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Discussion Starter · #201 · (Edited)
I haven't plugged up to it again to check misfires and smooth running, but last time I did (a day or so ago, I'm wearing the diagnostic port down to a nub) it wasn't registering any misfires and smooth running seemed a little higher on cylinder 4 (chain end). Cylinder 4 seemed to be between 0.6 and 1.2, whereas the other cylinders were between -0.3 and +0.3. Should I be worried about the cylinder 4 reading?

Meanwhile, this arrived. Ebay special but it works surprisingly well!

The tap noise is definitely louder at the vacuum pump end. The vacuum pump its self doesn't seem too bad when I probe the cover, but probing the rocker cover bolts at the right hand side of the engine are loudest.

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Discussion Starter · #203 ·
might just be a noise you have to live with for a while until either gets worse or goes away if things settle down perhaps,
It's like the Hilux mouse... When I can't find the source of the squeak, I just leave it until it eventually either dies or breaks something (y)

MOT booked for 1st of Dec, so will mess about with it some more until then and see if I can improve things a little. The regular rev dip and stumble is more of a concern for the emissions if I'm honest.

I may reset the timing again, I'm thinking that I whilst setting the inlet and exhaust timing I will rotate both cams slightly anticlockwise to ensure that the Vanos sprocket is at it's hard stop position and remains perfectly timed. That inlet cam always seems to drift after running and end up that fraction retarded for some reason. The only movable part is the Vanos sprocket so I'm assuming that somehow the cam manages to slip forward slightly during the torquing process. Hope that makes sense...?
 

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did you hold the camshaft perfectly still with a 27mm big spanner ie must use one all they will go out of time everytime, i also set all camshafts up and bottom sprocket ie loose, then add the spring tensioner so under load on the guides,, i then do up the crank bolt 40nm plus 180 degrees if you can get it there 6ft bar will, i then hold exhaust camshaft with spanner 20nm then plus 90 plus 90 is how i do them you can go 20nm plus 180 degrees but it harder to do it that way, then do same with inlet one,, I have been doing them like this for a long time now and every one is spot on first time when I rotate engine 4 times and relock, that dummy tensioner adds a fail point to get it wrong if do it to tight or to loose,, hence why use the spring tensioner as the preload it will always have . done one today like it first time no messing,
your hunting around could be leaking valve perhaps ie the back pressure in to inlet can flag inlet pressure faults, same as pcv valve in the rocker cover can add unmetered air in to manifold and cause the car to hunt between lean and rich etc,
 

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Discussion Starter · #205 · (Edited)
Ok, getting somewhere I think...

Checked the timing again last night. The exhaust cam is always bang on, but the inlet cam always seems to end up that tiny little bit retarded, the tool never just falls on as it's supposed to, theres always that 2 or 3 mill gap between the exhaust half of the tool and the inlet half as per my previous picture.

So I pulled the inlet Vanos sprocket off again, locked the timing, and instead of just trying to hold the Inlet cam steady as I torqued it, I purposefully rotated it as far clockwise as I could within the tool and kept clockwise pressure on it whilst I torqued it up. I figured I needed it to be as advanced as possible given that it always ends up slightly retarded

Anyway, put it back together, reset adaptions, controller, relearned limits, and fired it up.

It's so much better, almost acceptable. Don't get me wrong it's still not the nicest sounding engine but it is running quite smooth.

I took the rocker cover off again tonight to recheck the timing and the timing tool now just falls on with both halfs bolted together 👍

Still seems to pulse slightly, not sure if this is normal, and it does make a regular sound, not quite a knock or a tap, just a regular sound, again, not sure if this is normal.

I think it's definitely now MOTable, booked in for the 4th of Dec.

I did check the inlet camshaft end caps and oil seals, the seals are in one piece, but there is some shallow grooving on the cap. You can bearly feel the grooves with your finger but they are quite visible. Let me know what you think...

(Final adaptations shown in 2nd from last pic)

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i rub a bit of scotch brite on those a few rubs if lines go away they are ok if dont then worn, you could to prove a point clean and dry area lightly add wellseal to the outer edges where rings sit and i mean a very very thin smear put back together and run it see if improves it if dose you know its that welsseal will give a temp seal, if it is this then its a anther camshaft and end caps at least
 

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Discussion Starter · #207 ·
i rub a bit of scotch brite on those a few rubs if lines go away they are ok if dont then worn, you could to prove a point clean and dry area lightly add wellseal to the outer edges where rings sit and i mean a very very thin smear put back together and run it see if improves it if dose you know its that welsseal will give a temp seal, if it is this then its a anther camshaft and end caps at least
I was reading a post, not sure if it was on this forum or not, but you can apparently get manufacturer replacement rubber seals for these. Will see if I can dig out the post, but I'm sure it gave the part number.
 

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Discussion Starter · #211 · (Edited)
Getting closer I think. It might have a faulty lifter or two.

I've also established that my MaxiPro thinks that cylinder 4 is at the vac pump end, so I've been focussing on the wrong cylinder.

My MaxiPro Cylinder 4 smooth running numbers were always reading higher than the others, so I suspected the problem was related to the cylinder at the chain end. Also when I killed injector 4 using the MaxiPro it seemed to be in sync with the mild misfire and tap.

Anyway, thinking that the problem cylinder was at the chain end, I stripped out the rockers and the hydraulic lifters. They all checked out fine, no movement on any of the bearings or anything. So I stuck the lifters in the vice and squeezed all of the oil out of them. They juiced well, plenty of oil.

Rather than refilling them manually I put them back in empty to see what would happen (expecting them to fill up automatically themselves). Stuck it all back together and fired it up - firing on three cylinders. Scanned it and MaxiPro said misfiring completely on cylinder 1... ah, Interesting!

Anyway ran it for a bit, didn't get any better, still on three cylinders. Reset controller, and relearned. Still the same, not getting any better at all.

So at least I've figured out that the MaxiPro thinks that the chain end is cylinder 1, and that the original smooth running issues were with the Vac end cylinder.

So I stripped the rocker cover again and manually refilled the lifters I had emptied in the chain end cylinder. Apparently they dont fill themselves very well automatically.

So turned my focus to the Vac end cylinder that has shown higher smooth running figure (around 2.5 ave, in comparison to 0 to 0.3 on all other cylinders).

I stripped the rockers and hydraulic lifters out, you can do this without removing the spring bolt as long as the valve is not compressed by the cam lobe.

Stuck both the lifters from the Vac end cylinder in the vice, one spat plenty of oil out but the other was mostly air. I then refilled them both with fresh oil and reinstalled. Fired it up and it ran the smoothest it's ever run with barely any audible tap.

I got excited at this point, thought I'd fixed it so took it out for a run. First couple of minutes I could hear very little noise at all, it ran and idled well, then gradually it started tapping and lightly misfiring again.

So I've learned three things today...

1) MaxiPro reads the cylinders like a normal car, so in reverse of how the cylinders in this wee pile of French shite are ordered.

2) The Hydraulic lifters dont fill themselves, well not quickly anyway.

3) If the hydraulic lifters are empty then the cylinder wont fire at all (I didn't expect this, I thought that it would fire but just tap loudly for a moment until the lifters filled themselves).
So, I'm going to presume that if the lifters arent fully pressurised i.e. if they lose some oil, then it could potentially cause the cylinder to slightly misfire - could be my issue...

Anyway, another call to the dealers (PSA) on the cards tomorrow for a couple of Inlet lifters for cylinder 1 (MaxiPro cylinder 4) - ...Vac pump end.

...kin love this car. Stay tuned for the next installment...
 

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strange that both snap on diagnostics and delphi diagnostics reads them as cylinder 1 gearbox end goes right back to having certain scan tools i guess just puts another layer of crap in the way of working with them, i always squeeze them out and then refit as they are and all fill after a good hour of running , would also suspect oil pressure issue when they dont or you have a couple broken ones , the n16 I done recently was a fire it up misfires and hunts around for 2 minutes then after that just got more and more silent over a hour, if not got high enough oil pressure can give what you have
 

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Discussion Starter · #213 · (Edited)
So my monkey brain processing works like this...

Vanos essentially advances or retards the timing on both the Inlet and Exhaust Cams/Valves, it doesn't have much effect in varying the amount of pressure/force applied to the Hydraulic lifters so we'll park it for now.

The eccentric shaft is different though, it essentially varies how much the valves open and close so it does directly influence the pressure/force applied to the lifters. Have you ever seen how little the valves move when the eccentric shaft is at it's minimum? You barely see any movement at all, and the valves are essentially almost closed.

When the car is started cold there is no tapping noise, it runs and sounds quite normal, there's very little noise and no regular slight misfire. This is also true when the revs are held above 1k rpm. However, the tapping noise appears very suddenly after around 45 seconds to a minute from start up, at the same time as the revs begin to drop the tapping then starts. The tapping doesn't start gradually, it's sudden, as though the engine makes a mechanical change at this point. I think the ECU adjusts the eccentric shaft to a minimum value here, so the valves are opening very little at idle state.

I think at cold start when the revs are held intentionally high by the ECU, the eccentric shaft is definitely in effect, but not fully. The valves are opening a little more than at idle state, so there's a reasonable amount of movement applied by the rockers via the cam and eccentric cam lobes, enough movement to open the valve even if one lifter is a little soft. It may not open as much as the other inlet valve in the same cylinder, but because the eccentric shaft is in effect the valve opens more than it does at idle, so a valve opening a little less in this phase due to a soft lifter has much less effect than at idle where there is very little valve movement - hence no slight miss over 1k rpm.

However, once the engine has been running for 45 seconds or so, the ECU begins to reduce the revs, and at the same time rotates the eccentric shaft back to reduce it's effect on the valves. The camshaft lobe has a lessened effect, the valves don't open as much, and any give in the lifter could mean that the valve might now only open a little, or maybe even not at all - hence the slight miss at idle, because only one inlet valve in the cylinder is opening.

In terms of the tapping, it is loudest when the eccentric shaft is at it's minimum and seems to disappear when the revs climb above 1k rpm, or when the eccentric shaft comes into effect. It also coincides exactly with the slight miss. When I say it disappears above 1k rpm, it really just quietens down a lot, and in actual fact when driving the car between 2k and 3k rpm the noise converts to sort of a worn cam sort of noise, although the cams aren't worn. I think when the eccentric cam comes into effect the additional valve speed (obviously the valves must move faster to cover the increased throw) and and also the additional force on the lifters masks the tap and makes it sound more like a worn cam.

The tap at idle sounds almost like a worn bearing tap, I think it may be caused by a half empty lifter just being compressed lightly by the rocker when the eccentric shaft is at it's minimum. I think the bearing tap like noise might be the lifter just compressing and then pinging back to it's fully open state without having any effect on the valve because there's not enough oil in it for it to stay solid and push the valve down.

In essence, I think the tap is the lifter pinging back to open, rather than a tap due to it being compressed. When it's compressed enough by the state of the eccentric shaft, the oil that remains in the lifter will damp the sound, it's not metal on metal. However when it pings back open there's no oil to suppress it so it's metal on metal - hence it's quieter at higher revs when the lifter is actually pushing the valve down, and only starts tapping when the effect of the eccentric shaft is almost fully removed.

There you go, clear as mud, and all pure and complete conjecture of course. When the new lifters appear (ordered today) I'm sure I'll be back on here complaining that it's still tapping and missing slightly at idle 🙄
 

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when you get new lifters soak them in engine oil over night and can also just before fitting them pump them while in engine oil get all air out see what you have, another thought is maybe oil feed hole to a lifter or two is blocked and not getting oil,, get a guitar string and feed in the oil holes clean them out is possible, yes what you say is how it all works , the concentric shaft controls lift of all valves higher the revs higher the lift , and when on idle the inlets are not fully open , i know the inlets are nearly closed when head is off and concentric is on its bump stop, when you turn key first time the shaft moves to around 10mm off the bump stop so inlet will be open enough to run bare in mind its a port injection system so must have some open valve room to work,
 

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Discussion Starter · #215 ·
By the way, PSA wanted £42 per lifter. The PSA parts guy even recommended I go to Euro Car Parts for them, so I settled for 2x after market lifters at £12 a piece from Euro Car Parts.

I like to stick to OEM, but there are limits.
 

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Discussion Starter · #217 · (Edited)
Nup, didn't work

Still determined to sort this thing, but not sure where to take it from here.

It's weird, it now comes and goes. Sometimes it runs almost perfectly with no miss at all and barely a tick. Other times it ticks away and presents almost a full on regular miss. The miss always comes with the tick, and the two disappear together. The tick happens at the same time as the miss, literally. I've pulled the coil pack plug, and also disabled the injector for the gearbox end cylinder and both confirm that it's the culprit.

The smooth running figure is always higher on the gearbox end cylinder when its ticking hard and missing properly, and I've seen misfires register at this cylinder also when its ticking hard, so the problem is definitely at the gearbox end cylinder.

You're going to say it could be the valve seats, but I hand lapped all of the valves personally when I had the head off so would have noticed if if there was an issue. The warm compression figures are 192, 188,188,188 from the chain end cylinder to the gearbox end so again it doesnt indicate a seat problem.

Just dont really know what to try with this thing next.

I've replaced:

Chain
Tensioner
Guides
Both Vanos Sprockets
Inlet Vanos Solenoid
Valve stem oil seals
Hand lapped all valves
Both inlet lifters on gearbox end cylinder
All piston rings
Cat
Both O2 sensors
Full exhaust
Spark plugs
I've also replaced the injector at the chain end (before I realised that the Maxipro was reading the cylinder order backwards)

Wonder if its worth trying the injector at the gearbox end?
 

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devils advocate ,,, when installing piston rings are sure never broke one, , are you sure the two top rings the gaps where 180 degrees apposed and the word TOP was pointing at top of piston ,, also conrod end caps are you sure all went back on correct direction and on correct conrod, also at any point when building back up could a valve got very slightly hurt ie bent , i have known a few on here that have timed them the first time and not got it right,
 

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Discussion Starter · #219 ·
devils advocate ,,, when installing piston rings are sure never broke one,

- Fairly sure, I had to give each one a tap with the butt of a hammer to transition from the installer tool to the cylinder bore, but I can’t say there was too much resistance, and using the borescope I can see that there’s no scoring on the bores.

are you sure the two top rings the gaps where 180 degrees apposed

- Absolutely certain, I went 02:00, 08:00, and 23:00 for the oil ring. Don’t the rings ultimately rotate and find their own location eventually anyway?

and the word TOP was pointing at top of piston

- ah, I can’t recall doing this. Not to say I didn’t, but I can’t recall

also conrod end caps are you sure all went back on correct direction and on correct conrod

- Absolutely certain, I was meticulous

also at any point when building back up could a valve got very slightly hurt ie bent , i have known a few on here that have timed them the first time and not got it right

I’m confident that there has been no valve piston interaction

Wouldn’t broken or mis aligned rings, or bent valves show up in the compression readings?
 
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