1986 Mercedes E300 Few Questions
 

Hello, I have recently acquired a 86' Mercedes E300. I am very excited, due to my long love for the older Mercedes styling and looks both inside and out. Yet after having it for just a day I have noticed a few quirks.

First off the car does overheat after just sitting for a little while. I have already diagnosed this issue as being the electric fan. However, I don't want to order a new fan until I am sure that it is the fan that is actually the issue. So I am guessing I should check first for power supply to the fan. I do have a meter to measure for this and am first looking for a little guidence on how I should go about figuring that out.

Secondly, I am told by the previous owner that he furnished new brake pads not too long ago. He is a close personal friend and gave me the vehicle kind of "paying it forward" after something I gave him a hand with a little while back. That just being my ground for the fact he isn't lying to me. However, while driving the indicator light for Brake Pad Wear faintly flashes, and not all the time, oddly enough generally while just driving. Any insight into that would be fantastic. If not I can just bring that issue to a mechanic.

Thirdly, me being no expert I wanted a little insight in to this as well. My friend told me he provided new bushing for the shifter. ( I am unsure if that is helpful, but thought I would add that) Yet when using the automatic transmission, when I select the gear I want e.g. Reverse there is generally a pause and then kind of a little jerk when it is actually put into gear. Same follows putting it into drive, expect a shorter pause. The pause is merely just a few seconds. I have a few guesses on what it could be (:() but wanted your guys' input. I experience no jerking when actually driving and the car shifts between 1st 2nd and so on.

Your help is greatly appreciated.

Shea

On the transmission issue, check your fluid level. If it is low, it acts just like you are saying. Check for leaks, or for bad modulator valve on transmission sucking up your fluid. Just my two cents from my 420 respect. Steve

1 overheat, my 300e drives around 90c w.o ac on, if you park it temp likely jumps up to 110 on restart, that electric fan only comes on above 110. my car rarely gets to 110 just idling. (on the temp gauge, not sure 'actual' temp .... check coolant?


2 break pad wires were replaced? they are pretty annoying to do, if they werent replaced the bare wire might be rubbing the rotor causing flashing,

Thanks for the input on the tranny, I fluid levels was the first on my checklist I just have been so busy today I have had the option to check it yet, but early tomorrow I will for sure.

Also on the overheat issue, see thing is I don't recall exactly where the temp gauge was, however, the A/C became warm, and the needle was nearing yet not in the red zone. However, I may conduct a test to confirm this. So theoretically if the electric fan is functioning, what's my next step? I will check coolant levels as well.

could be your cluth fan

You mean Fan Clutch? :rolleyes:

You can connect the 2 wires at the reciever dryer to jump and force the fan to go on, to make sure its a bad electric fan motor.

As far as the transmission, how many miles are on the car? Sounds like the transmission may just be tired. My car has a 2 second delay going into reverse. 283,000 miles.

FWIW, 1986 W124 should be a 300E, not E300. Later US E300s were Diesels....

Well so you would think... but the car only has 92,000 miles on it. I reckon it could be 92,000 rough miles but idk.

Hows the fluid look? I'd throw fresh fluild/filter at it.

It's a 300E.

Next, your fan clutch is probably dead along with the radiator. As stated, aux fan only comes on at very high temperature for high speed and low speed for the A/C.

[quote=redassag00;1928701]You mean Fan Clutch? :rolleyes:

yeah that thing:D

Shea,
1) Replace the thermostat and see if that resolves the rising temperature issue. The existing thermostat may be sticking and not opening completely.
2) Pull all 4 wheels and visually inspect the brake pad thickness. Perhaps your friend replaced the front pads and now the rears are shot, or vice-versa. It's also possible that one of the calipers is sticking and the brake pads on that wheel wore prematurely.
3) Change the transmission fluid and filter ... should be done every 30,000 miles.

Could you point me towards what I should use for fluid and filter specifically fluid.

Any DexIII/Mercon compatible ATF is fine. I use the cheap stuff from the local auto store. Keep it clean and change it often.

Be sure to drain the converter too.

Overheating at idle is not normal even if the electric fan is inop. Check you coolant reservoir for oil residue for signs of a blown headgasket as well.

I do agree try a thermostat first since it's easy and check fan clutch next.

overheating
 

Since your car is a 1986, you may have the old version of the fan, I believe its blades were white. You need the fan with the black blades. I don't know if the fan clutch was also updated; Phil should be able to help you on that. I did this switch on my early production model 1988 300ce using parts from my later production 1988 300ce parts car and the overheating problem I had disappeared immediately. Hope this helps.

Your right
 

I do have the white fan blades, so I need to check into updating this?

Wear sensors are on the front wheels only on an 86 300E.
Most likely symptom is a grounding of the (re)used wear sensor.

Jim

Hrmm... my 1990 has the white fan, I assumed since it was late it was updated.

Have a PN handy?

x2 my 90 has white also

Here's what I found:

Up to 045442 - 103 200 03 23, black fan with eleven blades

From 045443 - 103 200 04 23, white fan with nine blades. Can be used on models up to chassis brake w/ fan clutch 103 200 04 22.



Whatever that means, I don't know :D

I'll check tonight which color is correct; I have the old one in my garage and the one that fixed the overheating problem in my car.

I have a mid 90 build date on my 300sel, so I'd venture to guess the white fan is the updated/late one.

Either way, I have no overheating nor do I have cooling issues. Most of these cars I have purchased all had original radiators, hoses, belts at times!, thermostats, etc. I dropped about 3-6°C when installing JUST a new radiator in my 300SDL. :eek: Significant drop.

I opted to go with the higher thermo for the M103. There's an 87°C or the 79°C, 188.6°F or 174.2°F. The latter just seemed too low for winter use for proper operating temps. With the 87°C I never get past 95°C at idle in traffic in the summer.

If you can't drop $600 into a cooling system rebuild, you should probably rethink these cars. Then people balk at spending a few hundred more to replace all the vac/rubber connections under the hood too... makes me wonder at times.

They're cheap for a reason, NEGLECT.

Good News
 

Well once problem solved... I think. Well I was messing around under the hood today and why I hadn't checked it I haven't a clue. But in the fuse box I opened it up and much to my surprise of course there was a blown fuse. This was the fuse for the Auxiliary fan... So 10 seconds later I start the car up and sure enough I hear the fan blown away. I sat in the car at idle for about 5 minutes and I encountered no real issues. The needle only reached the 90 degree line or so, but never breached like previously.

Then I decided I would go ahead and flush the radiator while I was at it, and to my relief the fluid wasn't too bad, some specs of things here and there, but no traces of oil like residue. Filled her back up and it appears to be cooling even a little bit better even after fixing the fan.

Still while sitting at a stop light for a little while the A/C isn't as ice cold as I would like, but I can settle, it still blows cold, just not ice. Plus I realize what car I am dealing with.

Still have the transmission flush to do, thats next on the list. I'll let you know how that one goes.

The AC at idle in these cars is mediocre at best, even with R12. Be sure to have tint, this helps greatly.

Also, verify your fan clutch is working, the condenser is clean (the fins) along with the radiator.

Yes
 

Well I had planned to slowly replace many items on the vehicle just to insure its reliability. But thank you so much for all of your help. Also my gas mileage isn't amazing, I would say about 17-18. I have heard they can do a little better than this. I was going to do a tune up anyway, which should have some effect I would hope any other suggestions. Suggestions for spark plugs?

Checked last night and I can confirm that the white fan is the updated version.

Oil
 

I have looked at a few threads about this subject, yet it ends up being more of a debate than an actual informative discussion. Yet I need to know. What engine oil should I use? Just to review it is an 1986 Mercedes 300E W124 with 93,xxx miles on it. The previous owner, a good friends wants me to but Amsoil in it, some 25,000 mile stuff; idk. I am a bit apprehensive about it just because I don't know if this stuff is going to be appropriate for a vehicle of 23 years. So any help would be great, obviously with such a necessity money isn't an object. Also oil filter?

You must run NON-resistor plugs. H9DC, Bosch or BP5EFS, NGK. Dealer carries the Bosch, I think the board does too. NGK are easy to obtain also. Do yourself a favor and order 12-18 so you have spares. M103 plugs don't last forever.

That fuel economy doesn't seem too bad for an average. The '86 has a deeper axle gear than the '87+ as I am told.

Check for vac leaks too, most of the rubber is going to be hard as a rock under and around the intake manifold... it's cheap enough to replace to rule out potential issues. This is a good weekend project. Oil leaks are also vac leaks...

The upper timing cover likes to leak, the valve cover does, the oil filler cap, the oil dipstick tube, these are all oil and vac leaks.





Be sure there is little to no oil consumption before you go to synthetic. If it drinks oil, pouring $7-10/quart oil in once a week will get really old, really fast. My 300sel is up to a quart every 250-300 miles! But I do have 260k on it, I only did valve stem seals to slow the loss. The new head is scheduled for late this year or early next.

I'm not a fan of the once a year/25k oil intervals unless you do LOTS of freeway driving. Oil is cheap, a new motor is not. You need to do oil analysis tests during that duration and for $20 they cost... it adds up. When I run syn I change the filter every 5k (and add a quart) and drain the crankcase at 10k. That usually takes me 5-9 months.

Mobil 1 is the only company that makes an oil filter with a synthetic media for the M103, so they're the filters I use. They trap smaller particles than a standard filter, which is good.

Oil weight per the manual, you'll want 10W40 to 20W50 in your climate. I do 20W50 year round for conventional or 15W50 synthetic.