Mouse or others, car questions

[blueaguave]

I just got a 98 Neon (for free, remember). Anyway, the oil pressue light flickered on and lingered for a few seconds at a "warm start up" (after driving all over town and stopping for gas), then I added oil and haven't seen it since. My understanding from older cars is that you never want to see the oil pressure light at all. But in this car, it looks like it burns a little oil,and as long as I top it off once a week it shouldn't be an issue.
So, do the newer cars use this light to tell you oil is low? I don't think the engine compression is shot, I don't hear any knocking or tapping, it is only 5 years old. I am getting a tune up soon anyway. But I have been lead to fear this light, but it would have come on at long stop lights if it is a major problem, right?
Thanks

[blueaguave]

I would ask some dudes I know, but you know more about cars than most guys, thanks!

[beffie]

I should let Flash field this one.

In my experience... You should get it looked at by someone knowledgable (at a garage or if you know someone) and if there is a problem get it fixed as soon as possible. And since you got the car for free (my one sister gave me her old car once, best one I've had yet!), if you have to invest a little money to get it in shape/keep it fit it's worth it! You should treat your car like you would treat your lover as long as you take care of it's needs and keep it happy... you'll be happy too! HEY! It was a man that told me that! LOL GOOD LUCK!

I'm not familiar with Dodge Neons, but with Chevy Cavaliers(1984) it can kind of "pounce" on you and "throw a rod" = NOT good!

[Mouse7088]

LOL Blue!! You wouldn't believe the car task we had this weekend (changed head gaskets, valve cover gaskets, Intake manifold, the whole kit-n-kaboodle)...sooooo boy do you have some timing! LOL!
Ok...here are some obvious and maybe "not so" obvious questions.......

Are you POSITIVE you are using the correct oil weight when you're "topping it off"???? Or even when you have changed it completely? Believe me, this is ez to confuse, Kenny thought the Jeep was 5 weight, nopers..I found out it took 10.

When you go to top of the oil is the cap at ALL difficult to remove??? Once yu DO remove it is there ANY milky looking ring on the underside of the cap??
Are you POSITIVE when you put the cap back on it is threaded correctly and tight?

Are you noticing ANY uncommonly more usage of coolant??

[blueaguave]

Originally Posted by Mouse7088

LOL Blue!! You wouldn't believe the car task we had this weekend (changed head gaskets, valve cover gaskets, Intake manifold, the whole kit-n-kaboodle)...sooooo boy do you have some timing! LOL!
Ok...here are some obvious and maybe "not so" obvious questions.......

Are you POSITIVE you are using the correct oil weight when you're "topping it off"???? Or even when you have changed it completely? Believe me, this is ez to confuse, Kenny thought the Jeep was 5 weight, nopers..I found out it took 10.

When you go to top of the oil is the cap at ALL difficult to remove??? Once yu DO remove it is there ANY milky looking ring on the underside of the cap??
Are you POSITIVE when you put the cap back on it is threaded correctly and tight?

Are you noticing ANY uncommonly more usage of coolant??

I believe it was changed and topped off at the correct weight, 10W30. In fact, my first instinct was to add 10W40, a heavier weight, since the oil pressure light flickered on. But, I added the correct weight, and it has not come on since. Anyhow, my understanding is that using heavier oil is just "buying time" if your car really has compression problems.
There is no residue and I believe the cap was properly put on and not hard to remove.
So, I think it was just low oil, and I had been driving around a lot on an unusually warm day (for winter).
I mean, the only other thing I can think of is the oil pump is starting to go, but then I would see it on a consistent basis.
thanks Mouse!

[Mouse7088]

Oops...just thought of a couple of more things, hee hee...

Have you changed the oil filter? Is IT on snug? If you did replave it did you wipe a layer of oil around the "brim" before installing it?

Has your temperature gauge been reading the normal temp??

K..lastly, have you disconnected your battery at any time since you've had your car? Our 95 Olds has all that computerized "stuff"...when I disconnect the battery for any reason I have to drive it for like a mile at 35 mph so it resets itself, like relearning.

[blueaguave]

Originally Posted by Mouse7088

Oops...just thought of a couple of more things, hee hee...

Have you changed the oil filter? Is IT on snug? If you did replave it did you wipe a layer of oil around the "brim" before installing it?

Has your temperature gauge been reading the normal temp??

K..lastly, have you disconnected your battery at any time since you've had your car? Our 95 Olds has all that computerized "stuff"...when I disconnect the battery for any reason I have to drive it for like a mile at 35 mph so it resets itself, like relearning.

actually, the first thing I did is get under the car and tap the oil filter to make sure it was secure. The temperature guage has been reading normal, in fact, if anything this car runs a little "cold", the fan kicks in before the guage reaches halfway, which is bad for mileage but obviously good from an oil pressure standpoint (in any event it hasn't changed)

I had the battery tested, but it was at the same time as the oil change.

So,do you think it was just low oil on a warm day? Whats the verdict, MS Good-wrench?

[Mouse7088]

Wanna know my "true" thoughts??? LOL! I think trying to use a heavier weight oil is ok IF you hear that dreaded slight tapping, JUST because of any wear and tear you and you bro may have put the engine through...more like if your brother drove it a lot or in the case of seeing that glaring Check Engine/ Service Engine soon light. Otherwise stick with the recommended oil weight.

Now...it could have just been on THAT day it was (the oil) was low, but you could also have a leak in a gasket, WHICH will only get worse over time. You could also have a fairly simple "O ring" leaking...which was something we ran into Sunday AFTER all of the gaskets were replaced.
Is your exhaust more "stinky" and/or more white? You are definitely burning more oil some where when you notice that.
I'm glad to hear there is no temp. change or coolant usage.
Remember that PCV Valve can also make your warning lights act "off".
Make sure you're not overfilling your oil when you're topping it off. If you know someone that works on cars you can go to Advance Auto Parts (not sure about Auto Zone) a get a "doohickie" (lol) on loan to check your pressure....I'm not sure, but I *think* you have to have an air compressor. I wouldn't feel too comfy about having to top off the oil on a regular basis...like as in weekly. The garage I initially took my car to just to have this test ran was going to charge me $27 for a half hour test...it was worth it to me insteads of running around trying to get an air compressor, BUT they didn't charge me for it...the slip said $54 for that thing...not because they had my car under this test, but because my car was there longer than a half hour (mind you my oldest son kept watch to see when they pulled my car out of the parking space and into the garage)....uhhhhhh, I don't think so. My butt wasn't going to pay anything other than $27 since I was there the whole time w/ my 3 kids watching Ed, Edd and Eddy!!!!! I can do that at home for free...
If this light comes on again...try to get it looked at...ya know, it could even be one of those deals where it's JUST the stupid light flickering...LOL! My old boat of an Olds had the "Check Engine" light on for about two years...LOL...I had around 300,000 miles on it so there WASN'T a problem with the engine..LOL!

[Mouse7088]

Crud...another comment I forgot in my above post...the oil pump..could be of course or some sort of goofed up oil pressure sending unit..somethin' like that. As you know, I don't know all of the correct terms Anything to do with oil leaks these days instantly makes me think of head gasket or intake manifold...SOOOOOOO I could be having a one track mind right now..LOL! The older cars are so much more "right to the point"...not all of that computerized gadget stuff. Remember....you also may want to look at the fuses for those nice little "warning" lights.
Ummmmmm...what size engine do you have anyways...LOL! Funny I just now ask this..LOL! Just curious

[Mouse7088]

Wanted to do a little research before I had to run out the door....I wanted "general" info, not just pertaining to your vehicle year, make, etc...


TROUBLESHOOTING LOW OIL PRESSURE

by Larry Carley, Copyright 2000 CarleySoftware.com

The first indication of trouble may be a flickering oil pressure warning lamp or a low pressure reading on a dash gauge. If the warning goes unnoticed or is ignored, the next clue that something is amiss may be valve clatter as the hydraulic lifters or lash adjusters are starved for oil and ingest air. If the motorist keeps on driving in spite of the obvious warnings and audible protests from under the hood, the next sound he hears may be rapping or knocking noises from the rod bearings—which will eventually be followed by dead silence as the engine seizes and the vehicle coasts to a stop.

All engines will lose a certain amount of oil pressure over time as normal wear increases bearing clearances. But unusually low oil pressure in an engine regardless of mileage is often an indication that something is seriously wrong and requires immediate attention. So anytime a customer complains of a low oil pressure condition, or mentions any of the symptoms that may be due to a loss of oil pressure (warning light on or flickering, low gauge reading, valve noise or bearing noise), don’t delay in investigating the cause.

CAUSES

In a high mileage engine, low oil pressure is often due to a combination of worn main and rod bearings and crankshaft journals. The oil pump itself does not create pressure. It produces flow and the resistance to that flow produces pressure. Resistance is created by the orifices in the engine block through which the oil flows, and the amount of clearance between the bearings and crankshaft journals. As the bearings wear, clearances increase allowing increased flow which reduces pressure.

Okay, so you already knew that. But what you may not realize is that it doesn’t take much of an increase in bearing clearances to cause a noticeable drop in oil pressure as well as noise. This applies to brand new engines as well as high mileage ones.

Excessive bearing clearances (more than about .001 inch per inch of diameter of the crankshaft journal) can cause up to a 20 percent or greater drop in oil pressure, which may in turn have an adverse effect on lubrication elsewhere in the engine (such as the camshaft and upper valvetrain, especially in overhead cam engines). Whether the excessive clearances are due to normal wear or "loose" assembly tolerances makes no difference because the end result is exactly the same. Excessive bearing clearances will also increase engine noise and pounding, which over time can lead to bearing fatigue and failure.

Recommended bearing clearances vary a great deal depending on the engine application, but many engine rebuilders today aim for about .001 to .002 inch clearance in the main and rod bearings. This compares to as much as .004 inch of clearance that may be present in some new engines from the factory!

Excessive clearances elsewhere in the engine can also reduce oil pressure. This includes wear in the lifter bores, excessive clearances between the camshaft journals and cam bearings, and excessive end play in the cam. Of course, any cracks in the oil galleys, leaking galley plugs, or leakage between the oil pump and block will also reduce pressure.

The only cure for low oil pressure due to excessive bearing clearances is to reduce the clearances by replacing the bearings or overhauling the engine. Installing a new oil pump or a higher pressure pump won’t help because the bearings have too great a leakage rate to hold the required pressure. Installing a higher volume oil pump can increase flow and regain a little lost pressure. But the underlying clearance problem will still be there, which will accelerate bearing noise, wear and fatigue.

Another common cause of low oil pressure is wear or excessive clearances in the oil pump itself. Specifications vary, but as a rule gear type oil pumps should have less than about 0.003 inches of end play between the gears and cover. The clearances between the teeth and pump housing should usually be less than about 0.005 inches. With rotor style pumps, the clearance between the outer rotor and pump housing should usually be less than 0.012 inches, with no more than about 0.010 inches between the inner and outer rotor lobes. Too much clearance inside the pump will reduce the pump’s ability to pump oil efficiency, which reduces flow and pressure.

Because of the close tolerances that are required inside the oil pump, debris of any kind can cause havoc if it gets sucked into the pump. Anything larger than the minimum internal clearances can score or jam the pump. Debris such as pieces of old valve stem seals, gasket material, plastic chips from a worn timing chain gear, bearing material, casting flashing, sand, dirt, etc., may be harmful or fatal if ingested.

But how can this kind of crud get inside the pump, you ask? The screen that’s on the oil pump pickup tube in the crankcase only prevents relatively big pieces of debris from being drawn into the pump—and even then it doesn’t always do that because most pickup screens have some type of bypass valve or vent that allows oil to bypass the screen if the screen becomes plugged or the oil is too thick to pass through the screen. The holes in the screen itself measure about 0.040 inches square, which are huge openings as far as debris is concerned. But the holes are large by design so the screen will flow an adequate amount of oil when the engine is cold and the oil in the crankcase is thick (which is why you should always follow the vehicle manufacturer’s recommendations on oil viscosity). All this means the oil pump is the only engine component that is continually lubed with unfiltered oil! The oil does not pass through the filter until after it leaves the pump. So any abrasive debris that finds its way into the crankcase will first pass through the pump before it is trapped by the filter. No wonder oil pumps wear out and break.

Restrictions in the pickup tube screen can choke off the flow of oil into the pump, reducing flow and pressure. Even a relatively small amount of varnish buildup on the screen can restrict oil flow at higher engine speeds. A coating only .005 inch thick on the screen will reduce the total "open" area of each hole to .030 inches, causing a whopping 44 percent reduction in oil flow!

The pressure relief valve, which may be located on the pump body or elsewhere on the engine, can be yet another cause of low oil pressure if the valve sticks open or is held open by a small piece of debris. The relief valve is designed to limit oil pressure as engine speed increases. The valve opens when pressure reaches a preset value (typically 40 to 60 psi). This vents oil back into the crankcase and limits maximum oil pressure in the engine. The reason for doing so is to prevent oil pressure from reaching dangerous levels. Too much oil pressure can be just as bad as too little because excessive pressure can rupture the oil filter or even blow out pressed-in oil galley plugs in the block.

Low oil pressure may also be the result of air in the pump. If there’s too little oil in the pan, air can be drawn into the pump. But this can also happen if the crankcase has been overfilled. The oil can become aerated (full of tiny bubbles) because it’s making contact with the spinning crankshaft and is being churned into foam.

Sometimes the engine may become starved for oil at higher rpms because the oil isn’t returning quickly enough to the crankcase. The underlying cause here is usually severe varnish buildup that restricts the oil return holes in the head.

Leakage between the oil pickup tube and pump, as well as between the pump and block can also suck air into the pump. It’s not unusual to find engines where the pickup tube has fallen completely off, causing a complete loss of oil pressure.

A plugged oil filter can be yet another cause of low oil pressure. When the oil leaves the pump, it passes through the filter before going on to the bearings and oil galleys. All filters create a certain amount of resistance to flow that increases with the rate of flow. But the amount isn’t much, typically only a couple of pounds. But as the filter becomes clogged with debris, the restriction created increases. Eventually the point may be reached where no oil will pass through the filter element. So to prevent such a blockage, a pressure relief valve located in the filter or where the filter mounts to the block is designed to open if the pressure differential across the filter exceeds a preset value (typically 5 to 40 psi). This allows the oil to bypass the filter and keep on flowing. But the engine’s oil pressure will be reduced to that of the bypass valve. Replacing the plugged filter will solve the problem.

DIAGNOSIS

A good place to start your diagnosis of a low oil pressure condition is at the dipstick. Check the oil level to see that it is at the proper level (not low and not overfilled). If low, the engine may be burning oil, leaking oil and/or be neglected. Adding oil may temporarily remedy the low oil pressure condition, but unless the oil level is properly maintained by your customer the problem may reoccur.

If the engine is leaking oil, recommend new gaskets or seals to fix the leak. If the engine is burning oil, the valve guides and seals are most likely worn, but the rings and cylinders might be bad, too. A wet compression test and/or leakdown test will tell you if it’s the valve guides or rings and cylinders that are worn. The least expensive fix in the case of worn guides would be to install new valve guide seals (if possible) without pulling the head. But the best fix would be to pull the heads and have the guides lined, knurled, replaced or reamed for oversized valve stems. Worn rings and cylinders would call for a complete overhaul.

Also note the condition of the oil and make sure it is the correct viscosity for the application. Heavier viscosity oils such as 20W-50, straight 30W and 40W may help maintain good oil pressure in hot weather, but are too thick for cold weather driving and may cause start-up lubrication problems especially in overhead cam engines. Light viscosity oils, on the other hand, such as straight 10W or 5W-20 may improve cold weather starting and lubrication, but may be too thin for hot weather driving to maintain good oil pressure. That’s why most OEMs today recommend 5W-30 for year-round driving in modern engines.

If the oil level is okay, the next thing to check would probably the oil pressure sending unit. Disconnect the unit and check the warning lamp or gauge reading. If the warning light remains on with the sending unit disconnected, there’s probably a short to ground in the warning lamp circuit. Likewise, if there’s no change in a gauge reading the problem is in the instrumentation not the engine.

Bad oil pressure sending units are quite common, so many technicians will replace the unit without checking anything else to see if that cures the problem. This approach might save you some time, but it’s risky because unless you measure oil pressure directly with a gauge attached to the engine you have no way of knowing if pressure is within specifications or not. Most warning lamps won’t come on until oil pressure is dangerously low (less than 4 or 5 lbs.). So don’t assume the absence of a warning lamp means oil pressure is okay—especially if the engine is making any valve or bearing noise.

If a check of oil pressure reveals unusually low readings, check the filter. It’s possible the filter might be plugged with gunk. Ask the customer when he last had the oil and filter changed. Or, replace the filter and see if that makes a difference.

The next step would be to drop the oil pan and check the oil pump pickup screen. If the screen is clogged with debris, you’ve found the problem. Also, check to see that the pickup tube is properly mounted and positioned, firmly attached to the oil pump (no leaks) and is not obstructed.

If the oil pump is mounted inside the crankcase, the next step might be to remove and inspect the pump. Open the pump cover and measure clearances. Also, check for scoring or other damage. A broken pump drive would tell you something entered and jammed the pump. If the pump is worn or damaged, replacement is the only option.

If the pump appears to be okay, the next step would be to measure the rod and main bearing clearances. Check the clearances on the main bearing closest the pump (since this has the greatest effect on pressure), and clearances on the furthest rod bearing (since this will show the greatest wear). If the bearings are worn, they need to be replaced. But before you do so, carefully inspect and measure the crankshaft journals to check for wear, scoring, out-of-round and taper. If the journals need attention, the crank will also have to be reground or replaced.

Other checks might include camshaft end play, and/or pulling a valve cover or the intake manifold to check the cam bearings and lifters. Remember, excessive clearances or leaks anywhere in the engine’s oil supply system can contribute to low oil pressure.

OIL PUMP INSTALLATION TIPS

If you’ve found a worn or damaged oil pump that needs replacing, read all the instructions before you attempt to install the new pump. This is common sense advice but it’s amazing how many people assume they know how to replace an oil pump on an engine they’ve never replaced a pump on before. There can be surprises, so take a few minutes to review the instructions.

Most pump manufacturer’s do not recommend using a sealer on the pump mounting. Use the gasket or O-ring that’s provided. The risk of using sealer is that if too much is applied, some of it may end up inside the pump or block the pump’s passageways.

Toss the old pickup tube and screen and replace with a new one. Yes, you can attempt to clean and reuse the old screen but it’s risky. The bottom cover often hides a lot of debris, and solvent can loosen "hidden" debris inside the tube that will later be sucked into the pump.

Use the correct installation tool to seat the pickup tube in the pump. Don’t force it in with a hammer as doing so may deform the pump housing and/or damage the tube.

Make sure the pump is properly mounted, and that the pickup tube is properly positioned before replacing the oil pan. The pickup screen should usually be about ¼ inch above the bottom of the oil pan. This will reduce the risk of drawing in debris that settles to the bottom of the pan. Make sure the pickup is not too high because you don’t want it sucking air either.

The pump should be primed before the engine is started. This can be done by adding some oil to the pump before it is installed (packing the pump with grease is not recommended). If the pump is driven off the distributor, the distributor can be removed so the pump can be turned with a drill to prime the system.

Another alternative for all types of pumps is to use an aftermarket aerosol priming system that feeds oil under pressure to the engine through the oil pressure sending unit fitting. This type of system was originally developed for rebuilt engines, but can be used in any application where the engine should be primed before it is cranked.

Install a new oil filter and fill it with oil (this doesn’t work with filters that mount sideways on the engine unfortunately) to eliminate the delay in lubrication that normally occurs when the engine is first started after replacing the filter.

Finally, start the engine and make sure oil pressure is within specifications. Use a mechanical pressure gauge and don’t rely on the dash gauge or the warning light to verify that the repairs you’ve made have eliminated the low oil pressure problem.

[bikergirl]

mmay be something wrong with coolent