greetings fellas

forgive me for i have sinned: i had my (regular car/truck) mechanic change all the fluids in my 86. my engine sounds louder than before...i don't ant to say tapping but i think its the best way to describe it- other than by sound. tatatatatatatatatatatatata.

could this be the result of the oil he put in?

 

Hmmm. I'm not sure. I don't think so.

The old "XK" engines such as your seem to prefer heavier oils with 20/50 being the usual favorite unless you're in sub-freezing climate.

If he installed the light oil commonly used in modern cars, such as 5/20 or 5/30, have it changed again and see if anything changes.

Others will chime in.

Cheers
DD

 

The oil grade needs to match what Jaguar specified when the engine was in production, or pretty near it, like 15W40, or 20-50 like Doug says. The "kerosene" oils of today lubricate OK, but you can get some noise. Of course you could have loose tappet guides.

You might care to check the valve clearances as a precaution. If one is very wide you have likely bent a valve if the engine stood for many years.

 

In no way meaning to alarm but does your XK have the stake down kit? I'd call the guy and ask what grade he used. I always ran 20/50 in my XK, 4.2

 

im almost positive that he put in 10w-30

 

I don't think 10W30 is really suitable for that engine.

The XK is a different era to modern stuff. Remember the engine was designed during WW2, then started manufacture in 1948 on second-hand machinery !

Have a read here: -

The Jaguar XK Engine / AJ6 Engineering

 

I drained the 10-30 and went with 20-50. I can def tell a difference for the better