What does oil in Coolant look like (diesel engine)

[hod05]

What does oil getting into the Coolant look like in a diesel engine? My Coolant is brown looking. Makes me wonder if its getting oil into it.



My E250 has a Coolant leak and is dripping onto the road. It's booked in but I need to make a 2 hour round trip drive between now and then garage visit. I'm concerned to drive if the oil and Coolant are mixing.

Would it be very black? Would it be obvious? Is there an easy way to tell?

 

[Doug1234]

Looking at the pictures there is zero evidence of oil and water mixing

 

[hod05]

Looking at the pictures there is zero evidence of oil and water mixing

What about the brown looking Coolant? That's what I'm worried about. If it's just an external leak I'll top up and do my trip

 

[Blobcat]

Brown coolant is likely to be rust, possibly insufficient rust inhibitors in the system previously. Flush it out and fill with the correct spec coolant for your engine.

 

[tpn]

Did you not check the fuel filter housing as per your other thread?
Oil/coolant mixing not evident in those photos.

 

[Uncle Benz]

Diesel oil in coolant is black sludge floating on the top of the coolant in the reservoir. You don’t have that, 100%

 

[hod05]

Did you not check the fuel filter housing as per your other thread?
Oil/coolant mixing not evident in those photos.

Yeh I seen those posts and most people suggest it could be the fuel filter housing. I ran the engine but cannot see any leak. But there is a puddle under. I'll remove the filter and have a look inside.

I just wanted to ask about the fluids mixing because I need the car at the weekend but can't get it repaired earlier than next week.

Definitely wouldn't drive unless I'm fairly confident it isn't mixing.

Seems like a lot of knowledgeable people have said it doesn't look like it's mixing.

So if it is just the fuel filter housing is it ok to drive so long as its kept topped up? Or can it lose all Coolant suddenly from this fault?

 

[mioba]

oil and water dont mix, dont see layers there, where they can mix due to high shear leads to an emulsion - not present.

Fix leaking part
flush and clean system
good tiime to do stat

Stop worrying

 

[tpn]

Yeh I seen those posts and most people suggest it could be the fuel filter housing. I ran the engine but cannot see any leak. But there is a puddle under. I'll remove the filter and have a look inside.

I just wanted to ask about the fluids mixing because I need the car at the weekend but can't get it repaired earlier than next week.

Definitely wouldn't drive unless I'm fairly confident it isn't mixing.

Seems like a lot of knowledgeable people have said it doesn't look like it's mixing.

So if it is just the fuel filter housing is it ok to drive so long as its kept topped up? Or can it lose all Coolant suddenly from this fault?

There is no guarantee that the seal will not give way with disastrous results.
Remember the little Dutch boy with his finger in the hole in the dam That is if it is the seal; from a distance it is all conjecture, that is why I asked you to look.
I would not want to be responsible, or partially responsible for such a disaster.

I do not remember you stating how quickly your coolant is going down and that may be relevant in your driving risk calculation

This is a unit that I replaced recently. It was not leaking but as I was replacing the inlet manifold it would have been mad for me not to replace this at the same time.
The section at the very bottom is where the very thin piece of plastic, that supports the off round part of the seal, breaks away.
you can see how it can escalate to a bigger leak given the opportunity of higher motorway temperatures and extra pressure on the coolant system.
It is only a very thin piece of plastic with very light torque settings
.

 

[tpn]

Better view of how thin the bottom section is

 

[hod05]

Thanks for the advice everyone. Is it possible to top this up with distilled water from Halfords? I'm not sure I want to use tap water and I don't want to risk mixing in the wrong Coolant.

I've not driven it since I noticed the leak but I'm wanting to buy a 5l bottle of distilled water so I can use the car tomorrow then it'll be at the garage flushed and replaced properly next week.

I'm going to check the fuel filter now am I right in thinking it's a couple of screws to undo and reinstall?

 

[tpn]

I don't think anybody here will advise you to drive with a coolant leak, that is your call.
As for topping up you will not do any harm, in the very short term using the likes of Prestone Coolant/Antifreeze.

However if you use that, Prestone etc you will need to flush out the system and refill.

(Comma Xstream G48 in a correct coolant and can be safely mixed)

If you use distilled water it will dilute the coolant and can only be brought up to strength by adding a concentrated coolant.

If it is the housing you will not lose a lot of coolant-a gallon will be more than enough to top it up.
But it is all conjecture at this stage, water pumps also leak.

You have not stated what the rate of coolant loss is.

As regards having a look at the bottom of the housing and below it there is no need to remove any screws.
If you see screws you are in the wrong place.

There are two shiny, hinged, spring loaded clips on the side of the housing. Clip these out at the unhinged end and the filter can be lifted out.
No need to disconnect any of the fuel pipes.

 

[hod05]

I don't think anybody here will advise you to drive with a coolant leak, that is your call.
As for topping up you will not do any harm, in the very short term using the likes of Prestone Coolant/Antifreeze.

However if you use that, Prestone etc you will need to flush out the system and refill.

(Comma Xstream G48 in a correct coolant and can be safely mixed)

If you use distilled water it will dilute the coolant and can only be brought up to strength by adding a concentrated coolant.

If it is the housing you will not lose a lot of coolant-a gallon will be more than enough to top it up.
But it is all conjecture at this stage, water pumps also leak.

You have not stated what the rate of coolant loss is.

As regards having a look at the bottom of the housing and below it there is no need to remove any screws.
If you see screws you are in the wrong place.

There are two shiny, hinged, spring loaded clips on the side of the housing. Clip these out at the unhinged end and the filter can be lifted out.
No need to disconnect any of the fuel pipes.

It doesn't look to have lost anything in the last week although it's not driven. I had a look and saw the two clips for the filter but couldn't remove them by hand. I topped up with distilled water required about half a tea mug full to cover the sensor went for a little drive doesn't look to have gone down but I didn't go very far. Let it idle for 15 minutes and looked around but can't see anything. For all I know it could have been slowly leaking for weeks and only just got low enough to trigger the sensor. When I noticed it the level was just below the sensor. I'll see what happens when it goes to the garage

 

[tpn]

Put a flat screwdriver inside each clip and just flick them out. They are too tight to push out with your fingers

 

[hod05]

I don't think anybody here will advise you to drive with a coolant leak, that is your call.
As for topping up you will not do any harm, in the very short term using the likes of Prestone Coolant/Antifreeze.

However if you use that, Prestone etc you will need to flush out the system and refill.

(Comma Xstream G48 in a correct coolant and can be safely mixed)

If you use distilled water it will dilute the coolant and can only be brought up to strength by adding a concentrated coolant.

If it is the housing you will not lose a lot of coolant-a gallon will be more than enough to top it up.
But it is all conjecture at this stage, water pumps also leak.

You have not stated what the rate of coolant loss is.

As regards having a look at the bottom of the housing and below it there is no need to remove any screws.
If you see screws you are in the wrong place.

There are two shiny, hinged, spring loaded clips on the side of the housing. Clip these out at the unhinged end and the filter can be lifted out.
No need to disconnect any of the fuel pipes.

Ended up doing the trip. Topped up so that the sensor was completely covered which took about half a mug full of distilled water. Drove 80 mile there. Checked and didn't appear to have dropped, drove 80 mile back and its hard to tell of its gone down at all. If it has its ever so slightly temp was fine. Garage this week. I'm now questioning if it even has a leak but it had dropped so it must have gone somewhere. Probably a very slow leak. Hope they can find it

 

[tpn]

You need to wait until its is cold to see exactly how far it dropped

 

[hod05]

You need to wait until its is cold to see exactly how far it dropped

It was cold I checked it the next day after driving 80 miles. Then a couple of hours after getting home again.