under presure!

before i go down the new head gasket route,what else would presurise the radiator,im looseing around eighth to quarter of a liter out the overflow over a couple of hundred miles,still gettin hot air through the vents,as i took the idea of putting a bottle on overflow pipe ,as it seems to do it under fast motorway speeds....the vans only got 228k on the clock.

Thunderrider.
Looks like a gasket, have you always used the MB coolant? Eric

Bad radiator cap?? .. With a head gasket problem , I think you would loose a lot more water and have other problems like overheating, water in oil.. Most auto parts store have a tool to see if combustion gases are in coolant.. Is the engine temp. normal?

torqczar said:

...
Most auto parts store have a tool to see if combustion gases are in coolant.. Is the engine temp. normal?

Click to expand...

I'm not certain of the price of those test kits, but it seems like the thing to do to confirm or deny the source. That is if the old tells of smelling for a sweet smell at the exhaust pipe or steam in the exhaust isn't present. Good luck. vic

I am having the same experiance only worse. Don't start on the head gasket until you talk to doctor A. The kit your looking for is called a block leak test from napa.
Its $ 40.00 at some and $50.00 at others so check around. The fluid that comes with the kit works with diesel engines. Are you getting bubbles from the Rad cap in the morning when its cool? In my opinion there is a possible quirk with some T1N engines possibly through the EGR valve. My van started doing the same thing. Then got worse. It will put out massive amounts of white smoke through the exhaust at idle and gobble coolant. If i shut off my van when it is puffing smoke and pull the radiator cap the smoke will stop. Then i put the cap back on and as the pressure builds the smoke comes back. Sounds like a head gasket yes? But it is not. Because i have never heard of an intermitant head gasket leak. I give my van a "treatment" and am able to get the van running normally again at least for a 1000 miles or so. This has happened twice to me. If your van gets worse or looses heat or starts puffing white smoke, I will talk you through a "treatment" Its free except for some coolant. Sometimes i am glad i don't have extra $ because if i did my van would probably be at a shop getting a new head gasket.

theres no white smoke,the van runs fine no over heating hot air thro the vents,driving round town with little short motorway trips seems ok,if i do a couple of hours of hi speed motorway thats when it happens,ive drove about hundred miles and no water in bottle but that was light motorway use over a short distance,so ive not checked the water level,i swapped the rad cap off another van and still happens.the water i had in the bottle was blue with no trace of oil in....as for sniffer testers no one in uk seems to use them seems there cheap they not used!!

thunderider said:

theres no white smoke,the van runs fine no over heating hot air thro the vents,driving round town with little short motorway trips seems ok,if i do a couple of hours of hi speed motorway thats when it happens,ive drove about hundred miles and no water in bottle but that was light motorway use over a short distance,so ive not checked the water level,i swapped the rad cap off another van and still happens.the water i had in the bottle was blue with no trace of oil in. I lose 1/8 - 1/4 L out the overflow

Click to expand...

Seems to me there is no problem here, except the rad was overfilled by 1/4Liter, when hot it expanded and left the radiator. If it loses nothing after the 1st 1/4L then it's perfect.

What is the temp indicator showing on the motorway?

Are you sure it's going out the overflow and it's not something like a water pump seal or a pinhole leak in the radiator?? Those can be difficult to find if they are small enough leaks.

since the last time i topped up id did about 1200 miles or so with no coolent loss then checked it bout quarter of liter in the bottle,topped it back up, tuesday then drove round ok did bout 600 miles the checked again today then neely a litre in the bottle....exactly the amount to the max mark!!surley if head gasket it would be all the time not just speradic preasurissing??,basically i check the bottle most days the all of a sudden if get fluids in there...wouldnt it do it constanly if gasket gone?

this morning iv took the rad cap off,let it get up to temp on tick over no visible bubbles,but if i rev the engine for 30-40 seconds 2000 rpm the water "white frothy" let revs go down the froth goes,no oil in water,no water in oil,is the froth normal is that the bubbles under "load"??

I was losing coolant very slowly. The level light would come on occasionally. I tightened every hose clamp I could find and it stopped.

the hoses are rock hard,i lost water yesterday that the light came one...bout a liter,all goes in the botlle i attached,untill the pipe blows its self out the bottle,but i called an independet merc garage,he recond they dont blow head gaskets as they are metal,recons more likely to be a cracked head....suggested i got it preasure tested...this sound plausable?? how much is a head??

and water only up to the max mark in the header tank??

Pressure testing certainly plausible, the heads have been known to develop porosity around the injector seats. Shouldn't be difficult to find someone who could do it. Be aware that pressure test results aren't always 100% guaranteed though - a colleague had that experience once...

If you need one I'm guessing the head would cost £1,250 to £1,500.

bloody ell cheaper just to buy another engine!!

Following similar troubles as yours, I replaced the head gasket on my 311.

If you I was in the same situation again I would take it to a rolling road, run it up under load and see if I could find any leaks, also put a sniffer in the exhaust.

it seems no one in the uk seems to use sniffer tester just reliey on go old fashoned english scratching the head!!

You can buy a block test kit but they aren't regarded as reliable on diesels, they indicate unburnt hydrocarbons and part burnt hydrocarbons and are more relaiable for finding petrol combustion products.

If you can find a rolling road, you can see any leaks.

Good luck with you van.