Club 80-90 Forums

A water hose sprang a leak. It wasn't very old and perished, but it was due for replacement. The light came on, I saw the steam and stopped straight away. The temp gauge was still reading normal and the engine did not smell overheated and wasn't making the "ticking noise". I "bodge fixed" the hose and put water in to the correct level. I really needed to be somewhere on time, just 4 miles away, so I did not bleed the rad, but drove carefully, free-wheeling, with the motor off as much as I could. I left the engine lid off at this point. It boiled up, chucking coolant into the top up tank after a mile or so. I stopped, topped up again and this time left the dalek cap off so as to run with no pressure. It boiled up again. At no time though did the gauge go more than a smidge over normal, maybe a max of 3/4 the way over. Naturally I was watching it like a hawk. I got to do the drop off I had to do, only just in time for the deadline (my job would have been in jeopardy if I had failed).

Note, this is almost certainly the ONLY time in many years that I had left my phone at home = bloody typical eh

I then had time, so, in a lay-by, I filled up and went through the full correct bleeding procedure (which after an oil in water situation ~8 years ago I am very experienced with). During doing this I was very concerned about the continuous "stream" of bubbles coming from the expansion tanks feed from the bleed rail pipe. It wasn't "gobs" of air as one would expect, but even after much topping up and bleeding (engine bay and rad) these bubbles kept coming. I was (and still am to a 50% extent) thinking "that's exhaust gasses"

I did however now get the 15 miles home. I then drove it 12 miles to Jim to get the 2 trailing arms fitted (~£750 in total, incl bushes and new rear brake cylinders, shoes and pipes etc) I then drove it home. I then removed the bodged big metal (left hand) pipe and fitted my good spare one and started all the top up / bleed / top up / bleed process again. It seemed to take ages, much longer than in my previous experiences years ago.

Now the odd bit. During this I still witnessed all these bubbles going into the expansion tank. Once I was satisfied that it was all bled, I left it ticking over for quite a while to see if it would over pressurise or boil up or chuck water into the top up tank. Eventually the big fan came on. I turned it off, bled a bit more air from the rad, went and looked at the tanks. Top up tank level was where I had left it. Expansion tank took a pint or so, presumably for that last bit of air in the rad. I fired it up, no dalek on and was very surprised to note that there were no air bubbles coming.

Since then, about a week ago, I have not used it at all. Been using the Scirocco for work commuting etc, being a bit disheartened with the van after the money it cost me on the arms, and then in the very same week, this, which looked, and still might be, a big expense and might result in what I said in the "Members only" post about all this situation.

This weekend I will stop putting it off, and take it for a long test drive and monitor what happens and make decisions accordingly.

Just to say, I am familiar with bleeding these vans having done it a good few times for routine reasons. It's just the chain of symptoms, and that last "proper" bleeding, where for ages (maybe 30 minutes or more of running time) there was that constant stream of little bubbles. It just didn't seem normal, but then it appeared to stop doing it. Very odd.

Sorry for the long post.
Technical opinions invited.

John.

If this were me I would be conducting more tests, driving it normally , and monitoring the temp and coolant level
It really sounds to me like your bodged ( get you home ) repair may have had a big hand in this

Now you have repaired it properly , and bled it properly you should be able to diagnose it properly ?
If it does it again, get a exhaust gas sniff done

Exactly, don't give up on it yet.


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Mocki wrote:If this were me I would be conducting more tests, driving it normally , and monitoring the temp and coolant level
It really sounds to me like your bodged ( get you home ) repair may have had a big hand in this

Now you have repaired it properly , and bled it properly you should be able to diagnose it properly ?

What the man said ^^

I found that @r$€ in't air bleeding (as it has to be where we live) has always worked fine but plenty of up and down-ness of normal driving will show any issues ... keep your phone and plenty of water with you

Good luck and remember the offer is always there .... zero cost from my end.

Ian

Firstly, once again Ian, thanks for your VERY kind offer
I won't take you up on it though as the responsibility would be too much for me to chance (read on).
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

It chucked it's water into the top up tank yesterday, after a 12 mile run. It didn't overheat (according to the gauge and my examination under the lid).
I topped it up, bled it and drove it home. When I got home, I was surprised to note that both the rad pipes under the van felt far too cool, even the feed pipe to the rad. "Thermostat" I thought. Even though it was a new "Marle" one a couple of years ago, I removed it, tested it in a pan of boiling water. It opened. I drenched it in cold water, it closed. Repeated a couple of times. I have read that this can "unstick" a sticky stat.

As a precaution, I back flushed the entire system, bleed rail included.. No crap came out that I could see and the rad flowed perfectly well.

Re-filled, bled thoroughly, drove it up to temp, all ok, My infra red temperature gun now showed normal temps on all the relevant pipes. I left it ticking over until the fan came on, ok. BUT, I have been here before

I will drive it again and see what it does. It's really starting to pee me off this is.

Thinking out loud ..

Have you tried the Dalek cap ? (toot test)
What's the level like in the top-up tank when hot and then again when cold ?
Is the coolant going down at all ?
Circulation is good ? (pump)

Ian

^^^ Tests here seem very variable on this occasion.

Dalek cap = all good, and I have a spare which when fitted makes no difference.

Top up tank = I have it 1/3rd full when cold (expansion tank brimmed of course) - Sometimes, when good and hot, the expansion tank chucks coolant (water at the mo) into the top up tank to the extent it fills right up and overflows.

Coolant in the expansion tank does go down (on test drives), sometimes within minutes (too much for a simple head gasket fail, and no steam from exhaust). Other times it does not go down, even to the point were the rad fan has kicked in (Aprox 20 - 30 minutes idling) When I say the coolant "goes down", it does, but the level returns when I gently release the pressure (remove the cap very slowly).

From my observation of the return feed to the expansion tank, which looks very healthy (other than the bubbles, sometimes) the pump is OK.

My thinking is, it is exhaust gasses getting into the "main" bit of the system and displacing the water. BUT, sometimes, like yesterday, after a full flushing, checking the stat, bleeding and topping up etc, it did not do this "bubbles coming up into the expansion tank" thing, and it got up to full temp (rad fan kicked in) with the expansion tank staying full and without out displacing any water (other than the normal "bit" which sucked back on cooling). I will take it for another road test today, but I fear it might end up the same as it did yesterday. It's as if it was an intermittent head gasket failure, but that can't happen.

This is why I say "this is starting to really pee me off" = I cannot replicate the symptoms with any reliability.

I am going to have to find a garage that can do a RELIABLE sniff test aren't I. Trouble is I live a bit out in the sticks and the only local garages I wouldn't trust to check the tyre pressures !!

p.s. - I think this is like the guys who, when the oil light starts to flicker at hot tick-over, prefer to think it's a faulty £5 switch rather than knackered crank bearings. It's got to be a head gasket hasn't it

^^^^ I'm also going through the same thing as yourself with exactly the same symptoms including a small amount of micro bubbles in the header tank. I can leave the van on the driveway and everything will operate as normal, engine gets hot, thermostat opens, radiator and all pipes gets nice and warm, water circulates nicely and radiator fan operates. However when trying to go on a longer run I can get between 10 and 15 miles and it will start to overheat and chuck coolant out the overflow tank, The temp gauge will go from normal to 3/4 immediately and throw on the red light, there will be a lot of pressure in the system but the radiator is freezing cold as is the top pipe at the thermostat housing which suggests that it is not opening. = full of air

One of the problems I have however is that it doesn't do it all the time. The last trip away it did this 4 times on a 30 mile journey but on the way home the next morning it was as if there was absolutely no issue. I checked the coolant level and pressure when we got home and everything was fine.

I have so far replaced the radiator, thermostat, dalek cap, thermostat housing and top and thoroughly flushed the system. I still use the van locally for short journeys with no coolant loss or overheating and I have already had a sniff test done which was negative for exhaust gasses but beginning to wonder. One thing I did find recntly though was that 2 of the head studs (the front one and one of the middle ones) were not overly tight, both on the left hand bank looking into the engine bay. I tightened them up but not with a torque wrench and I am pondering checking them all correctly but the fear of snapping studs prays on my mind. The van is due it's MOT this Saturday where I am getting another sniff test done. I will let you know of the outcome.

ghost123uk wrote: It's got to be a head gasket hasn't it

Working through it logically, SOMETHING is displacing the coolant and that something can only really be a gas as it expands and contracts, it isn't oil. It doesn't do it all the time so it's something that's failing rather than failed under load.

Does the heater get hot in the cab ok ?

What's the history with the engine ? Rebuilt before ? Studs ?

It sounds almost like a cracked head that's opening and closing, OR maybe the more obvious gasket.

Is the coolant (water) clean ? No deposits at all on the level sensor ?

Ian

Hello John,

Long time no speak..

I've done the stuff in members only..we should talk..

but, staying on topic..

My 2 Eurocents worth...

If you remember I had 'Disciple of sketch' here 2 years ago with mysterious over heating, water chucked out syndrome..

After much bleeding, testing, thrashing, lunch, cruising and overheating..

Turned out to be the plastic impeller on the water pump that had 'unbonded ' itself .. and so only worked at revs.. under load..

Hope you find a solution soon,

Onwards and upwards..

Cordialement,

John

Highroller wrote:I'm also going through the same thing as yourself with exactly the same symptoms including a small amount of micro bubbles in the header tank.

Well, flippin heck. Reading though your post it certainly does seem exactly the same issue, whatever it is (I'm going with head gasket or cracked head).
Do come back and tell us what your second sniff test result is.

sarran1955 wrote:Hello John,
Long time no speak.....
Turned out to be the plastic impeller on the water pump that had 'unbonded ' itself .. and so only worked at revs.. under load..

Aye, hope you are well.
Re pump, the visible flow I can see in the expansion tank leads me to think the pump is OK. I could be wrong though

Ian Hulley wrote:Working through it logically, SOMETHING is displacing the coolant and that something can only really be a gas as it expands and contracts,

Agreed

Ian Hulley wrote:Does the heater get hot in the cab ok ?

Yes

Ian Hulley wrote:Is the coolant (water) clean ? No deposits at all on the level sensor ?

Coolant (now 100% water) is clean, just the (clean) micro bubbles on the surface. Not looked at the level sensor probes, what are you thinking there ?

Ian Hulley wrote:What's the history with the engine ? Rebuilt before ? Studs ?

Bought off billy738 on here about 8 years ago. It came out of a project van that never got finished as the owner got too old and sick. It was a genuine VW re-con and I am pretty convinced it had not been run much, if at all, as it was VERY clean under the rocker covers and seemed to "run in" over the first few weeks I used it. Since then it has run beautifully, is mechanically very quiet and uses no oil between changes.

Ian Hulley wrote:It sounds almost like a cracked head that's opening and closing, OR maybe the more obvious gasket.

Agreed - I am taking it for a sniff test later this morning.

What's the verdict John? Fingers crossed for a positive result.

waiting with fingers crossed as well!

I haven't had time to go into town for a proper sniff test yet and will be working away all day today, so will likely do it tomorrow.