90 toyota 22re 4cyl.... My oil pressure gauge usually stays in the middle, but today after a 70 mile trip, it dipped to Between not registering and the mark past it.

It would have blown up by now, had it not had any oil pressure. After some searching I've found the gauges are crap, and that I'm probably using too thin oil. I'm using 10W30 now, but will swap to 20w50 shortly.

I'm thinking its the oil pressure sending unit, It is using oil, but not smoking at all. I can smell burning oil some what frequent. Is that a sign of a bad sending unit?

 

How many miles are on your engine? Has the motor been used and abused in the past? and When was the last time you changed the oil?

I run 10w30 on my 22re and reading from my hardline gauge I get about 65 - 70 psi driving and about 25 - 30psi idling (but mine lobes on idle so I expected it to be low anyway).

I've noticed my stock gauge never really registered right so it could just be the gauge or the sender.

 

I'm unsure of the mileage, the speedo cable was broke when I bought it. It shows 147,000 miles....but i'm sure its over 200,000. I dont think the truck was abused, per say.... just not maintained to the level I keep one.

Changed the Oil the weekend I got it, April 1st. Isn't due for an oil change yet.

The burning oil, and the gauge getting wierd all started at the same time. I just started driving it 157 miles a day monday, so if a vehicle has a weak spot, these trips will sure exploit it.

 

Are you sure its burning it and not just leaking it out?

 

Thats what I mean....I apologize for not clarifying. Its leaking onto the engine from somewhere, and burning on the hot engine. When the sending unit goes bad, does it leak out?

 

It's ok, I ask too many questions anyway lol. Unless its punctured or loose it shouldn't leak. Can you see where the oil is leaking from? Just grab a flashlight and follow the trail of oil or where its burning at and just narrow down the possibilities.

 

I haven't been able to find any source of a leak.....My guess is it only does it under pressure, or when it gets hot enough and thins out. I was hoping this a symptom of the sending unit going bad. Must be a valve cover leaking out the back.

 

More than likely...I would start there. It wouldn't hurt to go ahead and change the grommets on the valve cover bolts while your at it. Sometimes they don't come with the gasket.

 

I appreciate the help. I'm gonna change the oil pressure sending unit, see if that fixes the oil pressure readings. No noises or rattles, but my luck it'll commit suicide with out warning.

 

No problem, let me know what you come up with!

 

Drove it today, and at startup the oil gauge goes to the middle and stays. As the engine gets hot, it gets lower and lower, till it finally isn't registering. Ideas?

 

That's because when the engine is cold the oil is thicker so it will build more pressure. As it warms up the oil gets thinner so it won't have as much pressure.

 

Not showing any oil pressure at all now. I let it sit and idle for along time today. 30-minutes, then drove about 15-20 miles.

SO, either the gauge isn't working and my oil pressure is fine. OR my motor is gonna blow through the hood going down the interstate Monday. I will update.

 

Not meaning to offend or anything but how much oil is in the motor and when was the last time you changed it? Dumb question but might as well get it out of the way lol

 

No such thing as a dumb question....unless I'm the one to ask it.


Changed the oil when I got it, first of april. Isn't due for an oil change yet. Oil was about a quart low after a 175 mile trip. Topped it off today before I started messing with it.

I reached down and unplugged the sending unit, looked at it, and plugged it back in. So i'm sure that has something to do with it. My best bet will be to plug a mechanical gauge into it, so thats what i'll do when I get paid. If it survives that long.

 

Thats what I did, just rule out the electronics and go with a hardline..I just got a three gauge pod from autozone for like $25..but in order to use one of those fittings on the block you need to re-tap the hole for the sending unit, unless you find a metric fitting.

 

Check the connector on the sender. Mine was very loose and started to lose contact while driving and that made it look like pressure was falling. My '85 has the rubber boot over the sender and no way to check the connection w/o pulling off the boot. I found the brass strip in the connector had gone flat with time and I pulled it out and re-bent it to make it hold tighter on the button on top of the sender. No problems since then.

 

I've put about 450 miles on it already this week, and I either have the best 22RE engine ever built, or its the sending unit/gauge.

 

my truck started doing the same thing as this earlier in the year, still havent quite figured it out yet. It would be fine until the truck heated up and then drop down to non-registering. Mind you this happened twice, both on 400 mile trips so i guess its gotta be the sender/guage. Or else our 22RE's are just wicked badass!

 

See my earlier post about a loose connector. If yours has the big rubber boot covering the sender, that connector can slip off and you would never know it, except for the low reading on the gauge.