Pressurised coolant tank

[Y98jpa2]

Hi wondering if anyone can help out a little bit I’ve just brought a mk7 62 plate transit 140 bhp fwd on 109000 miles
It test drove fine no problems loads of history head gasket water pump timing chain and tensioner turbo and loads of other bits done at 70k test drove fine no issues opened coolant cap after test drive all seemed fine I picked the van up this morning drove a short 10 mile drive home and noticed coolant leaking quite bad out of the reservoir checked all connections nothing seamed to be leaking directly from cap took reservoir off tipped upside down and showed cap leaking brought a new cap headed off to work all seemed fine! Got home tonight and checked to see if it had sorted the problem and the cap literally exploded as I undone it loads of pressure and a small amount of coolant loss drove the van all day didn’t over heat did some research and decided to check egr valve cooler and noticed there was no pipe coming off this so guess it’s been by passed and mapped out am I stupid to think the head gasket couldn’t be gone in only 39k miles no oil in coolant or coolant in oil no white smoke overall van drove really well really clean and tidy van so gutted to think I’ve brought a dud any help much appreciated!!

[T350camper]

Before you start panicking, just do a few basic checks first. The cooling system on a Transit is quite large, so there's a fair amount of coolant in there. The system (like all modern systems) is pressurised and it will retain most of that pressure until the residual temperature returns to about 20 degrees. Taking the cap off when it's still hot will result in rapid depressurisation and perhaps even localised boiling. I would check the level is correct (not overfilled) and drive the van, then allow it to completely cool before removing the cap.

You can get a better idea what's going on if you still have concerns by attaching a pressure tester and watching the gauge as the engine hots up. You can also get chemical sniffer kits to detect exhaust gas in the system. There's lots of possibilities and I've heard that Transit head gaskets are normally quite strong (assuming it was fitted correctly). Likewise the cooled EGR's once bypassed from the cooling system shouldn't interfere with pressure.

There may have been an air lock if the old cap had problems. Take things one at a time and give as much info as possible when you report back. Plenty of help on here from experienced guys.

[Y98jpa2]

Before you start panicking, just do a few basic checks first. The cooling system on a Transit is quite large, so there's a fair amount of coolant in there. The system (like all modern systems) is pressurised and it will retain most of that pressure until the residual temperature returns to about 20 degrees. Taking the cap off when it's still hot will result in rapid depressurisation and perhaps even localised boiling. I would check the level is correct (not overfilled) and drive the van, then allow it to completely cool before removing the cap.

You can get a better idea what's going on if you still have concerns by attaching a pressure tester and watching the gauge as the engine hots up. You can also get chemical sniffer kits to detect exhaust gas in the system. There's lots of possibilities and I've heard that Transit head gaskets are normally quite strong (assuming it was fitted correctly). Likewise the cooled EGR's once bypassed from the cooling system shouldn't interfere with pressure.

There may have been an air lock if the old cap had problems. Take things one at a time and give as much info as possible when you report back. Plenty of help on here from experienced guys.

Hiya mate thanks for having the time to read and reply ! New to the forum so still figuring it all out but as I slight update I left the van to cool over night and went to open the coolant tank again this morning from cold and unfortunately still full of pressure to the point it’s literally exploding inside off to do a sniff test now will report back with results another worrying thing I’ve been pointed out is all the radiator clips have been changed to new jubilee clips some of them having two on rather than just one in hind sight should of been obvious but I guess pipes were blowing off left right and centre and they’ve tried sorting the problem given up and left it a new buyer !

[metalworker0]

I left the van to cool over night and went to open the coolant tank again this morning from cold and unfortunately still full of pressure to the point it’s literally exploding

you don't have to do any sniff test ..the above alone says to me, its head gasket, or cracked head.

all the best.mark

[Y98jpa2]

I left the van to cool over night and went to open the coolant tank again this morning from cold and unfortunately still full of pressure to the point it’s literally exploding

you don't have to do any sniff test ..the above alone says to me, its head gasket, or cracked head.

all the best.mark

No coolant loss just stupid amount of pressure no white smoke or coolant in any oil
How long do you think it could last like this im a small business owner movano broke on me last week brought this hoping it would be a suitable replacement and the worst has happened could I use it for a few weeks to raise some money ?
Also if the head gasket was repaired at 70k and it only being 110k now is this van even worth repairing or is it just a bad one thanks again for all reply’s !

[T350camper]

If it's got that much pressure, then I have to agree with metalworker. Not really anywhere else that much pressure can come from. Sounds like the previous owner knew about this and bodged it to sell. Don't think you can really use it a lot more until fixed. Sorry mate.

[metalworker0]

What you can do

1. Join the AA or RAC - you don't want a hefty tow charge when it leaves you stranded - so you need more than basic cover you need RELAY as well - this is something you have to do
2 . You can Wait for it to blow off a hose or release pressure via the header tank cap .... then after, you temporally fixed the hose you're driving home slowly with header tank cap removed.
3. Put something like "K-seal" in the coolant and cross fingers that it gives you a couple of months or days or weekshttps://www.ebay.co.uk/itm/280632033402?
4. Be ready, have cash set aside to hire another van.
5 Have all the parts ready to fix it ...buying after the event may cost you more, as you're panic buying then, those parts are: if its done more than 150,000, will include cam chain kit.
6. Watch the temperature gauge all the time.
7 Dip the oil at least once a day ..once it's got mayo in the oil or oil rises stop driving.
8 Be prepared . find out who can fix it for you, know who you can use to get it done at reasonable price .
You're on borrowed time now!

Note when a head gasket is repaired there are two ways of doing it ../a proper job were if head face is warped or corroded it is skimmed ....or a botch where everything ignored and new head gasket installed only without any prep or consideration - so you may have a warped head, unprepared job or worse cracked head ..as being the reason repair did not last long.

all the best.mark

[andz327]

Head gasket done at 70k is very strange to start with
Is the small hose/pipe to the expansion tank pumping water through ok ?
Is the power steering pump turning water pump ok ? The coupling between the two are known for the spline to get worn and catches at low revs but not at higher revs
EGR cooler definitely not got coolant hoses connected ??

Sent from my SM-G990B using Tapatalk

[Y98jpa2]

Trying to figure out how to post pictures but there is no pipe connected to the cooler witch made me think they’ve already bi passed it also new jubilee clips all over the hoses so guess they’ve already blown off before power steering pump ok small hose also pumping back into coolant ok I’m wondering weather to cut my loses with it put a 12 month mot on it Tuesday and send it to we buy any car was offered 2300 after they’ve knocked me down abit so all in 700 loss but it did take me to work for two days is it worth throwing money at a cooler or is everyone convinced head gasket or head
Thanks for reply’s and lucky have rac business just torn between getting it fixed or flogging it to we buy any car it’s a really clean van for age I’m gutted lads !

[metalworker0]

if the coolant hoses are already off the EGR cooler, then putting them back on isn't going to fix it, the hoses are usually taken off to prove that cooling problems are not happening or happening because of that ..so disconnection of the egr cooler was a test carried out, that wasn't put back.

As regards getting rid, you'll have to do the maths ..i don't know what you paid for it ..i don't know if "we buy any car" do tests on it. if they do and find fault, yes they will buy it, but at a scrap value price.

if you repaired it yourself assuming the timing chain is good ..the price would be gaskets plus machine shop skim ... or worst case - new head if cracked ...as to you paying to have all the work done its going to be a minimum of £1200 by a back street garage.

all the best.mark

[Y98jpa2]

Hi guys slight update with my transit still going after 5k miles doing long runs for work most days and still hasn’t overheated pressure also got better after a week or so I guess the seal on the cap has gone letting the pressure out as when I check it in the morning there’s no more explosions…. temp gauge was fluctuating and was running poor on start up throwing up a traction control fault on the way to picking my labourer up every morning decided to change thermostat housing and the van now runs fine in the morning no more faults but on long moterway journeys after around an hour the temp will go down to 60 and slowly creep back to the middle also noticed my fan isn’t working so will check relays and fuses tomorrow but any other ideas of what to check is there anything else it could be other than head gasket not had a transit before but have had head gasket failure and I’m almost sure it would of overheated by now ! I’m based in Bristol and have drove this van 4/5 times down to Cornwall and back
Any help or ideas appreciated

[metalworker0]

also noticed my fan isn’t working

Temperature will be all over the place with the fan not working, mostly very high ..it should not be driven with the fan not working, especially in the temperatures we have had in the last few days ...if driving with no fan has not completely buggered it ..then you have nothing wrong

you have sort of fixed the stat????? or have you ? see paragraph below . now .fix the fan ...and hopefully no more problems

may have been just that all along.... stat and fan

Going down to 60 means that your new stat is stuck open or faulty. (a stat should hold the engine at a constant temperature ..something over 80)

or is it missing and has been left out by who ever worked on your van - which will disguise all the symptoms of a head gasket, and make you think that it's fixed until the winter comes along and you have no heat in the engine.

To be honest - I don't know what to think after your latest answer.

all the best.mark

[Y98jpa2]

Morning mark im at a loss with it myself i changed the stat to a generic from euro parts is it worth grabbing a ford genuine part ? I just changed the whole housing and will check if the old housing did have a thermostat … Did some live data tests yesterday on moterway to Bridgend and back about a 2 and a half hour round trip and temp ranged from 55-80 I’ve changed the relay fans still not working has any one got a wiring diagram so I can dig abit deeper one thing I did notice is a have glow plug fault with cylinder one and cylinder one also contributes slightly less nothing major reading of 0.938 out of 3 when the rest are 0.999 am I right by saying if the cylinder was cracked or warped it would be working harder than the rest ?

[metalworker0]

If you are confident you've fixed the thermostat ..
Change the heat sensor ..as it could be this that is faulty
Note~ its the sensor that puts the fan on
The heat sensor gives forscan and the pcm the data on temperature

Temperature should be steady and above 80 degrees once stat has opened if its wavering as low as 50 ...Something is wrong - perhaps the sensor is buggered ..and temperature is right.

i don't know where this sensor is located, as i cant get into the parts diagrams site .catcar.info

all the best.mark

[Y98jpa2]

Is that the sensor on the thermostat housing as that was changed aswell I think for what it’s worth I’ll try a gen ford part im facing the probability I’ll be facing a big bill soon just trying to prolong it as much as I can I no air locks in the system can cause problems with the stat would exhaust gasses cause the same fluctuation ?