Is the N54 engine as bad as the internet makes out?

[Court_S]

I’m seeing an E92 335i tomorrow which looks and sounds like a really good car.

My only real concern is the N54 engine. Everything on the internet reads like it’s a complete pain in the arse with rattling turbos, failing HPFP and dead injectors which now cost a fortune to fix.

Despite this, I’m still tempted by one (especially the E91 that I’ve been talking to a PHer about).

[naturalaspiration]

It is not a bad engine at all, provided somebody else had footed the bill for the revised parts you mentioned. Not only that they are expensive, some may be on back order, such as injectors, if I understand correctly. Service history essential, check yourself that injectors have been replaced with the last version. Hook up INPA, read error codes, clear, drive, read again. Engine and gearbox (if automatic) as a minimum. Buy with eyes wide open.

I admit to have been stuck in the naturally aspirated, port injected I6 world. And I kinda like it there. :-)

Edited by naturalaspiration on Saturday 2nd April 00:12

[helix402]

The internet tells you to change all six injectors at a time. Whilst this is best practice I’ve changed single ones without issues.

[Court_S]

Thanks.

There are two that I am looking at pretty seriously, an E91 and an E92.

The E92 has been owned by the same person for 11 years, run with BMW’s extended warranty. It has had the HPFP and one turbo replaced. I need to do sone digging around the injectors. One benefit of this car is that I could put it back under BMW’s warranty (at a price) because it’s got a full dealer history.

The E91 has not long had the injectors changed to index 12 but there is nothing in the history to suggest the turbos or HPFP have been done.

[anonymous-user]

It’s not the engine. That’s a pretty solid engine as they go.
It’s the ancillaries as you point out: waste gate flutter/rattle, water pump, and HPFP. All of which now have revised parts and are more reliable than before but not without fault. As in failure rates are reduced but inevitable as with most moving parts. BMW had an extended warranty in the states where the HPFP is covered for 10 years/100,000 miles. Even the injectors were revised. Delphi to Bosch IIRC.

[helix402]

Re injectors Autodoc has Bosch ones for £95 each, afraid I don’t know what index.

Make that £269 for VDO and not in stock! Maybe £95 is for an old index.

Edited by helix402 on Saturday 2nd April 08:17

[anonymous-user]

naturalaspiration said:

It is not a bad engine at all, provided somebody else had footed the bill for the revised parts you mentioned. Not only that they are expensive, some may be on back order, such as injectors, if I understand correctly. Service history essential, check yourself that injectors have been replaced with the last version. Hook up INPA, read error codes, clear, drive, read again. Engine and gearbox (if automatic) as a minimum. Buy with eyes wide open.

I admit to have been stuck in the naturally aspirated, port injected I6 world. And I kinda like it there. :-)

This. Reminds me of my love affair with the C350. Something about NA.

Edited by naturalaspiration on Saturday 2nd April 00:12

[naturalaspiration]

helix402 said:

Re injectors Autodoc has Bosch ones for £95 each, afraid I don’t know what index.

Make that £269 for VDO and not in stock! Maybe £95 is for an old index.

Edited by helix402 on Saturday 2nd April 08:17

Good luck with those on Autodoc. :-)

[Court_S]

helix402 said:

Re injectors Autodoc has Bosch ones for £95 each, afraid I don’t know what index.

Make that £269 for VDO and not in stock! Maybe £95 is for an old index.

Edited by helix402 on Saturday 2nd April 08:17

Saw those Bosch jobbies. Surely they’re better than a dead index 7 or similar?

Those VDO ones are about the same price as the index 12 ones from the UK.

[helix402]

Court_S said:

Saw those Bosch jobbies. Surely they’re better than a dead index 7 or similar?

Those VDO ones are about the same price as the index 12 ones from the UK.

I’m not sure why they are so cheap. If I needed some I’d cross reference the BMW part No from realoem with Autodoc’s listing. AD are pretty good on listing manufacturers part No’s.

[naturalaspiration]

helix402 said:

Court_S said:

Saw those Bosch jobbies. Surely they’re better than a dead index 7 or similar?

Those VDO ones are about the same price as the index 12 ones from the UK.

I’m not sure why they are so cheap. If I needed some I’d cross reference the BMW part No from realoem with Autodoc’s listing. AD are pretty good on listing manufacturers part No’s.

They are "cheap" because they are port injectors, most likely N52 ones. Nothing to do with direct injection on N53.

[bmwmike]

naturalaspiration said:

They are "cheap" because they are port injectors, most likely N52 ones. Nothing to do with direct injection on N53.

Yes for some reason autodoc lists solenoid injectors as compatible for n53 and, sounds like, n54 too. They may only be £95 but they won't fit. VDO are the only manufacturer and there are internet chatters about them throwing in the towel for making n53/n43 injectors. Considering the size of the market (and the ongoing demand!) i'd be surprised at that but who knows, perhaps covid supply chain impacts are at play too. N54 injectors work in n53 engines and presumably the other way round. I'd hazard a guess that n63 injectors work too,in both engines.

[W201_190e]

Had a couple of timing chains needing doing on these now. Much rarer fault than it is on the four cylinders, but it can happen.

[survivalist]

I had a E91 335i with the N54 for 5 years, plenty of stuff was replaced in that time and the BMW warranty was worth it for me. From memory:

Water Pump
High pressure fuel pump
Injectors
Coil packs
Rocker cover gasket
2 sets of rear springs
Gear selector (sport mode stopped working)

Also got goodwill to cover 80% + for

Rear dampers
Rear window hinge

Not have a F31 340i and have to say that apart from the extra space and the 8-speed auto box I prefer the E91. The N54 is a phenomenal engine, although I’m not pretty sure mine was mapped when I got it as the B58 in my 340i feels a bit gutless in comparison.

[Tea Pot One]

I had two N54 engined cars ... both Z4 35iS's ... one 2010 and the other 2013 ...

No engine related issues at all thankfully and a thoroughly enjoyable engine.

[helix402]

survivalist said:

I had a E91 335i with the N54 for 5 years, plenty of stuff was replaced in that time and the BMW warranty was worth it for me. From memory:

Water Pump
High pressure fuel pump
Injectors
Coil packs
Rocker cover gasket
2 sets of rear springs
Gear selector (sport mode stopped working)

Also got goodwill to cover 80% + for

Rear dampers
Rear window hinge

Not have a F31 340i and have to say that apart from the extra space and the 8-speed auto box I prefer the E91. The N54 is a phenomenal engine, although I’m not pretty sure mine was mapped when I got it as the B58 in my 340i feels a bit gutless in comparison.

What happened to all the springs?

[megenzo]

Ive had my E91 6MT for 13 years now, fantastic bit of kit, Ive done over 100k in it, it has now done 160k, most of the things you mention have been replaced but none of these have failed again so the replacement parts seem better than the originals.

I'll be selling mine during this year but only to get a v8 while I can otherwise I'd keep it.

[Mr Squarekins]

Tea Pot One said:

I had two N54 engined cars ... both Z4 35iS's ... one 2010 and the other 2013 ...

No engine related issues at all thankfully and a thoroughly enjoyable engine.

My Z4 35iS - 2015 had two new turbos, under bmw warranty, thank god.

Lovely engine, but not built for longevity without replacement of some expensive bits l think.

(loved mine).

[MikeM6]

I had a manual, LCI 335i so it must have been pretty rare. I really enjoyed the car, but the spec was great which really helped.

The engine was mostly reliable, but I did have the injectors go 5 days into my ownership and so it cost a packet to put right. I also had the water pump go, but other than that it was a reliable engine and gearbox.

Tons of torque where you wanted it and it sounded decent too. I managed 152mph on the autobahn without any real effort. Could also be quite economical when you try, but then again, anything is economical compared to my M6 and the MGB!

[Court_S]

Thanks all. I’m slightly nervous but am still really tempted; I liked the car I drive today.