Misfire/hesitates at certain speeds.
10-20-2016, 11:47 PM
#1
Newbie
Thread Starter
Misfire/hesitates at certain speeds.
Good morning all. Newbie here with a problem 2002 C180 classic (automatic) with the 111 engine. Long story... when I leave first thing in the morning for a 200km round trip, the car starts off flawlessly for the first 5km or so. Thereafter, between the speeds of about 85km per hour up to about 140, the car seems to surge/hesistate or feel like it's having the odd misfire when accelerating. It often comes with a sort of brrrr noise coming from underneath/the rear of the car whilst it's misbehaving. Have had a full on diagnostic/interogation done on the vehicle which shows all clear, changed the plugs, fuel filter, etc. had the gearbox checked, no change. Tried driving with the ESP switched off, no difference, as I thought maybe one of the wheel sensors was faulty. One of our local Merc experts says it's a mystery, and he needs the car for a couple of days to investigate. Unfortunately, I can't really spare it for that long. Any ideas anyone?
10-21-2016, 08:24 AM
#3
Newbie
Thread Starter
Thanks. As mentioned, there are no codes to post, the diagnostic showed all clear. Sorry, but what should I post pictures of? Will do if I know what to take pictures of. As per the cat, it doesn't have one, has been replaced with a normal silencer- according to one of the local Mercedes boffins, it's standard procedure in this country, and doesn't affect the vehicles performance.
10-26-2016, 03:16 PM
#4
Newbie
Thread Starter
Ok, so a local Mercedes boffin has had the car for the last two days, but still can't find the problem- he has, however, suggested that it could be a transmission problem, something about a clutch lock-up? Does this make any sense to anyone out there? Please?
10-26-2016, 09:52 PM
#5
Super Member
boffin??
What the heck does that mean?
Boffin - Wikipedia
In British slang, a boffin is a scientist, engineer, or other person engaged in technical or scientific work.
Hmm, according to Google the original poster is likely British. Oh well, since he/she is stuck in OLD England, while I get to be in NEW England
, I guess that I'll be nice and answer the question. 1) Don't tax our tea! No taxation without representation!!!!!!! :-D
2) Yes, it does sound very likely. A knowledgeable certified automotive technician
would be able to take an advanced scanner in the car for a road test and to do data logging.When the car/engine started to act up, the scanner would capture the engine conditions (any misses, running lean/rich, sensors acting okay, etc) along with all of the data from the transmission (lock up requested, in lock up, torque convertor slippage, etc).
So, from the data, and understanding the data and the car, a knowledgeable certified automotive technician could surmise the problem is very likely a clutch lock-up problem.
Note, I said "very likely", not 100% sure. That's why good knowledgeable certified automotive technicians are in demand.
3) If the original poster was born in America and lives in America, then I take back my answer above, since the original poster used some weird slang that belonged to those tea-taxing Red Coats!
The following 2 users liked this post by RedGray:
shadenfroh (11-06-2016),
slimjim (10-27-2016)
10-27-2016, 01:09 AM
#6
Newbie
Thread Starter
Thanks for the above, RedGray_ I actually grew up in an ex-British Colony, in the late 1940's, so excuse the language. Live in South Africa now, so everything is different to the American way! The "Boffin" mentioned classifies himself as a Mercedes specialist, so won't argue. He did say, however, that he drove the car with his diagnostic laptop plugged in, but got no readings off it. His opinions were based on a chat he had with a transmission specialist. The only thing I can add to the problem is that I find the problem is not so severe when driving in the rain, in fact, it virtually disappears! Could this clutch lock-up be heat related?
The "Boffin" mentioned classifies himself as a Mercedes specialist, so won't argue. He did say, however, that he drove the car with his diagnostic laptop plugged in, but got no readings off it. His opinions were based on a chat he had with a transmission specialist. The only thing I can add to the problem is that I find the problem is not so severe when driving in the rain, in fact, it virtually disappears! Could this clutch lock-up be heat related?
10-27-2016, 10:38 PM
#7
Super Member
Thanks for the above, RedGray_ I actually grew up in an ex-British Colony, in the late 1940's, so excuse the language. Live in South Africa now, so everything is different to the American way! The "Boffin" mentioned classifies himself as a Mercedes specialist, so won't argue. He did say, however, that he drove the car with his diagnostic laptop plugged in, but got no readings off it. His opinions were based on a chat he had with a transmission specialist. The only thing I can add to the problem is that I find the problem is not so severe when driving in the rain, in fact, it virtually disappears! Could this clutch lock-up be heat related?
The "Boffin" mentioned classifies himself as a Mercedes specialist, so won't argue. He did say, however, that he drove the car with his diagnostic laptop plugged in, but got no readings off it. His opinions were based on a chat he had with a transmission specialist. The only thing I can add to the problem is that I find the problem is not so severe when driving in the rain, in fact, it virtually disappears! Could this clutch lock-up be heat related?It's just that people often misspell words.
And "boffin" (a common colloquial term used in Britain during WW2 for the technical experts) is close to "buffoon" (a ridiculous but amusing person; a clown.
Back to the tech.
I agree that is could be torque convertor or lockup related.
Still, I would first want to see that better verified by looking at the trim levels, MAP/vacuum level, sensor levels, any misfires, and the transmission data (telemetry) when the engine does the weird behavior.
I can't image a certified Dealer mechanic tearing into the transmission on your car without doing the above. Even if it takes two mechanics, one to drive the other to watch the data (they should have data recording capability).
If they can't read the engine data (and likely transmission data) on your car when it's being driven, then imho, that's a major problem!
Vacuum leaks (gaskets, hoses, etc) can do weird things and act weirdly.
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11-05-2016, 05:41 PM
#8
Junior Member
It could be the lock up in the transmission. Which tends to engage around 80 km/h. I had a BMW 740 before which had a faulty torque converter most noticeable on light throttle in inclines on the highway. It caused small jerks in the car from time to time. Perhaps something to try.
If it is the TC acting up, the temperature / transmission fluid quality could be impacting the behaviour.
Good luck.
If it is the TC acting up, the temperature / transmission fluid quality could be impacting the behaviour.
Good luck.
The following users liked this post:
slimjim (11-06-2016)
11-06-2016, 12:52 AM
#9
Newbie
Thread Starter
Thanks, Shadedmoon- co-incidentally had a long chat to a transmission specialist last week, and he seems to be pretty confident that the TC is faulty. The car will be going in to his shop on Tuesday for further checks and repairs. Will post the results once I have the car back.
11-06-2016, 06:55 AM
#10
Do you happen to have a dealer around you? I would definitely seek another opinion from a person who can work confidently with STAR (many people have STAR, few people can utilize it). From what I read, you have only chatted with people. Find a mechanic who can show you data and explain to you what happens and why and doesn't get agitated by questions.
