1991 Mercedes-Benz 420 SEL Maintenance Tips

[@kentj1]

My car died, and it showed classic bad alternator problems. Because of your video, I replaced the regulator for about $12, and the car works perfectly again! You saved me so much money, thank you for putting these videos out.

[@beautifulbodybykevii9484]

Your vocal delivery is spot on. Not dead, not shrill, not salesman- much like an intelligent teacher. I have a '91 300sel that took several tries before starting. A very loud scraping raucous began after a hard acceleration. I lifted the hood but couldn't determine the source of the noise. It cut off a few minutes later, cranks but hasn't started for 2 months. Temperature & oil pressure were normal, no check engine light. Had smelled gas for a couple weeks. Noticed a few drops of fluid smoking & dripping on the exhaust behind the rear door the day before. Fuel pump primes. If I can believe the young man at Autobahn Auto in Hampton I have spark, fuel, & timing chain's OK. I know little about cars but since Aug 12 have literally spent hundreds of hours online researching the problem. Any thoughts would be greatly appreciated! Other than needing a new battery when I got the car a year ago from a doctor, it has always been reliable. The day before this I did have a shop put on 2 front tires & do a Hunter balance to resolve an interstate shimmy.

[@Devan_Bolin]

Watch his 57 min walk though video he helped me so much

[@kentj1]

If you ever have another Mercedes Maintenance Tips video, I will be the first to watch. I have the same car, same color and everything, and your video was just so helpful!

[@klwthe3rd]

Just found your channel through this excellent video. I can't wait to watch your other videos about this beautiful 420SEL

[@garykaye99]

Excellent videos - thank you. Got an 88 420SEL and they are really good cars. i learned something new about the hood wow what a nice feature.

[@GarrardAT6]

Wow...Even though that style of Merc is a common sight over here, I've never seen a hood in that position! You could almost use it as sail in an emergency...haha!!! Those fuses were a very common over here in most vehicles up to the mid 80's, we know them as 'continental fuses' they always suffered corrosion at the ends. It looks like the window has come out of the guide...Be careful it doesn't drop inside and smash when the mechanism is down. Beautiful car though! Amazing Condition! :)

[@markpicotti2610]

I'm considering getting a 91 420sel, I appreciate your time and effort in this video. I'll be sure to let you know if I ever have any questions about it. Thanks again 😎

[@shadowrider460]

You should be fine. The differences in the numbers may be due to a date code or manufacturing location. You have saved yourself allot of money over purchasing a new alternator. I've now got over 180,000 miles on my original alternator and it's still going strong.

[@cokeypokey1]

Your window problem sounds as if the glass has come out of the scissor track.

[@bethhall8925]

Great videos, I just bought a 1990 420sel. I was able to fix the windows easily thanks to your videos. Now I have a new problem. It has started sputtering and sometimes cutting off. I have looked around and one possible cause is a vacuum leak. I spotted a crack in the same hose you were referring to in this video. My mechanic said it was a worthless part and not my problem. My question is... what is the name of that part or part number. I cant find it anywhere. Thanks

[@abdimona]

what part of VA are you from? I saw a VA inspection sticker on your windshieldI have a 560SEL with a rough idle. is there any way you can make a close up video of your car idling?

[@Z0MBIEMASTA]

I have a rough idle that I will be tackling next. It smooths out under load....strange. It was a one owner car and very well maintained, starts quickly and drives like a powerful cloud lol. I will let you guys know what I find out. Any info is appreciated and yes I read the previous comments I'm about to start by looking for vacuum leaks

[@craigjoseph9374]

I'm about to embark on removing an engine out of my 88 420SEL. Do you have any tips or suggestions that will help with the process?

[@seanm.1026]

For anyone wondering there's a plastic part that slides back and forth on the track to raise and lower the window. That part can split leaving it open on the front or back side. The arm will pull away without moving the window since that piece is broken and the ball moved free. Think of a shoulder with half a rotator cuff.

[@funnyture]

I found it most helpful for my car. Thanks a lot.

[@MrMundaa]

I HAVE A 1989 420 SEL MISSING HOSE ON AIR FILTER WHERE DOES THAT GO?

[@rbruce63]

What a beautiful place and car! Some day I'll be able to buy one and work on it!

[@steveolto9805]

My Volvo 940 had that straight up hood, awesome feature!

[@ataristeve9753]

Those hood hinges are neat! I've never seen that before. They need to sell those to retrofit on other cars. I can imagine that would make bleeding the brakes on that old Lincoln much easier.

[@Wierdcrap]

Man dude I love you so much for this extra info got an 89 and well I have a lot of work on it so this greatly helps

[@simone4993]

Hi Shadow fantastic vid also great ignition fix to... can you tell me please in this vid ...what are the 2 sensors right on the thermostat housing? Thankyou

[@Z0MBIEMASTA]

Love these cars picked up a cherry 1986 all black exterior w grey interior. 170k for $1800. I replaced the fuel pumps and can help anybody who needs it

[@PIERUCCIO69]

Good tips ty.I have a 1989 560 SEL with a few different issues.It seems as though the injectors are seeping a bit of gas and need some seals or o rings changed.I also have a rear main seal that is leaking.Car has only 95 K on it...I guess the age makes it want some attention.Regards,Piero

[@haitisongs]

I had the same window motor problem. The bolts may be too tight. Try decreasing the torque. Mine still works after I loosened the bolts a tiny bit. Let me know.

[@shadowrider460]

Sounds like a partially bent mast or possibly an area of the internal nylon cable where the teeth have been worn off. The masts are actually removable and can be replaced without replacing the entire OEM assembly. Try to keep the OEM unit since the aftermarket ones don't fit the contours of the fender precisely.

[@vondajackson5287]

I have a 1991 Mercedes Benz 420 SEL and all my windows quit working at the same time and i dont know where relays are located or if thats what it could be could use some help.

[@AhsanAli-zs1ru]

Many thanks for sharing such an informative video. I would like to check the wear on the voltage regulators, however it is hard to take the screws out - specially the one below, as there is not much space for screw driver to fit in. Would you advice any special took-kit / Phillip screw driver set etc. that I could buy. As an FYI just became the proud owner of a 420SEL year 1990 with only 70K miles. Thanks for your help !

[@AhsanAli-zs1ru]

Hi There, so here is my current issue. The Antenna on my 420SEL is working but not opening up completely. It goes up probably 30% and then gets stuck. I left my car out for a week and this is happening since then. On closing the radio the antenna does goes down. Any suggestions / recommendations is highly appreciated.

[@sonny1234thebig]

Hey man, I loved your informative video. I just bought a 1986 420 SEL, extremely clean on inside and outside. Amazing car, amazing body. The only problem I have is the engine shakes a little while on “drive”, and smooth on neutral.. possibly engine mount. What do you think? I’d love to hear back from you. Thank you.

[@harrynj22]

i just got a 89 420 and the steering is bad is there a site that i can get a power steering pump filter and can i use any power steering fluid?

[@VincentBellJohnson]

This was a great video. Post the repair on the window repair it will be helpful. thanks for your help.

[@Ozkartez]

is it very difficult to flush the tank on a 126? im having a bit of trouble with the engine just shutting down when a press the pedal

[@ohsoflyvids]

my pcv i checke it and its very hard i also checjed the cank case and theres some sludge any suggestions?

[@westhavenor9513]

I believe the common term for those type of fuses is torpedo fuse. I switched all mine out with brass-conductor fuses when I acquired my '84 W126. A couple of the fuse values were pretty hard to obtain in brass/copper, but I eventually located them, from Europe I believe. Watch out for fakes too, with just a gold-colored element. They're complete trash.

[@1974charger123]

Great video. I did notice that you had mercedes repair manuals in the trunk of your car. Can you tell me where you got then, how much you paid and the part number? Thanks...

[@gbenz6494]

You still own the 420sel?

[@clide427]

Hey I found your video very informative I'm actually purchasing a 1988 420 SEL this Friday and was wondering if there were any reoccurring problems or anything I should know and look at before I purchased a vehicle it has 88,000 original miles one owner and is very clean with no rust is there anything I should look for I'd appreciate it if you could give me some pointers I'm very knowledgeable about cars but not this one so much it's just in such good shape and the owner doesn't know what he has and is rich so I'm able to get it cheap thank you hope to hear back from you

[@shadowrider460]

The main thing to look for is fluid leaks. The seals, hoses, and gaskets on these cars tend to get very brittle over time compared to the American cars. Also check the drive shaft flexible couplings. They tend to crack and fail and when they do, can cause significant body damage from the drive shaft flopping around violently.

[@clide427]

Check my reply or comment to 10 other sections I was trying to get a hold you there posting was old I've already had the car for a couple weeks now

[@AhsanAli-zs1ru]

Thanks ! I managed to took out the voltage regulator and to my surprise found significant wear on atleast on the two terminals. I am now ordering the new one. The number on the old VR reads 1197311023 (similar to what you had), however on ordering new one it says 1197311028. It looks exactly similar atleast on the web. Did you buy the new one with the same part number. Any advice here would be great. Thanks again for your help !

[@dakasgem9433]

Great info - thank you

[@Tokopol]

What is the mileage on this vehicle? That context would be helpful for people looking at 420SELs to know when to expect these kinds of things.

[@julianpalacios1835]

Great video my friend, I have a 1988 420SEL and I notice the AC blow a little cold but I can't feel the air come out from the front vents, any advice....Greetings from Silver Spring, MD

[@shadowrider460]

It could be a failing blower motor (too much friction in the bearings), or a stuck blend air door causing some cold air to come out of the vents, and some to come from the floor outlet.

[@kend5939]

Had this same problem - all the air came out the defrost vents. turned out to be a vacuum pod behind the passenger side dash (behind the glove box or airbag). Not horrible to replace, but not fun, either. The part was reasonable - $60 or so - so I went ahead and replaced both of them while I was in there. Center vents work perfectly now and air blows nice and cold. The failsafe in these cars is that if one of those vacuum pods develops a leak (and there are six or 7 of them, total, in the HVAC system), the system goes into limp mode and puts all air out the defrost vents so in a worst-case scenario, you can clear the windscreen when required.

[@PastorGeek]

Curious. Are you Napoleon dynamite’s brother?

[@khajajeelani8518]

I got both of your replies, but I am having issues with my email account, so I was unable to read the entire content. I'll check them once I resolve the access issues. Thanks for responding.

[@jesusamador2473]

I love my 91. I was lucky to find a one Owner car in blk/blk

[@bagarre48]

great video... have to do a head gasket replace (ugh) because of blowing it and trying to fix it with head gasket seal, finding out that it is a joke and waste of money.... I actually thought that when picking it up and still bought it and than I was stuck sort of. Anyway thanks for the video.

[@shadowrider460]

R&R of the head gasket on these things is no easy task but it's really the only way to repair it properly for a long lasting repair. Good luck with everything. I hope you can keep it running and on the road. :-)

[@bagarre48]

***** so I still have not done it but driving the car and used the so called "nano technology" fix and what a joke.... should have known better. Every two days or so I have to add water and it is obviously going somewhere. Not under the car and not in the oil (as far as I can tell)... The point is that I do not like it and makes me nervous. I believe I have put on about thousand or so miles since I did a quick fix (if there is such a thing)... bottom line I might have screwed the car up for ever. She is an amazing piece of machinery and I pray to the universe to have mercy on me because would be great to have her for longer... oh well... this technological mambo jambo is getting to me sometimes. Shadowrider460 the best videos ever! Changing the trany fluid right now and trying to figure out how to turn the v-8 by hand so I could get to the bolt on the torque converter. Fan has to come off and sparkplugs out... might be the only way.

[@pejhonsetareh4723]

ive had 3 of my windows that's fallen into the door and wouldn't roll back up, very annoying problem

[@alexstator7375]

W126 is still the best looking Merc. And I've never seen such a well kept W126 like yours. Does your headlight wipers still work?

[@shadowrider460]

As far as I know, yes. I just recently replaced the blades.

[@6KHwy]

Did you fix the window?

[@shadowrider460]

Yup. All power windows work like brand new. :-)

[@theredneckguru7811]

what a sweet color!

[@MrMundaa]

420 SEL OXYGEN CONECCTION UNDER PASSENGE CAR CANT FINDIT HELP

[@The2thman]

The 126 rear window regulators have a poorly designed slide. It is the weakest point of a well-made car. I try to never lower the rear windows. They work fine and last much longer if you don't use them. LOL

[@unclemikedavis4210]

Dude about that window?it sounds like the windows of its track thats the bars that lower and raise it thats why when you put it up the hit the bottom of the window a bit.So just look for the window to be off it's track in my opinion.

[@bobl78]

so great cars...easy maintenance...todays cars require alternator to be changed if brushes are down, manufacturers ask you to buy new car

[@hiramabiff9545]

So my uncle died and he had one an 1989 420SEL there is 100k miles on it everything works except he didn't want to fix the A/C I really.want to get it he would.drive it to the office

[@westhavenor9513]

Use Akebono brake pads to solve the brake dust problem

[@MrMundaa]

3CAN YOU SHOW ME WARE CONNECTION FOR OXYGENSENSOR

[@ashleypatterson4053]

👍👍

[@Devan_Bolin]

Black and white value

[@theredneckguru7811]

Did you fix the window?