Hi guys,
I have a Chrysler 300m 2004, 3.5. I have done a replacement of the timing belt at 100 000 mark with a chrysler dealer.
It has been misfiring for a while since. I brought it to a dealer who told me that the camshaft crankshaft and oxygen sensors need to be changed. So I did. (camshaft and crankshaft were changed with the dealer. Oxygen sensor was changed with independent with generic not factory sensor because the dealer did not have it.)
It did not solve the problem. Now the car is shaking and sometimes cannot accelerate. I even change spark plugs and battery.
I brought it to an independent, the mechanic told me that there is 3.8 degrees difference between cam and crankshaft sensors. They are out of sync and suggest that I should bring back to the dealer who replaced the timing belt.
When I brought the car to the dealer, they told me that chrysler 300m 2004 tolerates up to 12 degrees difference so the cam and crankshaft are not out of sync. Nothing to do with the timing belt that they installed.
I called the independent mechanic but he told me that in general it’s 1 to 1.6 degree.
Who is right?
The dealer…Anything within 5 degrees fits into manufacturing tolerance. After all it IS a rubber belt…
You are looking in the wrong place for your misfire…Check your exhaust system for back-pressure. ( plugged converter)…or a malfunctioning EGR valve…
The independent mechanic is correct. The cam and crank sensors must be synced exactly. It doesn’t matter if the belt is made of rubber. It’s a reinforced rubber belt so it can’t stretch to compensate for the mistiming.
This shows how the timing marks must align exactly when installing the timing belt on your engine. http://www.ricekiller.com/forums/thread76681.html
Tester
Along tester’s comment, the dealer screwed up, I think.
Thank you for your comments. I am confused since one says it is out of sync, the others say 6degree is tolerable. The dealer told me that 12degrees tolerance is in the spec.
Between 1,6 , 5 and 12 it’s a huge difference.
Also it’s only one bank that is misfiring.
I have the experience of neither Tester nor Caddyman, but when I read your comment, it seemed pretty clear to me that the timing belt install went bad. So put me down for continuing to chase the dealer about the timing belt job.
The dealer told me that if the timing belt was installed wrongly, I won’t be even able to drive. It should have problems from the beginning like right away after I took the car, but it went bad after like several hundred miles. Also the dealer told me that the o2 sensor is generic and not factory, so it might be the reason according to the dealer. ( I changed the camshaft and crank shaft with the dealer and according to their diagnosis. The o 2 sensor needed to be change according to the same diagnosis, but they didn’t have in stock so I changed it with an independent. )
The engine will run with the timing belt off by one to three teeth, I have seen a number of 3.5L Chryslers with the timing belt out of time. The customer usually notices a rough idle, not a misfire. Perhaps the belt is off so much the spark plugs are becoming fouled.
P0016 cam sync signal can be caused by an intermittant cam signal or the belt is installed wrong. Checking the fuel trim data can support the suspicion of the belt being out of time, the bank that is off will show +10% or more greater fuel trim than the other side. This may be why they believe the oxygen sensor needs to be replaced.
I think you should give up with the dealer and have the check the timing belt, should take about 20 minute to verify timing. It will take about 1 1/2 hours to reset the timing belt.
I own a 2000 300m with 128k miles and did my belt at 111k with no problems something seems fishey maybe the tech at the dealer should double check the timing to make sure nothing has moved or changed. I also would asume this started shortly after they did the timing belt job? there is only 1 cam sensor on this car they could have mistimed the engaine when they installed the new belt. just thinking out load when ypou changed the spark plugs did they all look the same as for colour or any of them look different from one or anouther.
Two things: I’m not an expert on these matters, but I would think 12 degrees off would be WAY out of spec. Much as I hate timing belts, they are a hell of a lot more than a chintzy rubber belt. They have very strong tensile reinforcement in them and are not that elastic.
Aren’t there two cams, one for each bank? Possibly one is out of sync while the other is fine. This would explain the problem with one bank of cylinders. Also, I believe the cam sensor reads the driver’s side cam position.
The car is still with the dealer, and I have no news. I will have to call tomorrow to ask.
It has been with the dealer for 5 days and they still cannot figure out why (they still do not think that the cam and crankshaft are out of sync and also they still think that there is nothing to do with timing belt.) The 12 degrees tolerance were communicated by the chrysler engineer, he say he will give me a copy of the email.
If they’re only reading the cam sensor vs. the crank sensor, I don’t know how they’re determining that the other cam is in sync.
which “other” cam they should check?
the car has only one cam senser but two camsharts ojne on each head ,they would have to check the base timing or re check to make sure when they did the timing belt something did not change. they would have to tare done the front of the engaine i don’t know any other way to check the other cam’s base timing . the cam sensor is in the timing cover on the driver side of the car so they (dealer)needs to check the p.s. cams timing or better yet re check the whole job.
They said they did a good job. And the car can tolerate up to 12degrees differences in camshaft and crankshaft sensor.
I’ve seen old timing chain engines with the chain worn badly enough that the cam timing is retarded 5-10 degrees. The ignition timing can be compensated for by simply rotating the distributor as the chain and gears wear…Even with the cam timing retarded, these engines seldom have any drivability problems…
As long as the crank and gears were correctly positioned when the belt(s) were installed, that"s about all you can do…Cam timing is not critical, a few degrees wound not cause these kind of problems. There is something else going on here…
The the computer can adapt/adjust for a limited amount of manufacture variance in the tone wheels/sensors but mechanically the cam timing must be correct. If one of the cams is off by one tooth the driver will notice a performance issue. If the left cam is off by one tooth you’ll get a check engine light.
During the 5 days the car has been at the shop I hope they took the time to check if the timing belt was installed correctly.
Has the check engine light been on since the timing belt was replaced? If so what are the fault codes?
Do you have misfire fault codes? There are other problems that can cause a misfire.
I seem to recall that this is a rather COMMON problem with this vehicle actually. I was wrestling with one with the same issues…was a 3.5L engine in a Concorde I believe? Yeah…look this up in chrysler forums THEY SHOULD BE WELL AWARE OF THIS ISSUE…
Also make double xtra sure the cam phasing is as close to perfect as possible…bec if they are out of phase youre chasing your tail…until they are corrected. But trust me on this…this issue is COMMON…and the 300 folks out there in forums are well aware of it… It will save you a lot of time.
Blackbird
Double clutch is correct…12 degress…is WAY out… Timing is just that TIMING…and it has to BE ON TIME… Big Ben the clock isnt 12 minutes slow…because that would be the wrong time… Same with engines…they need to be timed perfectly to operate…the ecu is operating on the principle that the cam phasing is correct…so it will spark the plugs and fire the injectors based on the crank and cam phase…THEY CANNOT be out of phase…
SO like i said…double double check that cam timing…needs to be perfect… Now 1-3degrees out is acceptable…it just happens… BUT NOT 12…no way no how. I remember doing the T belt on that motor…it was tough…and I did wind up with it out several times before I got it right
The “COMMON ISSUE” I was referring to was where the timing of the cams was spot on…and still had a misfire…I should have said that in my original post…My Apologies
Blackbird