Thanks it's an easy try so I'll have a go at that! Fingers crossed.
Oil leak, underneath spark plug
- Thread starter DaveS
- Start date
Right took the rocker covers off again and checked the cylinder head nuts.
The front bottom one on both sides was definitely looser than the others. The Haynes manual doesn't give a torque setting as there's a specific procedure for tightening them, so it was difficult to assess the correct figure, but I went by building up the torque setting from the other solid nuts.
I also found another oil leak which was confusing matters from the oil cooler pipe at the banjo bolt low down on the LHS. Anyway all tightened fixed and put back together so ..... lets hope this does the job.
The front bottom one on both sides was definitely looser than the others. The Haynes manual doesn't give a torque setting as there's a specific procedure for tightening them, so it was difficult to assess the correct figure, but I went by building up the torque setting from the other solid nuts.
I also found another oil leak which was confusing matters from the oil cooler pipe at the banjo bolt low down on the LHS. Anyway all tightened fixed and put back together so ..... lets hope this does the job.
It's quite important that the cylinder head bolts are torqued the same (I struggle to think how you could guess the torque from comparing it to an already torqued nut?).
Why didn't you just follow the proper procedure and torque them all up?
Well logic suggests that the cylinder head bolts have NOT been torqued the same for some considerable time, so whilst yes you are correct, clearly in practice SOME tolerance is permissible as it's been running generally fine albeit with a minor leak.
Presumably this is what's been causing the leak.
I took the approach that undoing everything and redoing it all from scratch wasn't something I wanted to do as I could make the problem worse.
It was obvious that just one nut was looser.
So logically I thought that if I could ensure that I didn't go over the torque on the good nuts then getting close to them would be better than it is now.
So I set about trying a low torque setting on the good nuts to get a feel for where they were. E.g. a setting of 20NM didn't budge the good nuts but turned the loose one. Then moved upwards from there without actually moving any of the good nuts. I got up to about 40NM.
Again the situation before was such that one of the nuts was less than 20NM so I can't have made it any worse.
It's unlikely that retorquing all the nuts could make it worse (unless you stripped a stud or something). However the thing with your comparisons with a torque wrench is that nuts that have been set for a long time have a surprising amount of 'stick' - when trying to undo them they often require quite a lot of force (way more than the correct tightening torque) and then let go with a crack. So by comparing to a 'good' nut you run a real risk of over tightening the loose one.
The only way to be sure is to slacken them off one by one, oil them and retorque according to spec. This is exactly the procedure used at the initial 'first service' retorque (probably in your Haynes manual?).
Trullion
Registered user
It occurs to me that the reason the bottom front head bolts were looser than the others could be because someone has not done a good job of setting the rocker shaft end-float. Whatever, I would be inclined to re-torque all the head bolts.
Yes fair point. I was very careful and probably if anything under torqued because I was very concious of this.
Ok will consider going back AGAIN and doing it properly.
Sorry one question. The reference to rocker end float sent me looking for what I do at service time and no mention of this in the Haynes Manual so mines not been done whilst I've been doing the servicing, couple of years or so.
Then I found Steptoes guide on checking clearances and the end float.
There is no mention of doing all the cylinder head bolts / nut's here? So surely if I just do this one by slackening off and the tightening to 20NM + 180 degrees then that should be fine.
Then I found Steptoes guide on checking clearances and the end float.
There is no mention of doing all the cylinder head bolts / nut's here? So surely if I just do this one by slackening off and the tightening to 20NM + 180 degrees then that should be fine.
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