Technical Car/Motor Issues > BMW 3-Series E46 - 02 2.5 Suggested Maintenance
Thread Author: Pezzer Replies: 15

 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - Pezzer
Evenin all, had the Touring 3.5 years now (64k-107k)and have only really changed the fluids, filters, discs and pads along with the front bushes and LCAs.
However she is starting to not rev as smoothly and feels a bit asthmatic, and is a bit lumpy before reaching normal temp sometimes hunting and cutting out.

I think it is probably worth changing the plugs is there anything else relatively simple that might be worth doing by this mechanical idiot which will improve the running ?

Thanks in advance
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - bathtub tom
I've googled LCA and am none the wiser.

May I suggest posters avoid 3LAs?
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - Pezzer
Lower Control Arm ....
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - Zero
>> I've googled LCA and am none the wiser.
>>
>> May I suggest posters avoid 3LAs?

NP.
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - bathtub tom
NP.

nondeterministic polynomial time?
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - Number_Cruncher
It's difficult to help without seeing/hearing/feeling what the engine is doing but,

in addition to changing the plugs, it might be worth giving the throttle body / throttle plate and idle air control (if the engine has one) a good clean with carburettor cleaner.

I've also found that when you've checked through engines of this age and older, and sorted all the obvious problems, that you can often effect a significant improvement by renewing the lambda sensor - even when the lambda sensor isn't flagging any fault codes, and isn't failing the check of monitoring its output with the engine idling. The effect is one of sharpening the engine's response, and reducing any shunting and driveability problems.
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - Zero
>> Evenin all, had the Touring 3.5 years now (64k-107k)and have only really changed the fluids,
>> filters, discs and pads along with the front bushes and LCAs.
>> However she is starting to not rev as smoothly and feels a bit asthmatic, and
>> is a bit lumpy before reaching normal temp sometimes hunting and cutting out.
>>
>> I think it is probably worth changing the plugs is there anything else relatively simple
>> that might be worth doing by this mechanical idiot which will improve the running ?
>>
>> Thanks in advance

10 years old? I would be looking into clearing all the breather pipes and crankcase ventilation system. And the fuel filter changed. Does it have HT leads or are the coil packs mounted onto the plugs? If not look at new leads as well as plugs.
Last edited by: Zero on Fri 12 Oct 12 at 22:58
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - Dog
This may help: goo.gl/PhkVU (Amazon)
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - Pezzer
thanks for these suggestions although I think some are beyond my capabilities.... fuel filters and Lambda sensors.
I will give all the hoses and breather pipes a check, out of interest how would you clear the latter?

I see also that coil packs are £40 quid each assume recommendation is to change them all (6).

 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - Dave_
>> out of interest how would you clear [breather pipes]?

Bit of rag on a straightened wire coat-hanger has worked for me before. Add in some methylated spirits or petrol to remove all traces of oily gunk.
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - carmalade
I doubt if it will need coil packs.A failed coil will cause a misfire and bring the engine mil light on.More likely to be an engine breather fault on this age of car,located under the inlet manifold system,or associated pipework.Also a failed camshaft sensor can cause similar issues,but may not show the Mil light.hth
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - TeeCee
I'd treat it to a set of plugs and probably a set of decent HT leads as well. You'd be amazed how much difference the HT leads can make in the cold and damp.

Look for greyish patches on the HT leads, if you find any they're shorting to earth and due a change.
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - carmalade
Unfortunately you will struggle to find HT leads on these.This car has 6 coils over plugs set-up.hth
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - Collos
The coils tend to break down easy to test and replace but it also has two camshaft sensors and a crankshaft sensor any defect in these cause cause rough tickover.They also like BMWs suffer from worn from drop links and front wishbone wear especially the rear swivel rubber.The crankshaft sensor is a sod to get to takes a few hours and lot of kit needs to be removed to get to it most common fault on BMWs.
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - Collos
One more point when coils do start to go wrong they do not put the MIL on, normally misfires on e46 petrols are coils,plugs,cam shaft sensors(there are two)and crankshaft sensor.
 BMW 3-Series E46 - 02 2.5 Suggested Maintenance - Auntie Lockbrakes
Recently changed the plugs and fuel filter on my '05 A4 V6 and it seems to run a lot more smoothly.

Does the gearbox oil warrant changing on BMWs of this vintage? It's a serviceable item on the A4...
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