The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support STM Tuned
Please Support ExtremePSI

Oil pump seized

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

503oneG

Proven Member
30
11
Sep 25, 2020
Beaverton, Oregon
So I tore down my block last night and found #2 rod welded to the crank. During inspection I noticed the oil pump was extremely hard to turn. This car is new to me, I have new short block with a good crank but What I’m wondering, is it possible that the balance shaft delete kit caused the oil pump to fail? I’m debating keeping balance shafts on this new block
 

Attachments

  • F7A68C4F-7520-4DF5-930C-2BFAFABC4478.jpeg
    F7A68C4F-7520-4DF5-930C-2BFAFABC4478.jpeg
    1 MB · Views: 56
  • 2ABDFF0C-0EF6-41BB-9957-E7EEC03F8531.jpeg
    2ABDFF0C-0EF6-41BB-9957-E7EEC03F8531.jpeg
    853.8 KB · Views: 70
Last edited by a moderator:
If it used the delete stubby shaft without the oiling groove, then it absolutely could cause the oil pump to seize. The cheap aftermarket stubby shafts don’t have the oiling groove. OEM does. Search on here to find the visual difference
 
You must be logged in to view this image or video.
Awhile back it was a popular thing to have the oil pump balance shaft turned in a lathe to remove the counterweight portion but retain the long shaft. This was done in order to support the pump better -as opposed to having a stubby shaft with much less rotational inertia.

With aftermarket parts of questionable quality being used for bs deletes, I think this might become popular again.
 
Last edited:
Does the b/s delete really equate to significant performance gains? Or is this presumed on some theory, and now everyone who wants to go fast proceeds with this rather simple mod? I’m honestly asking, since this seems like a hugely popular item. Frankly I love how smooth the 4g63 runs in stock form. I’ve owned 4-cyl motorcycles and cars, and they all had a certain amount of characteristic harshness (especially Subaru), except my eclipse, which has a similar sound, but not the harsh feel. I would not sacrifice that unless the power jump were sizable, and the longevity left intact.
 
The balance shafts are not eliminated for power gains at all, they are eliminated to eliminate balance shaft bearing failure and subsequent engine failure.
 
The balance shafts are not eliminated for power gains at all, they are eliminated to eliminate balance shaft bearing failure and subsequent engine failure.

Correct, but I'd say it's more to delete the balance shaft belt, less so for the bearings, but that is one less failure point.

I am a fan of the cut down OEM shafts as @delta448 posted, but on the past couple engines I've used oem shafts cut down to just the stubs and had no issues.

Most of the issue with balance shaft eliminations are the non-grooved stub shaft and improper timing belt tension (too tight).
 
isnt the timing belt tensioned via tensioner?
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top