Cross posted on Matthews Volvo Site & Swedespeed

Hi all,

I posted a thread about 9 months ago about a car I had just purchased. I am still fighting with the car, and wanted to update the information and hopefully gain some new insight.

The car is still misfiring, it seems to do it in extreme temperatures only. I stopped checking codes basically all spring because of it being a very busy time, but we didn't have any instances of flashing CEL and the "slow down or shift up" message. It started happening again as the weather heated up to the 90s+. The car also stalled immediately after starting a handful of times since I've owned it, my husband thinks he didn't turn it long enough, I don't recall having that issue when I started it.

Two weeks ago, I took it to have the AC lines replaced as they were leaking. They also recharged the AC. Since that happened, it stalls out any time the AC is on and I am idling. At stop lights, immediately after starting, etc. The only time it seems to be fine idling with AC, is when I start it up in the morning for the first time. They said the voltage is dropping to 9v when it stalls.

Car needed a new catalytic converter when I bought it, I had one installed yesterday. Really worried about ruining the new one since we still can't figure out why it is misfiring.

Since owning the car I have:
changed spark plugs (not OEM, planning to swap soon)
replaced bank 2 oxygen sensors (as a first step with the CAT code)
replaced fuel pressure sensor
changed air filter
changed fuel filter
cleaned MAF
cleaned throttle body (didn't replace gasket, planning to do that today)
replaced the battery that was bad (was the original)
replaced(?) ground wiring (the mechanic told me they did this)

the grounds being cleaned/replaced/whatever seemed to help the random flashing CEL, it started only misfiring right after a stall. Yesterday when I picked it up from the shop, it had been sitting in the blazing heat (inside thermometer read over 100 degrees) as I accelerated and pulled from the shop, it did a full misfire with flashing, it also stalled at least 2 times. I can't remember if the light turned off on it's own and came back, but on my way home, I had the codes checked at an auto part store, it was a misfire in 6 of 8 cylinders, 1 and 5 were okay. Usually it's all cylinders. Today while on a test drive, the CEL came on, but no flashing. I had the codes pulled and it was in 4 cylinders.

The only other code I've had more than once is the crankshaft position sensor (p0336), when the shop brought it in for the AC they found that code, it has come back about 2 or 3 times in the last 2 weeks. The shop said they swapped the sensor and didn't see a change in performance.

Sorry for the novel, I am at my wits end and just need this car to be safe to drive my kids in! Any input is appreciated.

 

a quick update

I ran a test run, at about 8 miles after resetting light, the car stalled with the AC on at a light, but immediately picked itself back up. As I made the turn, it started flashing CEL and so I pulled over and stopped. When I started it back up, the code was gone. I drove it to the place I had been earlier in the day & he pulled the codes, misfire in 7 cylinders, crankshaft position sensor, AND A FREAKING P0430 CAT CODE. I hoped to never see that code again. Please tell me that since yesterday I didn't already burn up a new cat, this makes me feel like the $1000 repair I did yesterday was for nothing.

 

Was the standard troubleshooting for a misfire done like I mentioned? Since this is so permanent, it should be very easy to diagnose.

 

I asked the mechanic when I dropped it off if they had done troubleshooting for misfires, they said they had and were convinced it was the grounds, they didn't tell me specifically what the troubleshooting was. Like I said above, the grounding did seem to help with random misfires, but it still misfires immediately following a stall.

 

I don't think they know what they are doing, to be honest. Fuel pressure needs to be checked (and monitored during a stall, preferably). The intake system needs to be checked for leaks. Compression should also be checked, though I doubt it is the cause since so many cylinders are misfiring.

 

I agree that they may be stumped with my car, they are called "Autobahn" and are European mechanics, but I think it's more VW, Audi & Mercedes, that's what's in their lot. Unfortunately, the Volvo mechanic in my area was completely useless, put on new 02 sensors (I later found out they had been changed 4 months before via Carfax research), gave me "shop credit" when I asked him about it and then he had it at his shop for a few days until the credit "ran out" and eventually and told me to dump the car.

After they did the repair for the catalytic converter yesterday, I could hear much more engine compartment noise while starting/driving. I also had hot air blowing on my foot. The car is also vibrating like it never has before. I used to have some freeway vibration around 60-70, but this is near constant.

I am taking it upon myself tonight (before I take it back to them) to test the things you mentioned. Heading to rent the tools now.

 

Any Volvo dealer nearby? They have free diagnosis. I'd be curious as to what other codes may be stored that generic scan tools won't read.

 

They've had it twice, they told me they thought misfires were a fluke & they wouldn't look at it again until I spent their $3500 on a new catalytic converter. I just had that done (not by them), so I do want to take it up there & see now.

 

Yikes. Sounds like no one is competent there. Though, a plugged cat could cause a misfire so they probably didn't want to charge for a bunch of tests when they already knew you had an expensive repair ahead.

As for the vibration, sounds like whoever did the cat messed up something when reinstalling the subframe.

 

Yikes is right, especially since I just dropped so much on a catalytic converter and still have the code pending. I had tests done at the dealership, government emissions, and another shop to tell me if it was bad, they said it was tracking and that it was.

 

I don't really doubt the cat was bad. I wouldn't be surprised if this one is setting codes if it's used or a cheap aftermarket one though. I don't think it's causing the misfire.

 

I got a used exhaust manifold from Erie. Hoping the part wasn't bad considering the most expensive part of the repair was the huge labor time, and that means I potentially have to pay that amount 2 more times (removal and 2nd repair).

 

any other ideas?? please help, it's been 9 months & i don't feel safe driving the car! i told my mechanic that when i had the battery and alternator tested months ago, it read a high ripple (.6) and he says in his gut he doesn't think it's the alternator, I don't know want to push a 800+ repair to have it not do anything. is there any chance that the ripple reading could have been a false reading because the battery was so low?

 

I'd bet against the alternator.

What were the results of the fuel pressure check, intake leak check and compression test?

 

I had a mobile mechanic come over because I am sick of not seeing what is being done. He plugged in his big Pegisys computer and I saw all the codes that have been stored.
Past Codes:

BCM:
C0045-01 Brake Pressure Sensor B - General Electric Failure
U0428-29 Invalid Data Received from Steering Angle Sensor Module
U0126-00 Lost Communication with Steering Angle Sensor Module
U0001-00 High Speed Can Communication Bus
U0114-00 Lost Communication with DEM
U0401-64 Invalid Data Received from ECM

TCM:
P0744-00 Torque Converter Clutch Solenoid Circut Intermittent

Read Codes:
CEM:
1A52 Communication with DDM
DF17 No Diagnostic Code Description Available
E000 Communication with Control Module Faulty
1A64 Communication with AOC Module

DIM:
0001 Mileage Manipulated

Also, the P0430 was there, misfires (as usual). He cleared the codes and one of the times the car was started and idling the CEL came straight back on, we checked and it was P0336. He went from thinking the battery was bad (it showed only 6v after the big computer was left plugged in), then thinking alternator because the voltage was jumping from 14.40 down to 14.20ish in one jump. He said going down by .2 or .3 is okay but not that high of jumps. Then after the sensor code came up he thought it was that. He is getting an OEM sensor and installing tomorrow. Any direction or opinions from here?

 

The CEM-DF17 is concerning. That is a network problem and isn't something that is usually easy to diagnose if it's actually problem that occurs intermittently.

There are two cats. Which one was replaced? That code is for bank two, which is the cat closest to the firewall.

A damaged flywheel is a possibility since that crank sensor code keeps coming back. Its a long shot, but a possibility.


I'm pretty sure I've mentioned fuel pressure and intake leaks a few times. If you don't want to check the basics, I can't help you any further. Good luck.

 

I asked the mechanic shop to do those tests when they had the car earlier this week, as I was unable to rent the tools I needed. They told me no problems were noted.

The cat that was replaced was the right one. I supplied the part to them, and what I ordered was the right.

Should I take my car to the dealership to update all the software? Once when I talked to them, they said sometimes it makes things more messed up then before.

I'm also changing spark plugs to OEM volvo branded when he does the crank sensor tomorrow.

 

This is not a software issue.

 

Long overdue update on the issue:

Volvo spark plugs from the dealer and an OEM crankshaft position sensor has solved my misfire and stalling. I have not had those issues again since it was repaired 2 weeks ago (although I was out of town for a lot of it, but the issue was extremely consistent & easy to replicate). What we are experiencing now, is still having the P0430 code. We have put in a new cat, and changed o2 sensors about 9 months ago. I found out today that my old mechanic used Walker brand for the o2 sensors. Considering an OEM crankshaft position sensor worked when an aftermarket didn't, is it possible that this is also caused by non OEM sensors?? Or is it possible that the cat I put in is bad? What tests would I do to test the cat is working properly?

Thanks for your continued help.

 

I'd say it's more likely that the wrong plugs caused a misfire that set the crank sensor codes, but it doesn't matter as long as it's fixed. That DF code is still concerning.

I always strongly recommend against aftermarket oxygen sensors, so that is where I would start. Of course, used parts are always a gamble, so if the code returns, it looks like the gamble didn't pay off.