Another OM651 coolant leak

[MercedesDriver]

This morning I got a message low coolant leak just after starting, topped it up and here is what I saw - photos taken from underneath left hand side


That’s the only wet place in the engine bay. What’s that down there that leaks coolant? The ribbed hose looks too big diameter for coolant but again I’m probably wrong.
Photo from above, darken wet hose visible deep down, sorry I couldn't get a better photo

I’ll try to book it for service early next week but am curious to know what to expect.

 

[grober]

Most likely cause of a loss of coolant is the water pump.

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[MercedesDriver]

Most likely cause of a loss of coolant is the water pump.

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Thanks grober but why would the big hose get wet, it’s quite at the distance from the water pump. Do you know what is this part with the big hose attached?

And the location of wet part from above

 

[mm450exc]

There are three sources of coolant leaks.

1. Water pump (get a Geba)
2. Thermostat housing
3. Water housing by the EGR cooler (under fuel filter)

Could be oil on that intercooler hose (mine looks like this). My valve cover was loose and oil went down the back of the engine and then all over the place at the bottom. Check all bolts on the valve cover.

 

[grober]

the big hose is the intercooler pipe that leads to the inlet manifold.
see the first page illustration here. http://autocats.ws/manual/sdmedia/mediadb/mb_Acrobat/einf/204/einf_br204_cdi_OM651__en.pdf
like mm450 exec says that " coolant" damp appearance looks more like oil or hydraulic fluid possibly from the power steering pump above it

 

[MercedesDriver]

Many thanks guys. I’ll definitely have to book it with indy to sort it out till Friday.
Fingers crossed it wont hurt much.

 

[pmcgsmurf]

We've still not got to the bottom of a leak on one of our OM651 cars, did the fuel filter housing/EGR.

When we have time it will be water pump next, car isn't used a lot so no urgency on it.

 

[MercedesDriver]

We've still not got to the bottom of a leak on one of our OM651 cars, did the fuel filter housing/EGR.

When we have time it will be water pump next, car isn't used a lot so no urgency on it.

I’ll try to book it with Gem Tech on Monday to see if they can sort it asap. I really didn’t need this to happen now 5 days before our trip to France.

 

[MercedesDriver]

Today update on the leak issue: It's the water pump. I hope I'll have my car back tomorrow.

 

[Smart320]

Sounds like a reasonable result, hopefully now a trouble fee trip

 

[MercedesDriver]

Sounds like a reasonable result, hopefully now a trouble fee trip

I wasn't expecting this imho, she has only 102k miles and I was expecting maybe a thermostat housing (thermostat changed 2 months ago) but not water pump. I've noticed last week on first morning starts that she would kind of struggle making a turn and the noise she was making was like some of the bearings is too tight, but now it's clear the water pump was the culprit. At least now she should be good for another 100k miles.
It wasn't planned or budgeted, but I'll go on a trip without having to think what's wrong with her.
Guys in Gem Tech were really great and accepted to fix her in such a short notice, I called them today at 10, drove her at noon, and they called me back with the diagnose at 3pm. Really pleased.

 

[Smart320]

I must admit my ML has only done 75 k miles and been well serviced but I am budgeting for a big unexpected bill just in case!

 

[MercedesDriver]

Most likely cause of a loss of coolant is the water pump.

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You were right, as usual.

 

[MercedesDriver]

Just a final update on this matter which might help others in tracing the source of the leak on OM651.
So, I was told that it was not possible to trace the leak while the engine was warm and that it only started leaking from the water pump once it cooled down.
That's it. Solved.

 

[Tasawar]

Hi guys. Hope you are all doing well and can help me. I have changed my fuel filter housing on my car. I top it up with coolant but it's leaking out. I can see all the fluid under the filter housing. Have I put the filter housing on wrong. The one I bought had three holes and the original only 2 holes. I dont think that matters. Why is it leaking. I am thinking that's the part I put on and they is a lot of fluid there. Under the car I can see all the fluid dripping