GM Truck Club Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
I have a 2005 Envoy SLE 4WD. Just a couple of weeks ago, I noticed my oil pressure moving from 40 psi at idle to nearly 60 psi when accelerating. GMC dealer says this is normal. Anyone else have a similar problem or a possible solution?
 

·
Registered
Joined
·
2,630 Posts
When did you notice this fluctuation? Was it during a downshift? or very hard acceleration?

Sounds like they could be normal readings though.
Your oil readings should fluctuate depending on what the engine is doing. But if it's bouncing around at an idle, then that could be something of concern.
 

·
Administrator
Joined
·
4,886 Posts
Did you just suddenly notice it, or did the rates change over time? Maybe you put a different weight oil in that produces different readings? Just throwing out ideas.
 

·
Registered
Joined
·
2,630 Posts
Maybe you put a different weight oil in that produces different readings?
Good point, we've had some members on this site who've had trouble with their vehicles after taking them to the quick lube shops, and having the wrong weight put in. Have you recently had your oil changed?
 

·
Registered
Joined
·
3 Posts
Discussion Starter #5
The fluctuation happened after a 3 hour trip. It had been 2k miles since the oil change. When the oil pressure started changing, the change oil light had come on. It was another week or so before I got the oil changed.

What happens is at idle the pressure is 40 psi, then just under normalacceleration it will go up to nearly 60. Then cruising it will stay around 50 or so. It used to only move maybe 5 psi at the most.
 

·
Registered
Joined
·
2,630 Posts
How many miles on your rig?
Do you do your own oil changes?
Do you know if a new kind of oil filter was used that is different from the previous one?
At the last oil change was synthetic oil used in place of regular oil, or vise-versa?

I would say do an early oil change, and make sure you get the right oil. I'd also suggest doing the change yourself, if you can. That way you know it gets done right. Oil can break down, and the as it gets older it loses it's viscosity, and becomes thinner. If this oil has lost it's viscosity you're likely to see fluctuations. See what your pressures look like after the change.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #7
21k miles. No, I don't do my own, but I always take it to a GMC dealer. I do not know what kind of filter was used. The last oil change did not use synthetic. When the oil pressure started changing, the change oil light came on, and I got it changed the next week. The light went out, but the pressure still fluctuates. I agree that the gauge is still in the normal range, but it just bugs me when things change with the gauges and I am told from the dealer it's normal. Thanks to all for the replies, it's giving me a lot to think about.
 

·
Registered
Joined
·
2,630 Posts
Sorry I couldn't be of more help. I agree with you about when things change from the norm.
As a last resort, you could take it to another dealer. You'll see that I like to pit dealer against dealer.
I would tell them your story, and explain that the last dealer dismissed your concerns about it, and see if they try to help you out.
In most cases they'll try to go the extra mile to win you over as a customer. If they tell you the same thing then perhaps your engine just passed another break in point.
 
1 - 8 of 8 Posts
Top