I have a 2005 300c that has developed a surge when it is at a constant speed, (most notably around 35). I had a code “P3497” pop up a few weeks ago, I changed the oil and it went out. About a month ago I had the transmission flushed at the local dealer so the fluids are fresh. The car is all stock and I pull a trailer with this car but the load is under a 1,000 pounds. I am perplexed with this issue, if anyone has any ideas please let me know. Thank you.
I know about the oil that is why I changed it. The code went out after the change but the symptoms started about 600 miles later. The car stalled on me twice yesterday and has yet to pop another code. After restarting it ran fine. I’m starting to get a little worried that it is going to strand me on the side of the road and that is the last thing I need.
P3497-MDS RATIONALITY BANK 2
Theory of Operation
When all criteria has been met, power is supplied to each MDS Solenoid when the engine is making a transition
from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that
coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse,
decoupling the valves and camshaft.
When Monitored:
Transition from 8 to 4 cylinder mode.
Set Condition:
O2 sensor readings on Bank 2 side indicate a lean condition while in 4 cylinder mode.
Possible Causes
INSUFFICIENT OIL PRESSURE ACTING ON THE LIFTER LOCKING PINS
OIL PASSAGES RESTRICTED
LIFTER
MDS SOLENOID
There is much more in the service manual, most of which requires the Starscan tool and engine disassembly.
How many miles are on the engine?
Have the oil and filter been changed at recommended intervals with recommended type and grade of oil?
Has the engine operating temperature been pushed to high extremes?
Do you frequently drive short distances during which the engine does not reach proper operating temperature?
Are you using the recommended octane fuel?
If I were having this problem I'd start with an engine flush followed immediately with an oil and filter change to more or less assure that the oil passages were not restricted, and go from there.
It sounds to me like he was having the code before he did the oil change. Since then his code is clear and no more issues that way... the surge and stall at 35mph seems to be a new issue. No more codes with this new issue, correct? Do you have any mods at all? Tune etc?
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Silver06hemic: You hit the nail on the head, (no wait that’s an old Buick lol) Yes the code cleared after the oil change and this is a new issue. The car is stock; no mods or tunes. It is also a sporadic issue I drove the car all day today with no problems yet yesterday I didn’t think I would get to my destination. No new codes have popped, yet.
Thanks.
A quick and easy change that can sometimes assist with rough idle and surging is the cam position sensor... also the crank sensor can cause some issues as well. The parts are inexpensive and anyone can change them who could change a tire or do an oil change. My cam sensor was puking and she ran rough and stalled a lot... no codes... 5 min change and fixed. Now if its not that then it was a cheap start... from there crank sensor... from there it gets more technical and more expensive. Not a for sure fix but its a good start and cheaper than dumping it at the dealer to pour money into or to hear 'could not replicate'...
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The Following User Says Thank You to silver06hemic For This Useful Post:
Ok folks I changed out the crank sensor and it was no help. However I did notice that this problem seems to happen just after I get gas, (and no I do not over fill the tank). The problem does seem to lessen after a few miles. Before I go out and buy a cam sensor are there any other suggestions related to fuel? BTW on the 5.7 the starter must be removed to replace the cam sensor. Not recommended when the engine is hot. Still an easy job though.
The cam sensor is the more common fault as silver06 first mentioned. Another item to take care of is the throttle body. When did you last clean it?
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Pedator, CAI, MDS indicator, ESP/BAS defeat switch, Tranzformer, blacked out wire mesh grille, smoked and flashing side markers, 9005 2400k 65W fogs, Euro rear fogs, debadged and demolded, 255/45/20 Nitto 420's, Boss 338 wheels, painted calipers. Glovebox & cup holder LED Mod. Blastin Bob 6db reso delete pipes. Euro LED side signal repeaters, 55/35 window tint, BT catch can. Color matched tail lights. Custom front lip. LED interior lighting.
Next: Lower with BCR Coilovers.
Last edited by Montreal300; 01-13-2013 at 08:36 AM.
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Surging at speed
371rwhp/392rwtq
Still got the hiccup
Linear Mode
