Oil filters flow rates

I just had my oil changed at Jiffy Lube and the informed me that the dealership had put the wrong filter on my 98 Honda Civic DX… they said that the one on my car was for newer models and had half the flow rate of the one required for my car… while I’ve not noticed a decrease in MPG, the car has seemed tired… which I attributed to age and the 97,000 miles. This oil change revealed a bit of oil blow on the airfilter… what damage has been done to my engine?

There’s not enough info here to tell you what, if any, problem you have with your car.
I will say that you should not put any faith, or even your car, in the hands of Jiffy Lube.

At only 97k miles your engine should be fine. The only way it would not be fine would be if you bought the car used and do not know the history or you have run it out of oil, overheated it, or just flat drove the wheels off of it.

Oil in the aircleaner housing could point to a something as simple as a clogged PCV valve. It’s very cheap and easy to install.
If the oil problem continues then a leakdown test could be performed to test the condition of the valves and piston rings.

At this point I would not worry too much.

I doubt if you have a problem.  Decreased mileage would be hard to pin on a smaller oil flow rate.  Even if you had a slower flow rate, it is not likely to have caused any damage, unless it was enough to trigger the oil light.  

Your message has brought up two additional issues. 

First dealers are no better than other sources of car car over all and they tend to be more expensive.  Second All quick lube places should be considered guilty until proven innocent, because they usually are.  Don't visit them, even to ask directions we see all kinds of problems from them. 

Good Luck

Add my voice to the chorus. I would never put much faith in anything told to me by an employee of a “quicky” oil change place, nor would I take my vehicle there for any reason. How do they determine “flow rate” through a filter? I think they were just trying to sell you something.

Even if for some strange reason the dealer installed a smaller filter your oil flow rate would not decrease. There is a bypass valve in the filter adapter on the engine block that opens and allows oil to bypass the oil filter if too much pressure builds up. This is to prevent engine damage in the event that an oil filter is plugged or partially plugged. A filter that is too small would behave similar to a partially plugged filter; some oil would bypass the filter due to the higher back pressure caused by the filter.

Ignore Jiffy Lube. They are not even close to mechanics but simply everyday people trained to change engine oil and sell extra services. I think they were just coming up with a plausible reason to have you pay $40 to change a $5 air filter.

No damage they were just swaying you way off in the wrong direction. I personally would not go to any Jiffy Lube but find a independant mechanic or even use dealer for quickie oil changes(some do at better prices than chains).

There are two types of oil filters. Full-Flow which have bypass valves. This type allows all the oil to flow thru the filtering media and has a by-pass valve in the event the filter media becomes pluuged. And are usually the larger filters. Then there’s the By-Pass oil filters. These filters only allow some of the oil to flow thru the filtering media while the rest by-passes the filtering media. These are usually the smaller oil filters and have no by-pass valve.

Because your vehicle uses a smaller oil filter, it means it’s a By-Pass type oil filter. So there’s no way the filter can effect the flow rate of the oil passing thru it. Even if the filter media is plugged, the oil just by-passes it.

For the oil on the air filter, I would suspect a problem with the PCV system and not with the oil filter.


Excellent post Tester. I see you found your “Bold” text button…

I agree with Tester’s post and I have something to add. Honda used to use a shorter, larger diameter filter for this generation of cars. The newer cars use a narrower but longer filter that works just as well. Honda eliminated the shorter wider filters about a year ago so that the new and old cars all use the skinnier filter. It works just as well and if it is good enough for my Honda dealer it’s good enough for me. The confusion is that the newer filter LOOKS smaller but it isn’t and it certainly does not have a different flow rate. The OP has not done any damage to their engine due to the narrower filter but perhaps they should avoid going to this (or any) Jiffy Lube shops.