Cadillac Owners Forum banner

1 - 20 of 21 Posts

·
Registered
2013 ATS
Joined
·
19 Posts
Discussion Starter #1
Hi Experts, wanted to get your input on this issue

The car is ATS,2013, 2.0L Turbo

  • It started with a P1101 for a few months. The car was excellent , This indication just came and go without any symptom (it clears itself)
  • The guys in the garage told me that this is probably very small vacuum leak or a throttle issue (need to replace it) but it does not worth it to fix this.
  • Because there was no effect of this I ignore it
  • Last week, I push the gas too much and then I got a Cylinder MisFire (P302).
  • I needed to replace the Spark and the Ignition coil for Cylinder 2
  • I've ordered the a new throttle (~150$) to be on the safe side :)

The car works now, but there are new symptoms:

1. The car is very laggy in 2K RPM, it shakes and I feel that something is not good
2. Idle RPM: ~750 RPM, 770-740. The engine sounds good, but once in a while (every 2 min) there is a small glitch (with OBDII I don't see it)
3. I feel there is no power , especially driving up in the mountains
4. Gas consumption is very high +30-40% higher than normal
4. OBD load value (idle) seems high (~22%)
5. MAF sensor works fine (3 g/sec)
6. Oxygen sensors (3) were replaced 5 months ago. Feedback is working fine. Good sine feedback graph
7. Idle: Long term FT + short term FT is < ~5% -- an indication that there is no vacuum leak

My questions:
1. What should I check with OBD to verify where is the issue?
2. Is it possible that it is the throttle (the car was excellent before the replacement of the Spark, so I assume it is not the issue) I think there is a small issue in another spark/coil?

thanks
Hanoh
 

·
Registered
2013 ATS
Joined
·
19 Posts
Discussion Starter #2
I replaced the throttle as the shop guys told me and guess what? I was right.
It didn’t solve the issue. I bet it is the Coils
 

·
Registered
2013 ATS
Joined
·
19 Posts
Discussion Starter #4
@sadpanda thanks.
The oil was just replaced and it’s level is fine.
I’m going to replace all the other 3 sparks and coils (I think it would be good anyway after 6 years)

Next would be the injectors. Is there a way to diagnose to get a lead before replacing the engine :)

 

·
Registered
2013 ATS 2.0T RWD, DP, Intake, HPT, CC
Joined
·
2,404 Posts
when you feel there is no power going up hills, are you seeing boost when you get into the throttle?
 

·
Registered
'14 ATS 2.0T 6MT
Joined
·
464 Posts
have the coils tested instead of just replacing... read the plugs. scope the cylinders. check fuel rail pressure while idling and while driving/replicating problem. use scanner to monitor boost/timing/air flow/knock during driving/replicating the problem. usually better to diagnose/test instead of throwing parts at it... no guarantee the parts you are putting on are good.
 

·
Registered
STS 3.6 DI Performance | ATS 2.0T
Joined
·
240 Posts
Test it as @sadpanda suggest.
I would suggest to clean up MAP (not MAF) sensor. It's located on the big pipe which is connected to the throttle body.
Some guy from this forum reported issues with this sensor and cleaning it up sorted problems.
It's 15 minutes job wort to try.

It seems like boost/airflow/fuel pressure problem but do the OBD scan first.
 

·
Registered
2013 ATS
Joined
·
19 Posts
Discussion Starter #8
@Wojciech and @sadpanda I missed your answer. Thanks again.
Just to update.
1. Replacing the coils and Sparks didn't help. @sadpanda was right
2. BG44K helps and now the engine much better indicate that this might be related to the injection.
3. The throttle replacement solves the P1101 issue (I didn't notice with P1101 a rough idle, so I don't think it is related)

However, there is still a minor rough engine idle and at low speed the engine does not run slick (it is a bit jumpy)

I've tried to disconnect the MAP sensor, but it seems the screw does not match any of my Allen screws.
Is it Allen? (I saw that the MAF sensor has the same and it more accessible so I can test it on this sensor first) .

thanks
 

·
Registered
'14 ATS 2.0T 6MT
Joined
·
464 Posts
clean != functional but what ever.

did the MAF/MAP pass resistance tests? Do you still have CEL? Have you done any of the diagnostics I recommended? How did the plugs look when you removed them? Do you know how to read plugs? BG44K is a fuel system cleaner... Are you putting it in the tank? What fuel are you running? Its a DI engine so high octane is not enough, you need a high detergent 'top tier' fuel.

good luck
 

·
Registered
2013 ATS
Joined
·
19 Posts
Discussion Starter #12
@sadpanda thanks for your patient and your great advice
I'm new to car issues my previous cars didn't have so much issue :) so it is a great opportunity to learn.
It is my first time removing a spark plug, removing sensors and replacing them by myself.
The spark plugs was replaced a 5km back so they are new. I've looked into them (not expert) I think they are good (see pictures).
All the coils are brand new -- didn't help. I've order a new OEM Spak Plug ( AC Delco 19256067- hard to find them) they are on their way. I plan to replace them too .
I'm located in Israel and I've put the BG44K Pro in the tank (full) with 95 Octan (this is how it called here)- it is not the normal fuel without lead. There is a 98 octan which is better but you can't find it in all the stations.

In the local edition to the car book they asked only for better than 91 Octan so I think there is no need for 98

For the pressure test you suggested for the rail and the injectors. I don't know how to do it myself (there is need to remove the intake from the left side of the engine). I think asking the garage just to replace them will cost me less than to ask them to check them (the part in israel cost x5-10 than in the US so I order them from the US)
If there is a OBDII test or other simple test I would love to try it. But I think this is the only thing left ..

The symptoms are less sever now after BG44K so it might related to the fuel system. Let me know your advice given my capabilities


thanks
Hanoh
 

Attachments

·
Registered
2013 ATS
Joined
·
19 Posts
Discussion Starter #13
Hi,
I've just got the spark plugs and replace them all. The car is smoother now, but not as before. Now I was able to compare them. I see a big difference see last betwean #1 vs #4 plug. #2 was replaced a few weeks ago. All of them were replaced ~5-7k km.
Per NGK it seems as minor carbon fouling. Is it right? Does it make sense to replace Injectors and rail or clean them in some way?
IMG_20190822_185639.jpg
IMG_20190822_185708.jpg
IMG_20190822_185957.jpg
IMG_20190822_190006.jpg
 

·
Registered
2013 ATS 3.6L Luxury
Joined
·
328 Posts
Man the plug on the left looks terrible for such low miles since replacement. When you wipe plug tip on palm of your hand, is it oily or does it smell like fuel. If oily, I would do a compression test to see if you lost a ring. If you have access to a borescope, wouldn't hurt to have a look. There were a lot of incidents of 2013 2.0s having piston damage before Cadillac came up with a fix.
 

·
Registered
2013 ATS
Joined
·
19 Posts
Discussion Starter #15
@angel71rs, thanks for having a look. By the car manual the iridium should last 160kkm.

The spark plug is dry. It is not oily. There is no smell of fuel. It looks like a dry black deposit, it is easy to remove it by touching it.

Is it possible due to coil issue or BG 44k? BG44k + spark plug replacement improved the car dramatically. But I fell that there is still something else ..
OBD II diagnostic is good. Fuel pressure is good. It might be one injector that has a small clug (it might be the root cause of the Coil issue)
I read about the piston 2013 2.0T issue but it was fixed with the new Spark Plug (the one I’ve waited for, not simple to find them 41-125 12647827) and PCM firmware version. We are 6 years after the fix.

My question is this: is it likely an injection issue? It about 500$ to replace all of them to new one. is it likely after 120k-km? sound too early for Bosch to fail. Do you still think this is a piston issue? Why the deposit is almost on all the sparks (except one)?

Thanks
 

·
Registered
2013 ATS 3.6L Luxury
Joined
·
328 Posts
If it's not oily, then I too would suspect a leaky injector fouling the plug. I've seen cars where it was a bad leak and fuel smell was present, would even make the oil smell like gas. That is why one poster suggested checking the oil. But other leaking injectors, leak is less with no obvious fuel smell or other indications other than fouled plug. I'm thinking car runs better with fresh plugs until it gets fouled again.

With the port injected engines, there was a test port on the fuel rail you could hook a pressure gage up to. If pressure dropped quickly after you turned engine off, you were leaking system pressure somewhere.

It being DI, it has a high side fuel rail sensor that a tech can monitor with a scan tool. Maybe this pressure drop rate test can be done while monitoring with the scan tool. You wrote something about you couldn't test pressure because it required intake removal? I don't know what procedure you are referring to, but good thing you didn't try it. Pressures involved are really dangerous. Definitely do not touch, best left to a pro.

With more than one plug involved, could be excess pressure, don't know if that's possible, don't have experience with DI engines. But testing might show if that is happening.

I'd do the compression test just to eliminate that possibility, but definitely quit throwing parts at it until after tests are done. That is called shotgunning and is bad troubleshooting and expen$ive.

It's highly unlikely to have multiple coils and injectors go bad at the same time. Manufacturers do get a bad batch of parts occasionally, but in the internet age, those types of failures show up quickly on the forums. I haven't seen anything reported about failing coils or injectors, other than normal individual part here and there. That's why tests have to be done to try to identify the root cause.
 

·
Registered
2013 ATS
Joined
·
19 Posts
Discussion Starter #17
@angel71rs, I do agree with you about this "it's highly unlikely to have multiple coils and injectors go bad at the same time"
The engine worked fine before the coil replacement issue P301. The throttle is not related issue. So I'm looking for something that could explain all of the failures with my limited knowledge ..
With the first evidence of foul Sparks (3 out of 4) I'm trying to figure out the reason - it might be that all of them were foul and the one that clean is the one with the bad coil that was replaced -- which made me think that the guys in the garage should have replaced all the sparks else you have inconsistency between the chambers.

I think I will give it a 5-10kkm and will look into all the sparks again. The problem is probably still there.
Could it be just MAF/MAP sensors that make the PCM push too much fuel (as somebody already suggested in this thread but for my untrained eye it looks clean)?
Is there a procedure to tune the amount of fuel /MAF air?

The problem with this diagnosis that it is very minor, almost not noticeable and the garage guys like big problems with simple diagnostic (replace all the coils/replace all the sparks/ replace the throttle) which is more cost/time effective from their side
 

·
Registered
2014 ATS 3.6 Premium RWD, 2016 Corvette Z06, 2018 GMC Sierra Denali 2500HD Diesel
Joined
·
2,874 Posts
With a 2013 2.0T, I would do a compression test on all four cylinders because a lot of them did suffer damaged rings and lands before GM updated the programming and switched to cooler plugs. You are looking at both absolute compression readings and variance across the 4 cylinders. The compression tester is cheap and it is an easy test to run before you start fooling with other parts and tests and the compression tester is something you can keep in your tool kit for future automotive projects. It should have simple instructions for how to use but if not youtube videos will show you how to properly run a compression test without danger to yourself or the engine and how to do it under the proper conditions to avoid false findings.

Did GM provide any extended warranty for the affected early production engines? Check into this before doing any work that would invalidate any special extensions GM provided. I have a 3.6 so I didn't closely follow the initial problems and long-term response from the general.

As pointed out earlier, testing the fuel system on a direct injection engine is more involved than the same process on a port injected or other indirect fueled engine and the high pressure side is dangerous to deal with if you aren't familiar with the process. Among other "fun" things a small leak can do in a very high pressure system is inject the fuel under your skin. I wouldn't touch that system without the service manual.

Some scanners can show in real time the cylinder contribution for each cylinder as the engine is operating; the crankshaft speed sensor reads the slight change in crankshaft speed that occurs as each cylinder fires and this information is used by the ECM. If under/over is large enough, the ECM will set an error but you can see contribution rate variance before it reaches the extreme needed to set a DTC for contribution (or sets a DTC and illuminates the CEL for misfire). The scan tool can also read misfire counts per cylinder; a single or random set of misfires won't set a DTC until the count is sufficient in order to avoid nuisance warnings to the driver. This could be helpful in seeing if you have a problem with one or multiple cylinders. GM diesel engines adjust injector duty cycle to balance contribution but I don't know if the gas engines have a similar process; with diesel engines the injector balance rate is a good starting point for diagnosing issues.

A heavily fouled plug or an open plug can lead to coil pack damage. A heavily fouled plug results in greater current during discharge than normal and an open plug allows coil pack voltage to go very high and either can lead to coil pack failure. Whenever a coil pack is replaced, at a minimum replace the plug for that cylinder and the high tension lead for engines not using coil on plug design. IF there was an existing cylinder problem that led to carbon fouling, then the new coil pack and plug is only a temporary fix and if the garage found a single plug heavily fouled for the cylinder where the coil pack was replaced it could either be a result of a failing coil pack OR the reason the coil pack failed.

MAP, MAF, and O2 sensors are pretty picky and usually an error will be set related to these sensors before you get to the point where heavy carbon fouling can occur. If a previous owner used one of those aftermarket oiled filters, then a dirty MAF is certainly possible but I suspect the problem with your engine lies elsewhere because a problem with one of these should result in similar behavior/observation for all four cylinders and plugs.

Rodger
 
  • Like
Reactions: hhaim

·
Registered
2013 ATS
Joined
·
19 Posts
Discussion Starter #19
@rsingl thank for the elaborated answer. I have just got the BG MAF Cleaner. Now the car is almost perfect even though the sensor looked clean to me. I will try to clean the MAP too with the same spray.

Your suggestion about the misfire counter is great, exactly what I was looking for. I just found it with my ELM327 after a 200km drive and the information is something like this:

0,0,0,0 (MID$A2-A5) (10 last drive)
5,1,1,0 (last drive)

This metric is much more accurate and deterministic compared to my “drive feeling”

Is 5 misfires for 200km is good /bad?

I still need to find the reason for root cause of the Spark carbon fouling. Will monitor the misfire counter and do the compression test.
 

·
Registered
2014 ATS 3.6 Premium RWD, 2016 Corvette Z06, 2018 GMC Sierra Denali 2500HD Diesel
Joined
·
2,874 Posts
You are welcome and sorry I didn't see your post earlier.

That misfire count doesn't look bad to me because no engine is going to perfectly fire all the cylinders 100% of the time which is why the flashing CEL doesn't illuminate because of a single or small number of misfires. The counter will also catch a weak firing condition where the cylinder does fire but contributes far less power than the other cylinders and doesn't provide the same crankshaft rotational impulse.

Am I interpreting your scan data properly that the counts "5,1,1,0" are by cylinder and if so one of the things you look for is one cylinder that is consistently showing a significantly higher misfire count than the others. If cylinder 1 is showing 5 misfires compared to 1,1,0 for the remaining three then I would definitely take a look a closer look at that cylinder HOWEVER it could be the nature of this engine because I have never looked at the misfire count data for a typical 2.0T. Depending upon the layout of the intake and exhaust manifolds, coolant passages, knock sensor location, and ECM program specifics-you will sometimes find engines that have a tendency to show a propensity to have more misfires on a particular cylinder especially during rapid transitions in operating conditions (i.e. sudden increase in throttle where the last injector on the common rail sees lower pressure until the high pressure fuel pump is able to respond to the request for increased flow/pressure). But in any case, if there is one cylinder showing a high count then look closely at it because whatever causes that increased count may get worse (failing plug, coil pack getting weak and unable to provide a "hot" enough spark at high RPM and/or high cylinder pressure).

The cleaner may clear the problem if the sensors are feeding lower accuracy data than desired. But still look closely at any single cylinder with an apparent miscount number because sometimes when everything else is working perfectly it will help mask the true problem with another component. I relearned that lesson the hard way a couple of years ago when fighting an ongoing issue with a vintage ham radio transmitter that wanted to produce hum on the transmitted signal. Every few months, replacing a different tube would seemingly cure the hum issue but there was no way that tubes should be developing leakage issues at that rate and I found the root cause was a previous owner had replaced a power supply filter choke with a replacement part that looked absolutely identical to the factory original part but had too little inductance. Once I found the true fault, the other components didn't have to be absolutely perfect to provide a properly operating transmitter.

Rodger

@rsingl thank for the elaborated answer. I have just got the BG MAF Cleaner. Now the car is almost perfect even though the sensor looked clean to me. I will try to clean the MAP too with the same spray.

Your suggestion about the misfire counter is great, exactly what I was looking for. I just found it with my ELM327 after a 200km drive and the information is something like this:

0,0,0,0 (MID$A2-A5) (10 last drive)
5,1,1,0 (last drive)

This metric is much more accurate and deterministic compared to my “drive feeling”

Is 5 misfires for 200km is good /bad?

I still need to find the reason for root cause of the Spark carbon fouling. Will monitor the misfire counter and do the compression test.
 
1 - 20 of 21 Posts
Top