Gunnison , Colorado

Fellas,
Total non-mechanic here, so not asking how to fix cuz I wouldn't know what you are talking about anyway. I inherited a 1993 Sr5 pickup from my best friend who died of cancer. I was thrilled to get this truck as a rememberance of him. I've only had the truck for 10 days or so, and on my drive home with the truck from Kansas to Colorado I noticed that the oil pressure gauge reads right at or slightly below the "low" (first) line no matter what gear or rpm I am at. When first started, the gauge reads in the middle or slightly below but after 10-15 minutes of driving it goes back down to the first mark or a bit below. It idles at zero, on the L. No leaks, no burning oil and no engine racket. The engine temperature gauge stays rock solid in the middle, however, the check engine light did come on since I've had the vehicle. Not sure if it's related or not. Vehicle has 171,000 miles and has been well cared for as far as maintenace and oil changes.

I know I need to take it in and get an accurate pressure reading, but my mechanic won't be able to look at it for a few days and I am in agony thinking that this may be the end of Will's truck. My question is, is this likely going to be it for the engine or is there a good chance this will turn out to be an oil pump, sender, or something else? Anyone have experience with this? I'd appreciate any insight as to what to expect as the outcome of this once the mechanic gets a look. Thanks. Doug in Gunnison, CO.

xxxtreme22r

almost sounds normal just a little low, however do an oil change and maybe a higher weight oil like a 15-40 (yes it is ok to use diesel oil) or a 10-40. Possibly even a 20-50 but winter is here and probably not a good idea for 20-50 in the winter.

Since you just bought the truck that is the first thing I would do.

pruney81

Since you're in CO, and it gets cold here I'd try some Castrol High Mileage 10W40 first or Valvoline Maxlife 10W40 and see how it does.

toyospearo

Pruney and xtreme are correct IMHO.
Too low oil pressure can cause the rings to unseat in addition to a few other major catastrophe's.
Where we build engines we ask where the buyer is from. If he or she says "Willow Creek" or over Titlow Hill Summit we suggest keeping the motor in third gear going up and not fourth. Reason being the low oil pressure in 4th gear going up that, or any grade, can result in unseating the rings around the crank. Seen it happened a few times.
Correct pressure in the crankcase is very important. Letting your oil get low will cause similar problems in the 20, 22r and 22re or any motor for that matter.

Marc

It's probably fine.

Let your mechanic check the pressure.

It doesn't need much pressure at idle.

oldskoolstang

I don't have a factory gauge, but when mine warms up it has around 20-25 psi oil pressure at idle and around 60 psi at 4500 rpm. I'd say that as long as it has at least 10-15 psi at idle and in does go up in pressure with rpm that you, more than likely, will be fine.

Gunnison , Colorado

Surely some other folks have experienced this type of oil gauge behavior. Any guesses what it will mean?

jbw

I bought a 4runner with the 3VZE engine which had been sitting for around 4 months prior to me purchasing it. I changed the oil as soon as I got it, but noticed it getting very dark after only 300 miles or so and getting a lower than I was comfortably with oil pressure reading as time went on, similiar to yourself. I changed the oil again with standard 10w30 and a Napa (wix) brand oil filter.

My oil pressure is now fine, it sits an eighth to quarter inch further up the gauge than it did right after I purchased it, the oil is wearing as it should (ie: not getting pitch black after a few hundred kilometers).

My theory is that as a vehicle sits without the engine being hot from driving, the oil degrades and begins forming varnish and sludge in the oil pan. As you drive it after letting it sit for a while, that varnish and sludge get sucked up into the oil pump pickup screen, which is a fairly tightly woven mesh, especially after 170k of oil running through it, it could easily be gunked up, similiar to old arteries after many years of eating bacon! The oil pressure might drop because it now has restricted flow, but as long as you take care of it quickly, you probably won't have any problems.

I've got a few suggestions;

-Change your oil yourself if you're comfortable with it; before you change the oil you should take it out for a highway drive and let the engine and oil get really good and hot before you change it, this will keep the sludge and gunk as fluid as possible and in theory, should help clean the engine out. You could run something like Rislone oil treatment additive, which contains some higher detergents than normal oil and would probably break down the sludge and crud a little easier. I run this through my engine once and a while, but I only do it a few hundred miles before an oil change; who knows if it helps but it probably won't hurt. It might be a good idea to do a few short-interval oil changes if you notice the oil getting dark really quickly, it's cheap assurance and will help clean the engine out.

-check your curb idle speed, if it's not between 800-900RPM, you can adjust it very easily yourself. If your idle speed is low, the oil pressure might read a little low.

-DEFINATELY have the oil pressure gauge checked!!

xxxtreme22r

brand new rebuild here and my gauge at idle @ 750 rpm is between L & 1/4 when fully warm, that is with 15-40 valv.

You have 3 guys in here agreeing with changing the oil and using either 15-40 or 10-40 that have quite a bit of experience with these motors. You just bought the thing. Change the oil.

Teuf

Would not a thicker oil give a high false reading. ( whats easier to draw through straw, a thick shake or water. Lighter oil = more flow better cooling? Just a thought. And are not toyota oil pressure gauges kinda hit or miss sometimes? YUP just change oil. Go from there.

xxxtreme22r

not really teuf, Using a heavier weight oil in an older motor is not necessarily a bad thing. They tend to run a little warmer to begin with due to lowered cooling efficiency in both the block and radiator as well as the whole system in general among other factors. But if that oil is old and worn out or the filter is worn out, then his oil pressure will be low to begin with. Changing the oil will eliminate that. He was probably told the oil was changed etc etc by the P.O. which is why he is so fast to discount changing it.

They are hit and miss most of us know that, but why change the gauge sender when the thing most likely needs an oil change anyway and can be a cause of low oil pressure.

By thicker I meant in relative terms, we don't know what is in the motor. I believe there is alot of us on here using 15-40 in theirs.

Gunnison , Colorado

Ok guys, I really do thank you for all your responses. Although I was told by my friends wife that the oil was just changed prior to me picking the vehicle up, I will change the oil for sure. Question is, I live in one of the coldest spots in the US. Wintertime temps will be between -30 and +25 degrees Farenheit for the next 4 months. Knowing that, what is the thickest oil that I can use in these extreme conditions. Is there a particular oil brand and filter brand that might up the oil pressure instead of the Fram that is in there.

I really do appreciate all of the responses. Really cool that guys will help out a guy they don't know. Thanks. Doug

Teuf

Use a good synthetic 5 w 30 and a toyota filter, thats my 2 cents.

Teuf

oops meant 10 w 30

Teuf

Hold on I just saw -30 coooooooooold so, as you were, 05w30

pruney81

I live in Leadville and we're already seeing negative temps at night and I have been running Shell Rotella T6 5W40 full synthetic with stock Toyota filters and it's been running great, no leaks or oil useage to speak of.

That said, I'm moving back to Mass in a week and when it gets warmer out this summer I plan to run Shell Rotella 15W40.

But, my engine had barely over 100K when I switched to the full synthetic so it didn't cause me any issues, I would try Valvoline Max life 10W40 first and see what that does for you. And yes, these 15-20 year old gauges aren't totally reliable.

Teuf

I have heard a lot of good things about the Rotella, way to go.

tried4x2signN

Did the truck come with an owners manual?


If so, what did it have to say about this?

myyota

I would replace the oil presure sending unit, they can go bad and read low or not at all. The reason its reads high when you first start the truck is because the oil is cold, so its thicker, as it warms up it thins out so the oil presure goes down , that`s normal, but it should still read some were between low and the half way mark.

sb5walker

I'm sorry to hear how you came by your truck, but I'm sure it means a lot to you, and I understand wanting to take good care of it. Welcome to the forum and good luck with your new truck!

Well first, the gauges in our trucks are not very accurate, so it isn't uncommon for them to be reading at about the first mark when hot. But since yours is below that mark, I share your concern about it.

I know folks are very well meaning in their recommendations, but there is a lot of confusion about what the SAE oil ratings really mean and what is an appropriate oil choice. The right-hand number is the viscosity (thickness, or resistance to flow) at 212 deg F (100C) which is about operating temp.

The choice of what op temp viscosity to use should be based mainly on how loose the bearings are, the signs of which are high motor mileage and low oil pressure. Looser bearings call for heavier weight oil in order to maintain adequate oil pressure. In a low mileage motor with tight bearings, somethingW-30 is good, but higher mileage trucks or ones with low oil pressure like yours benefit from heavier weight oil like somethingW-40 or 50. Like several of the other posters here have, I recommend trying a somethingW-40 for your truck.

Since the thermostat will keep the motor at the same operating temp whether in summer or winter, and since the weight you should be running is determined basically by the condition of the bearings, people should be running the same op temp weight (right hand number) year round.

Basically, lighter oil flows better which is good for bearings, for cooling, and for gas mileage, but heavier oil can provide more protection for sliding parts like cam lobes and rings/cylinder liners. If too thin, oil won't protect bearings & sliding parts, leading to excessive wear. Also, too-thin oil results in low oil pressure, which means that adequate oil may not reach the bearings that are furthest from the pump. On the other hand, if oil is too thick, it won't flow into and through bearings, leading to oil starvation, overheating & bearing damage.

The number that you need to watch in the winter is the left-hand number of an oil's rating, the "W" rating, which is the weight at 0 deg F (-18C), and it's very important to use an oil with a low enough weight so it will flow well at the lowest temp it will see. Motor oils thicken up A LOT at low temps, and you will ruin your motor by failing to use a low enough W rating for conditions. As a rough guide, I wouldn't use a 20W-something below freezing, nor a 15W- below about 20F, nor 10W- below say about 5-10 deg F. 5W- can be used down to about -10 deg F. Below -10 F, a 0W- would be best, but there is absolutely no harm in running a 0W- oil even above -10.

Even a synthetic 0W-30 will be thicker at zero degrees than a 20W50 is at operating temperature. That's how much they thicken when very cold. It's very important to use a low number in freezing temps. This post has links to some videos that show how amazingly thick oil gets at low temps: http://www.toyotanation.com/forum/sh...69#post3026669

To sum up, choose the left number based on coldest temp expected, and the right number based on bearing looseness. So if you run 10W-40 or 15W-40 in summer, and live in an area with freezing temps in winter, then choose a 5W-40 or 0W-40 in the winter. Likewise if you run 10W-30 summer, use 5W-30 or 0W-30 in freezing temps, or if you run 15W-50 or 20W-50 in summer, a 5W-50 might work for the winter, or a 0W-40 in very cold temps.

The other major choice is mineral vs. synthetic oil. The biggest benefit of synthetic oils is their consistency in viscosity: they do not thicken up anywhere near as much as mineral oils in very cold temps, nor thin out as much when hot. This means that synthetics are a much better choice in areas with winters that go below say about 10 deg F as they will actually flow at startup, where the mineral oils may not.

Also, in order to make a mineral oil multi-weight, polymer molecules are added, which thicken the oil as it gets hot. A 10W-30 oil is a 10 weight oil with viscosity index improvers (VII) added. A 5W-30 is a 5 weight oil with more VIIs added. As the VIIs wear out, the oil reverts to its true weight, the lower number. So the other big advantage of synthetic oils is that because they have little or no VIIs, they will not shear, or lose much of their viscosity, over time and miles. This also means the synthetic oils can go longer between oil changes, which can offset some of their increased cost: just balance the price difference against the frequency of purchase. Convenience factors in too.

Don't use conventional 5W-30 in ANY engine: A mineral 10W-40 oil has about the most VIIs, and therefore vulnerability to viscosity breakdown, of any oil, so, if using conventional oil, a 15W-40 may be a better choice for a summer oil. The mineral 5W-30s are likewise really bad that way - almost all of them shear to too-thin 5W-20 weight within 2 or 3 thousand miles, so for folks using 5W-30, choose a synthetic like the excellent and affordable Pennzoil Platinum.

If using a good synthetic, there's no harm in using something like a 5W-40 year round. The full synthetic (group III+) Shell Rotella T6 5W-40 that pruney81 mentioned looks like it may be the ideal oil for your truck this winter. Flows real well at startup yet has great viscosity for middle-aged to higher mile motors, and because it's a diesel oil, it has plenty of excellent anti-wear additives like the zinc additive ZDDP. Walmart and Advance Auto carry Rotella oils.

For extreme cold, use a 0W-30 or 0W-40. A new winter oil that looks very promising is Rotella T5 0W-30 or 0W-40 - it's either a blend with mostly synthetic (probably Shell's excellent XHVI Grp III+ base oil) or, possibly, full synthetic. Its performance specs are outstanding. Plus being a diesel oil it has great additives. And it's a very good value for the $$. Those lucky Canadians can get ESSO XD3 0W-30 or 0W-40, both excellent winter oils. Petro Canada's Supreme Synthetic 0W-30 is an excellent oil too, if you are running 30 weight in your motor.

People tend to say a 0W-40 is "too thin". It is NOT too thin. Once the motor reaches op temp, a 0W-40 will be in the same range of viscosity as a 15W40. And the 0W-40 will be thicker when cold than the 15W-40 is when hot, so it isn't "too thin" when cold, either. In fact, Red Line 0W-40 is thicker at op temp than most 15W-40 oils: it's almost a 50 weight at op temp.

OIL FILTER

Good grief, don't use a Fram/Pennzoil filter! Every single study of oil filters has confirmed that those filters are garbage. For more filter info that you probably want, check out this thread: https://www.yotatech.com/forums/f116...filter-190242/

But bottom line, I recommend either the Toyota oil filter 90915-YZZD3 (rather than the very small 90915-YZZD1 which the dealer will try to give you). The D3 is same width as the D1, but is slightly taller and has 27% more filter media area, giving better flow and longer service life. Or, another excellent choice is the Purolator PureONE PL20195 which has the highest filtering efficiency of any filter I know of and which has excellent flow. Advance Auto carries it. I've found it definitely does keep the oil cleaner for longer than the Toyota filters. Like the YZZD3 it is taller than the stubby stock filter but it fits the 22RE easily & most 3VZEs. On the V6 it's a tight fit, coming very close to an engine mount. It clears on most engines by about 1/8 to 1/4", but on some, it has less than 1/8" clearance and on those I don't recommend using it. Use the YZZD3 instead.

For folks who insist on using the stock compact size filter (90915-YZZD1), the Toyota filter is the only one to use, unless you hate your truck and want to destroy the engine. The reason is that only the clever design of the Toyota compact filter gives decent filter media area (160 sq in). ALL of the other compact filters have MUCH less, most of them in the 104-110 sq in range. The Wix 51348 (Napa Gold FIL1348) that some people are fond of only has 104 sq in. of media, way less than the Toyota D1. Less filtering area means less flow and quicker clogging. Once clogged, oil will flow through the bypass valve, and that means not only will the oil not be filtered, but because most filters have the bypass valve at the top, the bypassing oil will flow along the filter pleats, washing many of the particles previously filtered right back into the engine. If the filter is poor quality, the bypass valve may not work or it may work at too-high a pressure, which would severely cut down on oil flow.

My rec would be Shell Rotella T6 5W-40 or Rotella T5 0W40 oil and either the Toyota 90915-YZZD3 or Purolator PureONE PL20195 filter.