My 89 Camry seems to have thrown a connecting rod the other day, I'm going to look inside to see what exactly is wrong and how bad it is, but I'm wondering why it failed in the first place (it only has 205k km on it).
It seemed the oil light would stay on for 2 or 3 seconds after I started the car, then go off and not come on again. I assumed thought that was normal as the pressure built up (though looking into it the light seems to go off at 4.3 psi or so). Is the light staying on at all a sign of trouble???
Connecting rod failure is one of the most common 'catastrophic' sources of engine failure. It can happen without warning eg a rod-cap bolt shears off,..or more commonly due to extreme wear and subsequent failure in lubrication of the said rod-bearing.
High mileage Taxis, depending on maintenance, can develop noisey rod-bearings which you can hear on a feathered throttle (inbetween power on and off) at about 50 mph or 80kph. Eventually the wide running clearances causes the oil film to breakdown under load, allowing metal on metal contact,..then a viscous circle of everincreasing oil-clearances followed by an overheated bearing followed by failure.
Dirty oil can cause accelerated wear which produces the same result. Your oil light will warn you all is not well by blinking on at low idle revs once the engine has heated up. At cold, the thicker oil and closer running clearances keeps the oil-pressure up,..so your slow light is not really relevant unless there is a problem with airleaks causing sluggish pump performance.
It turns out the rods are ok. I took the oilpan off today and it looks fine. Turning the engine with a wrench doesn't show any problems either. Nothing in the bottom end seems loose when I push on it, except for the lateral on the big ends, which seems to be within spec.
That was my first experience with an awful sound from an engine. I thought it was a rod because it was a an extremely loud clanking that I'm sure could be heard 2 blocks away (literally like something was whacking the engine block really hard). Also, the oil light was flashing on a bit when it was just a small clank. The engine runs, but makes that sound at idle, and gets faster with the engine. The oil level was fine.
Is it possible this is a bearing problem that I can't detect easily with the pan off? I took the valve cover off when the problem first occurred, everything looked fine, though I didn't turn the engine. The sound was so loud that it seemed it would be coming from a bigger part under great force.
Possibilities: For an engine part or accessory to make such a loud noise, means there will be excessive movement or fouling of moving parts (less common) to cause it.
-I'd be removing each plug-lead at a time, to see if the noise dramatically lessens, hence pointing to a particular cylinder: meaning a broken piston (piece of the skirt broken off causing piston noise as its lateral support is decreased), or stuffed rod-bearing. A loose gudgeon or wrist-pin which is floating against the bore is on the cards,..but fuming or blow-by increases rapidly also with bore damage. I think you said its automatic, so crank endfloat (which when excessive isnt that loud anyway) wouldn't seem to be it.
- a loose crankshaft pulley can be fairly noisey as it chatters against its key ( a small piece of metal which locates the pulley correctly on the crank taper).
-The cam-belt tensioner and idler pulleys, if loose or the tensioner spring has broken. Water-pumps can get quite noisey,...but a clanking noise? While you have the cover off,..check the oil-pump pulley for excessive movement.
- check the main cam (belt-driven one) hasn't got bad endfloat by pushing and pulling its belt-sprocket. You mentioned the cam lobes and followers looked OK,..not broken
-a loose TConvertor, Broken vanes in the torque-convertor, or something gone pearshaped in the transmission.
Use a long screwdriver as a stethoscope to check the following items. The idea is to carefully place the driver blade against various engine housings while you rest your ear on the handle end. Works well,..but obviously care is needed so it doesnt slip off.
- the AC compressor is a prime candidate for loud noises if it has failed. The power-steering pump may be it tho I haven't heard one go that noisey.
- check alternator with a stethoscope
If all these seem Ok,..there remains the balance shafts (oil-pan off for this one). If they have chewed a bearing out,..its possible low-oil-pressure and noise will result. Check for excessive movement.
Make sure you use stock Toyota filters. The anti-drainback valve of many aftermarket filters are not up to the job and they will drain out, requiring a refill on startup. I saw this on my '89 4-banger when I had it. Stock Toyota filters virtually eliminated any startup rattle from lack of oil pressure.
My '89 also once did this noise after sitting for a week without being run. Luckily it went away, and I never did figure out what it was, except some sort of oil delivery problem, even though the light was not on. CLACK CLACK, etc...
Hell,...this isn;t a case of bearing rattle before the galleries get primed? Soundz like it now you mentioned it.
In that case Factor,..there is little you can do about the problem, assuming you are using good quality oil-filters. A lot of engines especially older generation have this problem. Typically, you start the donk and for about one second, the engine rattles like a machine -gun. Sounds scarey,..but is of no real significance.
I've been busy taking it apart and putting it back together again. Tonight I'm going selectively disable cylinders and start it up, to see if I can identify if it is a specific cylinder.
If I can get the sound a lot quieter (it sounds like a 50 cal. machine gun now), I've got a cheap mechanic's stethoscope to identify the g area of the noise. So no fear about a screwdriver through the hear of a broom handle in the eye!
It did have a cheap oil filter on (I've learned my lesson), but it never had a rattle on startup, just the 2-3 second oil light.
I'm not too worried about the 16 year old car, I'm viewing this as a learning experience.
So you have the sound after sart-up and it continues? At this stage, Id change the filter, as it maybe causing a complete blockage. Normally a bypass valve guards against this,..but all the same. If its still noisy, I would get hold of an oil-pressure gauge (or any gauge which can register 50 or more psi) and screw it into the block where the oil-pressure sender lives. Some inexpensive fittings maybe needed,..take the sender with you when to check for the right fittings on the pressure gauge.
I've got a cheap mechanic's stethoscope to identify the g
Yes,..that fact shot the latest theory out of the sky.
Aye,..they say exp is the best teacher ( or close),....but a less traumatic way would be nice.
The more info you have, the better chance you have of finding the problem, apart from stripping the engine down.
Cold OP readings are always close to normal,..its when the engine has reached normal operating temp *and* the oil has also reached norm-temp, that true OP is shown. Normal idle is 4 psi,..at 3000 rpm > 35 -60 psi according to the manual I have.
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