Car has had timing chain replaced and is tight was replaced before all the problems started .
Walnut blasted valves they are clean. Was getting miss fire codes on all cylinders took to dealer changed out hpfp mis fire codes have went away. They Told me valve cover was bad causing mis fire and I had a leaking thermostat housing change out valve cover and thermostat .Still runs like crap giving the following codes . P2178and p1497. In and out of what I would car a limp mode as well. Thinking maybe ingnitiin coils maybe or the wires going to them? Just noticed top oil line on turbo is starting to leak as we'll guess that will be next on the list just keeps on getting better. Any thoughts would be much great ful . Good pressure on all cyclinders as we'll 190 psi on all 4.

 

Hi, the codes you list both relate to air/fuel issues not ignition. Per Bentley - The P2178 is Fuel Trim Limit Exceeded System TOO Rich, The P1497 is Downstream Throttle Air Leak. Personally I'd focus on looking for a vacuum /air leak that is driving a too rich condition. Do you have the Turbo Oil Line Heat Shield installed ?...this was put on by the dealer on my 2007S last year at no charge. I'm guessing you do if they did the HPFP.

 

You also might want to check the Intercooler for liquid oil caused by back pressure in the exhaust. If there is oil in the IC it may be getting into the engine and it can cause the misfire and pre ignition you are seeing. When turbos start to fail the rear turbo pressure seal will stop functioning and let exhaust into your engine. This pressure pushes oil out both the front and rear pressure seal. As the oil burns off of the catalytic converter it leaves behind debris and particles that slow the exhaust gas flow.

When exhaust flow is slowed or there is a blockage in the exhaust the exhaust gasses will excape through the turbo into the engine pressurizing the engine. This will cause oil to be pushed out the front pressure seal of the turbo and into the Intercooler and intake system. When this happens you get extra fuel (in the form of oil) into your engine. This extra fuel will change the AFRs because the O2 sensor can only detect the level of O2 not extra fuel in the exhaust. So depending on the amount of Oil fuel in the exhaust the ECU may decrease the fuel when it needs to increase it or increase it when it needs to decrease it. When you have extra fuel getting into the engine the fuel ratio can’t be calculated because the fuel is getting in without the ECU controlling it.
This is a really common occurrence for Mini Coopers with turbos and is what causes most of the high oil consumption and valves to coke up in 5K miles. 20 years ago when the pressure seal failed you would see the tell tell sign of blue smoke out the exhaust. However these days the emissions systems can burn enough oil smoke out of the exhaust to mask a broken piston or burned valve for a short period and we have seen this on more than one occasion.

If you have a back pressure issue you can see a wide range of problems most of them cause serious engine damage. Part of the reason is because the EGTs get so high they melt the non metallic parts of the oil line like the swivel seal. Which is likely the cause for your oil supply line leak. The unfortunate thing is that this also can cause piston, rod, or head gasket failure or the extra heat in the exhaust can burn the valves and crack the turbo and exhaust manifold. The following are symptoms/failures that we have seen however there are too many to list but here is what we have seen.

1. No symptoms
2. Turbo failure
3. Burned valve/s
4, cracked piston, bent rod/s, bent crank
5. Cracks on the turbo housing and or manifold
6. Rough idle, varies from car to car at all different RPMs and speeds.
7. Intake Valves coke really fast sometimes in less than 5k miles
8. High oil consumption like more than 1q in 5k miles we have heard of 1q in 1000 miles
9. Liquid oil in the Intercooler, we had a customer that told us he had 6q in his Intercooler.
10. Exhaust back pressure usually around .5 to 1psi at full boost pressure but we have seen up to 5psi.
11. Signs of oil on the outside of the compressor housing.
12. Premature head gasket failure
13. Every gasket on the engine leaks oil
14. Map sensor failure
15. Throttle plate failure
16. Miss fire or pre-ignition
17. Blue or black smoke out the exhaust

Most of the time these problems baffle most mechanics even veteran mechanics and dealers have no idea of the causes. People end up spending a lot of time and money getting things repaired that are not the cause of the issue. In some cases (most) we have even heard of the mechanics replacing the engines due to engine failure or miss diagnoses; however they never address the actual issue which is a combination of back pressure and turbo failure. There are a lot of people out there that are driving around in cars with bad turbos with clogged exhaust and new engines, one of our customers was on his third engine and the second one that blew up was a JCW motor. Once we told him how to fix the issue the car not only ran better but it is now one of the fastest minis on the road today.

The reason for this is because the turbo will perform normally until the thrust bearing in the turbo wears out due to the back pressure pushing the turbine assy into the thrust bearing. So most people believe that the turbo is still good because it is still functioning, however this is not always the case and a turbo will last indefinitely even with a failed pressure seal, if it was not for back pressure damaging the thrust assy you would never know the turbo was bad.

Anyway if you have back pressure the fix is easy just replace the turbo, DP, and oil supply line. Than idle the car a few minutes to cool the exhaust down so you don't damage the new turbo. Oil burns at 400f and your EGTs are about 1500f when you are driving 55mph, oil will burn right in the turbo after the engine is off and that is what causes the pressure seal to fail.

Not trying to scare you (no scare tactics) just inform you, please feel free to contact us if you need more info about this issue we will be happy to help. You can also test for back pressure if you have an air pressure gauge and an O2 sensor adapter Y or T. If you run the car up to full boost pressure and you get >0.0.psi there is an issue. Doing a check at idle is a waste of time and doesn't show you anything.
Good luck fixing your car and keep us updated on the fix, believe me whatever it turns out to be it will help other people with the same issue.


BTW like bakerg4 said the “P2178 is Fuel Trim Limit Exceeded System Too Rich” and “the P1497 is Downstream Throttle Air Leak” and they point to back pressure. If oil is getting into your exhaust and the ECU can lean it out enough you will have the error P2178. Also if excessive exhaust is getting into the intake you can have a downstream throttle leak P1497 error.

 

Great write up not sure it is what I want to hear but the truth sometimes hurts.. Let me ask you a question the vdo throttle body valve is not closed all the way in a shelf state is that supposed to be that way? I will pull the intercooler off first and check for oil any advice on the best way to get it off? looks like the front bumper has to come off to get it out is that right?


Thanks for taking the time to reply to my post wish you where a little closer to Texas.
Shad

 

Sorry to be the bearer of bad news but I thought you would like to hear about the problem now so you can fix it. If this is the issue you might end up damaging the engine before you figure it out. Happy to help, would hate to see you waste money on mechanics misdiagnosis since the don't have a lot experience with issues like this much less believe us when we tell them how to fix it.

No need to pull off the IC just take off one of the hoses and stock your finger or something in that can soak up the oil.

 

P2178 System too rich off idle, O2 Sensor bank 1 ( Pre-Cat )


Would also just check intake hose #10 for cracks and clamp #12 to see if secure.

 

Top hose was bad and it did clear the 2178 code but the 1497 code still came in . A bad time chain was causing the 1497 code .