good evening all
i have a problem with me magna the radiator busted and 4 hoses
i had the replaced today and all was sweet untill i noticed the pressure build up in the hoses
(new thormostat too) i took it to natrad and had a pressure test done on it,
it seems that the cooling system isnt creating its own pressure but the motor it helping just alittle.
so i came to the conclusion that
1. Head has crack
2. Head Gasket has a scratch (from when other mechanics rebuilt the motor)

ok the question is and for the life of me i cant remember how to take the timing chain of the cam gear so i can pull of the head, i know in other models you can use a screw driver for the tentioner but this model has automatic tensioner
how would i go about getting the tention of the chain so i can get the head off

93 TR Magna Auto 4 cyl, multi point injection

the timing chain does not have to be removed from the gear all you do is slide gear and chain towards drivers side of car and the gap in head near gear is big enough to just lift head straight up hope this helps

the timing chain does not have to be removed from the gear all you do is slide gear and chain towards drivers side of car and the gap in head near gear is big enough to just lift head straight up hope this helps

nope if i move towards drivers side i will be pushing it onto the cam again.
i cannot move it towards the passanger side cause there is still tention and there is this dicky thing underneath the camgear itself stopping me from moving it down or really do anything with it

To get the top sprocket free of the head/cam,
Remove the distributor and the distributor drive gear from the front of the sprocket.
There are also 2 x 12mm head bolts in here between the timing case and head.
Then slide or prize the sprocket off the cam and to the LHS of the car a few MM to clear the camshaft pin, it should move out and down even thought the chain is under tension.
The sprocket is supposed on sit on the Tin plate, it's attached to the block. sitting the sprocket here also lets the timing chain tensioner come out a bit. The head can be removed over the sprocket.
Putting it back together can be "fun". The sprocket needs to be lifted to go back on the cam this pushes the chain tensioner back and some astrons have ratchet locks on the chain tensioner, this has to be released to get the sprocket high enough.
Most locked tensioners have a release lever that can be pushed down on with a long rod or screwdriver somewhere along the back of the guide,
Be prepared to remove the timing case if you can't find the release lever and also refit the sprocket to the cam before tensioning the head just in case it has to come back off to get the timing case off.

Make sure when you get the head done it is shaved properly (within specs). Other wise you will get timing chain noise like you've never heard.


I had the same problem and it was $200 more for a new motor than to replace the head with a new.

Guess what I did.

skim it 25thou and adjust the timing chain, give you some better fuel econ and torque

Make sure when you get the head done it is shaved properly (within specs). Other wise you will get timing chain noise like you've never heard.


I had the same problem and it was $200 more for a new motor than to replace the head with a new.

Guess what I did.

ok just an update
the car is back on the road again did it last week
turned out to be a crack between the valves in pot 2, water jacket was alittle busted, there was water wash in all cylinders, and the head was warped like there was a hill :shock:
wish they made a better head for them to soft.

went out and bought a reco head for $440 and away we go.

just another question for yas in all of the bores there was black stains in them, i asked Martins Engine Reconditioning and they didnt know what it was from.
i have seen it before but not in a car. i seen it in a 2 stroke YZ125 still didnt know what it was from. only thing i can think of at the moment is that it was from the water

any gueses

It's it oil or carbon/soot?