Engine Power Loss

[Apex]

Ok, I'll just get to the point. I know exactly why my 3.7 has lost power. I think I may have touched 7000 miles before I changed the oil. It was full synthetic Castrol GTX, but even so, it was way overdue when I finally changed it again yesterday. Working night shift is tough, and it has enhanced my procrastination.

Even After I changed my oil, it still has a noticeable lack of power. My engine's running a couple hundred RPMs higher on the interstate, and even small grades require that I hit the accelerator harder.

My questions revolve around what I have to do to get my power back. Engine flushes? Or is my problem probably more serious and costly? (Which would be my luck)

I took a look at this stuff as well. Sounds about right; compression loss due to not changing my oil. Go figure, I know. Here's the link.http://www.restoreusa.com/Engine_Restorer.html?gclid=CLiph_Xc-pwCFZJM5QodOXrDbA

Any help would be appreciated guys.

 

[Powerslave]

Synthetic oil? You aren't overdue till about 24K miles, only the FILTER was overdue... I have left Syn oil in for over 12K miles, and just changed the filter at 6k, and topped off. The fact is, with full synthetic, theoretically, you can run 50,000 or more miles with just changing the filter every 6000, and topping off. This was tested, and went 100K with synthetic...

There has to be a coincidence here, because a simple oil change won't cause a power loss like that, unless the engine is burning oil, and you'd see and smell that from the tailpipe. If ran fine WITH the old oil in, the newer oil would not make a difference like that. I know what it seems like, but there has to be another explanation. Plus, if you replaced it WITH synthetic, that's even more coincidental...

These pistons have higher up oil rings, for better cylinder lubrication, and there are issues with this design. You would have to have had metal filings in the oil to damage either the cylinder walls, or compression rings. DO a compression test, you'll know right away...

How many miles on the engine?

Also, your link does not lead to data that says the old oil caused the problem, only that with ALL engines, that it happens.

Is there an exorbitant amount of oil in your breather filter? That is, if it isn't so OLD that it would be only because it was NEVER changed... If there is oil soaked or leaking from the breather filter, then you have too much blow-by, thus bad compression rings.

 

[brucebotti]

To me it sounds like it could be a transmission problem (slipping causing rpms to be higher at same speed on Interstate?). Or, you could have a brake caliper hanging up / dragging. Of course this is just a guess on my part. I do know that 7000 miles without an oil change shouldn't hurt it.
Bruce

 

[kb0nly]

7k on full synthetic shouldn't be a problem. I run GTX blend in my vehicles and change every 3k, but even with the blend at 3k the oil looks a LOT cleaner than other brands i have used in the past. I'm sold on the stuff, seems to keep the engine cleaner. Why not run full synthetic? Well its mainly cost for me, and i don't mind crawling under and dropping the oil.

I would guess you have something else causing the problem. When did you last change your air filter? Spark plugs? Any odd smells, something overheating, etc? Any odd noises? Does it feel like its stuttering at higher speeds?? Higher RPM at highway speed could be a torque converter or transmission problem, dragging brakes like someone mentioned, or any number of other things.

A good friend of mine was changing his oil and used the parking brake when he put it up on the ramps. He released the parking brake and backed off the ramps but noticed it took a lot more pedal and RPMs to back up and drive off. The parking brake was frozen part way on even though the parking brake was fully released inside.

 

[Apex]

The more I drive it, the more I feel it's a transmission issue. The first post was after I drove it home from my parents, and though it had lost power. My fingers are definitely crossed.

 

[belvedere]

7k on syn is NOT a problem.