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Oil change 78 T/A 400

Posted: Fri Dec 11, 2009 4:52 pm
by Midn12e
Hello,

I need help!!!

Ive done done an oil change on my 78 Trans am that I think has a 400 1970 or 71 GTO engine in it. (Yet to be confirmed nuts it a 400).

After consulting the hand book it says in needs 5 quarts of oil.

I drained the existing oil to find that only 2 came out (granted it was on a bit of an incline)

I pour in the full 5.

In the morning I checked the dipstick and from what I can tell theres loads in there and Im parranoid theres to much oil in there. The dipstick has one line (about 2cm from the bottom) annd i dont know if thats a min or max line. Currently the oil is showing its miles above that.

The only other marking on the dipstick is a kinda slanted E symbol.

I have been told that the T/A doesnt need much oil but dont know how much!

Please help as i know it sounds simple but this is my first Yank Tank and would like to keep her running and not spray oil everywhere.

Thanks,

Steve.

Re: Oil change 78 T/A 400

Posted: Fri Dec 11, 2009 5:39 pm
by SUPERCHARGEDGTA
I assume that is 5 american quarts (just under 5 ltrs)
that will include the filter, did you change that?
not sure about older 400's, later (late 70's) engines used less than that, mine used to leave a little left over from the old 1 gallon cans

Re: Oil change 78 T/A 400

Posted: Fri Dec 11, 2009 5:40 pm
by SUPERCHARGEDGTA
should be 2 lines on the dip stick for sure

Re: Oil change 78 T/A 400

Posted: Fri Dec 11, 2009 6:04 pm
by Midn12e
Hello,

I changed the filter.

Ive re-checked dipstick and there is only one line. Im assuming this isnt the original stick.

The fella who owned this before has just told me it didnt need much oil. ive just drained some oil off so its level with that line and so far there isnt any grinding or clanking!!! the oil pressure gauge is no where near the red either.

On reflection when i checked the level before the change it was at about the same as that single line but i didnt know if that was correct either.

Re: Oil change 78 T/A 400

Posted: Fri Dec 11, 2009 6:18 pm
by SUPERCHARGEDGTA
sounds good
could have had a dipstick adapted
as long as presure is good, then should be ok

Re: Oil change 78 T/A 400

Posted: Fri Dec 11, 2009 6:27 pm
by Midn12e
Thanks, how long do you have to own one before yah stop worrying about these things??

Re: Oil change 78 T/A 400

Posted: Fri Dec 11, 2009 7:05 pm
by webbel
Midn12e wrote:Thanks, how long do you have to own one before yah stop worrying about these things??

never :oldrolf: :oldrolf:

Re: Oil change 78 T/A 400

Posted: Fri Dec 11, 2009 7:54 pm
by lutonmatt
never worry about the car iinfact dont worry about anything lol if it blows up then so be it just make sure it does it good i say :lol:

Re: Oil change 78 T/A 400

Posted: Fri Dec 11, 2009 9:04 pm
by SUPERCHARGEDGTA
::)

Re: Oil change 78 T/A 400

Posted: Fri Dec 11, 2009 9:54 pm
by banker
:-?

Re: Oil change 78 T/A 400

Posted: Sat Dec 12, 2009 4:45 pm
by Brauster
If a jobs worth doing its worth doing well.

same comes for breaking things

Re: Oil change 78 T/A 400

Posted: Thu Mar 06, 2014 6:40 pm
by thirdgen
this is my motor now and that line on the dipstick is low for sure n i had about 3 litres of oil is i was lucky !

including the filter i have put in 4.7 litres now 5 quarts so the manual says and notched the dipstick with a hacksaw for a full mark . i guess its been running on 3 litres of oil for years :shock: must be a good engine :oldrolf:

Re: Oil change 78 T/A 400

Posted: Thu Mar 06, 2014 9:17 pm
by SUPERCHARGEDGTA
always thought they held about 4 ltrs
better a little low than too much

Re: Oil change 78 T/A 400

Posted: Thu Mar 06, 2014 9:27 pm
by thirdgen
I only had 2 litres from the sump.

Also put in 10/40 semi is that ok ? Oil pressure is much higher than before. But with a oil change it always is I guess.

Re: Oil change 78 T/A 400

Posted: Thu Mar 06, 2014 11:41 pm
by SUPERCHARGEDGTA
10/40 semi is good enough :thumb:
most engines don't have roller rockers and semi maintains viscosity and lubrication (and the pressure that some oils can stand before being forced out etc)
also they have hydraulic lifters too
as a city & guilds qualified engineer before changing to mechanics I studied lubrication technology
there are a lot of misconceptions over oil types and viscosity ratings and temperature ranges

Re: Oil change 78 T/A 400

Posted: Fri Mar 07, 2014 9:37 am
by bhm1712
Robin says for these old Pontiac motors you should be running mineral oil 20w50.

Re: Oil change 78 T/A 400

Posted: Fri Mar 07, 2014 10:57 am
by thirdgen
i have read that last night too. i can always change it again in few hundred miles give it a clean out.

Re: Oil change 78 T/A 400

Posted: Sun Mar 09, 2014 8:55 am
by jonbullnose
i would never run these engines on semi syn !!!! change it before you use it it will damage the engine semi syn gets very thin when warm it will blow the big ends and cause lifter problems as well it also has no zinc or other aditives in needed for the cam to lifter lobe bearing surface it will also wash all the crap out the sump as it is much thinner and these engine always get piston blow by so will add fuel vapour to the oil and make it evan thinner
as ian said 20/50 is needed halfords classic is ok or i use valvoline from real steel :thumb: