'08 Lacrosse low oil pressure

Was hoping to get some advice regarding an '08 Lacrosse low oil pressure indicator. About a month ago, after starting the car and the “dummy” lights going off, a “low oil pressure” readout came up in the odometer area. The words were there for about 5 seconds, then went away. It was odd, but didn’t think too much of it, it went away and didn’t come back about a month later. When it came back, checked oil level and that’s o.k, but noticed a gasoline smell to the oil. Took to dealer on Monday, and they “best guess” changed the oil pressure switch and they said no evidence of fuel in oil - not sure what the “evidence” was. Also, no overflow seen in the crankcase. Next day, indicator comes back on. I’m not “well-versed” in cars, so have been looking around on the nets and have seen this could be anything from intake gasket to pressure regulator to fuel injector that could be the issue. The oil looks normal, too. I’ve also seen that it’s possible to get some fuel in the oil on short trips. I do mostly in town driving 5miles in/out, a little highway driving (for about 5 miles down the highway 2-3 times a week), and errands. Purchased car in 2011 with 33k miles, at 49k miles now. Oil changed about 2.5 months ago.

My concern is that this could slowly be leading up to an catastrophic engine failure, and I’d rather not have to replace the engine. Any advice is greatly appreciated! Thanks a bunch!

A gasoline smell in your oil could be caused by a leaking intake gasket and if so the gas could be thinning your oil which could make your oil pressure light to come on. Take it somewhere else and get a second opinion on the gas smell.

Could be sticking oil pressure relief valve. Since all motors have them. Rare issue though. Or bit of debris can keep valve slightly open. What motor is in car?

Thanks for the comments - I’ll definitely have someone take another look. The Lacrosse is a CX model with 3.8L V6; I believe is in an L26.

This may sound like a stupid question, is there a difference in mean of the oil pressure light and vs. oil pressure message (text on odometer screen)?


Sorry - that would have been a difference in “meaning” of the oil pressure light vs. text

Message says low oil pressure. Shop changes pressure sensor. Message returns? Is pressure really low? Is new sensor bad? Is PCM bad?

Have them attach a gauge and measure the oil pressure, engine warmed up.

I am going to guess that the oil pressure is indeed low because the oil is somehow getting diluted with fuel.

I agree with @shannondarst. Find another shop.

If it were gas dilution, the message came on the next day after an oil change, which seems a little soon for the oil to get diluted. They should have put a guage on it to actually check the pressure and guess that would be the next step. Maybe even you’re going to have to put a mechanical guage in the car just to make sure.

What bothers me is that OP says the oil smells like gasoline. That’s a pretty unmistakable smell, I would think.

It’s a bit premature to suffer a problem like this, but if the oil is gasoline diluted the fuel pressure regulator is a suspect. It’s certainly not difficult to rule out.

As to the oil pressure, the car was purchased with 33k miles on the clock. If it was a lease car that maybe saw one oil change, or none at all, in the first 33k miles then maybe the oil pump pickup screen is coked over.

If your oil smells like gasoline, it must be diluted by gasoline. That alone can cause low oil pressure. @ok4450 is probably right as to the cause. Get a second opinion.

A friend of mine worked for an enterprising car rental company which shall remain nameless. He said that they routinely changed oil on their fleet every 8000 miles.

The “oil life indicator” on the Buick LeSabre I drive regularly has said that the car has had 42% and 38% of oil life left when it was a quart low. Both times in the year I’ve had it, it has been a quart low at 7000 to 7200 miles. I could have added a quart, and probably gone to 10,000 miles between changes, but I changed it instead. Considering that GM warranties their cars, and expects owners to change oil based on those indicators, I think that 10K between changes is probably OK. 33K isn’t.

Thank you very much for all the comments and sorry for the long delay in response.

I took the car in for a second opinion. They hooked up a manual pressure gauge and determined that the oil pressure was normal at start at when running for some time (60lbs). No diagnostic codes, and suggested that a lot of fuel in the oil would give a fuel trim reading. Basically, no diagnosis of why the “low oil pressure” message was coming up. However, they kept the car for a few more hours and looked through some service bulletins. The only thing they said they could find was a service bulletin regarding after-market oil filters cause some sort of issue, and swapped the after market oil filter for an AC Delco filter. This was almost a week ago now, and the low oil pressure message has yet to appear. I drove approximately 200 miles this past weekend to go see Mom for Mother’s Day, and no low oil pressure message during that time. They still didn’t find evidence of fuel in the oil, though a couple days after initially taking the car in, the fuel smell didn’t seem to be a strong. Haven’t checked it since.

So, still no clue as to what happened, but will keep an eye on things until the next oil change.

Thanks again!

Also - not a lease car that I know of - did have a CarFax report before purchase that showed regular oil changes and one owner.

It sounds like they did a thorough job of checking it out. I’m unaware of the TSB they mentioned, but have no reason to question it.

If you have any more problems, write in, but I think you’ll be fine. The uel smell could have come from elsewhere.

CarFax is extremely unreliable as a source of information about a car’s history. The present themselves as if they have some comprehensive source of data about cars’ histories. They do not. And the data that they do have has been shown to be unreliable.

I’m sorry but you can buy AC filters at Walmart for about $4. I know others will argue but why put a Fram, Wix, or whatever on a car that new when you can get OEM for the same price?

What does Carfax show as regular oil changes? Sometimes, regular is not regular enough and one owner means nothing. Mountainbike is also correct about CF being unreliable.

Many one owner cars are dumped after the owners hear some prematurely bad news. I’m not saying this is the case here, but it’s also not exactly a rare thing.