Engine coolant headache

[Bosun20]

Sit back and get comfortable this might be a bit long.
I`ve got a 2.1 MV engine in a 89 westy.
It blew the rightside water jacket seal first and when i stripped it i would have said this was just from time.(200,000km+ on origanal engine)
After the rebuild,(new heads,water pipes,injectors,LA exhaust)it started running hot all the time.
Removing the stat helped but wasn`t perfect.
It was stripped again and got new barrels and pistons,new water pump and new(genuine) stat and housing.
It then blew the left hand water jacket seal after coverig about 200 miles and been parked up for about 20min.
So i stripped that side down again,couldn`t see anything wrong apart from the split in the seal.
After about 200 miles driving it did the same again on the same side.
So i`ve stripped it again and still can`t see anything wrong!
I`ve now cleaned all the rad out just in case and fitted a new fan switch.
I haven`t had chance to give it a proper run yet but the fan turns on and off as it should,the rad is getting hot all over.
When you drive along the motorway the temp needle is on the red light but if i open the front heater to hot the temp gauge drops straight away.
Has anyone got anymore ideas of a possible cause before i book the next recovery truck.

[Grun]

Bosun20,
You don't mention bleeding the system. Have a look at this link (in the wiki, top of page)


https://club8090.co.uk/wiki/Co ... ing_system

Mike

[AngeloEvs]

Just getting familiar with the WBX cooling foibles but I have read on here that the heater system alone requires 6ltrs of coolant and if running with the heater off, and then switching on, the temp gauge dips initially and starts to return to normal thereafter. Mine behaves like that but others may be better placed to confirm that this is normal.

[Fritz]

Bosun,,,,,,,,,,,,I admire your determination to get to the bottom of this,,,a lesser man would have torched it before now...

Anyway, a few questions::OK it blew a w/j seal in the first place, did you not ask why it did this and other than put a new one back on ? or did you rebuild it thinking it was due to age/mileage etc etc.

Then why 2 new heads (@ 250gbp each) or are we talking second hand ones ?

You can discount the LA exhaust as I have one of these and mine runs as it did before with the std system,,,,,,,,unless the back box is at fault and as a result causing the overheating problem. (if front pipes are blueing ie getting very hot you may have a blocked/restricted back box,,,,,unlikely but possible.

Don't forget if the motor has overheated the temp senders wil have also been cooked and you may be getting a false reading from these.

Have you checked small bore pipe that lives inside the engine bay as well as all the pipes that branch off this bleed pipe,,,,,,,,also have you replaced the expansion tank screw cap ? as this can cause all sorts of overheating problems when it is on its way out......

So to re cap,,,,,make sure all pipes are not restricted in any way, if rad is suspect change it (you may as well a you have done almost everything else). Replace temp sender on stat housing (the one facing forward NOT the one on the side) Change expansion tank cap for a new one (from Brickwerks) not GSF or any other source than VW or Dr Baxter.

From what you have told us ,my guess is a radiator fault/blockage WHY for the simple reason when you open up the vents into the cab the temp gauge climbs down from it highest point,,,,,and even lower if the blower is also used.....I guess...


Regards

Fritz,,,,,,,,,,,,

PS, Replace only one thing at a time or you will not know which bit has fixed your problem.....

[Bosun20]

Thanks for all the help.
Believe me i`ve wanted to kill this van a few times now, but i`ve been a mechanic for years now and i don`t let cars beat me.
I used every way i now and have been told to bleed the system to make sure i`ve got all the air out.
When i brought it the bloke told me it had a leak on the engine but only a small amount. I changed the anti-freeze as he had not done anything to since bringing it over from Germany.
After this is when the first seal went, this lead me to think he might have added rad weld which i had disturbed.
The heads are New New. One had a crack in it you could see down the intake port. The other had a alloy rot problem starting.
All sensors have been replaced and the cap,all Genuine.
I was thinking along the same lines as the rad being the fault but when it was running really hot all the time(after first rebuild) driving kept the temp gauge down. This makes me think that the rad was circulating fine.
Every pipe i could replace has been and i`ve checked every inlet and outlet for blockage.
Would the left side run hotter to caue the gaskets to blow?
Would air in the system cause the same problem in the same place?

[Mr Bean]

Thanks for all the help.

Would the left side run hotter to caue the gaskets to blow?
Would air in the system cause the same problem in the same place?

You don't say if you lost all your water. In a very recent post i relate my pressure cap story. It sounds like you are too bright to get caught like that. It seems to me that when a waterboxer reaches a critical low water point it runs away like Chernobyle. Out of interest I have just recovered from intermitent ECUitus and during my attempts to recreate the fault on the drive rather than have another toe home I deliberatelly tried to overheat the van. Even with the rad covered and the cooling fan disabled I failed to overheat the engine even in the recent hot weather. I have found my WB cooling system to be very capable if in good nick. Ignoring stuff like gross ignition timing and the I agree that the plumbing or radiator is a likely candidate. My ECUitus brought me close to ditching the injection and going for carbs if that is any consolation.
cheers
Ken

[syncrosimon]

Whilst working on syncroswedes 2.1 dj, and doing a coolant change, we found that the system was not bleeding right, and the thermostat was not opening properly. There is a little plastic turn screw on top of the thermostat housing. This is turned a half turn to let the air out of the top of the thermostat housing, allowing hot water to touch the thermo, and for it to open. On syncroswedes motor, everything was hot, except the thermostat. The little pipe should get hot to the touch, when you open the valve, so we took the plastic top off the thermostat, and found that the pipe was blocked. We blew out about 4cm of sludge from that pipe, then had to open the very small bleed hole, probably 1.5mm with a drill. We replaced everything, and hey presto, no more erratic temp problems.
I think that the design of the system means that air collects above the thermostat, and prevents it from opening as it should.

If the your van has had rad weld in the system it could have blocked the other small engine pipes, that are there simply to remove air, and blocked the blue expansion cap, as mentioned by fritz, if the system cant expand and contract through the cap, that might cause premature seal failure, and erratic temp running. The cap iirc releases pressure at +14psi into the top up bottle, and visa-versa under vacuum, to top system up. I would suspect the rad weld.

[Aidan]

MV with LA exhaust, which oil filter are you running ?
How's the temps generally on/below half, over half ?
There was a batch of crap head water gaskets a few years ago, I had three go on a rebuilt engine of mine, all split in the same place, top corner through the lip, no 1 cylinder in my case, or number 4 if it's on that side, we tried three different suppliers, gsf, euro and an independent, ended up with a a second genuine vw one and three years later it's fine. It almost looked like they had been stapled to something or someone in the factory was wicked and had a little dig at them. Lasted between 275 and 2000 miles each time.

[Bosun20]

I`ve got the smaller oil filter.
The needle is sitting lower part of the light.
It never gets hot before it blows,the light just comes on for low coolant.
The gaskets i was using were Victor Reinz kit from GSF.(does bothsides)
I`ve now rebuilt that side with a Elring kit.(only comes as one side)
The new gasket does look different from the old,looks better made.
But what you say is whats happening. When i looked at the old gasket it looks like it was made to thick,it`s as if the head, when tightened down,is trying to push the gasket out and so splitting the corners.
You have possibly just become my new best friend.

[Mr Bean]

I`ve got the smaller oil filter.
The needle is sitting lower part of the light.
It never gets hot before it blows,the light just comes on for low coolant.
The gaskets i was using were Victor Reinz kit from GSF.(does bothsides)
I`ve now rebuilt that side with a Elring kit.(only comes as one side)
The new gasket does look different from the old,looks better made.
But what you say is whats happening. When i looked at the old gasket it looks like it was made to thick,it`s as if the head, when tightened down,is trying to push the gasket out and so splitting the corners.
You have possibly just become my new best friend.

Yes I recently joined and was so overcome with all the help and advice I got that I still well up over it.
Cheers
ken