Daily Dilemmas - Titan Silver E46 325i

[Chanderpaul 15]

Some say it's never to late to start a project thread, so here I am after 5 years of ownership starting the story of the constant woes and joy my E46 has given me.

Returned from overseas travel and needed a new daily that wasn't just a bog standard corolla for A to B.  Previous flat mates had a few BMWs and sold me on how nice they were to drive and how easy they are to work on.  Found this delicious M sport sedan on the trademe, gave it a once over and purchased it. The car had roughly 183k km when I bought it.
Previous owner/s had a few receipts and the person I bought it off, had the car 'stolen' from their driveway whilst it was idling for a joy ride. So had a new wheel or two, new front bumper and some of the cooling system.

Previous receipts I found in the glove box:

Window regulator - 2012

Water pump - 2013

Thermostat - 2013

Idler pulley - 2013

Oil filter housing gasket - 2017

VANOS Oil line - 2017.

After working on an old holden commodore with not the greatest online parts stores, I was shown FCP Euro and all of its delicious goodies. So I got straight into it with some standard servicing parts;  Cabin air filter, Engine air filter, Spark plugs, Engine mounts, Power steering reservoir.

Did some daily driving and enjoyed the awesome ride quality of a BMW and the M Sport suspension. 

Enjoyed the COVID lockdown living at my BMW friends house and got lost done. Went on another shopping spree;  Fuel filter, front brake rotors and pads,  VANOS rebuild kit, VANOS oil feed line, Trans filter and fluid, Water pump, Thermostat, Coolant hoses, Coolant expansion tank, Rocker cover gasket.

 

Continued enjoying BMW ownership.  Had a few little issues with a rough idle and the car stalling infrequently. Cleaned out the idle control valve and inspected the intake pipes.
Found one with a crack so got a new one from pick a part. Issue seemed to be resolved. Continued to be a nice daily driver.  Could feel the front left getting noisy and failed on a front ball joint. Sourced new front control arms and got to work replacing them.  Tricky job but doable with right tools and a few swings on the mini sledge hammer. I only managed to get one done before I had to pack up my house and move to Blenheim / Picton.

Oil level sensor had been on the fritz for a while and the F connector on the intake pipe snapped so I made a 3d printed one that did the job until my latest parts order could arrive;  Air intake pipes and F connector, Fuel pump, Bosch Ignition coils, Spark plugs, Oil level sensor.

I have been constantly chasing lean engine codes bank 1 and 2 on this car for years.  Slowly trying to find all vacuum leaks as they seem the most likely culprit after reading lots of E46 forum posts.  I noticed my DISA seal was very square, so measured it up and found an O-ring to fit. 

But now the car will not idle when cold. It dies after 1 second unless you give it throttle.  And when it does start revving low and trying to stall it makes one or 2 loud clunks. If i hold some throttle on and manage to get out the driveway and on the move it will accelerate and cruise with no issue and when I reach work it will idle with a slight roughness.

Have yet to find time to investigate but will check the idle control valve and have a hunt around the vacuum lines when I do.  Next step I'm thinking all new CCV pipes etc and possibly intake manifold off,  hidden coolant hoses and new intake manifold gaskets. Also add to the list a left rear wheel bearing which has suddenly become very noisy.  I have ordered bearings and begun to create a list of tools required for the job.

 

 

[Chanderpaul 15]

I also replaced the aircon fan hedgehog blower resistor.  Fun job if you enjoy breaking your back and being upside down. 

 

Forgot about the other dilemmas this beautiful car has burdened me with.  Airbag fault due to the wiring of the drivers seat belt tensioner. I checked the plug and wiring and couldn't find an issue. Went to Pick a Part and found a tensioner. Got my seat out and then realised the plugs were very similar but not the same. I reset the fault light to see if it would come back immediately anyway. It stayed off for a few months but now it is back.  No Pick a Part in Blenheim so I need to figure something out for that.

Next drama - Rear brake light fault. I have searched the forums high and low and it seems to be a fault possibly in the wiring loom going to the boot lid.
I have checked and my car has the modified light housings with the better earth. I have had a quick visual and did some resistance checks and could find any high resistance to earth.  I think it is the boot lid right hand side brake light.  Tried new bulbs but no luck.  So will investigate further because....

Along side my P0171 and P0174 lean codes, I get P0313 - misfire detected with low fuel, which is what prompted me to do a fuel pump and ignition coils as precautionary measure. P1620 - MAP cooling circuit signal high - Map cooling thermostat control circuit signal high. Not sure about the thermostat one as it is a new Borgwarner unit.

After reading E46 forums, I feel like some of these issues are caused by the earth fault on the brake light. 

Any help on the above would be greatly appreciated.

 

[Cement 871]

Hey and welcome my E46 brother ... can't be of any help with your issues sorry but thought I'd say hi

[Eagle 1662]

Lean codes are mostly vacuum leaks on these engines so you need to start with a pressurized smoke test, waste of time imo trying to find leaks without one.  You can DIY one easy enough with hardware store etc parts and most people have an air compressor. 

Test is pretty simple - Remove airbox and ducting, remove the MAF and install a airtight zip lock bag etc on the front on it and re-install it. You can then either remove the F connector from the intake boot in front of the maf and pump smoke in there, or you can use the rubber capped intake ports at the back of the intake manifold (which can leak). This requires removing the cabin filter, housing and side of the ecu box which is straight forward but gives you even more room to see any possible smoke.

[Chanderpaul 15]

Awesome. I've got a compressor available, will look into the smoke machine and see what I can discover. Appreciate the help!

[Chanderpaul 15]

Did a smoke test with the home made setup. Worked well but might need a higher resistance wire or some more patience as I set the oil on fire.

Found a lot of smoke coming from under the intake manifold so I have ordered a full CCV kit.  Need to determine if I will take the intake manifold or do the reach around.
Also the breather hose to the rocker cover so had to make do with a coolant line to keep it going.

Also got sick of the loud rear left wheel bearing so tackled that job. Once you have all the tools its not a bad job, just a pain that it is the left one and you have to get the exhaust makes access tricky.
But totally worth the effort to have a lot less road noise now.

Still idles horribly at times so will investigate further when I tackle the CCV replacement. 
 

[Vass 831]

44 minutes ago, Chanderpaul said:

Found a lot of smoke coming from under the intake manifold so I have ordered a full CCV kit.  Need to determine if I will take the intake manifold or do the reach around.
Also the breather hose to the rocker cover so had to make do with a coolant line to keep it going.

Might be worth pulling it if it's never been off before. Makes the CCV job a lot easier and gives you a chance to do a bit of a cleaning job and also tackle some other jobs whilst you're in there. It's a good idea replacing the two plastic coolant pipes that run under the intake manifold (#6 & #8 on the schematic below). Those always rot and break off at the point where they attach to the block and the head, can often cause annoying coolant leaks that are hard to get to.

Just took off and reattached the intake on mine this past week, not too terrible a job. I'd go that route if I ever need to replace a CCV again.

[Eagle 1662]

Doing the CCV without manifold removal isnt too bad if you have done it before. but as above id take it off and do the pipes at the same time.   

[Chanderpaul 15]

15 hours ago, Vass said:

Might be worth pulling it if it's never been off before. Makes the CCV job a lot easier and gives you a chance to do a bit of a cleaning job and also tackle some other jobs whilst you're in there. It's a good idea replacing the two plastic coolant pipes that run under the intake manifold (#6 & #8 on the schematic below). Those always rot and break off at the point where they attach to the block and the head, can often cause annoying coolant leaks that are hard to get to.

Just took off and reattached the intake on mine this past week, not too terrible a job. I'd go that route if I ever need to replace a CCV again.

Thanks for the advice.  Sounds like I will have to find a quiet weekend and get the manifold off. I had a look on RealOEM at the diagram and ended up down a rabbit hole with a huge shopping cart of things.   What parts would you recommend as a minimum?  

#6 & #8 coolant pipes,  Intake manifold gasket.  -  Are things like fuel injector o-rings and o-rings for the air distribution manifold something I should also consider?

Also does anyone have experience with the 02 Pilot mod or similar with M54s ?

[Vass 831]

2 hours ago, Chanderpaul said:

Thanks for the advice.  Sounds like I will have to find a quiet weekend and get the manifold off. I had a look on RealOEM at the diagram and ended up down a rabbit hole with a huge shopping cart of things.   What parts would you recommend as a minimum?  

#6 & #8 coolant pipes,  Intake manifold gasket.  -  Are things like fuel injector o-rings and o-rings for the air distribution manifold something I should also consider?

Also does anyone have experience with the 02 Pilot mod or similar with M54s ?

Good old shopping cart blowout, happens every time

I don't think the injector & distributor O-rings usually go bad, they're not exposed to direct oil or particularly high temperatures, but then again they're fairly cheap and you might as well I guess. I changed them on mine but that was part of an engine rebuild and not much was left untouched by the end of it. You could take the injectors to a machine shop and have them professionally cleaned & flow tested whilst they're out, usually costs about $15/each but that's an extra optional step.

Another cheap item to replace is the oil dipstick seal/O-ring where it goes into the oil pan - common source of leaks and the dipstick gets in the way when removing the manifold and will need to come out anyway.

Other stuff - give the throttle body and idle control valve a good clean whilst they're out. Lube up the ICV a bit before putting it back on - good writeup on how to do it at the bottom of the first post on here. The gaskets for those two might be worth replacing although they don't commonly fail - go for it if they're cheap enough.

Check the condition of the DISA valve. The shaft can sometimes break off, there's also a metal pin at the tip of it that can fall down the intake into the combustion chamber and grenade the engine. Haven't seen that happen on any of the E46's I've had but the risk is there. There's rebuild kits out there but that's probably a separate mission (if you end up going that route eventually, be careful to get the right kit as they're different between 2.5L & 3.0L engines and some suppliers don't specify which one it's for). At minimum, replace the DISA O-ring - there is no factory replacement available, the original seal is molded into the body of it, you'll have to cut the old orange one out and get a generic O-ring as a replacement. I got mine from Seal Innovations but whatever O-ring supplier you've got locally should be able to help.

Potentially replace the intake boots if they're showing signs of aging, another common source of vacuum leaks. And then give the MAF a clean with the special spray.

But yeah, as you say it is a whole rabbit hole you can go down and it can snowball real easily. Just depends on how far you want to take it really.

Edit: Can't say much on the 02 Pilot mod, sorry. My old M54B25 did start having oil consumption issues but I went down the engine swap & rebuild route instead.

Edited August 28, 2023 by Vass

[Eagle 1662]

Yeah really don't need fuel and air orings since you don't have to remove either of them but upto you. Oil dipstick is the main one as above.

I'd do the ccv system then monitor oil usage before other mods.

[Chanderpaul 15]

Thanks for all the help. I will try to reduce my shopping cart to something reasonable and get the ball rolling.

I have replaced all the air intake pipes, F connector and did the o-ring on my DISA valve. Will try to lube up the ICV as shown in the link.

3 coolant hoses (# 5, 6, 8,) CCV kit,  intake manifold gasket, throttle body gasket,  dip stick o-rings 

Edited August 29, 2023 by Chanderpaul

[Eagle 1662]

I would add the nipple caps on the back on the manifold too, 2 smaller ones and a bigger one. Always seem to be cracked to some degree. Can be done later but very easy with it completely off.

[Olaf 3317]

replace DISA valve, if it hasn't failed it probably will... dropping the Pin into your combustion chamber.  Inexpensive insurance.

Have a good look at the high pressure fuel hose supplying the injector rail.  They're getting old now - if yours is crusty, replace.  Nobody wants a fuel fire under the hood,

You're on the right track, taking care of the intake vacuum leaks.  cooling every five years.  plugs and a full set of coils after your cuurnet work (if you havent already) and it'll be a sweet runner.

Jared @Eagle is spot-on about those nipple caps (ooh err), Jon spotted those on mine recenty and we replaced them at same time as HP Fuel Hose.

e46 325i motorsport is a sweet drive.  They reward if treated to thorough maintenance.  We've had our 325i Touring for 11.5 years, no plans to replace it.

 

[Chanderpaul 15]

I tried to limit myself on FCP.  Should be enough to get the job done I hope.  I will check the fuel rail inlet hose whilst I am there and hope it is in good condition. 
The car still playing up a bit and would love to get it fixed so I can enjoy some trouble free summer cruising.  Totally agree Olaf they are a sweet drive.

Oil dipstick o-rings

Intake and Throttle body gasket

Intake manifold nipple cap

3x water pipes

Manifold air temp sensor o-ring

Air distribution o-rings

CCV kit I bought already.

 

 

[Chanderpaul 15]

In the mean time I got sick of having the rear tail light fault and after searching a few forums and watching the 50s Kid video on repairing his tail light loom I gave it a crack.

My right hand boot lid light was not working so checked all the bulbs etc and found no 12v at the bulb holder.  Pulled the loom apart and the wire was broken along with another couple that had cracked insulation and one that was nearly broken so i did a few repairs.  All the old tape residue makes it a prick to move the rubber boot but got there in the end.

 

Edited September 21, 2023 by Chanderpaul