Low oil pressure...

A salesman once told me that the fuel injected car I was buying needed its choke cleaned... The people who know something about cars work in the service department; those who can sweet-talk a customer work in sales.

Not familiar with your vehicle and its 'little screen'. Are you sure it was 'low pressure', not 'low oil level' alert? Low pressure warning is typically a big red light, saying 'Engine' or something like that, not a barely noticeable message on a little screen.

If it's under warranty and going for service, I would advise you: a) If you are positive about the 'low pressure' warning, not to drive the car and call the dealer for instructions. b) Not to do anything (including draining oil) before you bring it in b) Insist on a service guy, not a salesman explaining what the problem was and how they fixed it. If it was indeed low pressure warning, I would like to see readings from a mechanical gauge (warm engine), even if they diagnosed it as a bad sender.

Hi,

Used? Rental? Either way, don't drain any oil, take it straight to the service dept. where you bought it. If you didn't buy an extended warranty you might give that some heavy thought too. How many miles? I have a great tendency to believe idiot lights and guages, I would probably try to take this car back for a refund. And I usually don't get buyers remorse.

PS Overfilling the oil a little is not likely to make your low oil pressure light go on.

Salesmen are usually idiots and/or completely ignorant of anything but financing terms. Many will say anything to make a sale.

Don't do anything but take it back and explain what it's doing and ask them to fix it. When they claim it's fixed, ask them what they did. It is not at all unusual for the pressure senders to go bad and cause the light to come on indicating low pressure. And it's very easy for them to test the actual pressure by hooking up a real pressure gauge in the shop. Half an hours work and they will know whether it's the sender or a real engine problem. It is very unlikely it's actually overfilled. All the recent cars I've had have shown "overfilled" on the dipstick when the correct amount of oil is put in them. I think it's how the manufacturers cut down on complaints about "oil burning". By making the dipstick calibration so that with the right amount it shows a half quart "over filled", it can burn a quart every 3000 miles but you'll think it only burned half a quart because it would only take you half a quart to bring it back to the full mark. Basically it's a way for the casual owner to think it never burns any oil because it will almost never drop down to the add oil mark because it would have to use almost 1.5 quarts to do so, most cars only burn a quart between changes. Many burn much less.

Hello,

My penny's worth ...

Overfilling can cause serious problems if the crankshaft touches the oil surface and causes the oil to foam. The air in this foam is sucked into the oil pump, and causes the pressure to drop. If this situation persists it can cause damage. Usually it should inflict this damage from the first drive.

I'm not sure, but when the oil level descends below "touch height" as it is pumped into the engine, the oil pressure could be restored, avoiding damage. Anyone can correct me ?

Brian

"Ashton Crusher" schreef in bericht news: snipped-for-privacy@4ax.com...

No, the oil level has nothing to do with the pressure unless there is not enough oil to cover the pump intake. The sender is likely the source of the fault.

mike hunt

"Charles B. Summers, QOF." wrote:

Can we assume you earned your degree in something other than engineering? ;)

mike hunt

Brian wrote:

Thanks everyone... I've already changed the oil, so I hope that didn't screw anything up. It's going to the dealer this week anyway.

It shouldn't. Please post the results when you find out what's wrong.

Can we assume the oil pumps in your cars are happily pumping air like you pump BS?

Apparently your degree in something other than engineering, as well LOL

mike hunt

fan-jet wrote:

too much oil can cause aeration - which WILL cause low oil pressure. Also, gas in the oil will cause "too much oil" and low oil pressure as well.

As a mechanic and former service manager I have NEVER seen a dipstick calibrated to read overfull with the correct amount of oil in it. When full it should read full, and when down one quart/liter it should read low. No mechanic worthy of the name will let a car out the door more than 1/4 quart/liter over the full line (aprox 1/8-1/4")

Average oil consumption of today's fleet is less than 1/2 liter in

5000km or 3000 miles.

You are both wrong and right. Wrong in assuming only low oil level can cause the light o come on, and right in that the MOST common cause is a bad switch.

Foaming oil due to either poor/contaminated oil or overfilling is a VERY real danger.Low oil pressure due to aerated oil IS not only possible, but a serious problem when it happens. Air in the oil compresses, and the oil does not build adequate pressure - and air is not a terribly good lubricant.

The local ford dealer insists my 99 GT 4.6 takes 6 quarts, which is what they put in, which definitely puts it over the full mark. The owners manual for the car says 5 quarts.

My 92 Explorer calls for 5 quarts.

I changed the oil and filter in both about a month ago and put exactly

5 quarts in. I just went outside and verified the dipstick readings. BOTH of them read about 3/8" OVER the full mark. Needless to say, when the dealer put 6 in it was way over although it didn't cause any problems. If you have truly NEVER seen a dipstick read over the full mark when the manufacturers designated amount of oil was put in it either you need new glasses or you have never worked on fords.

1/4 inch over, perhaps. Usually over before running the engine, but on the line when the filter is filled. Depends too on the size of the filter. I have ALWAYS gone by the dipstick when filling. If the manual or chart says 6 quarts I put in 5, start the engine, check for leaks, shut down and top up to the line. On cars I am real familiar with, I put in what I know to be the required amount to hit the mark - and still check after running to be sure it is right.

Gotta be careful to be sure whether the spec is in Imperial qt, US qts, or Liters today - makes a big difference.

4 liters is more than 4 us qts, and less than 4 Imperial. 5 US = 4 Imperial. 3.78 liters = 1 Yankey gallon. Roughly 4.5 liters to the imperial gallon.