Hi folks..just bought a 1994 s320..am getting a tappet/knocking from the engine..hard to tell..it's loud when cold and quietens a little when warmed up..oil pressure when driving is at 3... am getting warm air through the vents..although it's not as warm as what it should perhaps be...</P>


now. had a couple of guys look at this for me and getting varying opinions..</P>


tappets??? piston bent??? valve timing out??? one guy said that the engine had been 'cooked' and thats caused the damage.</P>


ive been told to just change engine but its only done 114000kms which i dont reckon is that much</P>


any advice on what this could be would be great</P>


thanks, ed</P>


</P>


</P>

 

It sounds to me like the timing chain tensioner has jammed a tiny pin inside it. This is what my 200 merc did once causing the engine to knock and clatter horendously. I decided to replace the entire timing chain, and found that problem along the way. In the worst case cenario you could buy a second hand cylinder head if the old one has problems (ie bent valves).

To assist your troubleshooting i should mention that your car does not have tappets, it has a cam and cam follower assembly meaning there is simply nothing that could go wrong there. The piston connecting rods simply couldnt bend, as they are too strong for that. So it could only be the problem of the cam timing being out as a result of
A: Failing tensioner resulting in loss of tension caused by jammed tenioner or overheating of engine and loss of oil prssure reulting in loss of tension.

b: worn mechanism causing slippage of timing

I would advise that you obtian a haynes manual and check the cam timing before you crack a piston crown.

This means that if the timing is infact out as it sounds like, a valve could be smacking a piston wrecking it and therefore destroying the entire engine instead of just the cylinder head. (which isnt a huge problem or very expensive either if a second hand replacement is available)

 

thanks jucor</P>


that sounds pretty good as it echoes something else i was told today that it could just be the timing out and the valve is smacking a piston. </P>


will get it checked AGAIN!!</P>


Thanks</P>


ed</P>