Warm idle too slow - occasionally stalls 300E

[Brabus3.6]

Vlad & Will thanks for the replies. If it is serious enough to fry to ECU I will change OVP. The ABS light isn't flickering, it just happens to be the only light that 'self-tests' when the ignition is switched on. I thought however that if it fails it gives no power to the ECU, not allowing it to fry. Of course if I did fry my ECU I'd be screwed because Brabus have remapped it so it wouldn't be a simple swap! I believe I have a temporary 'fix'. The car is sometimes hard to start requiring some cranking & throttle to get it going. Sometimes it splutters to life misfiring. I put the lights on & observe the interior lights, they'll be dim. A few seconds at 3000RPM idle & the lights will brighten up with a good solid idle ~ 600RPM in D where it should be. I thought it must be the battery which is a 66Ah, 510A cold crank Bosch Silver. I had Halfords test it & it passed with exactly 510A & 12.75V. I thought that it required the 3000RPM after starting to recharge the battery, seemingly not. Once it is running the idle is good, not 'rock' steady like an ECU controlled S500 but stable, no hunting. I think the idle of my car will be rougher than a normal 300E due to the adjustable, not hydraulic, tappets. I spoke with George Fraser who said he'd book his electrical specialist in for me. I guess I'll do that in a couple weeks once I've settled into Uni.

 

[Brabus3.6]

OVP replaced - no change

I replaced the OVP with the new, updated, dual fuse one from MB. No difference to my problems but peace of mind that I won't have to do it in the near future I guess. The car is hard to start, sometimes requiring a couple of long cranks & accelerator depression. This happens cold or hot. When it's working seemingly properly the idle in neutral is ~1000 which seems high.

 

[Brabus3.6]

Visited George Fraser - no joy

Okay, finally back from Uni I took it in to see George Fraser today. Three parts were immediately mentioned, OVP, ICV & ECU. I told him the OVP had been replaced, the ICV cleaned & also checked by replacement at a breakers. A spare a ECU was on hand but thankfully that didn't change anything. I say that because my ECU has been remapped by Brabus and I dread to think of the difficulty in getting one of these now, so long after the cars production.
Well, the mechanic who looked over it slightly readjusted the mixture but told me that KE-Jetronic system diagnosis is basically trial and error. I showed him the proportionalty of current draw and idle speed. He and then George who glanced over it at the end told me to get a high capacity battery to match the 150A alternator, about 100A battery I was advised. I think I'll add an Optima Yellow Top in addition to my Bosch Silver 66Ah to deal with the audio system.
After inspection the car now has a new problem! During mid-throttle acceleration the car stutters, the power delivery is no longer smooth. This behaviour does not seemingly manifest itself after 3500RPM when it begins pulling cleanly to redline. I can only assume it is something to do with the air intake system which I will remove and carefully reassemble later. Anyone had this problem before? Could this possibly be the gearbox? P.S. George didn't charge me for the diagnosis as he couldn't pinpoint the problem.

 

[Brabus 300E 3.6]

Hi, i have owned a W123 230CE 1981 and it had the same symtons your descibed
1. hard to start
2. low idling to stall.
3. bad pulling untill 3500RPM after that it seams to be ok.

The problem was a lose hose under the intake system witch caused a lot of falls air to interfear with odd behavour ass result.
The hose was neer imposiple to reach from any angel, and therfore hard to find, but it was under the so called spider.!

By the way im looking at a Brabus 300E-24 3.6 from 1991
Can you give me some pointers to look after/fore.
What can the car do at topspeed? is it limmited to 250?

 

[Ian B Walker]

By the way im looking at a Brabus 300E-24 3.6 from 1991

Arnt we all

 

[ADY1983]

Arnt we all

Yep...

 

[Brabus 300E 3.6]

Hehe well. i acturaly found one for sale BRABUS 300E-24V 3.6 285HP
so therefore i ask here what to look after when bying this special car.

i know the 300E because my father has one, but it´s a regular 300E-12V 188HP model and im prety sure i want to by that BRABUS i found because i love that E model so much.

Compared to the new model that came after in 1993 this "old" model W124 is much more well crafted and there is not all these eletronical problems/faults as with the model that came afterwards.
That is what i have been told from all the mercedes owners, clubs etc. it´s commond knowlage between the pioneers in mercedes.

Btw.
Does enyone know what to be aware for, in a BRABUS tuned version of this beutifull car?
What is the engines week spots if there is eny?

 

[Brabus3.6]

Btw.
Does enyone know what to be aware for, in a BRABUS tuned version of this beutifull car?
What is the engines week spots if there is eny?

I have the M103 engined 12V variant which I do believe shares the same bottom end. I can only say ensure all Brabus specific items are working. It may have the Brabus Tempamatik system allowing oil or outside temperature to be viewed. If this is innoperative I know first hand that just the oil temperatue sensing bolt is over £130!
The biggie to watch out for is the head gasket. At 155,000km it may have already been done but if not it's only a matter of time. While the heads off you'd be mad not to do stem seals and valve guides. If you do your own work be prepared to be set back around £1,000 as just the head gasket is £440, valve guide work is expensive too as it's best left to the engineers. If you don't I wouldn't like to estimate the cost involved in doing this.
My experience with the car, having clocked up over 30,000 miles on it doing a water pump and a couple of head gaskets plus much more along the way is that provided you don't abuse it, it's little more trouble than a standard Merc. There is a dude on this forum and others with a Brabus 190E who has I believe, your engine. He would be better informed about your particular M104.

With regards to my problem last year of the dash lights not coming on it was because I had the wrong alternator. I had one from a 2003 car which used a new style voltage regulator incompatable with these cars. I swapped it for another 150A one from a C43 which has the single bolt VR and all is fine. I also managed to cut back down to one battery. The massive 975CCA optima can be doused (just!) in the original battery position of the 124 with slight modification (read - smashing) of the battery tray.

 

[Brabus 300E 3.6]

Thank you so much.

My first question is:

Why do the head gasket need to be changed/done after only 155.000 Km.
could it not only have to do with a regular abuse of the car or is it because the head gasket is a regular quality and not made specialy to the stronger engine specs,
i know litle about cars that are tuned use another meterial wich are more solid, made of complet alaminium i think.

Normaly you would´n ekspect a head gasket change on a car unless you abused the car or am i wrong?

and by the way, did you solve your engine problems with the odd idle and what where the problem?

 

[Brabus3.6]

Well the first head gasket went around the 96,000 mile mark. My uncle had the car at that point and the water pump blew out on him, head expanded causing head gasket failure. I'm not sure why the second only lasted around 15,000. It may be that the head wasn't properly checked for tollerences although I did give it in to an engineering company recommended by Mercedes. It could also be that it was a faulty head gasket, these things do happen. I believe both the M103 and M104 engines had head gasket problems. The Brabus head gasket seems to be of a different material to the Mercedes one although it's still just a reinforced, glorified piece of paper!
Of course prior to our purchase of the car at around 90,000 miles I don't know how it was treated. It's over 129,000 miles now though and still running strong (touch wood). The idle problem was solved with a 150A alternator from a C43 AMG and a massive 975CCA Optima yellow top battery. It still occasionally idles around 500RPM but more steadiy and has not (and I think will not) die on me. The worst thing about these low idle speeds that the engine was not designed to hold as it is NOT ECU controlled is that the oil pressure can dip bellow 1bar in the searing heat! I dread to think what it would drop to if it wasn't Mobil 1 motorsport oil and didn't have an oil cooler!
Idle problem now seemingly completely solved by a new set of Beru HT leads. This is combination with the 150A alternator was the key for me. I haven't tested my old leads but all my new leads were well within spec as they should be, ranging from 0.93kOhm - 1.08kOhm. The specs are 1kOhm +/- 20%. Engine is now slightly more responsive too, as if that was needed

 

[Brabus 300E 3.6]

Brabus 3.6-24

I am now the very happy owner of the BRABUS 3.6-24

It´s a realy good car i must say. but who would have thought different

http://www.bilgalleri.dk/html/gal_visbil.asp?ID=69175

http://videos.streetfire.net/search/brabus/0/e4e3495f-6ac3-420d-9903-98550131c912.htm

My car as i described had it´s head gasket replaced at 110.000 Km.
and then glas blowned the valves and valve guides as well and the gasket was replaced with a simular one from the 3.6 AMG version, i belive they are 100% the same. and it is not as expensive as the BRABUS gasket.

i am just wondering why the car tops at 240 Km/h ? as the org. 300E-24
I have the 5 speed automatic gearbox but the car seem to run out of power at 235-240Km/h like the org. 220 HP does.

I was very surpriced as i have read somewhere that this BRABUS 3.6-24 with 285HP and 385 Nm is surposed to reach the 272 Km/t at least in the smallere 190E with the same engine.

maybe i got a BRABUS with a normal 3.0 220HP engine? ( i hope not ) thats my big Worry. but how can i check if the engine is the real deal?

 

[Ian B Walker]

You could try writing to Brabus quoting your engine number and ask them if they have any record of it and what has been done to it. Just a thought.

 

[KLP 92]

When you say it tops out at that speed, is it beacuse its out of power or because its at 6000 revs?

I've had a Brabus 3.6 in a W124 CE before, i've topped 160 mph before with ease.

 

[Brabus 300E 3.6]

Hi.

I alreasy tried that.
and BRABUS did not keep eny form of system of the engine numbers or the sin numbers before after 1994 i think.
im also worried about it because the red engine top seems to be painted in res with a spray can hold by a person who has the pakinson syndrome so the paint is also on some of the wires and other stuff around the top. but maybe someone just repainted it with no sense of quality.

The engine does not top out at 240 Km/h it can take up to 7000 Rpms but at 240 Km/h it´s "only" going by 5500 rpms i think.
It just wount go further because it sems like it dont have the power to do so.


the engine also smokes alot blue when i start after a slow down with the engine brake. but there is no smoke when i just drive normal.
it uses up to 4 Liter/1000 Km.
the oil rings and lifters has already been changed i think so it´s not that. but with a camera you can se the oil leak is coming from the valves inside the cylinder as it drops oil down on the pistons, that should be a good sign i think as the pistons rings are not that easy to change.
So it is posible taht the valve guides are worn out so the valves are "rocking" and that way leading oil pased the oil seals
i must say it feels realy quick from 0-150 Km/h but after that it seems like the engine is not performing like it should do. maybe the wheels are to big and heavy i don´t know but i realy need some proof help i think.

You could try writing to Brabus quoting your engine number and ask them if they have any record of it and what has been done to it. Just a thought.

 

[KLP 92]

4 litres for 1000km = serious bottom end problems.

If you say the rings have been changed and its coming from the top i would redo the top end, new valves, vlave guides and seals. But 4 litres is alot for a top end!!

I would suspect this is the prob for your lack of performace sue to the fact the engines burning this much oil will definately affect the performance.

 

[KLP 92]

Are all 6 plugs wet with oil?

Your symptoms point to bottom end though, ie when your accelerating against the engine brakes it smokes.

 

[Dieselman]

He said the engine smokes after engine braking using over-run. This is a classic sign of valve seal problems.

You need to perform a compression test then a leak down test with compressed air. This will tell you where the problem is either valves or rings.
I go for valves although 4 litres of oil is a lot to go through in 1000 km. That's 1 litre per 250 km or 1 litre per 125 miles.

Generally smoke under acceleration is rings, smoke after decelleration is valves.

Is there much blow by when you take off the filler cap or breather pipe?

 

[KLP 92]

He said the engine smokes after engine braking using over-run. This is a classic sign of valve seal problems.

Sorry i misread the post, totally agree with you.

 

[SL300-24]

I am no expert .........but have you changed the idle switch? It cured a similar problem on my old 260E W124.......

 

[Dieselman]

Your symptoms point to bottom end though, ie when your accelerating against the engine brakes it smokes.

For a moment I wondered what you were saying here. I never knew MB or Brabus fitted Jake brakes to their engines.
Anyone whose heard a Jake brake in anger would know that would be a good sound

The kiddies with their dump valves would s**t themselves..