Overfull of oil

Recently I brought my car for an oil change. They put the recommended full synthetic oil in and when I left the cel starting blinking and the car idling extremely rough. I brought the car immediately back (only drove ~1/4 mi.). They discovered that they put too much oil in the car. Despite their efforts of removing oil and changing filter x2, they could not get the cel to stop blinking or the car running correctly. I brought the car to the closest repair facility with diagnostic capability and they noted the car was still 1qt overfull and multiple misfire, and cam shaft actuator codes were happening. Car was towed to dealership where they diagnosed fouled plugs attributed to too much oil. Oil change facility paid towing, repair and diagnostic bills for their mistake. In the subsequent 2 weeks my car was towed two more times to dealership. Once for going into limp mode after misfires and once for fuel pump dying. Is this all a coincidence or could this be repercussions from botched oil change? Dealership says it is just coincidental.

After second tow to dealership they switched the coils on one side of engine to other to see if misfire codes would show on other cylinders indicating bad coils. The misfires did not reocurr at all. Car is a 2007 Mercedes clk350 cabriolet.

The fuel pump is probably coincidence.

The misfire might also be, or the coils may have been sloppily reinstalled when the plugs were replaced after the overfill.

Never really thought about the coils being sloppily installed. That would explain why it now is not misfiring despite nothing new.
I kind of thought fuel pump would not be related however it all happened immediately following oil change. Car had been great prior. Did not know considering everything is connected in some way. Was a tough coincidence, was $1200 to change fuel pump and fuel level sensor. That seem about right?

Thank you btw

Yeah, $1200 for your car sounds OK. At least now your fuel pump should be good for many more years.

$1200 isn’t unreasonable for a fuel tank module for that car, the failure of which was probably coincidental to everything else.

BTW, the only places that should be doing oil changes (or anything, for that matter) to your car besides tire replacement are the dealer or a qualified independent shop with the proper tooling, experience, and service information for your Mercedes.

The fuel pump was a coincidence but it sounds like all the other maintenance…starting with the oil change…was just bad wrenching by inept technicians or so-called mechanics.

I agree that the fuel pump was just a coincidence.

The other things could easily be attributed to the overfill.

The oil change worker (I won’t call him a mechanic) put a few quarts of oil into your car. Then he went to count weather he will have enough NoDoze for the day because he partied all night.
Then he came back to your car and had forgotten that he had already put in a few quarts.


Or, he forgot to drain the old oil, and added the new oil to a full crankcase.

An iffy lube is never a good thing. If the light is flashing, the engine should be shut off. You should be able to drive with a steady light but don’t take just my word for that.

It was an iffy lube competitor, alvoline. I learned my lesson however I would have thought changing oil would be routine. Not of course routine enough for me to diy.

I had heard the same thing about the blinking cel.

“It was an iffy lube competitor, alvoline”

All of these quick lube places use similar business models:

Hire young kids who know virtually nothing about cars, give them truly minimal training, and then turn them loose on the very expensive vehicles of unsuspecting customers.
Push those kids to rush through their tasks as fast as possible, with no quality-control by supervisors.
When found to be in error, deny, deny, deny, obfuscate, obfuscate, obfuscate…until a lawsuit is filed…at which time corporate’s team of attorneys will do their best to defeat the claims for ruined engines, transmissions, differentials, and brake hydraulic systems.

The bottom line…If you care about your car (and your wallet), you should find either an independent mechanic’s shop or a decent, well-reputed dealership in your area, and then use them for your maintenance.
The cost will either be the same as the quicky lube place…or maybe even less.

As one of the veterans of this board used to say, Don’t go to a quick lube place–not even for directions…

I will heed your advice.

Okay, I give up. What is the year, make, model, and engine?

If your engine uses a Manifold Absolute Pressure (MAP) sensor it could have been damaged by the oil ingestion, as could your upstream oxygen sensor(s) and your catalytic converter.

When someone seriously overfills your oil, it can be whipped by the crankshaft into a froth, seriously increasing volume to where oil gets pushed up through the return channels into the space(s) under the valvecover(s). From there it can get ingested into the engine’s cylinders via the Positive Crankcase Ventilation (PCV) system. From there, it can contaminate the Manifold Absolute Pressure (MAP) sensor if you have one (some cars don’t) on the way to the cylinders, and once burned (if burned… it might just wet the plugs too much and get passed still in its fluid state) and (whether burned or not) contaminate the upstream oxygen sensor and catalytic converter(s). It can damage the downstream sensor(s) too, but those won’t affect engine operation… although they(it) can cause a code to trip.

In short, you need a good diagnostician. You’ll definitely need new spark plugs, and you just might have damaged the MAP sensor, the upstream oxygen sensor, the catalytic converter, and the downstream oxygen sensor. The wetted plugs, the MAP sensor, and the upstream oxygen sensor can definitely affect your engine’s operation, and the converter and downstream sensor will trip the CEL if damaged.

A full assessment and good documentation will go a long way in small claims court toward getting restitution fo the damages these guys did.

Sincere best.