VW T4 Forum - VW T5 Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #1
Hi all,

I had my can serviced shortly before the lock down. As part of that the trusted garage overhauled a out of the cooling system. Recently there has been a leak which has got to the point of about a litre a week now.

I was waiting to get out in to the garage but can't get hold of them for an unknown reason so thought I'd take a look myself. I got the engine pan of and the bottom of the engine was a bit of a sorry state. After cleaning everything up and getting repeatedly dropped on, I think I have finally found the culprit. I checked Haynes but can't figure out what the offender is and therefore how to fix it so I wondered if you marvelous folk may be able to help out at all??!

It is leaking from where a blue electrical connection goes into the front of the engine. Sorry I can't be more precise but I'm an absolute rookie! I did however get a picture of that helps at all? It's circled in red, and you can see the next drop forming! :(

IMG_20200509_153614~2.jpg



Any help greatly appreciated.

Best regards.
Rob
 

·
Registered
Joined
·
345 Posts
It's your coolant temperature sensor pal. The O-ring has most likely perished. It's a really easy cheap fix. If you buy the sensor off Ebay look for just campers for good quality, it will come with everything you need. Make sure you get the same colour sensor & check how many pins it has. It'll be 2 or 4 pin.
 

·
Registered
Joined
·
8 Posts
I did mine a couple of weeks ago, and basically changed the plastic coolant flange that it goes into as they distort over time, the same with the thermostat one too. It's a bit fiddly to do but took me less than an hour, just 2 x 10mm bolts and I could access most of it from the top, just the bottom water pipe to take off, and then you can take the whole assembly out, replace both sensor rubber seals and clips, and then bolt it all back in - I did buy a pair of those special pliers that can undo the pipe clips, which helped a lot! Brickwerks do the flange, seals and plastic clips and will post them out, cheap as chips, and don't forget to order some coolant too. Just don't do the bolts up too tight, they are only supposed to be torqued to about 10nm, and have a washing bowl ready underneath to catch the coolant coming out - I put most of mine back in as I had only changed the thermostat a couple of months ago so it was fairly fresh and full of coolant, I just topped it up with fresh anti freeze.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #4
Great. Thanks guys. I've just pulled the rad out and think I've found the offender... I think it's the seal in the top sensor. I don't think it's the flange as this was replaced (supposedly??!) In November. I have a video here.. New video by Robert Young


Does anyone know of the securing clip is on correctly? I think it is, as the sensor is wobbly I'm almost positive it's the seal that's gone...
 

·
Registered
Joined
·
8 Posts
I can't see the video- my old iPad is a bit rubbish - but the clip only goes in so far with a small gap between it and the housing. The sensor isnt tight in the hole like it would be if it was bolted though, so it might move a little, but it might be worth replacing the clips and o rings to be safe, as they're so cheap to buy. The sensor could also be broken and leaking, but that's unlikely, the fault will probably be the seals. If you have the radiator out it should be really easy to change the seals and clips.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #6
Thanks Joe. Yeah, my sensor probably has about 8 -10mm play when rocked side to side and you can see liquid leaking between the sensor and flange as well, I'm pretty sure that's the culprit! I guess I need to drain the coolant, is that done on the solid metal pipe at the bottom of the engine? There seems to be a nut you can undo there.
 

·
Registered
Joined
·
8 Posts
Just take the sensor out, and whilst some coolant will come out, just catch it in a washing bowl - I don't think it even half filled it and I took the whole flange off. Just pull the clip out, then the sensor, and then remember to take the old rubber o ring out.
 
1 - 8 of 8 Posts
Top