aowhaus

how about considering a snorkel intake if you are going to fjord through water.

RLE

This is a hydraulic lock and is not electrical. Water has no effect on the coil packs unless they are submerged.

Diesel Benz

I guess it is, but another post explains that the problem appear when you try to start the car. Would be odd if the water does not cause a lock when the car is driven but only when (re)started. And this was reported as the same issue.
https://mbworld.org/forums/3895752-post13.html

Glyn M Ruck

It is all about how much water is ingested. Water is incompressible. A little water & a lot of air & the engine will pump it out of the exhaust as a cloud or steam during the combustion cycle. The converse & the engine will try & compress water on the upstroke with the valves closed & bang - hydralock, bent rods etc.

Diesel Benz

Did you mean to response to my message? My point was that there cannot have been enough water for hydralock if the engine was first running and was claimed to get locked only at the next restart. If it did lock at start, there should not be any damage like bent rods, I assume. And where did the water come when the car was parked?

Sportstick

So, Glyn, after each time I hand-wash the car, the restart produces a cloud of white smoke at the exhaust. Am I washing the grille area too vigorously (garden hose water flow/pressure aimed at exterior only) ? Or, is this harmless?

Star & Laurel

The white smoke you are probably seeing after washing your car is water that is introduced into the exhaust from the tailpipes. you start the car and the heat from the exhaust will cause it to steam shortly after start. I doubt you are pushing that much water into your engine via intake side.

Glyn M Ruck

Once you have water in sufficient volume in the airbox & it goes through the MAF - center rear of engine - it sits in the inlet manifold and drains to the cylinder/s with inlet valve open while stationary. When you start - wamm! So yes there can be enough water & is. Go look at the design. Remember you only need sufficient water in one cylinder to hydralock!!

Glyn M Ruck

SS - I have never seen any water get into the airbox, past the filters, through the MAF & into the inlet manifold from washing the car. NEVER

Tatorr

This is mine's.

RLE

I've read his post and I think his explanation is a little murky. He said the car was splashed by a truck and the engine quit and when he tried to restart it..

When an engine is hydrolocked it stops dead as the rod or rods bend. If you wait long enough, the water MAY seep past the rings enough to crank the engine enough to open a valve to blow the water out. But, the damage is done even though the engine may start. There is nothing unusual about the air intake locations in the W204 but it's not a submarine. We have big rainstorms at times in my city and we see TV images of cars plowing through deep water with a bow wave coming over the hood. The drivers are oblivious until the thing quits and they have to wade to shore. About two years back we had a huge rainstorm here and I was told that just my dealer had six cars come in that had destroyed engines. The warranty does not cover stupidity but insurance does, lucky for them.

Hydrolock can also happen with a failed headgasket when coolant seeps into a cylinder but that happens over time. MB has produced plenty of engines that have developed leaky head gaskets, either coolant or oil.

The V-6s are not among them.

Diesel Benz

Come on, the water would wait in the inlet manifold while the engine is running. Then when the engine is switched off it would start flowing into the cylinder?

The air box could hold some water but it would get drained out from the drain hole, not to the engine.

Diesel Benz

The head gasket coolant leak to the cylinder could make hydralock happen while the car is parked.

I was wondering if the starter motor would have enough power to make rods bend, of course it also depends if there was only one cylinder filled with water and if the starter motor had almost a full cycle to gain speed or if the "to be locked" cylinder is already close to top dead centre. I certainly have not seen this, I interpret that you feel the starter motor could bend rods.

I've seen hydralock on old engines with an exhaust pipe heading up from the exhaust manifold (not a car ), rain may fill the manifold, specifically if the vehicle is parked in a place allowing water surging from a garage roof finding the way to the exhaust pipe. These old engines were so heavily built that hydralock still did not damage the rods (or starter motors were too weak).

If water enters the engine when the driver dives to a pool of water, one would expect the driver being able to avoid this by driving slow enough. But if one of the 204 bumber designs forces water to flow upwards and directly to the air intake, perhaps the bumper or the air intake could be improved to avoid this water flow. After all, a stranger in a city driving after heavy rain may hit a deeper than expected pool of water.

bulletspec

Are we here talking about a car or a boat?...

A car is not suposed to dive underwater!... with that said... if the water is above my foglight or reaching my tailpipes.... i wouldn't try and over pass it.... it's just plain stupidity...

^^^^^^^^^^^^^^

Those pictures AboVE of the Mercedes C class US Navy edition ... that's just................ unexplainable man!... how did you intended to cross that OCEAN with a Sedan??!?!

you can see the Tundra having a rough time in it's bumper section almost covered.. where did you think the water would reach the car?... door pin high?

Glyn M Ruck

Diesel - I fully accept that this is an extremely unlikely scenario but it has happened - not necessarily in this particular case - as I read this situation a "splash" was the bow wave from a truck that overwhelmed the intakes.

These vehicles have a very large intake cavity below the MAF in the intake manifold area. One would expect oblivious drivers to push forward until everything grinds to a halt & the damage is done. One engine I saw destroyed at my dealer was brimming full of water right up to the MAF grating.

There have been instances of lock taking place at attempted restart where less water was around that I can only believe were due to sufficient water collecting in the manifold to hydralock at least one cylinder. These engines do have powerful starter motors with crank 'till start programming. The starter gear ratio is very extreme. In a scenario with enough water present to lock one cylinder and another cylinder with closed valves actually firing you would certainly bend things.

Engines have locked on start up not related to coolant leaks so I guess it's just a matter of unlucky circumstance where all the conditions happened to be right.

JimPap

I got into to some fairly deep watch last year and am wondering if the rear differential has the potential of getting water in it causing it to fail later. Any thought?

FrankW

is that a real question?

if water can get into your DIFF that means you should be leaking oil already.

Diesel Benz

OK, I take your word on this and believe it can happen, at low or medium probability but at least possible.

This fact that one cylinder could already fire while the next one is waiting to face hydralock sounds another possibility that would certainly bend a rod. On a diesel this would be less likely because the diesel needs to wait for rail pressure building up before injection starts, not only wait till crankshaft and camshaft sensors report ignition sync.

Glyn M Ruck

The breather is on top of the diff housing & not remote on these cars. It is designed to try & keep water out but it is a vent at the end of the day.

The time that axles are the most vulnerable to water ingress is when the car & axle are fully warmed up. People don't realise that the rear axle oil can get to 150 deg C (300 deg F) on a long climb on a fully broken in axle. Let's say normal operating is 100 deg C plus.

If you run into deep water with the axle at this temperature everything contracts & sucks in water through the breather. The only way is to check.

JonMBZ

I wonder why cars dont have a type of rain/water sensor to shut off the engine/drain water once it has a large intake of water into the intake tubes. I am sure it can be made and done.

Tatorr

Yes, the water was up to the door pins.
I wasn't driving threw it lmao. It was parked on the side of the street because i was at a friends house. Came outside and saw that my car had turned into a german submarine.

bulletspec

I thought you drove it through.... but now that u put it like that, WOW! ... I really hope there was no big problem cause of that!


Good luck

Tatorr

Thank you.
Haha, oh no. I love my mercedes toooo much to make it a german submarine.
It rained like that for 3 days straight.
The car ended up being totaled out and they wrote a check for $33,600.

JonMBZ

just heard that someone hydrolocked one of our w204 rentals doh!

RLE

What with Southern California getting torrential rains today with deep water all over the place not to mention the mudslides etc., I'm wondering how many MBs will be coming in on the hook.