Engine oil change - what can go wrong

[Gnahp]

finally....

.

see you 30,000km later

[Gnahp]

while I was doing the air filter change

I noticed some broken plastic parts

1 - ECU harness connector cover, someone repaired it with cable ties but it didn't secure it properly, I suspect this is the rattling noise I heard randomly when the car is idling in gear

2 - broken plastic hose clip

I fixed it with cable ties, hopefully it will hold up

 

 

[Mkl22]

On 3/23/2024 at 6:16 PM, Gnahp said:

I just checked my W204 maintenance record

the misfire caused by the gunk accumulated at the back of the intake valves happened at 224k km

in the beginning I tried those injector cleaners, not improved after 2 bottles

ignition coils ok, spark plugs ok

symptom was misfiring momentarily when open throttle during cruising i.e. overtaking 

Direct injection right? Dump in 100% fuel cleaner will also do nothing to the valves. 

[Mkl22]

Toyota wish Corolla… 20sec change air filter! 😂

any slower means you cannot make it. 🤣

[Gnahp]

On 3/23/2024 at 8:02 PM, Mkl22 said:

Direct injection right? Dump in 100% fuel cleaner will also do nothing to the valves. 

yes, direct injection only

current car also direct injection only

likely need to do walnut blasting after I clocked some mileage on the car

here's a pic to let others following what we are talking 😁

[Gnahp]

On 3/23/2024 at 8:05 PM, Mkl22 said:

Toyota wish Corolla… 20sec change air filter! 😂

any slower means you cannot make it. 🤣

sian

please pay your mechanic to do it for merc

not worth to DIY

[Kklee]

On 3/23/2024 at 8:02 PM, Mkl22 said:

Direct injection right? Dump in 100% fuel cleaner will also do nothing to the valves. 

IMHO.
Must use specialty.

3M™ Intake System Cleaner
https://www.3m.com/3M/en_US/p/d/b40070747/

IIRC ( a long long time ago ),  Autosavers used to have something similar. 

[Gnahp]

On 3/23/2024 at 8:11 PM, Kklee said:

IMHO.
Must use specialty.

3M™ Intake System Cleaner
https://www.3m.com/3M/en_US/p/d/b40070747/

IIRC ( a long long time ago ),  Autosavers used to have something similar. 

those cleaner will only work on port injection where the fuel and cleaner is sprayed onto the back of the intake valves

fuel and cleaner spray directly into the combustion chamber in direct injection engine

no chance to clean the back of the intake valves

[Kklee]

On 3/23/2024 at 8:18 PM, Gnahp said:

those cleaner will only work on port injection where the fuel and cleaner is sprayed onto the back of the intake valves

fuel and cleaner spray directly into the combustion chamber in direct injection engine

no chance to clean the back of the intake valves

IMHO.
That 3M system is released thru the throttle body which will hit the intake valves.

The long time ago one I used,  comes in two bottles.  One is the regular fuel system cleaner via the fuel tank.
The other have the start engine, keep the rpm up and release thru the throttle body. 

[Gnahp]

On 3/23/2024 at 8:25 PM, Kklee said:

IMHO.
That 3M system is released thru the throttle body which will hit the intake valves.

The long time ago one I used,  comes in two bottles.  One is the regular fuel system cleaner via the fuel tank.
The other have the start engine, keep the rpm up and release thru the throttle body. 

I see, that will probably clean some of the light gunk when you use it regularly 

my W204 was chocked badly, I don't think those spray can dissolve it

I just found the OBDII scanner pic that I took 

on a hindsight, the misfiring is different from a bad coil/spark plug

bad ignition coil/spark plug misfiring usually happens during idling

for the choked intake port, misfiring happened during acceleration, that's when the demand of air is greater, and the choked intake port restricted it hence misfiring

 

 

[Kklee]

On 3/23/2024 at 8:37 PM, Gnahp said:

I see, that will probably clean some of the light gunk when you use it regularly 

my W204 was chocked badly, I don't think those spray can dissolve it

I just found the OBDII scanner pic that I took 

on a hindsight, the misfiring is different from a bad coil/spark plug

bad ignition coil/spark plug misfiring usually happens during idling

for the choked intake port, misfiring happened during acceleration, that's when the demand of air is greater, and the choked intake port restricted it hence misfiring

 

 

IMHO.
Probably need will need to use it regularly so that it won't get choked.
Likewise for fuel system cleaning,  each 10k oil change,  I use twice, at 5k and just before 10k. 

[Mkl22]

On 3/23/2024 at 8:37 PM, Gnahp said:

I see, that will probably clean some of the light gunk when you use it regularly 

my W204 was chocked badly, I don't think those spray can dissolve it

I just found the OBDII scanner pic that I took 

on a hindsight, the misfiring is different from a bad coil/spark plug

bad ignition coil/spark plug misfiring usually happens during idling

for the choked intake port, misfiring happened during acceleration, that's when the demand of air is greater, and the choked intake port restricted it hence misfiring

 

 

Yup. No use one. Waste time only. 
my coil misfiring was only on acceleration. Very very gentle no problem. Idle was fine. So a coil failure doesn’t mean only during idle. 

Edited March 23 by Mkl22

[Mkl22]

On 3/23/2024 at 8:44 PM, Kklee said:

IMHO.
Probably need will need to use it regularly so that it won't get choked.
Likewise for fuel system cleaning,  each 10k oil change,  I use twice, at 5k and just before 10k. 

Maybe every 2-3k you rev and spray into throttle body, even then I doubt it works. If so simple and good, internet every one will use this liao. No need to troublesome go blast with walnut. 
port injection is constant washing. 

[Beehive3783]

On 3/22/2024 at 11:33 PM, Comage said:

@Gnahp You're probably one of the rare few guys around owning a conti who still bothers to go order proper stock parts for repairs/preventive maintenance.

I seen so many a**holes out there who cheap out on parts and maintenance - just to own the conti badge.

Or those that pay 1 x price during initial purchase of the vehicle, and expect to drive it for the next 5/10 years without the need to pay a single dollar for any vehicle upkeep.

Or those who prioritise cosmetic upgrades like headlights, grilles and bodykits changes - over spending on resolving mechanical issues until an imminent failure is apparent.

Those people don't have money to do maintenance one la... all their money has gone into the instalments.  

[Soya]

On 9/24/2023 at 9:50 PM, Macrosszero said:

Specialized in everything!

Reminds me of used car dealers who advertise as "Specialised in all kinds of cars".....lol

 

[mersaylee]

On 3/26/2024 at 1:19 PM, Soya said:

Reminds me of used car dealers who advertise as "Specialised in all kinds of cars".....lol

 

With a commonality...best condition in town...😂

[Gnahp]

my wife, aka "the numb one" told me a few days ago - "....the car feels strange, no power when overtaking..."

I am the overly sensitive one, when the numb one said something seems wrong, you got to trust her, it is 100% not right

I test drove her car, everything seems normal, no fault code, started normally, idles normally, drives normally,  until I floor the accelerator on expressway

only 25% of the normal engine torque felt, turbo boost pressure will not go beyond 0.4 Bar, and there was a hissing sound on the passenger side engine bay when it was at 0.4 Bar

many possibilities ran through my head, but I'll start checking with the easiest and obvious one

Bingo! tikam also can hit jackpot 😁

you are looking at the silicon hose between intercooler outlet and throttle body, the hose clip / jubilee clip is loose and dislodged, the pressure built by the turbocharger is leaking from here hence the hissing noise under boost

after careful checking to make sure the hose isn't split or damaged, I reinstall the hose clip and tighten it, test drove, no more hissing noise under boost, boost pressure hit 1.5 Bar and beyond

I was discussing with my wife, this happened when the car is 2.5 years old, 92,000km, what could be the possible reason(s)?

1. lousy assembly line QC in Germany factory

2. lousy quality hose clip

3. meddled by lousy local mechanics

 

 

[Mkl22]

On 4/7/2024 at 4:18 AM, Gnahp said:

my wife, aka "the numb one" told me a few days ago - "....the car feels strange, no power when overtaking..."

I am the overly sensitive one, when the numb one said something seems wrong, you got to trust her, it is 100% not right

I test drove her car, everything seems normal, no fault code, started normally, idles normally, drives normally,  until I floor the accelerator on expressway

only 25% of the normal engine torque felt, turbo boost pressure will not go beyond 0.4 Bar, and there was a hissing sound on the passenger side engine bay when it was at 0.4 Bar

many possibilities ran through my head, but I'll start checking with the easiest and obvious one

Bingo! tikam also can hit jackpot 😁

you are looking at the silicon hose between intercooler outlet and throttle body, the hose clip / jubilee clip is loose and dislodged, the pressure built by the turbocharger is leaking from here hence the hissing noise under boost

after careful checking to make sure the hose isn't split or damaged, I reinstall the hose clip and tighten it, test drove, no more hissing noise under boost, boost pressure hit 1.5 Bar and beyond

I was discussing with my wife, this happened when the car is 2.5 years old, 92,000km, what could be the possible reason(s)?

1. lousy assembly line QC in Germany factory

2. lousy quality hose clip

3. meddled by lousy local mechanics

 

 

I would say shitty clamps by factory. Good quality jubilee clips hold very well. The cheap and fast install stuff by all manufacturer is just to speed up assembly. So 1 and 2. 
 

you might want to take dimensions and replace the hose and clips. Buy back orig hose but use breeze jubilee clips. The Subaru forester guys have had good feedback. They too faced shitty factory clips. 

Edited April 7 by Mkl22