P2178 P2188 - Leaky injector?

JohnnyBee323 · Post by **JohnnyBee323** » 29 May 2018, 13:24

Been having issues with my 2004 S60 2.5T.

Having hard starting problems, and the engine idles roughly up and down for a minute and then levels out. Seems to happen more when its hot out or the engine is still hot and go to restart the engine. Otherwise the car drives fine. Been pulling the code P2188 and P2178. Running rich on idle bank 1 and off idle.

I have had the vacuum leaks fixed, cleaned and tested MAF sensor, replaced both o2, fuel pressure and boost pressure sensors, and still having this issue. Some suggest it could be pcv, but I am not blowing black smoke, but occasionally get whiffs of gas when car is running. Others suggested it could be a leaky or faulty injector.

Can anyone with more proficiency help me diagnose the problem?

Post by **RickHaleParker** » 29 May 2018, 16:24

It could be anything that would mess with the Air/Fuel ratio.

Possible source per VIDA.

Upper limit:

intake air leakage
exhaust system air leakage
low fuel pressure
defective heated oxygen sensor (HO2S)

Lower limit:

intake air leakage
high fuel pressure
leaking injectors
defective mass air flow (MAF) sensor
contaminated engine oil
oil level too high
defective heated oxygen sensor (HO2S)

JohnnyBee323 · Post by **JohnnyBee323** » 04 Jun 2018, 08:00

RickHaleParker wrote: ↑29 May 2018, 16:24 It could be anything that would mess with the Air/Fuel ratio.

Possible source per VIDA.

Upper limit:
intake air leakage
exhaust system air leakage
low fuel pressure
defective heated oxygen sensor (HO2S)

Lower limit:
intake air leakage
high fuel pressure
leaking injectors
defective mass air flow (MAF) sensor
contaminated engine oil
oil level too high
defective heated oxygen sensor (HO2S)

Would intake air leakage be considered a leak in the intercooler hose? I just notice, on the back side of the intercooler hose, it looks like its leaking and has oil on it. We did a smoke test, and it didn't leak out of that pipe for some reasons, but it definitely looks worn down and probably leaking. Would be great if thats all it is.

Post by **chrism** » 04 Jun 2018, 10:56

I recall this conversation. I was one suggesting a leaky injector(s). Did you you ever try bleeding the fuel pressure off through the schrader valve immediately upon shutting the engine off to see if it helped smooth things out upon restarting? It's a super easy test - shut off the engine; bleed the fuel into a rag; wait 5-10 minutes; restart the engine.

Post by **oragex** » 04 Jun 2018, 14:02

Another easy test is to fire up the engine and while it's running rough, unplug one by one the injectors. See if there's one that when unplugged the engine reacts differently than for the 4 others.

But to give an idea about how large the possibilities are, after mine was driven a bit with a faulty coil, now the engine runs a bit rough just like yours for 1-2 min then it's smooth. Just because (probably) either a piston ring or a valve was affected somehow when I drove it with un-burn fuel inside the cylinder with the faulty coil. It seems to go away when the engine is fully warmed up.

Post by **RickHaleParker** » 05 Jun 2018, 07:28

We did a smoke test, and it didn't leak out of that pipe for some reasons,

The intercooler is after the MAF, any air leaking out or in would throw off the metered air measurements.

It may only leak when there is a pressure differential. A smoke test does not produce a pressure differential. If it looks worn, remove, cap one end then stretch it as you look down the center in strong lighting. This can reveal leaks a smoke test cannot.

sjanssen15 · Post by **sjanssen15** » 18 Jun 2020, 12:19

@JohnnyBee323
I have the exact same issue with my S60 2.5T AWD as you do. P2178 error, almost always when its hot outside and/or I restart my car when the engine is hot. What I also noticed is that it's really bad when the car is parked at an angle, up hill. Then the car gives the error, start idling rough and can even just die at idling. it also smells like gas when you try to keep starting it.
I also replaced the MAF,O2 sensor, new oils, new filters, compleet oil clean/replacement in the aut. transmission.

Would you mind sharing if you fixed this issue since this is a while ago? i'm searching for a solution for months now and this would really help. i'm looking into cleaning the throttle body and injector replacement.

Post by **jonesg** » 19 Jun 2020, 11:48

Try what chrism suggested above.
Get a rag and release the fuel pressure after driving the car.
After a few hours, key on a couple of times to prime the rail and see how it starts.
That will indicate whether a stuck injector is flooding the cyl or not.

sjanssen15 · Post by **sjanssen15** » 19 Jun 2020, 14:07

Thanks for the response! Maybe a noob question, where can I find this schrader valve? I want to try this and see if it can help a little before swapping out the whole injector(s) because they are quite expensive.

Post by **jonesg** » 19 Jun 2020, 15:39

sjanssen15 wrote: ↑19 Jun 2020, 14:07 Thanks for the response! Maybe a noob question, where can I find this schrader valve? I want to try this and see if it can help a little before swapping out the whole injector(s) because they are quite expensive.

normally its on the end of the fuel rail .