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MASS air flowmetre on 88 260E?

3K views 8 replies 5 participants last post by  augapfel 
#1 ·
My check angine light comes on and off some time to eime and I will give you more details about the problem later but my question is; I took the car to the private benz repairshop in wakefield MA, and asked him about the check engine light and what causes the problem generaly. He said it would be commonly Oxsygen sensor or coolant temperature sensor or MASS air flowmeter which is so expensive(he stressed how expensive it is). If I am not mistaken I read it here that these models(1988 260E automatic) don't have the air flowmeter. I told him that and he said "oh yeah these cars have Mass Air flowmeter underneath the air filter pan" and he seemed pretty sure. what I want to know is do these models realy have Mass Air Flowmeters? if they do where it is located. I also want to ask that, this guy wanted to charge me $80 bucks for check up on the computer for one hour to find out what the problem is. is it a good idea to pay him (yeah I know it is good but )who tells me that car has Air flowmeter if it doesn't.

my Car is 1988 260E and i bought it July 1st 2005 when it had 157250 miles on it for $1500. I knew the car for 5 years it was my mechanics car and I replaced rear and center mufflers, spark plug cables, ball joints, front coil springs, tires, rear thrust arms and I don't know what it is called but another part right by the thrust arm, bad handling. these arms are very important for the cars handling expecialy on highway over 60 mph. Car acts as it minds. The bushings were so bad and when you hit the break you could feel the kicking in the back very very deep and bothering. Changed them and since then eveything is perfect. I also replaced the Brake discs and pads and also flex disc(don't ever buy the cheap ones it only takes 1 month the break it)


So far I almost put 18000 Miles on the car without any major problem change the oil every 3000 miles with sentetic blend mobil, change air filter regular maintanance. I drive the car every day in the city and on highway and usualy put 100-150 miles a day.

The check engine problem usualy comes when the car is hot. in the morning around 6 am the temperature is aound 19-25 F engine starts very easly and runs very smooth. I drive almost 10 miles and do my first stop. after 20 minutes I start the car again and it starts lttle harder that morning, runs like 2-3 minutes while I am driving, and light comes on. car starts stalling at stop lights, you don't feel it when driving. I take the highway go by 45-55mph and in 5-10 minutes light goes away. I do like 15-20 stops during 20 miles in the city and after that if I turn of the engine for more that 15-20 minutes and start it again after couple minutes kight comes on stays another 5-10 minutes and goes away. I don't feel co much difference on performance or fuel effigency but when I stop at stop sign or light time to time it stalls and engine light might come on.

I always use 93 octane premium gas and try to by it from same places as I always do. in cith and higway traffic as I said I do 125 miles a day and so many stop and go I get around 250 miles per tank. If I go on highway it is around 350-400 miles per tank (driving in the limits)

I defiinetly want to keep the car as long as pssible and this is the only thing that bothers me lately seeing that check engine light.

I know it is kind of long but I just wanted to describe briefly what is happening with the car.

If I should be more specific please let me know with your comments.

And also if you want me to experience something or keep records of some stuff about car since I am doing so many miles with the car let me know if I can help.

Thanks
 
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#2 ·
The term "mass airflow meter" is not really an official Bosch term but nevertheless your M103 doesn't have one.

That term usually applies to L-Jetronic systems and describes either a flap moved by airflow or on later systems a heated wire whose temperature is changed by airflow. In either case, the sensor provides an electronic signal of airflow

Your K-Jetronic system rather has a mixture control unit that combines an airflow sensor and fuel distributor, the two being mechanically--rather than electrically--connected. It's indeed an expensive unit.

Your mechanic is using an L-Jetronic term to describe a K-Jetronic system.

Now, however, given that the K-Jetronic airflow sensing is nonelectronic, it's not possible for it to set a "check engine" light.

This is theoretical, but in actuality there is an electronic switch connected to the item in question called an airflow sensor position indicator that can set the light. The position is adjustable and essentailly cannot become nonadjustable.

Other things that can set the light include
-throttle valve switch, full load contact
-coolant temp sensor
-ox sensor
-TDC sensor
-altitude correction sensor
-electric actuator (EHA I think?)
-throttle valve switch, idle speed contact

These are all important items, but again none of them can provide an electronic signal to light the check engine light that in any way indicates the airflow sensor/fuel distributor is faulty.

Your mechancic just wants to replace everything in the hope it will fix something.

Associated with the check engine light are codes that indicate which component listed is causing the problem. Your mechanic should read the codes. Again, no codes exist that indicate bad airflow sensor/fuel distributor.

If you car truly needs a new fuel distributor it would be running poorly all the time.
 
#4 ·
As lkchris says, your car doesn't have a mass sirflow meter in the sense that a more modern car does. In other words, there's no hotwire MAF placed in the intake air ducting ahead of the throttle body.

On a M103 engine the volume of air entering the engine is measured by a spring-counterbalanced metal plate that blocks the intake manifold. Cranking the engine causes the plate to deflect a bit and once the engine starts running the plate deflects even more. The plate movement is transmitted to the fuel distributor assembly via an arm. It's all mechanical. Here's what it looks like:

http://bos-engel.com/benz/p5170019.jpg
 
#5 ·
sooo
he is lying (not realy there is something to measure the air that goes in to the mixture but it is not air flow meter.) he is just trying to change everytjhing as much as posible.

now next question is

is there any way that I can take it off and clean it or should I take it of and clean it. does it help with the stalling problem.

if I can What kind of material or liquid should I use to clean and if I touch it, do I change any settings that can effect the cars' engine idle. is it too sensitive to touch. I remember when I changed my 93 Passsat VR6's MASS meter I saw very thin cable in the diaphram and I gues that is the one sensing the heat of the air.

And my next plan is cahanging the O2 sensor. As I said before this car was my mechanics car before me for 5 years and he drowe it back and forth between home and work for 3-4 miles a day. The car didn't have a change to warm up for long time. I am thinking that caused the leading on O2 sensor. He said he changed the O2 sensor back it was while ago(maybe 3-4 years).


I didn't chec it but I assume I dont have the red led by the fuse box to identify that engine faulty code. I guess I should take it to the some place to read the codes or I should make my own tool to read it.

when I check these codes, should the check engine light stay on or can I check thhis codes any time I want. in short should check engine light present while I am doing the test.

After I got the codes is it going to be able to tell me (specificly address the parts) which parts are faulty and I should change/fix or is it going to tell me the possible faulty components generaly.

As I said other than this check engine light and stalling problem I have no trouble with the car. As soon as I am over with the firs 5- 10 minutes, the ride is smooth, engine is quite(I guess) and it never bothers me again untill the next 10-15 minutes stop.
 
#7 ·
I was interested in your description of problems with the rear thrust arms and the other part nearby the thrust arm causing bad handling, expecially on the highway at speeds in excess of 60 mph.
That describes the problem exactly on my 1992 260E, I had a 94 Diesel estate before with no problems so I know how it should feel, (solid as a rock).
I'd be grateful of any help and advice you can offer such as by describing where these things are and what they look like, also, if possible, how easy (or difficult) they are to remove and replace.
Thanks, Chris
Rutland,
England
 
#9 ·
And this is what it looks like when you ignore the symptoms for a long time:

http://bos-engel.com/benz/p6190005.jpg

Once the bushing is shot the control arms cut into the subframe. This shot is of the blue parts car that I bought a few years ago. Ridden hard and put up wet.
 
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