[egdoten99]

Hey everyone,

I’m new to e90post so I'm hoping I'm posting this in the right spot. I tried checking out a few other threads for help, but figured Id make my own thread, so here's the rundown:

In March of 2021, I purchased a 2010 e90 335i xdrive with 56,750 miles. Shocks were completely blown when I purchased the car. I unfortunately drove the car that way up until mid December 2022- when I installed Sachs front & rear shocks, H&R Springs, and I also purchased Bridgestone Driveguard Plus tires, all at around 80k miles. ( Will be installing new tie rods and getting an alignment within the week)

After having the new tires put on and installing the new shocks and springs, the ride quality barely improved. The car still shakes pretty bad over small bumps/ cracks in the road. And driving on the highway has been a nightmare as the car bounces/ shakes/ sways all over the place. Medium sized bumps in the road makes the car jump, especially at highway speeds. And when going over potholes, small or large, the entire car drops down so violently I think I'm going to blow a tire. These are all issues I've been dealing with since purchasing the vehicle, and the new tires, shocks and springs seemed to have made little improvement. I’m in MN so the roads aren't the best.

Before purchasing my 335i, I test drove a 2016 328i xdrive with 60k miles, and a 2011 335i xdrive with 120k miles. Both of those cars handled and rode like a dream when compared to the ride quality in my 335i. I’m not sure what I need to do next in terms of repairs, so any feedback is greatly appreciated.


2010 335i xdrive e90 w/ sport package, 80,200 miles
Bridgestone Driveguard Plus tires from Costco, 225/40/r18 fronts, 255/35/r18 rears
Sachs Front and Rear shocks from FCP Euro
H&R Springs from ECS tuning

[Jaronbwall]

Is it possible the Sachs suspension wasn't for a 335i? It really seems like the default settings of the suspension is wrong. Idk how to say it. Maybe the wrong spring/coilover combination.
I'd rule out the tires. That shouldn't affect a car the way you described. I did have a faulty tire one time but it only caused bad highway vibration. Nothing like "crashing" suspension over bumps, etc.

[whyzee125]

A couple things here:

RFTs don’t ride well. They’ve come a long ways but you’ll have immensely better ride quality with a non RFT like a Michelin pilot sport or a continental DW or DWS.

The other issue is that you’re likely still on stock bump stops, right? If so, you’re already sitting on them with the car just sitting so you essentially have no travel. H&r spirt are still pretty low and I recommend the e30 top hats for a little more front travel either way, but shorter bump stops are ESSENTIAL to have good ride quality with those springs. You want e36 m3 front and z4 (non M) rears. A lot of threads say z4M but that’s incorrect. My phones about to die but a little digging will get you the P/Ns you need.

[egdoten99]

[QUOTE=Jaronbwall;29658009] After checking, this looks like a possibility. I just compared the OE part numbers on the stock shocks to the ones I ordered. The front shocks have matching OE numbers. But the rears do not. On FCP Euro, there was only 1 option for front Sachs shocks. But with the rears, there were 2 options from Sachs. 1 that was “ up to 03/2010” and another that was “ From 03/2010”. They looked identical, and both were labeled as able to fit my 335. I went with the “ From 03/2010” as I thought my car was a 2010 build. But just checked my manufacture date on mdecoder and the date listed is October 2009.

-OE number on stock shocks removed: 33526779985
-Rear shocks installed,
https://www.fcpeuro.com/products/bmw...i-135i-311-410

-Front Left Sachs Strut, OE part # 31316780193
https://www.fcpeuro.com/products/bmw...-sachs-317-366

-Front Right Sachs Strut, OE part # 31316780194
https://www.fcpeuro.com/products/bmw...-sachs-317-367

-H&R Springs,
https://www.ecstuning.com/b-h-and-r-...ies&utm_term=1

[egdoten99]

[QUOTE=whyzee125;29658420] I was debating getting a set of Continental DWS, but ultimately decided on a run flat tire due to how harsh the ride quality was and still is ( was seriously concerned with blowing a tire). Yes, I am on stock bump stops. When I replaced the front shocks and springs, I also replaced the strut mounts, the strut mount gaskets, the strut bump stops and the dust sleeves. I also replaced the upper shock mounts on the rear shocks. That's all the supporting hardware that I replaced. It sounds like I should switch to the e30 tophats and the m3 and z4 bump stops, since I'll need to re-do the rear shocks anyways

[Jaronbwall]

I didn't realize you're running RFT. No joke those suck. That was the first thing I dumped and replaced on my car. The ride quality and handling was terrible. I picked up an OEM spare tire on eBay for $140 shipped. Bought a little hydraulic jack and carry tools with me. It's worth the trunk space hands down. Hopefully the bump stop replacement fixes this issue!
Fun fact: looks like I'm going down the leaking coolant/cracked radiator rabbit hole. I have some coolant steam coming out the kidney grills

[whyzee125]

You'll fall in love with your call all over again once you do the bumpstops & e30 top hats. That will solve your ride quality issue which should eliminate the worry of blowing a tire but I think you'll find the ride quality is fine with just the above. RFT's are a lot better now than they were in 07 when these cars came out. I also have the the P/N's now from a word doc since I'm at the computer

E36 front bump stops: 31332225377
Z4 rear bump stops: 33536770350

E30 strut top hats: 31331128524
E30 9mm spring pad: 31331128522

The top hats will give you 12mm of additional ride height/travel and the 9mm pads will give you an additional 7 for a total of 19mm as the stock ones are about 2mm.

I did both when I had Tein S tech springs and was in the same boat and I'm not exaggerating when I say it went from borderline un-drivable to riding better than stock while still looking aggressive. Keep us posted if you do it!

Here are a few people who have done the same:
https://www.e90post.com/forums/showt...1157626&page=3
https://www.e90post.com/forums/showthread.php?t=1404099 (posts 3 and 4)
https://www.e90post.com/forums/showp...postcount=7387

[pmachan]

Oh man, take off those tires and it will all change.
I bought a 328i in July, H&R cup kit, and the same driveguard tires, it was horrible.
I switched out to Michelin AS3+ in the same size, and its a different car.
DO NOT spend money on anything else until you get rid of those run flats.