VANOS test failed

[Vict0r]

Hi!!

I have news and I wanted to comment it here with you (in case it happens to anyone else). As I mentioned, I have changed millions of things out of desperation and without knowing where the error could be.

Before Ichanged the head gasket I didn´t have any problem, therefore I focused only on the things I had touched.

Error 1: Doing the vanos test with the Launch X431Pro, it always gave me vanos failures. As soon as I did it with DIS, it confirmed that the vanos worked perfectly (it was too late...it was all new...).

Error 2: The car kept failing and I started thinking: what if, with the fuel line disconnected, the fuel filter has dried out and now it doesn't let enough pressure through? This weekend I changed the filter (it wasn't more than 1 year old) and exactly! It was hard to blow through it! The car now burns without problems. I need to finish it and do longer laps, but I THINK the problem was there!!

Thanks to everyone for the tips!!

Regards!!

[BMWfanz]

S62 diaphragm springs slow down response

Is there any posts about S62 diaphragms? Haven't found any info about increasing response.

[Slideways]

no, I didn´t. Maybe it's a good idea...!

The car doesn´t memorize any electrical faults. I will check the following things:

1) New gasoline filter (although it is relatively new, the car has been disassembled for about 2 or 3 months and when air enters it, it may become "stiffened" and does not send enough gasoline???)
2) any unwanted air entry?
3) balance and reset the throttle bodies?

I think I'm more lost now than at the beginning... 😰😰😰

You want to check if the engine at operating temperature is holding good compression and sealing on all cylinders. Poor performance and difficult warm startup could indicate a sealing issue in one or multiple cylinders. Compression and leak down test usually are the first things to check after reading the DME for simple fault codes.

[Vict0r]

I'd expect a brand new VANOS unit to have lower response times, but those numbers look fine and are within spec. After the headgasket replacement, did you performed a leak down test with the engine at operating temp?

no, I didn´t. Maybe it's a good idea...!

The car doesn´t memorize any electrical faults. I will check the following things:

1) New gasoline filter (although it is relatively new, the car has been disassembled for about 2 or 3 months and when air enters it, it may become "stiffened" and does not send enough gasoline???)
2) any unwanted air entry?
3) balance and reset the throttle bodies?

I think I'm more lost now than at the beginning... 😰😰😰

[Vict0r]

Is that with the new vanos unit?
I *think* if the advance/retard response times are over 300ms it will fail the test, in a perfect world you would have 200ms response times or a bit under even.

My untouched 60k vanos unit had I believe a 204ms response time as its highest response time, once I did all the seals etc they did go up a bit unfortunately but still within spec.

Nice to see you got it going!

Yes, this is with the new vanos. I also expect the lowest times but...
After I find the real fault with the car and have time, I will replace the vanos with the old one and put S54 springs again. This way we can see differences

S62 diaphragm springs slow down response

Yes, I think so too...bad choice

[Slideways]

It's incredible...today I just did a vanos test with DIS (instead of Launch X431) and it passed the test.

After all the time and money I have invested in the VANOS, the fault was not there....😔😔😔😔😔

I will start to investigate where the fault could come from, because the car is running badly... 🙄:

I'd expect a brand new VANOS unit to have lower response times, but those numbers look fine and are within spec. After the headgasket replacement, did you performed a leak down test with the engine at operating temp?

[Cubieman]

S62 diaphragm springs slow down response

Glad I stayed with the S54 diaphragms when I went through my little vanos debacle.

[maupineda]

S62 diaphragm springs slow down response

[Cubieman]

Is that with the new vanos unit?
I *think* if the advance/retard response times are over 300ms it will fail the test, in a perfect world you would have 200ms response times or a bit under even.

My untouched 60k vanos unit had I believe a 204ms response time as its highest response time, once I did all the seals etc they did go up a bit unfortunately but still within spec.

Nice to see you got it going!

[Vict0r]

It's incredible...today I just did a vanos test with DIS (instead of Launch X431) and it passed the test.

After all the time and money I have invested in the VANOS, the fault was not there....😔😔😔😔😔

I will start to investigate where the fault could come from, because the car is running badly... 🙄:

[sapote]

I thought that the splined shafts could be twisted and perhaps could get stuck, and that's why I ordered the splined shafts of exchange with the Rattle kit installed (to discard this too...):

It's impossible to have a twisted splined shaft unless the cam somehow locked up (on a damaged engine).

[Vict0r]

Most FORWARD positions.

Yes, you are again right 😅

Old chain/sprockets can cause noise and other issues, but not timing if the chain is tight on the pulling side and good tensioner.

I changed the chain during changing the head gasket. When I changed the chain, I still didn't know what was coming... 😥

[Vict0r]

When I did some VANOS maintenance recently, I had trouble perfecting the timing. I eventually just buttoned it up, gave up on a few degrees of accuracy. Drawing on decades of experience racing bicycles, it caught my attention there was ‘slack’ introduced by wear in the timing chain and timing sprockets. I see you’ve replaced the chain, but not the sprockets. They are extremely expensive…probably the reason why they aren’t on the typical list of “what else should I replace while I’m in there”. I think it’s worth mentioning, but maybe not worth the expense of replacing.

But also, I noticed you had Rebuilt Splines (Beisan). What is that?

Yes, I did change the sprockets too, but it is not visible in the photo. How the cylinder head was out, I took the opportunity to change the chain, all the tensioners and the camshaft sprockets. The only one I didn't change was the crankshaft.

I thought that the splined shafts could be twisted and perhaps could get stuck, and that's why I ordered the splined shafts of exchange with the Rattle kit installed (to discard this too...):

https://www.probsten-tech.de/produkt/e46-m3-z4m-doppelvanos-2x-zahnwelle-spielfrei-einstellen-antirassel/

[sapote]

When I did some VANOS maintenance recently, I had trouble perfecting the timing. I eventually just buttoned it up, gave up on a few degrees of accuracy. Drawing on decades of experience racing bicycles, it caught my attention there was ‘slack’ introduced by wear in the timing chain and timing sprockets. I see you’ve replaced the chain, but not the sprockets. They are extremely expensive…probably the reason why they aren’t on the typical list of “what else should I replace while I’m in there”. I think it’s worth mentioning, but maybe not worth the expense of replacing.

But also, I noticed you had Rebuilt Splines (Beisan). What is that?

Old chain/sprockets can cause noise and other issues, but not timing if the chain is tight on the pulling side and good tensioner.

[sapote]

I did not remove the covers to check if the pistons were in their most rearward position. I'll do this on the weekend!

Most FORWARD positions.