E91 Straight Six Bearding

[preacherman]

Seek said:

Just wondering what experiences were with bringing an N53 engine to high mileage.

N52 engines are pretty troublefree, but how would you rate are N53 engines in comparison?

Most N53 specific pain points will be breaking pre-100k mls (injectors, NOX sensor/cat, fuel pressure sensors maybe) with the exception of the HPFP which would either last 20k or 150k Mine is on 112k mls and has had these done, bar the HPFP.

If these bits have been replaced and it's been looked after outside that then it's not too dissimilar to an N52. It's just that those bits make it so damn complicated with the closed loop system and diagnosing issues can be quite involved.

[speciald]

Mine is on 109k. Has had HPFP, injectors, NOx sensor replaced in 2023.

It's gone to the local independent today because it overheated in traffic on the M1 coming home on Thursday and lost all it's coolant. Not been the best start to ownership!

[bmwmike]

Ian Geary said:

Mine is a 5 series manual N53. I bought it in 2021 and was paying £250 for a bmw index 11 injector. Then it went up to £350 for a while (ml performance) and now I see they're £516 at ml performance (bmw probably more).

I waited too long to replace mine, but glad I did it all couple of years back, including coils, plugs and I also had to replace o2 sensors as well.

I have once coaxed the trip computer to show over 40mpg (a motorway journey after the battery had been disconnected a week or so) but more often it hovers between 24-31 mpg depending on usage. Most of my driving is <2 miles to take the dog on a walk.

Ultimately it's a brisk car though and there are larger cars that do worse mpg and have worse maintenance costs.

I am just starting to play with the idea of moving it on though - not so much for engine problems. But it's at that age of endless niggles, oil leaks, components beyond their useful life that just wear me out, and like the car, I am not getting any younger.

WOW they are £500 nowadays? ooooof.

I had a 5 series with the n53 too, but mine had the zf8 as it was the f10 version. Assume yours is e60? Zf8 and n53 made a lovely pairing but i'd like to have tried a manual. F10 manual might be a bit cumbersome but the e60 would be nice i reckon.

[p1stonhead]

Mines on 90k (just bought) and as far as I know on original injectors…..

[meddler]

Ian Geary said:

Mine is a 5 series manual N53. I bought it in 2021 and was paying £250 for a bmw index 11 injector. Then it went up to £350 for a while (ml performance) and now I see they're £516 at ml performance (bmw probably more).

I waited too long to replace mine, but glad I did it all couple of years back, including coils, plugs and I also had to replace o2 sensors as well.

I have once coaxed the trip computer to show over 40mpg (a motorway journey after the battery had been disconnected a week or so) but more often it hovers between 24-31 mpg depending on usage. Most of my driving is <2 miles to take the dog on a walk.

Ultimately it's a brisk car though and there are larger cars that do worse mpg and have worse maintenance costs.

I am just starting to play with the idea of moving it on though - not so much for engine problems. But it's at that age of endless niggles, oil leaks, components beyond their useful life that just wear me out, and like the car, I am not getting any younger.

On the assumption you have a code reader of some sort…have you seen any codes relating to the NOx sensor and/or cat? I only ask because your mpg seems low (even with the extra weight of a 5 series), and a malfunctioning NOx sensor can impact the economy you would otherwise gain from stratified injection (yup, another annoyance of the N53!).

[meddler]

Need to replace my engine undertray - it's absolutely wrecked!

As much as I'd love to pay £200+ to BMW for a piece of moulded plastic, I'd rather keep this one cheap. But I can't seem to find many aftermarket options that look trustworthy.

Has anybody had any joy with a particular aftermarket brand? Or an eBay special?

Mine is a 325i M Sport from 2011. I gather the M Sport undertray differs from the others.

Ideally I'd like it to come with all the fitting clips etc, because most of the existing ones are gone...but not essential.

Thanks all.

[JakeT]

I’d fine someone breaking a car and ask them to pull it. I’d then buy the clips from vehicleClips. I doubt anyone will want a lot of money for an old undertray

[danb79]

meddler said:

Need to replace my engine undertray - it's absolutely wrecked!

As much as I'd love to pay £200+ to BMW for a piece of moulded plastic, I'd rather keep this one cheap. But I can't seem to find many aftermarket options that look trustworthy.

Has anybody had any joy with a particular aftermarket brand? Or an eBay special?

Mine is a 325i M Sport from 2011. I gather the M Sport undertray differs from the others.

Ideally I'd like it to come with all the fitting clips etc, because most of the existing ones are gone...but not essential.

Thanks all.

IMO stick with OEM - every aftermarket one I've used on my E39s has warped and bent in no time; the OEM obviously doesn't and they come with all the necessary clips and fixings

[p1stonhead]

Very sleeper’y

https://ebay.us/m/PJqJpY

[JakeT]

Looks great. The ‘very reliable’ in the description might be a stretch, though.

[AmirGSXR]

RSTurboPaul said:

Will look forward to your review in due course

Apologies for the delay in writing the review, however, I have had the Birds B3 kit fitted for over 4 weeks now to my 2005 E90 330i and have driven 1000 miles providing me with good insight about how the cars behaviour has changed. As you will know, my front right coil spring snapped after 126k miles and 20 years of service. I decided to opt for the B3 kit which included new Bilstein dampers and uprated springs that are specifically matched for the E90 330i. The kit was £1339.98 from Matt Lewis Motorsport. I also decided to do a full suspension overhaul with genuine BMW parts and this included upper and lower spring pad rubbers, rear suspension repair kit and rubber pads, new pinch bolts, and importantly the sports top mounts which are stronger than the top mounts for SE suspension car (mine was originally on SE suspension). The cost of all the replacement suspension parts from Cotswold BMW was £489.12. When I went to pick up the car from the garage, I had a look at the rubbers on the rear top mounts, and they were perished. The front top mounts were in good condition, but given the age of the car, I wanted to ensure that all parts that could be changed were changed. Generally, all rubber parts were way past there useful life, so if you have an older higher mileage car, this is a good preventative maintenance job to do.

Before I tell you about how the car drives with the B3 kit, I want to provide a bit of context. I have owned numerous good handling cars and live in N.Wales so have ready access to some great roads. My other car is a MK7 Fiesta ST180 with KW V3 coilovers, polybushed and RARB. The Fiesta was setup by suspension secrets using a string and line kit with adjustments to camber and coilover setup. I take handling seriously and know exactly what good handling cars should feels like. I will caveat that with the fact that I am not a driving great, just somebody who appreciates the art of driving and is constantly learning and improving driving technique and skill.

Now onto the review - the standard SE suspension could be described as adequate for 90% of drivers who just want to get from A to B. However, for those who like performance driving, the standard suspension did not inspire confidence in the corners and you never really got the feedback from the tyres and chassis when pushing on – it all felt very numb. You therefore had to drive everywhere at 5/10ths . This is where the B3 kit changes EVERYTHING. Almost instantly, I felt the suspension enabled better communication of what the tyres were doing in terms of grip/slip etc. Also, I could better feel the chassis through the seat of my pants. The old SE suspension would cause the whole car to jolt and dip as it went over bumps or sunken manhole covers, but the the BIRDS kit reduced the jolts to almost nothing. Now, as I went over a severe bump, the suspension would just soak it up and you would not feel it in the cabin. In other words, the car soaks up all the bumps without transmitting them to the driver. Some of the improvement is likely to be the change from aged suspension, however, I did own the car since 66k miles when the suspension was relatively fresh, but my comments about not feeling what the car is doing still stand. I have read elsewhere (JakeT mentioned on this thread), that when runflats are ditched, the standard suspension cannot cope well with the reduction in sidewall stiffness and you get a vague ride and steering. I have always ran Goodyear Eagle F1 Asym tyres (currently on the 6), so the tyres have been a constant. The car is very agile and you can flick it through a series of bends and it changes direction quickly and remains very stable.

For normal driving, passengers noted how flat the car was during cornering. Nobody was being tossed side to side, and you could drive very smoothly while still being quick. The ride is less harsh than the KW V3’s on the ST180 and they both feel similar in terms of quality performance suspension, albeit both cars have markedly different characteristics. The Birds kits does lower the car but not by too much (it is noticeable though when looking at the car and when getting in and out). You can still get over speed bumps without catching except if the car is fully loaded with people, when I did actually have some minor scraping. As you will see from the pics, the rear is a little lower than the front, which makes sense as you have more weight over the driven axle. I hope this review is helpful to anyone considering the kit. I would 100% recommend it, and given I intend to keep my car for as long as possible, the cost doesn’t bother me. It gets very high SPG (smiles per gallon)!.

Broken coil spring






New suspension rubbers



Before:


After:

[JakeT]

Glad to hear you’re enjoying it, Amir. I agree with your impressions, it feels like the car really works the tyre, which I can attest to as I haven’t worn front tyres in any of my BMWs like this one. Corner entry speed is so much better. I’ve put nearly 100k on my car with Birds on it now. The previous owners that owned the car with the kit on loved it too.

[g3org3y]

Again I've been caught out with bad wear on the inner edge of the rear tyres. (Made me look a right tt at the garage as I didn't spot it!)

I know these run a bit of negative camber on the rear, but the extent of the wear on the inner edge feels excessive. It's also not easy to see unless you are actively putting your head under the car looking for it. Missed it again.

Is this normal on these? Every set of rears I've had on this car has worn this way.

Should I be replacing any other suspension components on the rear to prevent/minimise this?

[Swervin_Mervin]

g3org3y said:

Again I've been caught out with bad wear on the inner edge of the rear tyres. (Made me look a right tt at the garage as I didn't spot it!)

I know these run a bit of negative camber on the rear, but the extent of the wear on the inner edge feels excessive. It's also not easy to see unless you are actively putting your head under the car looking for it. Missed it again.

Is this normal on these? Every set of rears I've had on this car has worn this way.

Should I be replacing any other suspension components on the rear to prevent/minimise this?

Plenty of people will say it's normal. However, I've never had these issues on any of the BMW we've owned (all Msport chassis). I've always had a full Hunter alignment done after buying though, and will get them redone every few years just to keep it in check. I don't opt for any custom settings, just OEM.

It's possible that you might need some components changing. Did all my control arms, mounts and bushings etc 42k miles ago, as a few elements were utterly shagged, but I don't recall having any issues prior to that in terms of tyre wear.

[JakeT]

Top arms can cause that as they wear. Also sagging springs. Have you had an alignment done, and noted the rear camber? Again, as Mervin said mine haven’t done it usually at normal mileages. My 330i does munch them a bit, but not awfully at 235k.

[Mr Tidy]

My 330i is an SE, but in the 6+ years I've had it I've never had tyres wear their inner edges. I'd notice because I swap between summers and winters every year!

I wonder if it's only an M-Sport suspension issue?

[911Spanker]

AmirGSXR said:

RSTurboPaul said:

Will look forward to your review in due course

Apologies for the delay in writing the review, however, I have had the Birds B3 kit fitted for over 4 weeks now to my 2005 E90 330i and have driven 1000 miles providing me with good insight about how the cars behaviour has changed. As you will know, my front right coil spring snapped after 126k miles and 20 years of service. I decided to opt for the B3 kit which included new Bilstein dampers and uprated springs that are specifically matched for the E90 330i. The kit was £1339.98 from Matt Lewis Motorsport. I also decided to do a full suspension overhaul with genuine BMW parts and this included upper and lower spring pad rubbers, rear suspension repair kit and rubber pads, new pinch bolts, and importantly the sports top mounts which are stronger than the top mounts for SE suspension car (mine was originally on SE suspension). The cost of all the replacement suspension parts from Cotswold BMW was £489.12. When I went to pick up the car from the garage, I had a look at the rubbers on the rear top mounts, and they were perished. The front top mounts were in good condition, but given the age of the car, I wanted to ensure that all parts that could be changed were changed. Generally, all rubber parts were way past there useful life, so if you have an older higher mileage car, this is a good preventative maintenance job to do.

Before I tell you about how the car drives with the B3 kit, I want to provide a bit of context. I have owned numerous good handling cars and live in N.Wales so have ready access to some great roads. My other car is a MK7 Fiesta ST180 with KW V3 coilovers, polybushed and RARB. The Fiesta was setup by suspension secrets using a string and line kit with adjustments to camber and coilover setup. I take handling seriously and know exactly what good handling cars should feels like. I will caveat that with the fact that I am not a driving great, just somebody who appreciates the art of driving and is constantly learning and improving driving technique and skill.

Now onto the review - the standard SE suspension could be described as adequate for 90% of drivers who just want to get from A to B. However, for those who like performance driving, the standard suspension did not inspire confidence in the corners and you never really got the feedback from the tyres and chassis when pushing on it all felt very numb. You therefore had to drive everywhere at 5/10ths . This is where the B3 kit changes EVERYTHING. Almost instantly, I felt the suspension enabled better communication of what the tyres were doing in terms of grip/slip etc. Also, I could better feel the chassis through the seat of my pants. The old SE suspension would cause the whole car to jolt and dip as it went over bumps or sunken manhole covers, but the the BIRDS kit reduced the jolts to almost nothing. Now, as I went over a severe bump, the suspension would just soak it up and you would not feel it in the cabin. In other words, the car soaks up all the bumps without transmitting them to the driver. Some of the improvement is likely to be the change from aged suspension, however, I did own the car since 66k miles when the suspension was relatively fresh, but my comments about not feeling what the car is doing still stand. I have read elsewhere (JakeT mentioned on this thread), that when runflats are ditched, the standard suspension cannot cope well with the reduction in sidewall stiffness and you get a vague ride and steering. I have always ran Goodyear Eagle F1 Asym tyres (currently on the 6), so the tyres have been a constant. The car is very agile and you can flick it through a series of bends and it changes direction quickly and remains very stable.

For normal driving, passengers noted how flat the car was during cornering. Nobody was being tossed side to side, and you could drive very smoothly while still being quick. The ride is less harsh than the KW V3 s on the ST180 and they both feel similar in terms of quality performance suspension, albeit both cars have markedly different characteristics. The Birds kits does lower the car but not by too much (it is noticeable though when looking at the car and when getting in and out). You can still get over speed bumps without catching except if the car is fully loaded with people, when I did actually have some minor scraping. As you will see from the pics, the rear is a little lower than the front, which makes sense as you have more weight over the driven axle. I hope this review is helpful to anyone considering the kit. I would 100% recommend it, and given I intend to keep my car for as long as possible, the cost doesn t bother me. It gets very high SPG (smiles per gallon)!.

Broken coil spring






New suspension rubbers



Before:


After:

Excellent review! I have the Birds B1 on my 130i - it's fantastic.

[stevesingo]

Interesting stuff on the Birds.

I cheat I used when refurbishing the suspension on the wife's 330i saloon. I wanted Bilsteins but didn't want an a drop in ride height.

After researching the B8 kits I realised the damper part no was the same for 4cyl petrol, 4cyl diesel, 6cyl petrol, 6cyl diesel, across saloon and touring.

What was different was the springs - different for all. I made the assumption that a diesel engine is heavier than the petrol equivalent, likewise touring vs saloon. I took the gamble and ordered 6cyl diesel touring B8 kit.

When fitted, ride height remained stock.

Does the community know if that is the case for Birds?

[ATM]

g3org3y said:

Again I've been caught out with bad wear on the inner edge of the rear tyres. (Made me look a right tt at the garage as I didn't spot it!)

I know these run a bit of negative camber on the rear, but the extent of the wear on the inner edge feels excessive. It's also not easy to see unless you are actively putting your head under the car looking for it. Missed it again.

Is this normal on these? Every set of rears I've had on this car has worn this way.

Should I be replacing any other suspension components on the rear to prevent/minimise this?

Toe In

Most modern cars run toe in on rear to add stability

So both rears will be pointing in and pushing against each other constantly

Get GEO done somewhere competent and ask them to remove some rear toe and some camber and then you’ll have your wheels more straight - it won’t kill you

[helix403]

With standard alignment settings and parts in good condition the E9x range shouldn’t wear the inner edge of the rear tyres. Mine did with worn out dampers and incorrect alignment.