Technical really stubborn multi air bleed or failed multi air?

[beebe101]

Reposting to narrow things down and hopefully get some insight. My MultiAir brick isn’t actuating at all. I’ve primed it repeatedly, probably more times than I can count, and I’m willing to keep trying. That said, I’m unsure where the line is between air still being in the system and a deeper issue.

Oil is reaching the bleeder, and oil pressure is solid. The brick itself hasn’t been touched or tampered with. I scan the car almost every time I crank it, and I’ve never had any codes related to MultiAir failure. No faults, no hints.

To me, it feels like the brick isn’t getting power, but I’m not sure how to go about checking the wiring or electrical side of things. If anyone has a method for diagnosing power delivery or wiring faults on the MultiAir system, I’d really appreciate the help.

 

[bugsymike]

Just to clarify without locating old posts, is the engine cranking over as though no compression?
Remind me, was yours the one that the engine screamed during a near mis with another vehicle?
I assume you have already watched this video? ?
Worst case scenerio could be valve damage if it was yours that "screamed" , which you may only find by removing the "brick" which I am guessing would mean all the inlet valves should then be closed, so if a compression test was then done, if the fault was the "brick" you would have compression although obviously it wouldn't run, but it would indicate that the valves were sealing which I suspect may not be the case.
Please note this is only a guess based on my type of logic, so try at your peril.

 

[Zardo]

With or without sufficient oil in the multiair brick, in my opinon (I'm not a mechanic) there is no way to damage the inlet valves, except if the timing belt itself has ruptured or jumped several dents. Since without oil in the brick, the inlet valves stay closed. With oil in the brick, they follow the timing if they are electrically commanded.

In order to prime the brick, you would need either a pressurized oil dispenser and a very good seal between that dispenser and the ball-point valve, or crank the engine intermittently for a total time of about 20 to 30 seconds, maybe more if not primed at all and it's a new unit. (I did prime my new unit but still needed to intermittently crank the engine for a relatively long time). Intermittently because you don't want to fry the starter motor.

Check for a clogged multiair oil filter, check for OBD2 codes, and I believe you can do a test routine of the multiair actuators using AlfaOBD for example.

How did you assess that your multiair "isn't actuating at all"?

 

[bugsymike]

With or without sufficient oil in the multiair brick, in my opinon (I'm not a mechanic) there is no way to damage the inlet valves, except if the timing belt itself has ruptured or jumped several dents. Since without oil in the brick, the inlet valves stay closed. With oil in the brick, they follow the timing if they are electrically commanded.

In order to prime the brick, you would need either a pressurized oil dispenser and a very good seal between that dispenser and the ball-point valve, or crank the engine intermittently for a total time of about 20 to 30 seconds, maybe more if not primed at all and it's a new unit. (I did prime my new unit but still needed to intermittently crank the engine for a relatively long time). Intermittently because you don't want to fry the starter motor.

Check for a clogged multiair oil filter, check for OBD2 codes, and I believe you can do a test routine of the multiair actuators using AlfaOBD for example.

How did you assess that your multiair "isn't actuating at all"?

I may be wrong but I think the OP or someone similar spoke of an incident previously with a near miss with another car that involved a very high engine rev situation, after which engine failed.
I understand your thought re the brick only opening the valves the cam is directing it to.
By the way if as you mention, with no oil in brick the valves remain closed, and yet when videoed not starting they crank as though no compression.
My thoughts were with brick removed a compression test would prove or disprove the valves being closed perhaps, only a guess mind you.

 

[beebe101]

I thought I had posted this here earlier, but maybe it ended up on a different forum. I'm posting now because there are more MultiAir-equipped cars in Europe than in the US, and this seems to be a MultiAir-specific issue.

While driving one day, I mis-shifted. The engine revved but didn’t hit redline. It immediately died and threw three codes: one for cam position high, one for cam position low, and a third I can’t recall. None of them were correlation errors.

I got the car home and checked timing using lockout tools. The timing belt was only 600 miles old and everything was still in time. I cleared the codes, and the only one that came back was P0343.

After months of troubleshooting, I took it to a shop. They checked the wiring to the cam sensor and told me the oil pump was weak. Their recommendation was to replace the entire engine, which I guess would technically solve the issue. But the car still had enough oil pressure to keep the warning light off, and it never threw a low oil pressure code.

I decided to replace the oil pump myself. Before cranking, I primed the system with pressurized oil. While I was in there, I also replaced the timing belt and tensioner again, and cleaned the MultiAir filter (which had already been replaced 600 miles ago). That finally cleared the P0343 code.

Now I’m stuck. I’ve tried bleeding the MultiAir system solo and also manually while someone cranks the engine. Oil is reaching the head, but the car still won’t start. No new codes are being thrown, and I’m honestly at a loss. I’m close to giving up on this car.

 

[The Panda Nut]

Just to clarify without locating old posts, is the engine cranking over as though no compression?
Remind me, was yours the one that the engine screamed during a near mis with another vehicle?
I assume you have already watched this video? ?
Worst case scenerio could be valve damage if it was yours that "screamed" , which you may only find by removing the "brick" which I am guessing would mean all the inlet valves should then be closed, so if a compression test was then done, if the fault was the "brick" you would have compression although obviously it wouldn't run, but it would indicate that the valves were sealing which I suspect may not be the case.
Please note this is only a guess based on my type of logic, so try at your peril.

Really useful ideas!

 

[bugsymike]

I thought I had posted this here earlier, but maybe it ended up on a different forum. I'm posting now because there are more MultiAir-equipped cars in Europe than in the US, and this seems to be a MultiAir-specific issue.

While driving one day, I mis-shifted. The engine revved but didn’t hit redline. It immediately died and threw three codes: one for cam position high, one for cam position low, and a third I can’t recall. None of them were correlation errors.

I got the car home and checked timing using lockout tools. The timing belt was only 600 miles old and everything was still in time. I cleared the codes, and the only one that came back was P0343.

After months of troubleshooting, I took it to a shop. They checked the wiring to the cam sensor and told me the oil pump was weak. Their recommendation was to replace the entire engine, which I guess would technically solve the issue. But the car still had enough oil pressure to keep the warning light off, and it never threw a low oil pressure code.

I decided to replace the oil pump myself. Before cranking, I primed the system with pressurized oil. While I was in there, I also replaced the timing belt and tensioner again, and cleaned the MultiAir filter (which had already been replaced 600 miles ago). That finally cleared the P0343 code.

Now I’m stuck. I’ve tried bleeding the MultiAir system solo and also manually while someone cranks the engine. Oil is reaching the head, but the car still won’t start. No new codes are being thrown, and I’m honestly at a loss. I’m close to giving up on this car.

Yes it was your previous post I read.
Is it much of a pain to remove the brick and do a compression test with all the inlets presumably closed if no mechanical issue like I was suggesting.
My thoughts are that if a low compression with brick off it could indicate an old school mechanical issue such as the valves, but could be also tested with a "leak Test" using compressed air and the pistons locked on the firing stroke so exhaust valves also closed. I have used this test many times in the Motortrade to locate hard to find problems in the past.
Another thought although timing belt appears all good, is it possible on that engine for the cam pulley to be the "free wheeling" type that when fault happened caused the pulley to slip out of alignment slightly?
I bought a Fiat Punto some years ago that had been violently towed in an attempt to start it and caused the free wheeling crank pulley to slip.
During repairs I found the reason it wouldn't start in the first place was a corroded wire at the ECU, so all the other damage was caused by their towing.

 

[Zardo]

I don't know for the 500, but on the Punto Evo (Abarth version with turbocharger) removing the brick was a very big pain in the a.. Because of the tubing involved which has to be taken off and was seemlingly "glued together" because of age. Also you need to very carefully scrape of the sealant between the brick and the engine without putting flakes of sealant into the engine. It might block oil channels. And getting the correct liquid (Fiat original) seal wasn't easy. I'd never do this just to check compression.

Sometimes it's a very simple problem, like for example incorrectly refitting ignition cables so the sparks go to cylinders which are not ready to ignite the mixture. Maybe the cables have not been touched. Or some connector wasn't reconnected.

 

[beebe101]

I was hesitant to remove the air brick, but it seems like there’s no other option left. My main concern was timing, so the first thing I did was verify it using lockout tools. With the crank at TDC, the cam was also at TDC. I bore scoped the cylinders and didn’t see any witness marks from valve contact.

As far as I can tell, these are just installed with the gasket here in the US, but there’s very little solid information available on it.

 

[beebe101]

I don't know for the 500, but on the Punto Evo (Abarth version with turbocharger) removing the brick was a very big pain in the a.. Because of the tubing involved which has to be taken off and was seemlingly "glued together" because of age. Also you need to very carefully scrape of the sealant between the brick and the engine without putting flakes of sealant into the engine. It might block oil channels. And getting the correct liquid (Fiat original) seal wasn't easy. I'd never do this just to check compression.

Sometimes it's a very simple problem, like for example incorrectly refitting ignition cables so the sparks go to cylinders which are not ready to ignite the mixture. Maybe the cables have not been touched. Or some connector wasn't reconnected.

im not sure at this point nothing makes sense

 

[bugsymike]

I was hesitant to remove the air brick, but it seems like there’s no other option left. My main concern was timing, so the first thing I did was verify it using lockout tools. With the crank at TDC, the cam was also at TDC. I bore scoped the cylinders and didn’t see any witness marks from valve contact.

As far as I can tell, these are just installed with the gasket here in the US, but there’s very little solid information available on it.

There does seem to be a difference of thought, in so much as if no oil presure the inlet valves stay shut or open.
When you crank the engine over does it sound like no compression to you? Similar to a cambelt failure which I know you have elinated.

 

[beebe101]

There does seem to be a difference of thought, in so much as if no oil presure the inlet valves stay shut or open.
When you crank the engine over does it sound like no compression to you? Similar to a cambelt failure which I know you have elinated.

it sounds like no compression at all like the brick is bled or there was no plugs. i took my valve cover off and checked to see if all 4 cylinders were getting oil and they are i guess my ext step is to pull the air brick all the connectors for the air brick are connected

 

[beebe101]

at this point im just procrastinating taking the multi air off because it seems like a pain in the ass to put on

 

[bugsymike]

it sounds like no compression at all like the brick is bled or there was no plugs. i took my valve cover off and checked to see if all 4 cylinders were getting oil and they are i guess my ext step is to pull the air brick all the connectors for the air brick are connected

That's what I was thinking, although to me be honest it is not an engine I have ever worked on.
Like most modern electronically controlled stuff, great when it works but an expensive nightmare when it stops and most don't last as long as their predessors.
As an apprentice in late 60s I used to boast when going out to a breakdown that unless they had put a conrod through the side of the engine, I would get them going.

 

[Zardo]

Is it much of a pain to remove the brick and do a compression test with all the inlets presumably closed if no mechanical issue like I was suggesting.

Sorry for coming back to this. Let's assume all the inlet valves are closed and stay closed for the full 4 strokes cycle (because there's no oil in the multiair or the multiair unit was removed or the actuators are electrically disconnected or ignition is switched off and the engine is cranked externally, for example rolling down a hill in 2nd gear). This means no air gets in during the intake cycle. The exhaust valves will still open with the cam timing. So what maximal pressure will the compression tool actually mesure? Even with the exhaust valves fully closed in the compression stroke (and the inlet valves too, off course) there won't be any compression to mesure as compression of basically no gas volume (or a vaccum inside the cylinder) won't yield typical compression values. So I don't see any value in doing such a test. Because if you don't get the expected compression values, you won't know whether it's because of the inlet valves not opening or because of the exhaust valves not fully closing.

But to be fair, I've never done a compression test on a multiair.

The manual for the Multiair (Punto Evo) states:

1. Fit the connector (EX15) in the spark plug housing.
2. Connect the 50-bar transducer (EX05).
3. Connect the cable (EX01) to the 50-bar transducer and the Examiner SAM card.

Make sure that there are no leaks from the various test equipment connectors.

- Disconnect fuse F21 (15 A), located in the fuse box casing in the engine compartment.

- Select "PETROL CYLINDER COMPRESSION" on Examiner in the instrument environment.
- Fully depress the clutch pedal on versions with a manual gearbox or the brake pedal on versions with robotized transmission and crank the engine until the compression value appears on the Examiner.

To measure the compression pressure, start the engine using a fully charged battery.

- Repeat the test for the remaining cylinders.
- Check that there is not a great difference between the pressure readings for the cylinders.

 

[beebe101]

Sorry for coming back to this. Let's assume all the inlet valves are closed and stay closed for the full 4 strokes cycle (because there's no oil in the multiair or the multiair unit was removed or the actuators are electrically disconnected or ignition is switched off and the engine is cranked externally, for example rolling down a hill in 2nd gear). This means no air gets in during the intake cycle. The exhaust valves will still open with the cam timing. So what maximal pressure will the compression tool actually mesure? Even with the exhaust valves fully closed in the compression stroke (and the inlet valves too, off course) there won't be any compression to mesure as compression of basically no gas volume (or a vaccum inside the cylinder) won't yield typical compression values. So I don't see any value in doing such a test. Because if you don't get the expected compression values, you won't know whether it's because of the inlet valves not opening or because of the exhaust valves not fully closing.

But to be fair, I've never done a compression test on a multiair.

The manual for the Multiair (Punto Evo) states:

that makes sense on why it's 0psi because even with bent valves ive never see 0 psi across the board

 

[beebe101]

is there any way to test the air brick? it's getting oil oil to all 4 cylinders

 

[bugsymike]

is there any way to test the air brick? it's getting oil oil to all 4 cylinders

I can see you and @Zardo 's logic but I still think you would get some reading, as at present it sounds like nothing/zero, when cranked with brick in place. Some air would come in before exhaust valves shut as the piston come up on combustion stroke/firing stroke. It may not be optimal when compared to a normal test with valves opening and shutting correctly I agree, but still maintain some sort of reading should be possible.
The other option is to do a "leak Test"as I mentioned earlier. In that, you are introducing air (roughly 150psi) into the cylinders via the plug hole with all valves shut and engine locked on firing stroke on that cylinder and then you check for where it is escaping, i.e. exhaust pipe = exhaust valves. inlet manifold/ports=inlet valves, oil filler=piston/ring, radiator /coolant tank overflowing=head gasket/cracked head etc.
I have used that test since the 1970s using professional equipment (Sun Diagnostics on petrol engines originally and Bosch for diesels) however it is quite easy to make up adaptors as long as you have a good source of compressed air, using an old spark plug drilled out or for diesels a heater/glow plug or old injector and some airline hose and fittings. The only difference is the professional tool has a gauge so you can read the % of loss.
Another point I know for a fact is, if pistons/rings are damaged you will get a slight compression reading (maybe 40 psi) but if a valve is stuck open you get exactly zero.

 

[beebe101]

I can see you and @Zardo 's logic but I still think you would get some reading, as at present it sounds like nothing/zero, when cranked with brick in place. Some air would come in before exhaust valves shut as the piston come up on combustion stroke/firing stroke. It may not be optimal when compared to a normal test with valves opening and shutting correctly I agree, but still maintain some sort of reading should be possible.
The other option is to do a "leak Test"as I mentioned earlier. In that, you are introducing air (roughly 150psi) into the cylinders via the plug hole with all valves shut and engine locked on firing stroke on that cylinder and then you check for where it is escaping, i.e. exhaust pipe = exhaust valves. inlet manifold/ports=inlet valves, oil filler=piston/ring, radiator /coolant tank overflowing=head gasket/cracked head etc.
I have used that test since the 1970s using professional equipment (Sun Diagnostics on petrol engines originally and Bosch for diesels) however it is quite easy to make up adaptors as long as you have a good source of compressed air, using an old spark plug drilled out or for diesels a heater/glow plug or old injector and some airline hose and fittings. The only difference is the professional tool has a gauge so you can read the % of loss.
Another point I know for a fact is, if pistons/rings are damaged you will get a slight compression reading (maybe 40 psi) but if a valve is stuck open you get exactly zero.

yea even without the air brick in the compression reading was 0 i borescoped them again just to make sure and theres no witness marks. night now i dont have money for a leak down tester so ill just assume its good because all this happened while it was running and there was no chunks of metal on the oil. im going to see if i can cobble something together. on the borescope pictures theyre wet because while i sprayed in some oil to make sure it had some lubrication.

 

[beebe101]

i wonder about pulling the connector for one of the multi air solenoids and hooking a test light up to it and see if it triggers while cranking