Hi,

I was having this problem since I bought my 97TA 4 months ago. Basicly, oil pressure gauge shows 30-40psi at idle when cold, then drops to 0 as it warms up.

I know that the oil pressure gauge is correct, because I've replaced the sending unit as well as installed the mechanical gauge, which showed the same exact readings.

The gauge typicly shows 0psi at around 1-1200rpms, regardless whether I'm stopped or driving. I'm pretty sure that means that the oil pickup hasn't fallen off.

Pressure goes to 15psi when i hit 2000rpms and It shows around 40psi at 4,000rpms.

I went from using 5w30 synthetic to 10w30 dino, which only increased the pressure slightly.

Also, the engine has some slight leaks coming from the front main seal and crank area. The leaks are really small as no oil even reaches the ground.

Can anyone think of anything that could be causing this?

Thanks in advance.

 

If you're sure that's an accurate reading then I would say you'll be rebuilding the bottom end of your engine in the very near future as a complete loss of oil pressure is a sign of bearig failure.


Sorry man.

 

Well, the bearing failure would explain it, but the thing is there is no knocking or other noises that usually come with spun bearings.

The motor has been running like this for 4 months and about 4,000 miles without blowing up, which leads me to beleive that the bearings are ok.

I think I'll just switch to 10w40 next time and see if the pressure improves.

 

I did run my engine appr. 15 k. miles with 0 pressure on idle, but it wasn't very smart thing to do. The longer you run it, the more is probability, that you ruin bottom end completely. Did rebuild this spring and fortunately crank was still in good enough shape and I manged with turning it. My problem was caused by cam bearings, which probably got hurt, when I did install hotcam - they were completely shot.

So, you run on borrowed time.

 

OK, I will at the very least drop the oil pan and take a look at the state of the bearings. Is it too hard to replace them with the engine still in the car?

 

I wouldn't recommend replacing the bearing with the engine in the car. You will probably need to replace the cam bearings also, and if i remeber right this cant be done with the engine in the car. Just save up some money and build a killer bottom end to handle future mods.

 

Nope, cam bearings cannot be installed with the engine in the car.

-Shannon

 

Use 20/50 and see.That's a pretty thick oil and if the brg wear is such it will take up some slack when hot. May not be brg,may be a grain of sand in the oil pump relief.

 

So, if I put 20w50 in it, and pressure increases -- that means that the bearing wear was causing the problem?

Also, I'll put some seafoam in the crankcase, which will hopefully help clean out some of the buildup in the oil passages.

 

Yes,and it probably isn't dirty.

 

I would put a mechanical gauge on it to verify what your pressure really is. Driving around with 0 oil pressure is just plain crazy.

 

As I mentioned in my first post, I installed the mechanical gauge into the port above the oil filter and got the same exact readings.

 

Oops, missed the mechanical part. Unless you just want to do a rebuild, then you are crazy.

 

Think about this - the oil pressure sending unit is at the top of the block. So, you may be getting about 5 - 10 psi to the bearings at idle, which is enough to keep it from seizing, but the top end isn't getting any. When you rev it, the oil pump ups the pressure and everything is fine. I bet if you just put in a new oil pump with a white spring, everything would be fine. Granted, your rockers and lifters might not be in the best of shape. Or, you could just not ever let the car idle....

 

BULL.

OP is OP it doesn't go some places without going all places.Ya got OP at the bottom ya got OP at the top.