4AGE 16v Compression...

[FYADUP]

I have an 1991 AE92 GT-i, with presumably the smallport motor (red/black writing on cam cover)

Its done 280,000km and due to a leaky sump gasket is has been slowly losing oil.

i now have some funds to fix it - the oil in the car is about 1/3 full i would say by the dip stick.

I have been noticing vary odd faint sounds from the engine, but it has a loudish exhaust so hard to tell, but I am probably just hearing things and presuming something bad.

The noise could be due to low oil?

Anyway, im giving it a full service oil, coolant, plugs, filters etc and am wondering what numbers, an engine of these km's would produce in a compression test. I have looked on the net and found 179/180 to be standard for a new engine? So obviously with the age would be lower.

Just wanting to get info to see whether it is worht spending money on a service now, or get a better block to replace it then spend money on that.

Any thoughts would be great.

Cheers, Jason

[MR2BOY23]

Yeah should be something like that. Just make sure all the cylinders are similar compression that's what you'll be looking for

[FYADUP]

Well did a comp test today, using a screw in type Gunson hi-gauge comp tester.

In all 4 cylinders i got a reading of near on 240 in each - From looking around on the net, It seems farely high, but constant, so i guess means nothing is wrong with it?

Is the hi reading something to do with it being a hi-gauge as in hi read outs or?

Cheers, Jason

[allencr]

Is the hi reading something to do with it being a hi-gauge as in hi read outs or?

or the gauge is Bad or A LOT of carbon buildup or hi comp pistons with very low duration cam/s or a diesel engine. The hi-gauge is just its advertising BS name.
Wet or dry?
I'd say the gauge is bad, not just VERY optimistic.
I wouldn't even trust its seeming consistency.
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No noise is good noise when the oil level is low.
Also, what does 1/3 mean for the dipstick, how many L/Q did it need to reach full?

[Dell'Orto]

Wet or dry test? You did have the throttle open yeah?

[sergei]

The number is irrelevant as long as it is high enough. The number has almost nothing to do with compression ratio. It is a misconception.

If you do on hot engine, full throttle and fresh battery on good engine it can get up there in 220-240psi.


Even if gauge is reading high by 30%, the engine is fine if there is no difference between the cylinders.

[FYADUP]

What do you mean by wet or dry?

It was done on a farely warm engine, all spark plugs out, foot flat on gas and let it "chug" about 5 times, or until the gauge stopped at a number

Yer I guess the gauge could have been bad, but it did read almost exactly 240 across all 4, which I guess means nothing really wrong with it? (engine not gauge)

Just did a full service on it today, Had hardly any water or oil in it, radiator water was yuk, so gave it a good flush, new oil, oil filter, spark plugs, radiator flush, coolant and air filter - Just a standard repco one for now - Repco had K&N priced at $350 for a panel filter FTW! Anyone suggest any other good brands?

But after the service a mate kindly did for me today, she runs like a dream - more responsive and much more smooth to drive She has still got some good poke for 280,000km!

Makes me wonder about the browny water in my radiator, wrecked radiator cap and brown sediment at the bottom of the overflow bottle - what exactly was the mechanic i used to take it to doing when it got a service?

[craigt]

Are you sure it is a smallport?
Does it have the TVIS badge(or place for it) on the inlet manifold?
If it does it is a bigport