I've had ongoing problems with my tj vr-x. For about 18 months now when I first start the engine for the day there is a type of high pitch knocking sound that is hard to pin point but it sounds like it's coming from the top end valve area. For the first 16 months of this noise it would only sound about 2/3 of the time and when it did, would only last 10 seconds Max and disappear (then I would drive off).

Then after the last oil change a few months ago, the oil light would come on with this noise at first cold startup. And it also would not stop, noise and oil light, until I took off in gear. As if the oil was not able to get up to the top of the engine until in gear and power. I was told that i prob put to thin oil in and it is having trouble pumping it up at low rpm. I drained some oil out to the lower marker and that didnt do anything. I then put in a whole bottle of that thick stop smoke stuff to thicken the oil a bit, and that didnt do anything either. I then took it to a mechanic friend of mine and he did a full service on it, and also cleaned out the oil pickup, but he said it was pretty clean. This seamed to instantly fix the oil light problem at first, but not the knocking sound, but I think it did improve a bit. A week or so after this service I noticed the oil light come back on a few cold starts, but haven't seen it come on now for a few weeks.

Another thing that started to happen before i took it to steve the mechanic, was that it start accelerating erratically, and sometimes almost stalling and back firing during the low rpms after a gear change, very noticably when the engine is still cold, but continues to do this at all times now.

Not having much spare cash ATM, I didnt want Steve to start pulling the engine apart and diagnosing this problem further, so I left it at that for now. Steve seams to think it's a lifter problem, valves are not lifting as high as they should because of fatigue or what not.

So maybe some people hear have experienced or heard of this type of thing before. Can give advice for an easy way out, I.e whole new engine replacment instead of trying to fix this.

Some things to note is that the car has done some heavy towing over the years, and perhaps this is the reason for this problem.

Also, I have never had a full service on the gearbox. Fiuld changed etc, but never had a transmission place look at it ever, so i thought maybe the gearbox is a cause of this problem, I would think unlikely but I don't want to rule it out yet. Can anyone advise whether the gearbox could cause this?

180k kms 5 sp auto tj vrx.

If anyone has a good contact of someone that knows and worked with these engines before that i could maybe go to. Or if there is someone here that can replace engine/box for a cheap rate, let me know. I'm in Sydney.

Thanks for any help. Sorry for typos, posted this on my phone.

// BiGs

I could be way off here but i thought i would share the common problem i had with you in case it helps ;). The knocking could be the timing belt idler as this did the same for mine and some other magna owners i know. It may well be a sticky lifter.
But something i think i can help you with is the revving issue you are having. I would get the O2 sensor checked as i had this issue also. On my car it would seem to nearly stall every time i took off 1st and also when in low revs in all other gears. It almost feels like its missing yes?. But then once you hit 3000rpm it would take off like a ball of angry beavers. It was explained to me that the O2 sensor was not working and the car was running lean on low rpm untill it hit around the 3000rpm and thats when the MAF takes over the air fuel mixtures.
Please correct me if i am wrong amc experts.

Yeah they both seem to vilid causes to check. Yes is does sound really bad on the 2-3 gear change, as if it is missing so bad sometimes that it feel like the car is about to stall. I've been trying to pump the throtle when it sometimes just gets stuck at 35 km/h and seems to help it get out of the rut it's in. Then erratic power up to about 3000 when it takes off l Ike a rocket. So you could be onto something, thanks for the comment.

I'll wait for more possible responses but I think I'll get Steve to check this out.

At 180Kms, the engine should be in good condition, so that makes one wonder why the oil pressure light is coming on. This would also cause the tapping/knocking due to no oil getting to the hydraulic lifters which need oil pressure to close them up and stop valve noise. Low oil pressure can be caused by many things - worn oil pump, blocked oil pickup filter, air entering before pump, oil pressure relief valve cocked open, spring on oil pressure relief valve broken, worn bearing etc etc....but usually at much higher mileage than you have.
The surging etc also could have many causes but if it was me I'd start with the cheaper more common causes: dirty throttle body, vacuum line off/split, plugs or leads bad, ignition module/distributer/rotor cap bad/ blocked fuel filter/bad injectors or fuel pressure regulator. The missing sound like ignition to me. Good Luck.

Run a bit of injecter cleaner through it because that sounds like a couple of things going awry there

Gearbox has nothing to do with this. The other thing with o2 sensor is if you have a pretty high and noticable fuel consumption readout. High pitch cold start rattle could be Timing belt tensioner.

Sounds like a combination of a few things...I reckon it'd be to do with your oil pump being a bit shoddy then leading to your lifters not having had enough oil for..well 18 months??

Have a look at your sump to see if it has a dent in it . . . . . . . . .

Run a bit of injecter cleaner through it because that sounds like a couple of things going awry there

i would do this as had a car in the other day at work and it was running like it was miss firing even though i had change the spark plugs with new ones and did a base idle reset as they put a new battery in
it was still running rough then i checked the Leeds and they were OK and also took out the spark plugs again just to make sure that they where not cracked or the gap was not right they were good so then i clamped of the fuel return line and it ran like a dream unclamped it and went back to running rough again
so it ended up needing the injectors cleaned

Did cleaning the injectors help? What did you use?

If you are experiencing erratic behaviour and believe it may be o2 related, disconnect your o2 sensor (To the right of the pass footwell, white plug and a wire going into the floor under a plate) and go or a drive, if it acts normal, replace the o2. DO NOT LEAVE IT DISCONNECTED AS IT WILL RUN IN OPEN LOOP MODE.

Did cleaning the injectors help? What did you use?

yes it did took them out and had them cleaned by an injector guy that will come to our work when booked

So injector cleaner did not work? I had a rough idle and injector cleaner made it a lot better, but it's still a bit rough. Did you have any ticking/diesel type noise, I have and am thinking it may be the injectors.