Sam(WI)

I have a 95 truck with the 22re engine that has 165,000 miles. When starting it cold(Sitting overnight) the oil light goes out almost instantly. When starting warm (temperature gauge in the middle and the rpm at startup is only 850) the oil light will stay on noticeably longer. The oil was changed less than 500 miles ago. Shell 10w30 and Wix filter. Timing chain seems tight and engine in good shape overall. Just wondering if I should be worrying.

highonpottery

iTrader: (1)

no it's not normal behavior i'd say. it should be off once the engine starts up and builds oil pressure. 22re isn't known for having a great "oil gauge" as it doesn't give much info and they actually don't need a whole lot of oil pressure at idle speeds either, I know mine moves between idle and driving RPMs. i would maybe guess it's related to the oil sending unit - I believe it's under the oil filter area and is like a $30 part at parts store.

mct75

The short answer is that the oil pressure sending unit might not be reliable after so many miles and years. Unless you have a reasonably nice mechanical oil pressure gauge it's just a guess as to what the actual pressure is.

the_supernerd

I am dealing with this right now on my '88 22R pickup, so I have some advice, but I am also still looking for the problem. It is worth checking the oil pressure with a mechanical gauge as stated above. If it reads low after building, then it could be bearings or possibly the pressure relief valve is sticking in the oil pump, the oil pump itself, or the pickup tube is clogged. I would think those things could be ruled out if the pressure stays good once it builds, but I am not 100% sure on that.

Does your engine knock at all? Does it make any noise until the light goes out? How long does the light stay on?

Some filters do not have good anti-drainback valves and can cause this problem. A Toyota filter is cheap enough to try, especially if it started right after an oil change. I also noticed my '87 4x4 started taking longer to build pressure after the oil pump o-ring started leaking. I am thinking that it is letting air in when the engine is off so oil can drain back to the pan. It is easy enough to remove the oil pump if you want to check it with some feeler gauges and replace the o-ring.

If I find a solution for mine then I will post back if yours is not fixed yet. My next step is to pull the oil pan and check the pickup tube and possibly the bearings.

Sam(WI)

It has done this ever since I owned it. It does seem to knock until the oil pressure is built up when you start it when warm. It does it for at most 3 seconds. Only when it has been at operating temperature and sits for more than 30 minutes. Turning it off and starting it 5 minutes later everything is fine.

scope103

The oil light goes out quicker when cold because the oil is more viscous (same amount of pushing on something viscous will result in higher pressure).

Subject to the above comments about gauge inaccuracy, it is probably taking a "noticeable" amount of time to build up pressure when warm just because everything is looser. Once the bearing clearances open up with wear and time, there isn't as much for the oil to push against to build up pressure.

While you could carefully rebuild the whole engine, grinding all the journals so they fit the bearings perfectly, I would just switch to a slightly heavier oil. Like 10W40.

the_supernerd

Your problem sounds similar to mine, although mine has seemed to get worse over the years so it now takes a lot longer than 3 seconds. I do agree that thinner oil will take longer to build pressure, but it seems like 3 seconds of engine knocking is not normal. Thicker oil will help as stated above. I tried 20w-50 and it did build pressure faster, but the problem was still there.

I was looking through the FSM, and there are specs to check the oil pump with some feeler gauges. One measurement is with a straight edge to check the gears of the oil pump are less than .006" from the mounting surface. If the timing cover is worn at all, that would increase this measurement, but I could not find any specs for checking the timing cover. You might try removing the oil pump, checking everything, then measure the clearance between the gears and timing cover with some Plastigauge. I did find one person online who had to sand down the mounting surface of his oil pump to make it fit tighter against the timing cover and it helped a lot.

My timing cover has a groove in it from when a seal saver blew and took out my original oil pump, so I think that is my problem. I showed a mechanic the picture I took and he said that is more than likely my problem. Basically too big of a gap or groove can cause the oil to drain back into the pan at a faster rate than usual.

the_supernerd

If you do not want to tear into your engine, another solution would be to get one of those pre-lubrication systems that prevent dry start, assuming your oil pump has good pressure after it builds.

Sam(WI)

The knock doesn't sound like it is a rod so I think that it is probably just the timing chain?

the_supernerd

It is hard to tell without hearing it, but with no oil pressure it could be anything. The timing chain tensioner uses oil pressure, so the chain will slap around, but the bearings and the valve train make noise with no oil. Basically, it is all metal on metal with no cushion between parts until it has pressure. I would assume that if a bearing was bad, it would knock even after you had oil pressure.

The timing chain will make a lot more noise if the guide is broken. At 165k, the timing chain is probably about due to be replaced if it has not been already. It is worth checking the guides if you have not already done so. If the chain needs to be replaced, that is a good time to inspect the oil pump and timing cover, and possibly dropping the oil pan to clean it out and check the pickup tube.

First thing to do is to check the pressure with a mechanical gauge. Then you can see exactly how low the pressure is, and if the pressure is good after it builds.

scope103

Incidentally, while we're all advising him to check the oil pressure with a gauge, that's not trivial. Can anyone here confirm that the correct fitting is 1/8"-28 BSPT? If so, I guess we could use one of these: http://www.harborfreight.com/engine-...kit-98949.html

the_supernerd

1/8" BPT is the size I remember it being. If I recall correctly, 1/8" NPT will kind of fit, but it is not the right thread pattern so it is not recommended to use that.

Sam(WI)

I installed a mechanical gauge in the port where the light sending unit was. Cold start it was reading almost 60 psi. Idling when warm at 850 rpm it was hovering at just over 10 psi but increased as the rpm's where brought up.

the_supernerd

Even though spec says 10 PSI is ok, that seems low to me. I believe the pressure relief spring is suppose to open at 67 lbs if I remember correctly. Is 60 PSI your maximum pressure or will it rise higher with RPM? Mine takes time to build pressure after starting, but then stays between 20-25 at hot idle and reaches peak pressure fairly quickly when the engine is revved. I would remove the oil pump and inspect it or just replace it. Make sure the timing cover is not worn where the oil pump mounts. If you want to drop the oil pan you can check the pickup tube and screen. Other than that I think I would just use slightly thicker oil and see if that helps.

anndel

I have somewhat the same issue as you. I changed the sender to an electric one made by VDO back in 1993 when I first bought the truck and added an VDO oil pressure gauge. It starts up and the low oil light on the dash lights up for a few seconds then goes off. The oil pressure on the gauge shows about 20 psi at cranking then goes up to 70 psi at that time which the light goes out. to me everything is fine with the engine but I'm guessing it's time to replace the sender. the stock one had 1 tab connector and the VDO has 2, one for the gauge and one for the stock dash light.