oil pump going bad?

Snowwhitez71 · November 22, 2015

What are some signs that my oil pump is going bad? I've yet to have a mechanical gauge put on it but I'm thinking this is what my problem may be. I've checked my oil level and its been reading full and lately its been having a tick type of sound when its warmed up. Also, if it is the pump that's bad what are some good replacement pieces I can use. I have an '04 tahoe z71 with the 5.3 under the hood.

JaBradt85 · November 22, 2015

www.Rockauto.com

jcmd · November 23, 2015

What is the PSI reading on the dash oil pressure gauge at idle and under heavy load (like accelerating onto the freeway)?

Snowwhitez71 · November 26, 2015

From an ice cold start I have 40 psi but as the truck warms and is idling it drops to the last hash line (5 psi?) before 0, when the motor is put under a load it shoots back up to 38/39 psi. I was thinking that maybe the stepper motor in the cluster has gone bad but I'm rethinking my thought process being that there is a ticking sound when the truck is at idle and that's why I'm considering either the pump is shot or the pickup tube is clogged and not getting enough oil to the pump for it to operate correctly. This truck is my daily driver and this has been going on for quite a while, i just haven't had much time to try and get it addressed the way it should've been done.

jcmd · November 26, 2015

Did you try the pickup tube o-ring? If the o-ring is old, air can get sucked in and there is volumetric oil pressure loss. I had similar pressure issues and did the pickup tube o-ring. Now I have roughly 50 psi at start/idle and 60-65+ under heavy load. I suggest pulling the pan (which is a bit of a pain, but do-able) and cleaning the pickup tube/replace the pickup tube o-ring before the pump to rule that out first.

Snowwhitez71 · November 26, 2015

Ok I'll look into that this week coming up, I did have something new happen when I was leaving work. I hit the remote start and on start up I had a plume of blue smoke come from the exhaust, I do know that it's an oil burn indication but I'm wondering if there might be something more going on internally now?

Wires · November 26, 2015

Typically that sort of behavior from the cluster is either a bad sending unit, or stepper in the cluster. (The mechanical guage reading would sort that out).

Ticking can be caused by many things. My '00 5.3L had a tick, and it was an exhaust leak my the manifold. My '08 6.2L has the TSB diesel chatter sound while it warms up.

Snowwhitez71 · November 26, 2015

I was on that wavelength with the stepper motor in the cluster but I'm not 100% sure, I did forget to mention that there is a slight leak on the right side of the motor and that's another piece in my thinking it may be a mechanical defect

Snowwhitez71 · November 27, 2015

https://youtu.be/HsKqnm4XMVo

This isn't my truck but this is the same issue that I'm having, the only difference is that I have the low oil pressure alarm going off when at a stop/idle

jcmd · November 28, 2015

I'd check the sending unit for sure.

Snowwhitez71 · November 28, 2015

I did the oil pressure switch a couple months ago and still have the same issue, spoke with a tech from the shop I go to for service and he's thinking it may be the bearings are shot causing the oil pressure issue. Gonna have them check it out on Tuesday. He does seem to think that the motor could be done but can't say definitely w/o the reading from a mechanical gauge. If that is the case would it be more beneficial to have another engine put in or get rid of the truck for something else???

txab · November 29, 2015

Did you check the o-ring

Wires · November 29, 2015

Personally, I'd just toss on a mechincal guage to confirm before speculating on anything. It could be bad gauge cluster to blown motor. That's a wide range from phew to fark....

Snowwhitez71 · November 29, 2015

That's the idea for Tuesday, I'm trying to keep positive vibes that this can be rectified soon

jcmd · November 29, 2015

x2 on another gauge to test first. If that confirms low pressure and if the o-ring has never been replaced as far as you know, I'd definitely suggest trying that as well before you do a motor swap. My oil pressure would drop near zero sometimes and a few times the light did come on as well. The o-ring combined with cleaning the sludge out of the pan and flushing the pickup tube while it was out has helped for many, myself included.

I used a Fel-Pro FPG 72401 o-ring ($2.29 at NAPA). You'd probably want to do a new pan gasket as well, which is pricey ($47.99 Fel-Pro at AutoZone). You have to drill out the alignment rivets on the OEM one if it hasn't been done before, but it's all not too hard. All of this is definitely cheaper to start with than a new motor!

Here is a YT video that helped me: