Differences (if any) between the various M50 engine manifold

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worzel
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Joined: 12 Dec 2015, 10:31
Car model: 1991 525i Auto
Location: Merseyside

Differences (if any) between the various M50 engine manifold

Post by worzel » 28 Oct 2017, 13:38

Hi

I'm trying to find out if there any differences between the M50 inlet manifolds fitted to the 3 and 5 series.

My 1st question- any difference between a M50 on a 2 litre car and one on a 2.5 litre?
2nd question-Any difference between a manifold for a vanos engined car and non-vanos models?
3rd question- any difference between a manifold on a 3 series and one on a 5 series.

Pictures from sellers indicate (visually at least) no differences but then the seller specifies the size of the engine of the donor vehicle so I guess this indicates some differences.

Why asking- well- still have the (admittedly slight) problem of a brief surge when coming to a halt so I'm going back to 1st base and going thru possible air leaks on the induction side. I've already moved the idle control valve from its original placement under the manifold (clever of BMW to site it there- sure makes it easy to access) but the way the the hose connects the icv to the manifold has never impressed me much as it seems to be a precarious fit at best.
What I was thinking of doing is to blank off the original hose mounting point and relocate it elsewhere on the manifold but using a more secure method (not sure which at this point). Ideally I'd like to blank off the original mounting point and modify the throttle body to allow the pick up point to be just behind the butterfly but there doesn't seem to be sufficient metal to do this.

Obviously before I buy anything I need to know I'm getting the correct part.

Can you help with this teccy info?

Many thanks


John

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Discostew38
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Re: Differences (if any) between the various M50 engine mani

Post by Discostew38 » 31 Oct 2017, 19:55

worzel wrote:Hi

I'm trying to find out if there any differences between the M50 inlet manifolds fitted to the 3 and 5 series.

My 1st question- any difference between a M50 on a 2 litre car and one on a 2.5 litre?
2nd question-Any difference between a manifold for a vanos engined car and non-vanos models?
3rd question- any difference between a manifold on a 3 series and one on a 5 series.

Pictures from sellers indicate (visually at least) no differences but then the seller specifies the size of the engine of the donor vehicle so I guess this indicates some differences.

Why asking- well- still have the (admittedly slight) problem of a brief surge when coming to a halt so I'm going back to 1st base and going thru possible air leaks on the induction side. I've already moved the idle control valve from its original placement under the manifold (clever of BMW to site it there- sure makes it easy to access) but the way the the hose connects the icv to the manifold has never impressed me much as it seems to be a precarious fit at best.
What I was thinking of doing is to blank off the original hose mounting point and relocate it elsewhere on the manifold but using a more secure method (not sure which at this point). Ideally I'd like to blank off the original mounting point and modify the throttle body to allow the pick up point to be just behind the butterfly but there doesn't seem to be sufficient metal to do this.

Obviously before I buy anything I need to know I'm getting the correct part.

Can you help with this teccy info?

Many thanks


John
No difference between 3 and 5 series
But 2.0 and 2.5 are different in size
Life's to short to be driving boring cars
It's all about the old school

worzel
BMW Enthusiast
Posts: 33
Joined: 12 Dec 2015, 10:31
Car model: 1991 525i Auto
Location: Merseyside

Re: Differences (if any) between the various M50 engine mani

Post by worzel » 03 Nov 2017, 10:09

Hi

Many thanks for that info.

Sorry- another question- this time specifically about throttle bodies.

I seem to recall seeing a site that listed the original BMW parts numbers but I can't find it- any ideas on this and/or can anybody let me know the original part number for a Feb 1991 525i throttle body because I think the idea of bypassing the 2 hoses used to heat the tb, blanking off one and using one to act as a bypass for the air from the icv might work- but I don't want to use the one off my car as a test in case I mess it up.

Incidentally the throttle body on mine has 3 hose attachments- just what is the function of the 3rd/

Regards and thanks


John

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