Difference between M52TUB20 and M52TUB28

NickUK

NickUK

Zorg Addict
British Zeds
Joined
Oct 8, 2019
Points
59
Location
Cheshire
Model of Z
3
How, without looking at the plate on the engine, can one tell the difference between the M52TUB20 and M52TUB28 please? They look virtually identical and Google is not helping because it brings up images of the wrong engine either because of Google's algorithms or human error!

Thanks.
 
The M52TUB engines are all twin vanos and visually under the bonnet they are more or less identical. The 2litre had an 80mm dia bore and a 66mm stroke, whereas the 2.8 litre has a "square" set up, 84mm dia bore and 84mm stroke.
 
Both are identical to look at from the top as they are both twin VANOS and use the same inlet manifold and throttle body etc. The only true way to tell them apart is to look at the number plate on the engine, not always an easy thing to do when the engine is in the car.
 
I thought that would be the case. I just had a brief paranoid moment of thinking the engine in my car had been swapped to a 2.0 at some point before I purchased. It was registered originally as a 2.8. Does anybody know when the plate is on the engine please? I've read about it being somewhere near the bottom end of the dip stick but possibly at the back of the engine too.
 
What's made you think you've got a 2.0 in there Nick?
 
I would have thought that your 2.8 would have to drive fairly lacklustre to feel like a 2.0 as there is 40 odd bhp between them .
 
Stevo7682 said:
I would have thought that your 2.8 would have to drive fairly lacklustre to feel like a 2.0 as there is 40 odd bhp between them .
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As you know I have owned both, I straight line speed the difference is apparent but not as obvious as the difference in torque, this is massive, if you put your foot down in a 2.0l in fifth at 30mph it bogs down, in a 2.8 it pulls all the way to 90, also a major difference is when hill climbing, in the 2.0l I was forever down changing, not so in the 2.8, it climbs all but the steepest of hills in fifth,
 
It does feel more powerful than my other cars (two are around 160bhp) so I think it's probably a false alarm. The thing that triggered it was when I was looking for hose that goes from the secondary air pump to a one way valve on the engine I think. It is cracked beyond repair so I rang BMW asking for a hose and there was some confusion about what I needed. I then looked up '2.8' thinking there was only one, saw photos of the original M52B28 engine online and thought it didn't look like mine. That got me panicking and checking until I realised it is probably an M52TUB28 actually. I just got so far down the route of checking before realising that, I decided I wanted to make sure anyway!

I'll tell you what may sort this. Here's a photo...

IMG_20191112_215151.webp
 
Definitely a TU ( technical update) engine.
Twin vanos .
But like said externally the 2.0 tu and the 2.8 tu look the same .
 
would the throttle body size be different on a 2 litre...? just a thought... be 800cc less air to admit to the intake...
 
I'm very new to BMW and German cars. The Z3 is my first. I can't believe how many different engines they were sold with and how they can knowingly fit an engine without making it identifiable without searching for a metal plate hidden in a tight gap somewhere.
 
i did have a brief look on realoem to see if the throttle bodies were different but i was looking at pre faclift m52 engine single vanos so that would be different anyway... i cant find a 2.8 tub car on realoem... other than that engine plate or a measure of the bores..

I cant see any other way of determining the difference...

unless anyone else knows...

maybe injector sizes different ?

engine map would be different but that would be hard to find...

maybe ecu version would show 2.8 if plugged in to a scanner..
 
Sean d said:
Gold one is single, blue one is tub
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how do you find the difference in throttle response between the cable throttle and the fly by wire on the 2 litre ?

got to say i love driving my 2.8 using it mostly as my daily now, the throttle is stiff but a real nice stiff no real need to prod it hard as so much low down torque on the 2.8...

my biggest complaint at the moment with 2.8 is the 3rd and 5th gear gate issues and its very vague... i suspect it needs the shift pins replaced...
 
handsomejackuk said:
maybe ecu version would show 2.8 if plugged in to a scanner..
Click to expand...

Hmmmmmmm....

Can I plug OBDII into these or is it just that BMW port in the engine bay? It's becoming obsessive now!

Aside from all this, my original issue was that pipe. Does anybody know what the part number is please? Just to confirm, it's the pipe that goes between the secondary air pump and the engine (a one way valve attached to it I think).IMG_20191114_012353.webp
 
NickUK said:
Hmmmmmmm....

Can I plug OBDII into these or is it just that BMW port in the engine bay? It's becoming obsessive now!

Aside from all this, my original issue was that pipe. Does anybody know what the part number is please? Just to confirm, it's the pipe that goes between the secondary air pump and the engine (a one way valve attached to it I think).View attachment 122771
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Do a smog pump delete, @t-tony makes the blanks
 
NickUK said:
I thought about doing that. Feel free to send me a message with a price @t-tony. I take it the removal does not have any negative effect on the emissions test on MOT.
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It's only used during start up for a few seconds
 
NickUK said:
Hmmmmmmm....

Can I plug OBDII into these or is it just that BMW port in the engine bay? It's becoming obsessive now!

Aside from all this, my original issue was that pipe. Does anybody know what the part number is please? Just to confirm, it's the pipe that goes between the secondary air pump and the engine (a one way valve attached to it I think).View attachment 122771
Click to expand...
Get a blank off @t-tony and remove it, they are PITA and not required in the UK
 
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