Oil Pressure Problem

I have an oil pressure problem that I could really use some advice on.

At tickover, the engine sounds and runs fine, but when you rev it, it develops a slight knock at the top of the engine, as if the oil isn't getting there, and the oil pressure warning light flickers on. When the revs drop the noise goes away, and the light goes out.

Some background:

The engine has recently been rebuilt (by good engineers, whom I trust); I received it as a built lump and I fitted it into the car. As part of the rebuild, the oil pump was replaced with a new part from Toyota.

Once the engine was in, I ran it for about 30 miles with no problems, then suddenly this noise appeared (as described above). I suspected possibly the oil pressure release valve had become stuck, so I decided to take it out and have a look.

Upon removing the restraining bolt and then the springs, I tried to take out the valve using a magnet (on a stick), but it was quite hard to lift up. At first it wouldn't come, and even pulled the magnet off of the telescopic handle, but with some wiggling (and swearing), it finally came out. Now here comes my first question: should the valve be so hard to remove? I thought that it should slide easily within the chamber? I have checked for swarf or other objects within the chamber, but nothing, and the walls seem smooth. The valve itself is smooth with no sighs of scratching or anything?

My second question is, if this is not the cause, what could it be?

I was a little skint before, but I have now been able to purchase a sandwich plate and an oil pressure gauge, so I will be able to see exactly what is going on, but I am reluctant to put it back together again if there is somehthing I should check with it in pieces?

Any help would be very much appreciated.

Thanks

Tony

Ok, I might have been a bit premature on the condition of the valve itself; having just checked it again in daylight, rather than the dim, useless fluorescent tube in my garage, there are several virtical scratches all around it on the surfaces that contact with the housing.

From this I think it might have been a tad tight perhaps?

I'll attack it with a peice of emery and smooth it down a bit.

It does sound like some crap may have got in there in that case, which is a shame in a newly rebuilt engine

Before you hit it with the emery, can you post up a pic?

Odd that the oil pressure light came on when you revved it, i.e. when the valve would have been opening anyway. The oil pressure light indicates low oil pressure.

Also, if the oil pressure drops, there's nothing to rattle at the top of the engine because the 2JZ has solid tappets rather than hydraulic ones.

Strange. Hope you get it sorted.

Cheers for that; I was not best pleased, but I guess it was better that it happened while I was pootling along, rather than screaming it?

Unfortunately I've just read your reply and I've already cleaned up the valve and put it back in the car... :o(

I too was a little puzzled as to why the light came on when revved, but I can only think that it was because the valve was stuck, not at the top, but a few mm from the bottom, possibly restricting the flow?

However, I did have another good look at it just after I added my second post yesterday, and there was a significant 'blob' of metal which looked like the aftermath of a bad scratch. I cleaned up the surface and then had a look at the chamber itself; it was smooth, but I did find a few metal shavings in there (after much probing with cotton buds!), which I removed. I then cleaned out the pump with a little petrol, put some oil in there and started to re-build the front of the engine.

I haven't completed the job yet because I am awaiting the sandwich plate, and it will be a lot easier to fit with the air con and power stearing pumps detached; it's bad enough trying to change the oil filter (relocation kit on my Christmas list...), let alone trying to fit the plate and couple up a pressure gauge!

I'll post my progress when I get the parts.

Thanks again for responding.

Be very careful with 'stuck valve' theories.

People have been losing engines through the millenia because they discounted the oil pressure light, thinking it was an electrical fluke or whatever. You don't want to risk it being for real.

Without an oil pressure gauge you're really speculating about oil pressure though. If in doubt, I'd play it safe, stick a gauge and monitor things.

It wasn't really a theory as such because I had to damn near wrench the valve out of the barrel, and as I said, there were scoring marks on the valve and swarf in the pump, so I'm fairly sure it was, at the very least, a contributory factor.

I totally agree about being careful though, which is why I've bought a sandwich plate so I can add the oil pressure gauge which is sitting on my dining room table. I bought the gauge when the problem first occurred, but struggled and finally gave up trying to get it to fit into the existing pressure switch recess.

After searching these forums I found that everybody else agrees that it is far more hassle than it's worth trying to get it to fit in the original spot (including Toyota, who changed the design on the '98 model to use a modified union bolt), and the solution is to use a sandwich plate (or a '98 union bolt) behind the filter, or a filter relocation kit, both of which have additional taps on them for fitting a gauge (or two).

My reaction when the light flickered on was to stop the engine there and then and look for clues, which is how I found the problem with the pressure release valve. Having sorted that particular issue, I will rebuild it, add the gauge and go from there.

Thanks for the warning though, very much appreciated, and having had engines go bang from oil issues before, very much agreed!

The warning light is my friend.....

If I were you I'd be worried about where that metal came from, and where else it might have got. I know you said you trust your rebuilders - could you go and have a word with them?

I take your point, and it does concern me a little, but there was only two flakes in the oil pump, and a nasty scratch on the valve so I'm lead to believe one came from the other.

The reason I'm not too worried about swarf in general is because all they did was stip the engnie, replace one rod and the crank. The shell had been faulty (assumnption, but there was no oil starvation and no adverse wear on any of the other shells) and it had damaged the rod and journal. As such, there was no honing, or head work done that would create such nasty bits of metal. I was also running a TRD magnetic oil filter, which upon inspection did not yeild any other bits.

Do these magnetic oil filters actually work, or are they just a gimmick?

Do tiny pieces of swarf really stick on a mildly magnetised surface and STAY there, while being suspended in a thick, pressurised fluid?

When I lost oil pressure in my kit it was due to my oil pump drive breaking..only I was on the dual carriage way and had to drive a little way to the parking sign, by which time I was due a crank polish and new shells

Lucky it wasn't a regrind.

Oil problems suck.

Magnetic oil filters; gimmick? Not sure, I take your sarcasm, but I'm of the school of though that "you never know", and "every little helps", although I don't regularly shop at Tesco's.

All I'm saying is that I've checked the filter, the pump, the oil I took out of the engine, the inside of the cam covers, the ends of the turbo oil supply pipes and the sump plug; but found no swarf. Unless I take the engine out again, strip it and clean it all, I can't be 100% sure, but I'm fairly certain.

I could try an engine flush, but that does little for the metal bits; I'd climb in myself and run a rag through it, but at 6' 6" I'm a little large to get into the oil filler, and I've run out of nano-bots. Any other suggestions would be welcome though.

I believe that the magnets certainly help, but the filter is after the pump, so anything small enough to get through the strainer will go into the pump and potentially into the PRV.

Also, bearing materials can be up to 80% aluminium, so a magnet can be pretty useless for bearing debris.

Fair comment.

Perhaps I could simply ask any remaining bits of free radical swarf to pop out for a minute and then respectfully put my case forward, in the hope that they will agree to live elswhere?

Like I said, without another strip and re-build it's nigh impossible, so I guess I'll just have to suck it an see?

...Magnetic oil filters; gimmick? Not sure, I take your sarcasm, ....

There was no sarcasm there, just wondering aloud. The idea is not new, either.

Sorry geez, no offence meant or taken. Indeed, infection is difficult to convey.

To be honest, I wasn't sure whether it would do what it said on the tin, but I figured any extra couldn't hurt?

there is a school of thought that even if it can hold on to some ferous swarf, as the bits pile up they might let go altogether.

That might do more damage than good. Make of it what you will.

Magnetic sump plugs are a good idea IMO though.