water pressure 190d help !

[steve--o]

greetings from sunny almeria spain

i own a 1989 5 cylinder 2.5 deisel,i have always run it without a thermostat,as our avrage temps is 20deg or 40 deg in summer.
tha cars covered approx 225k miles and drives like new .

its been loosing water for the past week through the header tank over flow, (i think ) ive now fitted a new cap,and its seems ok ,but the cars still using water with no visable leaks
the car does not overheat or boil over and runs at approx 80 deg.

ive also removed the hoses made sure the block & rad are un blocked by running a hose pipe through them,and its all ok,ie plenty of water flowing

ive made sure thairs no air locks in the system,and if i run the engine with the header cap off and rev the motor,it dosent pressure /air bubble up (ie as it would if the head gasket had 100% blown )

my question is ,is thair anything else i have missed that will cause back pressure,or is it in with the spanners,head off,head skim and new gaskets :cry:

all advise welcome.
cheers
steve

 

[television]

Yes when the head gasket goes it blows the water system up.

Its spanner time

 

[meanie]

Had e few of the earlier engines go porous under the valve seats.

 

[steve--o]

ok thanks for the info,im realley wee,d off because i do the oils filter every 3k and it runs like new.

im in spain,and get all my motor bits shipped from uk as thay are 40 % more expensive here locally,the down side is ,its a 28 day wait for bits,so before im in and off with the spanners,can anybody help on mi questions listed
thanks again
steve

will it need the head skiming as standard practise ?

are thair diffrent thickness head gaskets ?

what other stuff would you recomend i need to order,& fit wile the heads off ?

 

[kth286]

Why can't the problem be the water pump main seal whilst the engine is running?

I would have expected it to need changing by that mileage.

 

[steve--o]

but how would that pressuries the system ?
also thair is no leak from the water pump
all explanations / help advise welcome,because im dreading the open head surgery
thanks
steve

 

[steve--o]

still need advise on what parts i need to order,head gasket thickness,if thairs anybody out thair in merc tinternet land that can help it would be greatly appreciated.
cheers
steve

 

[television]

I will check on the complete job tonight, you may have to jog me

 

[steve--o]

hi thanks,if i dont have the correct parts at hand its a 28day weight,as im in a little village in the almeria hills !

cheers

steve

 

[wireman]

It does sound like you have head gasket problems.

If antifreeze/corrosion inhibitor has been added (it should be) to the coolant it tends to discolour if combustion products are introduced to it by way of a slight cylinder to water jacket leak at the head gasket, it looks rusty when contaminated.
If no corrosion inhibitors have been used there could be a corrosion issue which has or will lead to the gasket failing.

You wont see a small leak at the pump gland if its hot because the leaking coolant evaporates before it can drip off.

I stongly reccomend that a thermostat be fitted regardless of your high ambient temperature.

If you do dismantle the engine be sure to follow the proceedures for cam shaft removal and timing chain tensioner fitting to the letter, the things can break if they arn't.

 

[Bolide]

Pinhole leak in the radiator or leaking water pump

I had a hole in the rad of my 250TD that could only be seen a minute or so after you turned the engine off. I assume the pressure rose in the system and it then started leaking

The diesels are not known for leaky water pumps

Nick Froome
www.w124.co.uk

 

[steve--o]

hi again folks

i have been checking the car,daily and now i have fitted the new rad cap,no more water loss,and not blowing out of the header tank.

BUT

still a lot of pressure in the system,although its drivable,i dont like the pressure,ie its inflating the top hose so it will only be a matter of time,before the rad or a hose blows

i can live with doing the head gasket as its a nice old merc,but now what i am really wee,d off abought is the thought that the head may be porus,as suggested earlyer on this thread.

has anybody ever used a sealer ie steel seal ?http://www.steelseal.com/faq.asp

,as if the head is porus im up shot creek ! and wondered if the steel seal,will sort the porosity.

im an enginner by trade,(but been off mi tools for 20 years,apart from mending mi old dears brit bikes )

but never really likes all this new engin in a bottle stuff ,however if the heads like a sponge could be an option,before i strip it,rebuild it,with a possible sponge head.

what do you all think ?

just out of intrest this sealer has to be used with an anti freezed thermostated engin or it wont work acording to the manufacter.

cheers

steve

 

[television]

I would try a sealer, things get better all the time with these things. You have nothing to lose

 

[wireman]

It is normal for the system to be pressurised when hot, the pressure cap will limit the cooling systems pressure to about 1 atmosphere, if it gets above this coolant will be lost, now that you are not loosing coolant the old cap must have been the problem, often on old caps the rubber disk that seals the cap gets enlarged and will stick in the seat thereby setting the blow off pressure low and allowing much more coolant or steam to escape once system pressurisation occurs .

As to the top hose becoming bloated this is to me an indicator that you also need to replace the coolant hoses before they fail and run the risk of killing your engine good style. With one atmosphere of pressure you get one tonne per square foot so the hoses do need to have some mechanical integrity. As you say it will only be a matter of time.

As for sealing additives for me they are best avoided, I have managed to choke up the water ways in a heater matrix after adding it, it did not cure what turned out to be CHG trouble and cost me a heater matrix which to be fair may have been halfway to blocking up in the first place..

 

[steve--o]

ok thanks
i was thinking of changing the hoses,as part of my service shedule anyway.

can anybody adisve the best place to buy hoses on the net ,ie mercedes quality,but pattern prices.

im still not a happy bunny though,because i understand the system runs under pressure,but if the waters at 80 deg and you remove the cap,the water pressure nearly blows the cap out of your hand.

up until 2 weeks ago thair was very little pressure,and the cap could be removed while the motor was hot / running with very little header tank over flow. so this to me points to a lot more pressure than it had.

cheers

steve

 

[television]

As a double check you could leave the engine running when its hot with the cap off, and the water should not blow out

 

[steve--o]

yes i have tried this,"BUT "it seems ok,ie if you rev it or leave it on tick over it doesent spill water as it would if the head had 100 % gone.

i think the porus head suggestion may be it as opposed to the gasket,ie a little more pressure than normall on a 60 mile run,wich is why im edging towards the bottle of steel seal.

i think il give it a try,but its not somthing i like ,but if the head is a sponge it may be my only option,apart from a 100 % tested recon head.

i will give it a go and report back.

cheers

steve

 

[Dosco]

ok thanks
i was thinking of changing the hoses,as part of my service shedule anyway.

can anybody adisve the best place to buy hoses on the net ,ie mercedes quality,but pattern prices.

suggest you use genuine MB.

 

[television]

When you apply the sealer, turn the heater to cold and off

 

[kth286]

I would never use any additives in the car.

Your car really does not seem as though it has that much of a problem.

Just replace the hose/s with genuine from Merc parts dept. Ask for discount.