As some of you may know my car died last month in quite a sudden catastrophic fashion.
Out of the blue it started to loose power and make all sorts of nasty knocking noises and then died, I did managed to get it safe and off the road before it rolled over and stuck its legs in the air.
As always when this happens I find myself looking down the road for a trail of oil and bits as I get out of the car which is a draw back from far to many exploded diffs and a few broken con rods, but to my surprise nothing not a thing. So I then open the bonnet expecting to find it covered in oil and bits of engine and again nothing, next I checked the cam belt and that was fine too so it was time to ring the AA and get it home.
Once home the hunt was on. I plugged in the computer and that showed no faults at all, then checked the timing and that all lined up so it was time to start pulling the engine apart as I now had a idea what had gone, thinking broken rockers.
As I pulled the cam housing off I heard the tell tail tinkling of broken rockers
Right then lets get a new set ordered along with a gasket and find a new exhaust cam as every single lobe was now looking like they had been attacked with a hammer.
I had a rocker fail the other year and put this down to me for some reason not swapping them all out then and only replacing the damaged ones. So with this answering the question why the hunt was on for the missing 124 roller needle bearing released in to the engine by the failed rockers. After finding 80 odd by fishing round the head with a magnet and through the sump plug hole there was nothing left to do but take the sump off, which on the 2.4 means you have to drop the sub frame.
Right then all accounted for lets put it all back together, job done lets start her up. OOOh that does not sound good, turn it off quick. Turned the engine over by hand only to now find tight spots so I double checked the timing using my locking tools and its spot on. Compression test the engine and that's fine so it rules out a bent valve. OK start it up again thinking the noise could have just been the lifters priming up and the tight spots was the good compression I got when I tested as it was only five spots per two revolutions.
After a couple of seconds it all quietened down as the lifters primed and adjusted. I'd also changed the power steering fluid too so a few full lock to locks to re prime the system at which point the engine stated to judder so I turned it off. For a change I checked everything again only to find nothing, so turned the engine over again and over and over, but it wont fire.
After much more checking I noticed that if you crank the engine over you can feel air pulsing out of the intake which means somethings not right and time to pull it apart again !
Ahhhhhhh ! all the exhaust rockers are broken again.
What the hell is going on. I know the timing is spot on as it was all locked in place with the cam and crank locking tools and still is spot on when checked. Only thing left was to check the actual TDC against the timing marks by dipping the cylinder and finding the true TDC. Ah-Ha we have a discrepancy against the true TDC and the timing marks on cam pulley by about 3 teeth.
Checked the cam pulley and that was all fine so time to check the crank cam pulley
Got You you little B*st*rd !
All the extra stain that the broken rockers must have put on the exhaust cam must of been huge and sheared the key off the cam crank cam pulley which had the slipped just a bit and rockers are no match for pistons.
Put it all back together again today and she lives, she lives !
So the motto of the story is it check the crank cam pulley if you've had a rocker failure, it only takes a couple on minutes to remove the crank cam pulley to check as opposed to over three weeks of messing about.