35 replies to this topic

[spiguy]

Hi. I was posting in someone else's thread and felt bad as I had basically hijacked it going hence this thread!

I'm investigating a sound on cold start which is like a wide valve clearance, sure it's only one rocker involved, and goes away after about a minute.

I ran it tonight with the rocker cover off to try coopermans trick of using a feeler gauge when running to find which one it is. Of course, it didn't do it! Typical. .

Is it possible to slide the rocker clear of the push rod to inspect rhe shaft or underside of the rocker? I could move it a bit but only as far as the push rod would allow. If I back the adjuster off a lot does that allow the rocker clear of the push rod?

I noticed there is some lateral play between the rockers and the shaft. Should there be?

Thanks

[sledgehammer]

sometimes the rocker wears with a valve stem imprinted on it , the feeler gauge misses this so the gap is actually larger

 

than the feeler measuring it

 

(I'm finding this hard to describe) 

 

the red bit is the feeler gauge

 

 valve lash.bmp   231.31K   162 downloads

Edited by sledgehammer, 04 March 2015 - 10:13 PM.

[spiguy]

Thanks, yes I understand that. I don't actually think that has happened in my case, as I can slide the rocker to the side a bit - I tried this tonight, and I pressed down on the rocker tip so that it was contacting the valve stem, and then I could still slide it to the side. If the valve stem was in a hole due to wear, I would expect it would not move side to side (this is my reasoning anyway). I must admit I didn't do this with them all, as some of the valves were opening so the rocker wasn't free to move.

 

In any case, I would like to be able to slide the rocker further to get a better look / feel, hence the question about whether backing off the adjustment allows the rocker to clear the push rod.

 

It's just weird, because often it will take about 30secs or 1 minute before the 'ticking' sound starts, then after about another minute, it goes away. Usually, when it is about to disappear, it will 'come and go' for a few seconds, then go completely. I had thought it could be oil related, like not enough oil to begin with, and then oil getting to it but there seems to be plenty oil running along the shaft and pooling at the head etc.

[sledgehammer]

I wonder if the rocker shaft is worn  - rather than the rocker it's self ?

 

& if the oil is taking a while to get to one of the rockers - then it goes quiet

 

putting a feeler in the gap should quieten the noise - as cooper man said

 

there are a lot of places in that area for clicking / tapping to occur when worn

Edited by sledgehammer, 04 March 2015 - 10:27 PM.

[cal844]

It may be the oil pump wearing?! Or as above valve lash

[spiguy]

I must admit, I haven't got an oil pressure gauge in the car yet, it's on the list! Any thoughts on whether you can move the rocker right off the valve / push rod for a better looksee without removing the whole thing?

[slidehammer]

It is a fairly quick job to remove the rocker shaft once you have the rocker cover off. I would get it off and make sure the pads aren't badly worn / pitted and whilst it is off clean out the oil way in the pedestal that feeds the shaft and the shaft itself to ensure good oil flow on start up. The rockers can be bought separately from Mini Spares if any are suspect.

[Dusky]

Well, easy to test of its the oil..just pour some oil on the rockers, then do a cold start

[spiguy]

Is there not an issue around disturbing the head gasket if you remove the rocker assembly?

[Spider]

If it only does it for a few moments on a cold start, try turning the radio up a little more 

[spiguy]

If it only does it for a few moments on a cold start, try turning the radio up a little more 

ha ha ... yes indeed, that is a good idea!  I tend to warm the engine up for 2 - 3 minutes before setting off so by the time I am driving it's stopped.

[Mini Manannán]

Warming up for 2 or 3 minutes isn't generally considered a good idea because the engine warms up far more slowly when not under load.  You're better off with 30 seconds for the fluids to get moving then get going; gently at first of course.

[jaydee]

Sounds like normal wear

Change oil to some quality oil (millers, valvoline etc..) first

[spiguy]

Thanks for the info and tips folks. Wonder if I could just restate a couple of questions that nobody has commented on yet, see what you think - can you back of the adjuster and then slide a rocker to the side, clear of the push rod and valve? Also, if you take the rocker assembly off, does this disturb the head gasket and if so is there a re-tightening process required?

 

Thanks

[jaydee]

Both undoing and tightening process requires following the spiral pattern as per headgasket removal, where undoing is just the reverse sequence.

 

 

To minimize the chance of breaking the headgasket seal, you need to back off all the adjusters so the pushrods are not rocking. This is not always possible..

 

Good luck.