Mercedes W126 420SEL Misfire.. Compression Test. Sad News

[@bobexsus]

Vito I don’t know how someone can keep up with so many cars but it’s good work your doing

[@VITOSGARAGE]

It’s crazy, right? Thank you for your support

[@craftedwithart]

Finally some V8 Benz. Keep it up

[@VITOSGARAGE]

Thank you so much!

[@charlestimmis273]

Vito: I dont know anyone else that does that much work outside... Kudos...

[@VITOSGARAGE]

Thank you! Check out my other playlists and videos. I have a lot of content

[@charlestimmis273]

@@VITOSGARAGE I am a subscriber.. I admire your work.. I have a w126 and do most of the work myself... Thank you...

[@unclepeanut8066]

I did the head gasket and found no compression in the first cylinder after wards. Sucks, sad very sad.

[@VITOSGARAGE]

Put oil in there and see if the compression goes up. It’s easy to replace the headgasket on this engine and there may be an issue with the valve not sealing properly. Could be due to carbon. And that’s why no compression. Don’t let this legend die!

[@Finnoctane]

Compression is low but still high enough that with fuel and spark it should fire. As a few others have said, maybe the injector is blocked. The spark plug should have some wetness if fuel is reaching the cylinder. Maybe test a new injector in a jar to confirm it’s ‘popping’, if not then the fuel distributor might have an issue. Also I think these V8s over time do get weak head gaskets at the rear according to my mechanic. Also it’s probably worth removing the valve covers at that mileage to confirm the oil rails for the cams isn’t loose due to aged plastic or the timing chain isn’t stretched since that’s catastrophic failure on this engine! Hope you get it sorted!

[@VITOSGARAGE]

Thank you for all the advices! I’m hoping it’s just the injector. That would be an easy fix then. And I’m planning to remove the valve covers to inspect the oil rails. I opened an oil filler cap and the right side oil rail felt okay, it wasn’t loose. But I’m still gonna remove both valve covers and probably just replace those plastic retainers. Thank you for your support!

[@unclepeanut8066]

Lots of helpful information! We need you on the MB FORMS

[@johnzeumer7757]

Fuel Injectors?

[@stephmomo9132]

Hi Vito, 2 bars to compensate is a lot, but..... positive thoughts ! A good oil change preceded by a flush and your W126 will start again for 100,000km :) Nb: You have surely already checked your idle control valve ? (in addition to checking your injector): Allez courage !

[@VITOSGARAGE]

Thank you sir, I’ll keep digging and we will see what happens. I need to change the oil on this car desperately first. I feel so bad running it with that old oil.. And I’ll check that injector too🤝

[@RandomSonomaMedia]

Try using engine restore oil additive. Mostly fixed rod knock and low compression on my lawn mower and a diesel tractor. Only $10 so worth a try

[@VITOSGARAGE]

That’s what I heard, sir! I’ll use some Engine restore additive along with fresh oil and maybe that’ll restore the compression in it

[@RandomSonomaMedia]

@@VITOSGARAGE good luck

[@ChristopheZ]

You can always try a can of "RESTORE"....It did work for one of my car in the past

[@VITOSGARAGE]

I’ll try that for sure. People had good reviews about that. Fresh oil and a can of Engine Restore

[@ChristopheZ]

@@VITOSGARAGE It absolutely worked for my car...so you never know!! also add two cans of liqui Moly MOS2 ( I put some in my W124 400E)

[@vintage76vipergreenBeetle]

Did you do a leak down test? On the bad cylinder?

[@VITOSGARAGE]

I’ll probably have to do it, sir

[@jefferyjohnson5421]

Hope you can save this car. It is a shame that the owner did not take good care of it.

[@VITOSGARAGE]

Either way this car will be saved. I’ll drive it with 7 cylinders for now, if needed

[@cons2899]

You dont need to remove fuel pump relay. You dont need to use ignition lock to crank starter. There is a special connector in the engine bay on passenger side, under plastic cover. Bridge the ports and it starter goes on. It is by design to measure compression, read the manual, товарищ.

[@VITOSGARAGE]

You have to remove the fuel pump relay and a crank position sensor connector to prevent the spark and fuel injectors from spraying fuel. Especially when doing the compression test. Spark plug wires were out and you don’t want the spark to be produced and not have a path to ground while cranking. That’s why I disconnected the crank sensor. And I know about that connector on the passenger side. It was easier to do it with a key. Спасибо🤝

[@manfredgeorgburggraf533]

Damn thats a big boy

[@VITOSGARAGE]

Big Long boy!

[@johnzeumer7757]

Maybe soak with seafoam for 48 hours, turning the engine one a day to loosen up those stuck rings..

[@VITOSGARAGE]

I’ve seen people overseas use different products to soak the cylinders in and to get the piston rings unstuck. I tried the sea foam but no luck. I’ll keep digging and brainstorming.

[@gcdc1975]

👍🇮🇪 Happy St.Patricks day👍 💚 Keep up the good work Vito👍🇮🇪😉

[@VITOSGARAGE]

Happy St Patrick’s Day, sir!! Thank you so much for supporting!🙂🤝

[@gcdc1975]

@@VITOSGARAGE Thanks for the reply👍 I have a 190e at the side my house lying up nearly 10 years.Just wish I had the money to get it back on the road. I love it so much, I dont want to sell it even though Ive had a couple of offers when people seen it(and I could do with the cash😂). It's such a lovely car to drive! They just dont make them like this anymore! Like you say we need to keep these cars going👍

[@VITOSGARAGE]

Dad Beste Oder Nichts! The cars back then were made with quality and love! Never sell your car, you’ll regret it forever! 🙂

[@johnzeumer7757]

I would bet that those injectors are shot

[@etets444]

put it in rice

[@VITOSGARAGE]

Rice?

[@etets444]

@@VITOSGARAGE i’m just joking 😅it’s what people say when something is broken. it’s of course sad that the owner wasn’t taking care of it especially not changing the oil. engine is the heart of the car 😔good luck hopefully she will be running normally soon

[@bobexsus]

@@VITOSGARAGE ya gonna need alota rice 🍚

[@VITOSGARAGE]

Ohhhh that’s what you mean...😀😀 And nooo, No Asian rice to a German Tank lol!😀😀 It needs some good German beer so we can both get drunk lol😀 But thank you guys, I’ll keep giving it love ❤️