M52 Lambda Sensors

[daslandroverman]

Right, my bargain M52 came without exhaust manifolds.
Not a great issue in the grand scheme (although the missing studs are a bit of a ballache) as I picked up a pair of manifolds for £20.

However, I've discovered that the lambda sensors in the manifolds have different plugs on them compared to the loom on the engine, as illustrated below.

Plug.



Loom.



I believe the engine to be from a 95 vintage E36 with an aluminium oil filter cap.
Can anyone with a better working knowledge of BMW's than I help me out here? Ideally without spending another £100 on new sensors as I've still got to cough up for having the ECU reprogrammed and various other bits for the job.

[adam73bgt]

Could the manifolds be from an M50 engine instead? I believe they're interchangeable between the two and there may be slight loom differences

What size is your engine? 1995 looks like it was a crossover year for M50-M52 engines

[daslandroverman]

You might have something there?
Although they were listed as being from an M52B28 from an E36, which my engine is also supposed to be.

I do wonder though as Google doesn't show any images of an M52 with an ally oil filter cap, but lots of M50's, although it does have an M52 inlet manifold on it, and came with a 5 speed auto on the back of it.

I guess I'll need to look at it and see if it's an iron or ally block, although it looks ally in the photo.





That's what I've got at the moment.

[adam73bgt]

Hmm interesting, certainly an M52 intake manifold but the oil filter housing as you say looks more M50, as does the cam cover as I think all the M52s had black cam covers, although they are interchangeable

As you say, the big tell tale will be the block material

[Rich]

Most lambda sensors are the same. Especially of this kind of era. 4 wire will have earth, heater (pair of) and signal. A bit of simple googling will reveal wiring them up. But it may be better to replace the sensors with the correct ones new as they only have a finite life. Replacing the sensor in my brothers T plate Mazda today changed the way the car drives despite there being no O2 sensor codes present.

[Badger]

I think I've still got a pair of M52 sensors knocking around, but unfortunately won't be able to check them until I get back to the workshop on Friday. This is what I worked to when I was wiring up my lambda sensors, hope it helps some!
www.lambdasensor.com/main/mcolours1.ht

[ChasR]

If it's a 2.8 the manifolds have come from then that could be the issue ; they may have come from an M52TU, where they are "sort of" an M54 but still very much an M52.

As an example you can't do the M50 manifold upgrade on an M52TU but you can fit an M54 manifold to liberate more horses.

Yes, the M52TU can be a tricky customer. AFAIK the 2.8s were M52TUs (Technical Update is what TU stands for, for those wondering).

[adam73bgt]

Feb 6, 2017 0:47:56 GMT ChasR said:

AFAIK the 2.8s were M52TUs (Technical Update is what TU stands for, for those wondering).

There were non-TU 2.8s as well as the E36 got the single VANOS version whereas the E46 got the dual VANOS TU version, I've not been looking for engine donors at all... nope not me...

[daslandroverman]

Feb 5, 2017 22:54:01 GMT Badger said:

I think I've still got a pair of M52 sensors knocking around, but unfortunately won't be able to check them until I get back to the workshop on Friday. This is what I worked to when I was wiring up my lambda sensors, hope it helps some!
www.lambdasensor.com/main/mcolours1.ht

I'd be interested if they're the right type.

Anyways, the block is Aluminium, so it's definitely an M52.
I asked the guy it came from for some details, which he came back with.

Reg was M3 CXT and he gave me an engine Code 28 6S1.

The reg comes back as 2,798cc, first registered in May 1995, although a quick Google does very little to reveal much about BMW engine codes asides the nomenclature.

Does this help clarify things any? I'm unsure.

[Badger]

Feb 6, 2017 20:58:16 GMT daslandroverman said:

I'd be interested if they're the right type.

Anyways, the block is Aluminium, so it's definitely an M52.
I asked the guy it came from for some details, which he came back with.

Reg was M3 CXT and he gave me an engine Code 28 6S1.

The reg comes back as 2,798cc, first registered in May 1995, although a quick Google does very little to reveal much about BMW engine codes asides the nomenclature.

Does this help clarify things any? I'm unsure.

No worries, will check them when I get back. If they're of any use you can have them.

[daslandroverman]

Much appreciated.

[Badger]

Feb 6, 2017 22:02:00 GMT daslandroverman said:

Much appreciated.

Heyup, had a root around in the garage but can't seem to find them - I guess they must have been chucked or something. Sorry about that!

[daslandroverman]

Nothing ventured, nothing gained etc. Thanks anyways.

Might just have to hardwire them then, a quote for a fresh set from the local factors came in at £75+VAT each, which you might note totals more than I paid for the thing in the first place, and I'm buggered if I'm coughing up the same again for 2 sensors.

I suppose partially my own fault for not buying a complete car for the job, but we live and learn.

[Badger]

To be fair I'd be tempted to look at lopping off the connectors and just use two standard 4-pin waterproof ones instead, provided the colours of the wires going into each of the plugs matches (as per the link I posted above).

I know what you mean though regarding donor vehicles - been in a very similar place!

[welshpug]

Probably missing something but those plugs look compatible to me?

[daslandroverman]

Not the best of photos of the plug, but it seems to have provision for locating legs with 2 different offsets, whereas the one on the loom is more circular with one locating lug.

Strange as all the googling/ebay searches I've done shows the plug that I have on the sensor, and nothing to match the loom on the engine.

[surprisingskoda]

You have an early engine and early loom, the sensors changed fitting around 1997. So they could be later manifolds - or they could be 5 series M52 manifolds which had another type of fitting on the sensors again. They're all the same sensor but the plugs do vary. The simple answer is to get a set of sensors for the correct year / use the donor reg.

Very early M52 engines did come with steel blocks, so that is never a guarantee.

M50 exhaust manifolds are cast steel, not welded stainless as per M52, so you don't have those.

The M52TU manifolds are also stainless, but longer, and the sensors coming out of those are very different type of plug, in fact I think on those they are the other way around (m/f) so totally incompatible.

[discostew38]

This is my M52 it has different cam cover and oil filter housing to yours (it does have M50 manifold)
It's possible you have a M50 and someone's swopped over the manifolds as the M50 intake manifold is quite sort after and fetch good money

[daslandroverman]

The block is definitely alloy which is the M52 hallmark, whilst SurprisingSkoda above has noted it's just an earlier version of the M52.

Still havent found sensors with the correct plug, but a big win on someone sending me an e36 workshop manual which includes wiring diagrams.

Should be fairly easy once its all in the car.

[andyborris]

link is good for electrics. Just print off what you need!