Quick question for you. My POS first gen has a pretty bad metallic rattle coming from the engine which at first I assumed was just the balancing shaft chain rattling away like it always does in these cars but I'm not to sure. At 1900rpm in drive its clearly audible but if you put the car in N and rev it right up to the red line there isn't a hint of the rattle. This to me doesn't make a whole load of sense, all the chain does is drive the balancing shafts and the oil pump so the actually engine load shouldn't effect it? Is there anything else it could be?

First of all, it is an issue reving an old engine to the red line, very dumb to be blunt

The chain will generally shut up under revs / load as it settles down due to the speed the shafts are now spinning.

I am happy to have a listen if you want

First of all, it is an issue reving an old engine to the red line, very dumb to be blunt

The chain will generally shut up under revs / load as it settles down due to the speed the shafts are now spinning.

I am happy to have a listen if you want

Yeah fair point about over reving it, its probably not helping the situation.

The bit that confuses me is it rattles like hell in drive at constant rpm but is silent in Neutral at the same constant rpm.

The higher the RPM of the balance shafts/timing chain, the less noise you will get. simply because the chain becomes more taught at higher RPM

PS, dont rev an astron to the redline. it'll break. dont rev any engine to the redline...things BREAK.

PS, dont rev an astron to the redline. it'll break. dont rev any engine to the redline...things BREAK.
lol a lot of engines out there are built better than an Astron

lol a lot of engines out there are built better than an Astron

true, but rev anything to the redline and it's bound to incur damage;)

Does this sound at all similar to the metallic sound you get when you rattle an empty paint can?

If so I could take a stab in the dark and say detonation......and no I dont have anything to back that up as to why it would happen :P however it is a noise that can happen under load, and not in neutral....to me atleast its very distinctive.

Does this sound at all similar to the metallic sound you get when you rattle an empty paint can?

If so I could take a stab in the dark and say detonation......and no I dont have anything to back that up as to why it would happen :P however it is a noise that can happen under load, and not in neutral....to me atleast its very distinctive.

wouldnt the knock sensor pick this up? if not, then the sensor would be faulty and throw up a CHECK ENGINE lamp.

Do astron engines even come with a knock sensor?

(not a smart **** comment, I just dont know)

Do astron engines even come with a knock sensor?

(not a smart **** comment, I just dont know)

Yeah. Theyre located in the most bull**** spot below the intake.

engine mounts? (1 or more, either way)

had the same in my 2g

have you done the chain guide adjustment on your first gen

that little cover on the timing case

special bolt B

Yeah I;ve readjusted the chain guide but that didn't seem to help.

I was thinking maybe it was knocking as first gen astrons don't have knock sensors it could be possible. I was planning on acquiring a timing light to check out the timing.

i would be looking at reasons for it to ping/detonate.. checked base timing?? injectors dirty? need a decarbon (subaru upper cyl cleaner works an absolute treat!)

have you tried running a tank of 98 ron fuel through it?? see if it does it less etc...

Ok I haven't got a chance to check the timing but I did put a tank of shell 98 through it and the noise has almost completely gone. Before The rattle was very loud and happened with constant and varying rpm, Now in the past 2 weeks that i've been using the 98 fuel I've heard the rattle maybe once or twice and only for just a fraction of a second when the rpm changed.

Now maybe it's just cause I'm cynical but I am never going to be convinced that simply switching to a fuel that this car was never designed to run on would make such a big difference. Honestly I don't care that much cause the car is going to a wrecker soon but its just freaking weird.

Mabey his timming was out and it was detonating to death. The higher octane fuel seems to have helped the situation. A complete tune may be in order and timming adjustment on the distributor.

regards

yep you definitly need to check BASE timing.. you should have the instructions on a sticker on the underside of the bonnet.. if not i have a 2nd GEN book that shows the correct way to do it.. for example with most toyota's you need to pop open the diagnosis box, and bridge T1 & E1, or TE1 & E1, to check the engines base timing.. this overrides all the external inputs from the knock sensor/temp sensor etc etc and allows you to change the base timing.. same thing if you were tuning a old carby car with the older style elecronic dizzy or points setup.. you would pull the vac line off.. same principle..

also note that excessive carbon build up in the chambers, and dirty injectors can also cause this problem.. to help clean the carbon out of the chambers/valves use a can of subaru upper cylinder cleaner as per the directions on the can.. the injectors.. most injector places can do them for $15-25 ea, for new filters/seals/orings ultrasonic clean and spray test.. usually cheaper if you pull them out.. and i would strongly advise changing the fuel filter!

mat