Hi ,i am still using coolant.car runs great.No smoke,no water in oil,trany ect..
Just uses about i quart of water every 50-100 miles..runs at perfect temp. Pulled plugs ,they all look normal.I think my intake must have a leak.
I am scared to pull it off because of the bad wiring on these cars.It has a new harness but o.e. electronic throttle and wire that is part of the it.
=====Has anyone had intake problems on this 94-E420 motor.=====
Strange never runs hot,seems to be normal coolant pressure and any thing i could fix i did.
I work with cars and found some hc's in coolant bottle.But that can still be intake.This has been going on for months but gets a little worse each few weeks
Lost
Rich

__________________
88 300E White, sold 9-04
88 190E Black 2.3 sold
90 300CE White, Grey sold 12-24-04
92 400E White,Grey Sold 5-06
90 300CE 91K Signal Red,Black Sold 2007
1989 300CE Smoke silver,Tan Sold 1-08
1993 300E 3.2 M104 motor
1991 300CE White,Grey
1994 E420 beautiful car,gone to new home
1994 E320 Smoke an Parchment.Beautiful car

Most likely going to be the headgasket,s ,pressurize the coolant system cold , and remove sparkplugs lf losing pressure , inspect with boroscope,
those engines never leak at intake,waterpump first culprit, radiator next,hoses,coolant bottle

Test the pressure cap.

Thanks for the replys,I will need to look inside the motor.Read on IATN that one person had a crack in his intake,but it sounds rare.
The amount of caps ect i have tried is crazy.All oe stuff. I am scared of pulling heads on an aluminum motor because the head bolts and stripping the treads in the block.
Just found out i am getting some cash soon.Time to buy a E430 of the 2000 2002 type.
This E420 is so clean but i will have to sell it.Before i do still want to find source of leak.
Thanks
Rich

__________________
88 300E White, sold 9-04
88 190E Black 2.3 sold
90 300CE White, Grey sold 12-24-04
92 400E White,Grey Sold 5-06
90 300CE 91K Signal Red,Black Sold 2007
1989 300CE Smoke silver,Tan Sold 1-08
1993 300E 3.2 M104 motor
1991 300CE White,Grey
1994 E420 beautiful car,gone to new home
1994 E320 Smoke an Parchment.Beautiful car

I had a problem with my E420 where it was losing roughly the same amount of coolant and I couldn't figure out where it was going. It turned out that the plastic nipple on the recovery tank (for the small hose) was cracked and leaking, but the coolant would seep under the tank and I didn't see it.

I finally noticed it once when I opened the hood right after a drive and specifically looked for leaks. I run a 20% to 30% ratio of coolant to water so it tends to evaporate quickly in the engine compartment. It was such a tiny leak that the coolant was mostly evaporating before it hit the ground, so there was no puddle to see under the car. Another common place for leaks is the tiny elbow on top of the radiator for the hose running to the recovery tank. If this leaks, you may not notice it after the car has sat a few hours after running.

As for pulling the intake off, you are looking at replacing all the petrified rubber hoses from the aft passenger side valve cover to the ETA. Also, the ETA cable has the same crappy insulation that the wiring harness has, so you will likely disturb that in the process if you can even manage to get the upper intake manifold off without removing the ETA. You would still have to lift the ETA cable up vertically to get the upper intake manifold off. You can see the ETA cable in the picture snaking its way out of the intake manifold to the aft passenger side where it plugs in.

Like the other guys said, I would look elsewhere first. I wouldn't want to remove the intake manifold on this car if it wasn't absolutely necessary.

Attached Thumbnails

   

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1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles

That is what has me worried.If i touch the intake my perfect running car can start acting up.The e.t.a scares me as it cost 2 much.I will check with a boroscope,verify coolant leak and then may sell car.I want a newer Benz.What is wierd is even the expensive stop leak did nothing to slow it down.
Oh Well
Rich

__________________
88 300E White, sold 9-04
88 190E Black 2.3 sold
90 300CE White, Grey sold 12-24-04
92 400E White,Grey Sold 5-06
90 300CE 91K Signal Red,Black Sold 2007
1989 300CE Smoke silver,Tan Sold 1-08
1993 300E 3.2 M104 motor
1991 300CE White,Grey
1994 E420 beautiful car,gone to new home
1994 E320 Smoke an Parchment.Beautiful car

I have heard they make some sort of testing strip that you can stick in your exhaust to detect if coolant is getting into the combustion chamber, but have not been able to find any.

__________________
1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles