spring becomes longer. I stretched it to 2.300" long and now I have a little better pressure but not where I want it to be at.
05-24-2009, 11:33 AM
GasGuzzler

I threw that pump away we talked about yesterday but it had a yellow or white (?) spring...
05-24-2009, 12:13 PM
RedHeartbeat

it was a bad one though. :laugh:

Didn't recycle that chunk of aluminum. I thought you were a hippie, aren't hippies big into recycling to preserve the environment? :laugh: I'm not a hippie, I'm a packrat/hoarder. :LOL:
05-24-2009, 10:57 PM
GasGuzzler

I have a pile of aluminum castings in my work area. You know I do...

Moze, Ryan, Rob, Mitch can I get a hell yeah?!?!?

:spit: