Coolant leak issues

[Serusa]

Hi all,
Apologies if this has been asked before. I haven't used this forum much but here goes.. I own a 1990 W124 230e with 83k on the clock and I have been loosing coolant for a few months now. The system was pressurised and the rad was found to be leaking so a new rad was fitted as was the coolant reservoir and cap. It seemed to resolve for a few weeks but started all over again. UV dye was put in the coolant to try and locate the leak but not a trace of the dye even when the car was on the ramp. No mayo in the oil either so my mechanic (who is not a Merc specialist) and I are at a loss. Any ideas/suggestions please? Thanks

 

[toolman1954]

Hi,
Welcome to the forum. Water does not just vanish into thin air, well only as vapour, so if your dye check has been negative then have you left a piece of card under the engine overnight to look for any drips? Just a simple check.
Have you pressure tested the system since the new radiator and radiator cap. Even left the system pressurised over night?
Are all the hoses in 100% condition as would be the hose clips. These need replacing on an older vehicle, rubber does not last forever.
I would also be inclined to do a compression test on the engine. Just look for two adjacent cylinders being a bit on the low side. Always useful to know the state of your engine on an older vehicle, despite only 83k.
I assume you have checked for water in the oil and a rising oil level.
Failing all that I would suggest it might be the heater matrix, especially on an older vehicle. Often this manifests itself on having a steamy inside of your windscreen, and some wet carpets or floors.
Now, only because you have an old vehicle, I might think that a dose of radiator sealant might cure what ever is the problem. Modern vehicles are not suitable for this type of treatment. But try the heater matrix first.

Steve.

 

[WDB124066]

Is it possible that you are buring water, do you get a static shock off the car now but didn't before this started...?

See if you can test for combustion products in the coolant, could be a head gasket failure.

 

[optimusprime]

Put your hand down the back of the engine cylinder head next to the place it meets the block .Can you feel any coolant in that area ? Took me ages to find my coolant leak after new coolant pump was fitted . The rear engine lifting eye is held on to the head with cap screws .On the lifting eye is an o ring seal,, this get hard opver time and coolant escapes from it and then it runs down the back of the engine.

 

[Serusa]

Hi all,
Thanks for all your very helpful responses.
There are no signs of any coolant drip underneath the car and the engine undertray is always as dry as a bone.
I have not experienced any steamy windscreen but I will check for any wetness on/underneath the carpets and also have a good look at the hoses and clips and reach behind the engine cylinder head and see if I can feel any coolant there. Thanks again, I will relay your suggestions for a compression test as well as a sniff test to my mechanic and hopefully they will point us in the right direction.
Sam

 

[Joesoap17]

if all else fails put a can of Kalimex K Seal in the system it will stop that slight loss.

 

[Serusa]

if all else fails put a can of Kalimex K Seal in the system it will stop that slight loss.

Thank you.

 

[Serusa]

if all else fails put a can of Kalimex K Seal in the system it will stop that slight loss.

Thank you.

 

[PGW124]

Note: k seal can clog flow heater matrix and or rad

 

[Justintyme]

Put your hand down the back of the engine cylinder head next to the place it meets the block .Can you feel any coolant in that area ? Took me ages to find my coolant leak after new coolant pump was fitted . The rear engine lifting eye is held on to the head with cap screws .On the lifting eye is an o ring seal,, this get hard opver time and coolant escapes from it and then it runs down the back of the engine.

Would this apply to the newer Merc's too? 2010 E Class w212 2.1 CDi ? I have a very slight leak too, but finding it hard to locate the exact cause.

 

[HITECH]

I used new age rad weldy stuff to plug a leak on my w03 as i needed the car for work and life and was too busy fixing everybody elses car to strip my own. it actually lasted 6/7 months. I had already found my leak with dye tho. it was leaking out a freeze plug that had corroded and rotted away bit by bit eventually leaking the coolant out like a tap on full blast. Before i got the freeze plug replaced i flushed the system with water over and over again to make sure it was clear. No damage was done to the matrix. Wherever it is leaking from on yours it wont be doing your thermostat any good. I had to replace mine shortly after replacing freeze plug. I suppose the fact it had done 180,000 miles it deserved to be changed lol

 

[Serusa]

Good evening folks, just thought I would let you know that a combustion gases test has confirmed cylinder head gasket failure. I am now looking for a competent mechanic to sort this out...

 

[Justintyme]

Good evening folks, just thought I would let you know that a combustion gases test has confirmed cylinder head gasket failure. I am now looking for a competent mechanic to sort this out...

And the only indication given that the head gasket was gone, was a loss of coolant? No mis-firing? loss of power? hard to start ? Etc. And how much coolant was leaking ( approximately ) 1/2, 1, 1.5,2 Ltr's etc. per day,week? Thanks, and Good Luck with the gasket replacement, keep us udated will be interesting ( especially some pics of the faulty gasket when its removed...)

 

[WDB124066]

Ask them especially to clean out the block while the head is off!

 

[Joesoap17]

Depending on what you value the W124 at I would still give the K Seal a try it cant make it any worse?

Have some in my XK8 at moment had a small leak couldn't find and it has gone away been in there 8 months no other issues.

 

[Serusa]

And the only indication given that the head gasket was gone, was a loss of coolant? No mis-firing? loss of power? hard to start ? Etc. And how much coolant was leaking ( approximately ) 1/2, 1, 1.5,2 Ltr's etc. per day,week? Thanks, and Good Luck with the gasket replacement, keep us udated will be interesting ( especially some pics of the faulty gasket when its removed...)

Yes, the only symptom has been the coolant loss....no loss of power or difficulty starting. I did have a slight misfire early in the year which was sorted with new HT leads. This car is mostly driven on weekends so it's difficult to be precise about the amount of coolant loss but I have been checking it weekly and topping up as necessary...no more than 50 ml at a time.

 

[Serusa]

Depending on what you value the W124 at I would still give the K Seal a try it cant make it any worse?

Have some in my XK8 at moment had a small leak couldn't find and it has gone away been in there 8 months no other issues.

Oh yes, that is definitely an option at the moment...

 

[WDB124066]

Does the car give you a little static zap every now and then by any chance...?

 

[Serusa]

Does the car give you a little static zap every now and then by any chance...?

No, I haven't experienced that all..

 

[optimusprime]

Wait till its warm weather ,than drain off and refill with water and pop in the tub of K seal run it for a week or so with K seal then drain it off refill with antifreeze ..