Melling Oil Pump, Wet Sump, Internal, Standard Volume, High Pressure, 7/8 in Inlet, GM LS-Series, Each

Fixed my oil pressure problem. Installing it was a hassle but what mechanical job isn’t.

I had a lifter fail on my 5.3 vortec 03 suburban. I pulled both heads, replaced all the lifters, springs and valve guid seals and put in a stage 2 cam. I had decent oil pressure before so I left the oil pump in place. I thought I dropped a bolt down the cam valley though so I pulled the oil pan and pick up tube. I reused the o ring on the pickup tube and that was a terrible idea. After everything was done I started the truck and had 40psi at idle but after the engine warmed up it would drop to less then 10 at warm idle. I decided to just order a new oil pump and because of the choppy idle I opted to up the oil pressure. This pump performs great! I used the installed spring, instiall the bolts hand tight and then spin engine 360 degrees to align the pump and then torque the bolts tight. I primed it by cranking the engine with the injectors unplugged on each valve cover. Once I plugged the injectors back in and started the truck it built pressure instantly. I attached 3 photos, one showing cold idle, one showing cruising and one showing warm idle. Oil pressure peaks just under 80 psi on hard throttle and never drops under 40 now. Very happy, hopefully I get another 240,000 miles out this engine now.

Not sure if this pump or the copper cam bearings that i replaced fixed the problem? No.. New performance build. 50 P.S.I. on Hot idle (I used the spring that came in the pump) at or slightly north of 75 P.S.I under spirited driving situations.. Thank you Melling for giving us broke backyard guys A value priced quality performance pump!! With enough stickers to keep my toolbox plenty fast too!

Great oil pump.

Excellent it’s a MELLING….

Worked great on a 5.3 lm7 holds about 70 psi cold start and 60 warm would recommend this part. Always be sure to take the cover off and inspect inside before installing though!

Don’t be afraid to purchase

really good quality as you'd expect from melling, good value

Great Melling part. Did AFM delete on my 08 Avalanche and decided to replace the oil pump while I was in there. Swapped out the high pressure spring for stock one, but in retrospect I could have just left the spring in. Oil pressure is within spec. 20 psi at hot idle and 10-12 psi increase per 1000rpm

Buena calidad

Genuine OEM from Mellings and excellent quality

قام الفني بتركيب المضخة لكن قام بإزالتها مرة اخرى والسبب حسب قوله أنها أضعف من المتوقع.

Great product but packaging and delivery disappoint. No packaging to protect product and was just left in driveway in full view. So disappointed.