97blKM6

I wanted to know how hard is it to remove and install and new oil pump in my 1997 Z28 M6?.. and is it worth doing it on my own or taking it to the dealer?.. I appreciate all comments.

1997 Z71

iTrader: (1)

Recently did mine. Unfornunately I had the trannmission out when I discovered a broken pick-up tube on the oil pump. This is on a 94 Formula. There is no way to get the oil pump out with the pan on. I could get the bolts out, but was unable to get the pump out between the pan and the block. I ended up using jackstands to support the rear and a cherry picker to support the front and dropped the crossmember. It was actually very easy. Carefull with the rack-n-pinion steering.

96capricemgr

iTrader: (1)

Oil pumps themselves really don't wear, now the relief spring can get weak and to change it you do have to pull the pump but I feel it important to understand hows and whys.

Why are you looking to change the pump?
If idle oil pressure is low bearings would be my concern, if high rpm pressure is low then the relief spring.

Melling has a $6 all metal drive for the oil pump might as well do that while you are playing. I seriously doubt the ARP version is worth the $12 they get seeing as the stock plastic sleeve is pretty reliable.

Ls1Bait

Yea if you have good oil pressure leave it alone. I had to rebuild my engine so I did a canton oil pan 6 quart and a melling high volume oil pump and I dont worry about anything. you dont want to put a high volume pump in an old motor.

letsrun97z

iTrader: (7)

dealership here wanted 738$ to do mine (gm) parts+labor how many miles on your car?

letsrun97z

iTrader: (7)

did you ever get it replaced?

speed_demon24

iTrader: (6)

Not always true, heres how mine looked with 100k on it.


And to the OP, its not that hard of a job. I changed my pump and pan. With the stock pan it's pretty easy, lower the k-member and take out the back 2 bolts on each side so you can tilt it back, jack up the motor, then unbolt the oil pan and slide it out.

the_merv

iTrader: (88)

It's a fun little project, I have done a couple.

Yes, the Gears in the Pumps do wear, everything wears.

projekt70chevelle

iTrader: (4)

Did mine a couple days ago, replaced it with a melling 155hv. It wasnt that difficult, but ended up taking me two days because advance decided to give me the 5/8 instead of the 3/4 pick up. Brought oil pressure up at idle and wot, but doesnt like to venture far above 45psi... i was hoping more for 60 or so. But im thinking its just the oil i used (mix of syn. mobil 1 5w-30, lucas stabilizer, and a couple quarts of valvoline syn. blend 5w-30 because i ran out) pressure seems to run alot lower when it heats up. But back to the subject on hand, i wouldnt do it if pressure isnt low. And yeah make sure you get the steel sleeve instead of the nylon.

I jacked up the front end, and used another jack on the hub to lift the motor. Gotta pull the starter and a couple motor mount bolts but other than that its not that hard.... just a pain.

96capricemgr

iTrader: (1)

There is a changable spring in the oilpump that bypassesback into the pan when it's pressure is reached.

The above picture looks to me like a debris problem more than wear, I have taken apart a few high milage pumps and never seen anything like that except in the one that had lost rod bearings at WOT, number 4 bearing was everywhere BUT between the rod and journal.

speed_demon24

iTrader: (6)

I know it was a debris problem the point of the post was that you never know what kind of shape the oil pump was in. I'm just hoping my bottom end is ok.
And the stock spring in my pump was weak as hell, it wasn't even seating the bypass valve all the way against the seat.

Formula350

iTrader: (3)

Here's a doosey for ya. This 94 TBI motor with quite a few miles on it (has to be over 130K) gets SEVENTY FIVE pounds still. With a good sensor and gauge lol

So, needless to say, we didn't touch anything that had bearings, or remove the pump any. Just re-gasket the thing, dropped in a B-body LT1 cam (since stock TBI springs can't handle over .450) with the roller setup and reassembled. (Man those springs squat on the lift! Kinda makes me a bit worried now).

Anyways, not to highjack. There's always the quick way to look, and just pull the main cap off the oil pump and see how the compression gears look out. Shiny I believe is normal, and grooved you'd want to worry about. Also, as said, there's pressure kits to buy, and a MUST is getting that metal drive-to-pump sleeve. This block we did had it, so I wonder if maybe it had an oilpump installed sometime in it's life. Again back on topic, our LT1s get 18-15psi oil pressure at idle, and somewhere around 30 (on a higher mile engine) to 45psi driving around. Mine, cold gets approx 55-60 @ 95K miles and about 35-45 (depending on outside temp) warmed up. I just run conventional oil.

If you have a welder, it doesn't hurt to put a small tack weld where the pickup meets to pump, just as added insurance that it either doesn't slip or flat-out fall off (heaven forbid).

The only tip I can provide, is undo the motor mounts and maybe jack up the front of the motor a little to aid in getting the pan off. You may or may not need to do that, but hey, whatever helps

GL, and have fun.

96capricemgr

iTrader: (1)

A high pressure spring to replace the one in the oilpump is $2-5, I keep a few "White" springs in the toolbox just incase I endup inside a motor, have a couple Melling steel sleeved oil pump drives too $7 instead of the $12 for an ARP and seeing as the stock plastic sleeve actually works fairly well I can not believe there is a meaningful difference between a Melling and Arp shaft. Melling afterall is the one making the pump, so I am sure they get it right when not restrained by OEM beancounters.

Just to be clear the reason I have the high pressure springs(65lbs) is not because I think the high pressure is necessary, what I am after is more the fresh spring. The high pressure just delays oil flow being bypassed back to the pan. A HV pump without a high pressure spring will just bypass back to the pan very early.