[BlueMax]

I have done 2500km after getting a JCW210 conversion done. I noticed a whirring phrrr type noise from around 4000 rpm upwards and went to the dealer. They listened to it and immediately decided to replace the harmonic damper (crankshaft pulley) This was done on Monday. It was late when I collected the car but I found the noise to still be there. Took the car back yesterday morning and took the main service tech for a ride. He was not sure what it was and said I should book the car in for a check today. Just after driving away the car started backfiring and making a constant loud ticking tappet sound. Managed to get back to the dealer with quite a very sick sounding car, struggling to idle at around 500 rpm. They have now traced the posible fault to a faulty hydraulic valve lifter/tappet. They took the tappet cover off and rotated the engine by hand. The valves open and close normally which should indicate that the valve stems are not bent, no springs are broken and there is no visible damage. They will be installing a complete new set of tappets/rocker arms/valve lifters whatever the correct name is because they are not able to isolate the suspect one. Questions:

1. Is there risk of head damage due to faulty/sticky valve lifters?
2. Would it have been possible for the piston to touch a valve if the valve was sticky or stuck, causing misfire?
3. Has anyone experienced this problem on a new head (not to impressed seeing it was a JCW head)
4. Are the same valve lifters used on the JCW head than a stock MCS?
5. Is there any special way to "run-in" the new parts?

Help will be greatly appreciated

[supercoopers]

1. Is there risk of head damage due to faulty/sticky valve lifters?


Yes, there is a risk that there could be damage to the head, but more likely to the piston crown and valve stems/face than the head face itself. Turning the engine over by hand is not enough to determine a bent valve stem; that is just sloppy and I would ask them to take the head off, remove the valves and check for lateral play in the valve seats if they really are too cheap to just replace the head and rocker assembly together...which is probably what they'll end up doing anyway.

2. Would it have been possible for the piston to touch a valve if the valve was sticky or stuck, causing misfire?

I think that you'd know about piston/valve contact on a bigger scale than a misfire i.e. the valve would most probably bend or even fracture off, causing nasty things to happen, but I could be wrong. Theoretically, valve/piston contact would cause a lapse in timing that could trigger a misfire.

The best way to determine valve/piston contact would be to remove the head and take a look.

3. Has anyone experienced this problem on a new head (not to impressed seeing it was a JCW head)

Not personally, but this is a risk with running hydraulic tappets in any car. One of the oil feeds in lifter arms may have become clogged with contamination from your oil, a possiblity if the particle was small enough and plausible since you have only just run in your car no? If not, was your car due an oil change soon?

4. Are the same valve lifters used on the JCW head than a stock MCS?

Yes, all the same valvetrain is used.

5. Is there any special way to "run-in" the new parts?

Don't stress the engine for prolonged periods at the same RPM i.e. freeway driving. You want to build up engine temp, but also vary the loads i.e. driving up some gentle inclines, then some town driving. Never go WOT for at least 1500miles and at that point, go for an oil change. Also, no going past 4500rpm for at least 1500-2000miles to allow for the piston rings to scuff the bores sufficiently and for everything else to bed in. If you are talking about just the head, then take it easy for 500 or so miles, and watch the oil pressure is sufficient if you have a gauge.

Hope that helps.

Henry

[BlueMax]

Henry, thanks for the excellent reply!

1 - I will talk to the dealer again

2 - As above

3 - The JCW installation was done at the first service - oil change (16000km, 10000 miles)

4 - Thanks for the confirmation

5 - Engine was run in properly. When the Works kit was installed, I did not go above 4500rpm for the first 1000km and used varying engine speeds. I then gradually opened up and highest I have gone so far on the Works has been 6800 rpm. Unfortunately I do not have an oil pressure gauge. It would have been nice if the MCS's came standard with oil temp and pressure gauges - the readout could have been incorporated in the revcounter display.

[roland2003]

Hi Guys, just seen this .Henrys covered this very well though.
The valves at full lift definatly do touch the pistons at TDC. Im supprised they couldnt hear which direction the sound was coming from .The crank pulley is heard through your left ear and head noises your right ear?! Anyway 2 things worth checking are that the cam-chain tensioner was released after rebuild and that the tensioner is not faulty. Finally a compression check should reveal if anything touched (bent) .
Best Regards Roland GTT

[herbie hind]

never ever did i say ever ? do you replace lifters without replasing the cam as well they have worn as a matched set but as far as head replacement well ... they should pull it at the very least to check guide play properly . valves could then be pulled and checked for run out .

[Capsaisin]

You've got that the wrong way round. Never ever do you replace the cam without replacing the lifters. New lifters are OK with an old cam, provided it is within spec and not worn out.

[BlueMax]

Thanks guys. I spoke to the dealer this morning and they have completed the replacement of all the lifters (not the cam). Remember the head has only done 2500km so wear should still be negligible. They also carried out a compression test and it checked out fine. The engine was run and the tapping/clicking noise is now gone, there is still a misfire - the spark plug on cylinder 3 is black so it seems to be the culprit. They are now looking for new spark plugs which may take a while as they do not have the high performance plugs in stock. At least they have provided me with a hire car (Hyundai Getz) which only make me miss the Mini so much more. Hopefully the next post will inform you that everything has been sorted out!

[BlueMax]

Picked up the car today, 4 new spark plugs have been installed. Looked at the compression test result and it looks very good. Glad everything is back to normal again, it pulls and sounds fantastic!