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E34 (1989 - 1995)

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  #51  
Old 08-27-2013, 03:50 PM
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Quote:
Originally Posted by Monsignor View Post
Your valves are not bent after sitting.
And I have driven the **** out of this thing once it was warmed up too....
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  #52  
Old 08-27-2013, 05:25 PM
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Doc, have you actually done a compression check when the engine sounds like it has no compression?

I guess the main reason I ask is because when my E36 had the bad DME (resulting in no fuel or spark), again, it sounded like it had no compression. At first, I honestly thought that was what was happening. However, on this M50 engine, during no fuel and no spark, that's just what it sounds like.

Have you checked your CPS? They have been known to die slowly and intermittently, though that is not usually the case.

Perhaps it's just my limited mechanical knowledge, but I have a hard time understanding how a bad VANOS could cause a loss of compression. Something in my gut is telling me that it is not that complicated.

Anyway, good luck and I hope you find the solution.
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Quote:
Originally Posted by noego View Post
It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

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  #53  
Old 08-27-2013, 05:33 PM
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Originally Posted by BMR_LVR View Post
Doc, have you actually done a compression check when the engine sounds like it has no compression?
Yes. zero..nothing and 160+ psi when it is running and warmed up.
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  #54  
Old 08-27-2013, 05:34 PM
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Quote:
Originally Posted by BMR_LVR View Post
Perhaps it's just my limited mechanical knowledge, but I have a hard time understanding how a bad VANOS could cause a loss of compression. Something in my gut is telling me that it is not that complicated.

Anyway, good luck and I hope you find the solution.
I am questioning everything.

Several locals have reported junking E34's for this exact problem, so the symptoms are there, but, thus far, there are no cures, or at least none documented...
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  #55  
Old 08-27-2013, 05:49 PM
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E34 Cranks Like Spark Plugs Are Removed:

Quote:
Originally Posted by Doktor Bert View Post
Yes. zero..nothing and 160+ psi when it is running and warmed up.
Wow. Definitely a head scratcher.


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Most problems are usually something simple !

Quote:
Originally Posted by noego View Post
It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

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  #56  
Old 08-28-2013, 06:44 AM
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Seriously, try unplugging the vanos solenoid. I'm unreasonably confident it will fire.
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  #57  
Old 08-28-2013, 09:21 AM
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Quote:
Originally Posted by Monsignor View Post
Seriously, try unplugging the vanos solenoid. I'm unreasonably confident it will fire.
At lunchtime I shall...
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  #58  
Old 08-28-2013, 09:55 AM
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i patiently wait!!!!!!!

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  #59  
Old 08-28-2013, 05:07 PM
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I unplugged the VANOS solenoid tonight, as Monsignor recommended. The engine did start better, although it ran and idled rough for the first 2 minutes, then smoothed out.

Interestingly, when I plugged the VANOS solenoid back in while the engine was idling full warmed up, the engine began to 'lope' and shake as if it was going to die, until I again unplugged the VANOS.

Hmmmmmm....
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  #60  
Old 08-28-2013, 05:10 PM
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You may be on to something there Doc .......
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Quote:
Originally Posted by noego View Post
It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

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  #61  
Old 08-28-2013, 05:20 PM
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Originally Posted by BMR_LVR View Post
You may be on to something there Doc .......
The VANOS should not be active at idle and it appears to be getting an activation signal, since it functions when I plug it in at idle.

Thoughts????
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  #62  
Old 08-28-2013, 05:29 PM
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Quote:
Originally Posted by Doktor Bert View Post
The VANOS should not be active at idle and it appears to be getting an activation signal, since it functions when I plug it in at idle.

Thoughts????
Oh man. I wish I could help you out here, but I know very little about the VANOS function. Hopefully Joe will chime in.
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Most problems are usually something simple !

Quote:
Originally Posted by noego View Post
It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

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  #63  
Old 08-28-2013, 05:39 PM
imae34driver imae34driver is offline
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While in there replace the vanos seal.. I did it, only a few bucks was very happy on my e36 m50.. Apperantly old seal material was crap! Imagine that a bmw rubber piece failing...

Glad BMW does not also make "rubbers" probably fail with any extended usage if you dont change them first! Hehe
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  #64  
Old 08-29-2013, 07:12 AM
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Quote:
Originally Posted by BMR_LVR View Post
Hopefully Joe will chime in.
Indeed he will!! This is my favorite thread currently <3

That exactly what i expected to happen. Your VANOS solenoid is broken. i have my old unit if you'd like; gratis, of course. Bolt it on, plug it in and see if its the fix.

PM me good sir.

Quote:
Originally Posted by BMR_LVR View Post
...but I know very little about the VANOS function.
Steve, is your car NV?
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Last edited by Monsignor; 08-29-2013 at 07:54 AM.
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  #65  
Old 08-29-2013, 08:11 AM
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UPDATE:

Attempted a cold start this morning after 30 minutes of running last night and leaving VANOS unplugged....same issue, no compression whatsoever.

Monsignor,

Wouldn't this problem be related to the DME map since the VANOS is getting an activation signal at idle????

Will be pulling the cover today (hopefully) to see what lurks with regard to the chains & tensioners...
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Last edited by Doktor Bert; 08-29-2013 at 08:12 AM.
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  #66  
Old 08-29-2013, 08:21 AM
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Quote:
Originally Posted by Doktor Bert View Post
UPDATE:

Attempted a cold start this morning after 30 minutes of running last night and leaving VANOS unplugged....same issue, no compression whatsoever.

Monsignor,

Wouldn't this problem be related to the DME map since the VANOS is getting an activation signal at idle????

Will be pulling the cover today (hopefully) to see what lurks with regard to the chains & tensioners...
Your solenoid is stuck open, probably partially, signal or not.

Theres an oil line on the bottom, banjo bolt style so there is contant oil pressure against the solenoid. The plug is to tell the vanos to open (or close) letting the pressure into the system, pushing the vanos gear into the cam shaft twisting it forward on its axis of rotation, advancing the timing. Having a VANOS system with a working solenoid will allow stock timing upon start up and idle.

Dont even need to remove valve cover for main timing chain tensioner. thats just on passenger side on the bottom of the head at the front.
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  #67  
Old 08-29-2013, 08:30 AM
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Quote:
Originally Posted by imae34driver View Post
Glad BMW does not also make "rubbers" probably fail with any extended usage if you dont change them first! Hehe
We would have more BMW engineers...
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  #68  
Old 08-29-2013, 08:33 AM
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Quote:
Originally Posted by Monsignor View Post
Your solenoid is stuck open, probably partially, signal or not.

Theres an oil line on the bottom, banjo bolt style so there is contant oil pressure against the solenoid. The plug is to tell the vanos to open (or close) letting the pressure into the system, pushing the vanos gear into the cam shaft twisting it forward on its axis of rotation, advancing the timing. Having a VANOS system with a working solenoid will allow stock timing upon start up and idle.

Dont even need to remove valve cover for main timing chain tensioner. thats just on passenger side on the bottom of the head at the front.

I see...and thank you all for responding.

Keep in mind this is now a 'Red Label 413' DME swap (from the no spark Silver Label unit) and the car ran fine for weeks until one morning recently when the 'no compression' issue began.

My curiosity, Monsignor, is why the VANOS responds to the connector being plugged in when, if I understand the system correctly, there should be no electrical signal until elevated rpm????
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  #69  
Old 08-29-2013, 08:39 AM
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Doktor Bert Doktor Bert is offline
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Quote:
Originally Posted by Monsignor View Post
Your solenoid is stuck open, probably partially, signal or not.

Theres an oil line on the bottom, banjo bolt style so there is contant oil pressure against the solenoid. The plug is to tell the vanos to open (or close) letting the pressure into the system, pushing the vanos gear into the cam shaft twisting it forward on its axis of rotation, advancing the timing. Having a VANOS system with a working solenoid will allow stock timing upon start up and idle...

I used to work for a race/tuner shop in Montclair and one of the owners had a E36 M3. He decided to pull the head and install a modified head (ported) and special cams.

Upon startup, he bent 3 valves and had to pull the head again. After replacing the valves, he again started the engine and bent the exhaust valves only in cylinders 4,5 & 6.

Puzzled by this, he again pulled the head and brought it to the shop where we could all investigate.

We finally discovered that there is a hollow bolt that secures the helix for the VANOS and this was left loose, allowing the camshaft to basically 'flop' when the engine was started, and since you lock the cams in place on this engine to time it, the 'flopping about' wasn't noticed.

It seems improbable that it would only bend the valves in 3 cylinders, but it did. Strangely, the bends were so slight that the engine only lost 15-20 psi in the affected cylinders and it actually ran OK, expect for a miss/roughness just above idle, that eventually went away...
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  #70  
Old 08-29-2013, 08:40 AM
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Quote:
Originally Posted by imae34driver View Post
While in there replace the vanos seal.. I did it, only a few bucks was very happy on my e36 m50.. Apperantly old seal material was crap! Imagine that a bmw rubber piece failing...
Hmmm....any part numbers for these goodies????
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  #71  
Old 08-29-2013, 08:43 AM
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Quote:
Originally Posted by Doktor Bert View Post
We would have more BMW engineers...
I LOL'd. seriously.

Quote:
Originally Posted by Doktor Bert View Post
I used to work for a race/tuner shop in Montclair and one of the owners had a E36 M3. He decided to pull the head and install a modified head (ported) and special cams.

Upon startup, he bent 3 valves and had to pull the head again. After replacing the valves, he again started the engine and bent the exhaust valves only in cylinders 4,5 & 6.

Puzzled by this, he again pulled the head and brought it to the shop where we could all investigate.

We finally discovered that there is a hollow bolt that secures the helix for the VANOS and this was left loose, allowing the camshaft to basically 'flop' when the engine was started, and since you lock the cams in place on this engine to time it, the 'flopping about' wasn't noticed.

It seems improbable that it would only bend the valves in 3 cylinders, but it did. Strangely, the bends were so slight that the engine only lost 15-20 psi in the affected cylinders and it actually ran OK, expect for a miss/roughness just above idle, that eventually went away...
Quite an anecdote. idk at what point that helix bolt would need to come out to swap a head though.

Quote:
Originally Posted by Doktor Bert View Post
Hmmm....any part numbers for these goodies????
Dr. VANOS <-- Go nuts. I did. If you have a table vice and a ratchet, you can rebuild your unit. Although i think its your solenoid thats busted.

I'm going to have to ponder your situation
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Last edited by Monsignor; 08-29-2013 at 08:48 AM.
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  #72  
Old 08-29-2013, 08:49 AM
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BMR_LVR BMR_LVR is offline
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E34 Cranks Like Spark Plugs Are Removed:

Quote:
Originally Posted by Monsignor View Post
Indeed he will!! This is my favorite thread currently <3

That exactly what i expected to happen. Your VANOS solenoid is broken. i have my old unit if you'd like; gratis, of course. Bolt it on, plug it in and see if its the fix.

PM me good sir.



Steve, is your car NV?
Yes ..... thank goodness. 92 M50, no VANOS.


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Most problems are usually something simple !

Quote:
Originally Posted by noego View Post
It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

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  #73  
Old 08-29-2013, 08:57 AM
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I dont think the silver/red label has any effect on this situation.

Maybe somebody can be a wall to bounce my thoughts off of, Bert? Steve?

Vanos recieves oil pressure to push gear into cam shaft advancing timing at high revs.
The oil pressure is sllowed into the system via a solenoid that is told to open/close.

My thoughts:
Your solenoid is stuck open, albeit potentially partially.
Even with it plugged in, the car should be telling it to be closed, but it is allowing pressure
Timing advanced

Plugged in or not, it would be allowing pressure? So if its plugged in, what is the car telling it to do? open/close? why should that affect the idle?

Solenoid must be working somewhat if it is reacting to being plugged in.
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  #74  
Old 08-29-2013, 08:58 AM
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Quote:
Originally Posted by bmr_lvr View Post
yes ..... Thank goodness. 92 m50, no vanos
AU CONTRAIRE!!!! VANOS is a fantasic system.
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  #75  
Old 08-29-2013, 11:59 AM
Doktor Bert's Avatar
Doktor Bert Doktor Bert is offline
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Quote:
Originally Posted by Monsignor View Post
I dont think the silver/red label has any effect on this situation.

Maybe somebody can be a wall to bounce my thoughts off of, Bert? Steve?

Vanos recieves oil pressure to push gear into cam shaft advancing timing at high revs.
The oil pressure is sllowed into the system via a solenoid that is told to open/close.

My thoughts:
Your solenoid is stuck open, albeit potentially partially.
Even with it plugged in, the car should be telling it to be closed, but it is allowing pressure
Timing advanced

Plugged in or not, it would be allowing pressure? So if its plugged in, what is the car telling it to do? open/close? why should that affect the idle?

Solenoid must be working somewhat if it is reacting to being plugged in.
I don't know, but the solenoid is receiving some sort of command at idle...maybe to retract????
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