Technical No compression on 2 cylinders after rebuild. 1.4L Multiair

[Sean0402]

Hey all, here’s an update the car. Here is a video I have taken with the current issue:

I’m trying to crank it over in hopes the oil will come up to the brick, I’ve had this sound for about 5-6 cranks today. Exact same sound each time. Tried bleeding with the Nipple in the oil cap, had oil come out the other day, now I have none coming out yet the oil on the dipstick is correct. Tried without plugs at first, same sound. I also made sure the alternator isn’t seized and I had a full battery charge.

Anyone got advice what else to test or if they can tell by the sound what I could direct my attention to possibly.

 

[bugsymike]

Hey all, here’s an update the car. Here is a video I have taken with the current issue:
View attachment 472006

I’m trying to crank it over in hopes the oil will come up to the brick, I’ve had this sound for about 5-6 cranks today. Exact same sound each time. Tried bleeding with the Nipple in the oil cap, had oil come out the other day, now I have none coming out yet the oil on the dipstick is correct. Tried without plugs at first, same sound. I also made sure the alternator isn’t seized and I had a full battery charge.

Anyone got advice what else to test or if they can tell by the sound what I could direct my attention to possibly.

To me that sounds as though it has a little compression, as though it is trying to build up oil pressure to work the valves.
I know little about these engine , but I believe the bleeding is mentioned online a lot so maybe there is a better technique to get the air out?
Are you getting any improvement on the compression gauge readings?

 

[Sean0402]

To me that sounds as though it has a little compression, as though it is trying to build up oil pressure to work the valves.
I know little about these engine , but I believe the bleeding is mentioned online a lot so maybe there is a better technique to get the air out?
Are you getting any improvement on the compression gauge readings?

It very strange. I'm still getting 0 compression at the moment. I've put the battery back on charge for tomorrow/saturday in hopes to give it another go. I'm just hoping that it is just a major air lock.

 

[bugsymike]

It very strange. I'm still getting 0 compression at the moment. I've put the battery back on charge for tomorrow/saturday in hopes to give it another go. I'm just hoping that it is just a major air lock.

Any way of priming the oil by using a vacuum pump to suck the oil out through the bleeder?
As I say, I have never worked on one, but is it possible to easily remove the hydraulic part and physically prime it before refitting, also I assume no way a gasket or seal is faulty, preventing oil from getting to that part to activate it.
If when it is off does that mean that all valves are shut or open as if shut you could do acompreesion test to confirm the issue is only down to the "multair" part?
Have you watched this? At least if it doesn't help, it may be useful to not flood the engine with fuel.
Here is another, you may have already seen these, but if not may help.

 

[bugsymike]

This may work?

 

[bugsymike]

My original search was "bleeding multiair"

Or this on a clean site but add the address correctly https://www.youtube. com/watch?v=41rYrKnOFK8

 

[PuntoHowTo]

Nasty thieves used to steal CATs off ICE cars. Those electric motors full of copper, aluminium and rare earth magnets, not even counting lovely lithium batteries make lovely prime targets.

Good luck making off with a 500kg battery pack from from an electric car

 

[ZaphodB]

My original search was "bleeding multiair"

Or this on a clean site but add the address correctly https://www.youtube. com/watch?v=41rYrKnOFK8

That's how owners refer to the car isn't it?

That bleeding multiair

 

[bugsymike]

Good luck making off with a 500kg battery pack from from an electric car

Mind you if they can steal JCB diggers a half tonne is nothing to slot in a container with a few 100 other ones, using a HIAB.
The problem may be if they flipped the EV over to remove it, a lovely surprise for the morning commute when owner gets to car.

 

[Sean0402]

So after spending about 4-5 hours today trying to get the car running, I successfully managed to bleed the air out the bolt below the oil cooler. Almost bled instantly which was great.

Proceeded to start the car, worked great for a few seconds then stalled on its own. Plugged in my machine and had cylinder 2 misfire. Thought there was no way it could be the piston rings or anything along those lines.. Tested compression, had 140 /150 on cylinder 1 & 4. Had 0 on piston 2/3 again. Tried putting oil down the spark plug hole creating the seal, still 0 PSI on 2 & 3. Decided to spend the next 4 hours disassembling the engine again. This is where I found this...

Bent intake valve on cylinder 2. Few bits of metal shavings on the piston top also. This is great to figure out the issue with cylinder 2 having 0 compression but also leads me with the question; Why does 3 (To the right) have 0 compression also? Head gasket didn't seem to have any bridges / flat spots. Perhaps where I've installed next valves on cylinder 3 (As seen in the image) has caused this? Maybe they're not seating correctly/fully?

 

[bugsymike]

What a bummer , after all that working getting it going.
When rebuilding engines, I have a good Sykes Pickavant seat and valve cutting tool which gets them nearly perfect so they only need a light grind with valve paste to seat them in, which I do by hand, so you can see a nice thin grey line where the valve and seat meet, then after cleaning them all totally of grinding paste etc. I oil the valves, seats and guides, make sure the valves move easily in the guides, then assemble with the valve springs and collets etc. Next I support the head off the bench and using a small hammer (well small to me) I gently tap the top of the valve where the cam would engage normally, this lifts it off the seat and then reseats, from experience I know if it is seating well and secure by the sound it makes, this also confirms the collets are nicely in place, then as long as engine timed correctly (not sure about multiair) and as I have correctly honed the bores, gapped the piston rings, fitted the pistons, I know the engine will have good compression so nothing mechanically will stop it from firing up.
Is it possible on the valve that is bent that the collet hadn't sat right in it's cap taper, so valve dropped and came in contact with piston?
Not sure about the number three one, some people use a vacuum tester to check for a good valve seal, others pour petrol into combustion chamber facing up with an old spark plug in and check if petrol leaking out of manifolds.
I am not familiar with the "brick" multiair hydraulic cam operation as to if it is possible for it to activate out of sequence allowing piston and valve to meet?
Presumably if that was the case the other cylinders valve would be damaged also.
Re the head gasket side , I see you didn't have the head skimmed/machined, did you check it and the engine block for flatness using a steel straight edge and 2 thou of an inch feeler gauge?

 

[Sean0402]

What a bummer , after all that working getting it going.
When rebuilding engines, I have a good Sykes Pickavant seat and valve cutting tool which gets them nearly perfect so they only need a light grind with valve paste to seat them in, which I do by hand, so you can see a nice thin grey line where the valve and seat meet, then after cleaning them all totally of grinding paste etc. I oil the valves, seats and guides, make sure the valves move easily in the guides, then assemble with the valve springs and collets etc. Next I support the head off the bench and using a small hammer (well small to me) I gently tap the top of the valve where the cam would engage normally, this lifts it off the seat and then reseats, from experience I know if it is seating well and secure by the sound it makes, this also confirms the collets are nicely in place, then as long as engine timed correctly (not sure about multiair) and as I have correctly honed the bores, gapped the piston rings, fitted the pistons, I know the engine will have good compression so nothing mechanically will stop it from firing up.
Is it possible on the valve that is bent that the collet hadn't sat right in it's cap taper, so valve dropped and came in contact with piston?
Not sure about the number three one, some people use a vacuum tester to check for a good valve seal, others pour petrol into combustion chamber facing up with an old spark plug in and check if petrol leaking out of manifolds.
I am not familiar with the "brick" multiair hydraulic cam operation as to if it is possible for it to activate out of sequence allowing piston and valve to meet?
Presumably if that was the case the other cylinders valve would be damaged also.
Re the head gasket side , I see you didn't have the head skimmed/machined, did you check it and the engine block for flatness using a steel straight edge and 2 thou of an inch feeler gauge?

I may take the valve block to a local machine shop just to be 100% certain the valves & surface of the block is in good condition. I'm unsure if the multiair could activate when its's not supposed too. I did make sure the timing was 100% before I cranked it.

 

[bugsymike]

I may take the valve block to a local machine shop just to be 100% certain the valves & surface of the block is in good condition. I'm unsure if the multiair could activate when its's not supposed too. I did make sure the timing was 100% before I cranked it.

Worth checking, I thought they had O rings also.
However my thoughts about the flatness of head and block were related to your zero read on number three cylinder, so more about head gasket seating etc. Unless the engine although it started had still some air in the brick stopping number three from working?