Overheating Diesel (still)

[Wavehead]

Hope someone can help here as I am at my wits end!

Bit of a saga this ..... my 1984 1.6 n/a diesel began overheating so after checking for leaks and changing the thermostat, pressure cap and checking the water pump I thought I had solved the problem when I took it for a test run the gauge read normal (although the heater only worked intermittently). As I pulled onto my drive I noticed that there was coolant gushing out and on examination I found that one of the metal coolant pipes had sprung a leak through corrosion and that the small top hose had split. I always knew that these needed replacing at some point so ordered the stainless steel ones from JK (£200) and fitted them last week with no major dramas. I flushed the cooling system through and re-filled with water after bleeding and a few test drives later, I was happy that it was not overheating although the temp gauge was up and down somewhat? Replaced water with anti freeze mix ... bled it .... another test drive then calamity ... the large top hose that runs from the cylinder head to the radiator and expansion tank .... exploded!! I am rather concerned as two hoses and the old metal pipes have now failed so am guessing there is a blockage somewhere (in the engine?)

I have run out of time as took a few days off work to get it sorted and am now running out of ideas so any help would be most appreciated, cheers Keith

[windysurfer]

Sounds like it could be presure in the cooling system caused by the head gasket leeking

Meggles had a similar exploding hose on his 1.6d caused by the HG failing

https://club8090.co.uk/forum/viewtopic.php?f=2&t=51630

[Wavehead]

Thanks for that ... yes it would appear to be an identical problem. I will get another hose and have the system pressure tested and post back with the outcome, Keith

[windysurfer]

Are the thermostat and pressure cap OEM?
I've read that both can cause problem is cheap copies are used.
Fingers crossed its something simple ( and cheap!)

[Wavehead]

Both pressure cap & thermostat bought from Simon (Mr Brickyard) so should be good un's? I guess the pressure test will reveal the cause. I guess it will be the head gasket ... just hope the cylinder head is ok as its only 5 years old

[meggles]

Sounds like it could be presure in the cooling system caused by the head gasket leeking

Meggles had a similar exploding hose on his 1.6d caused by the HG failing

https://club8090.co.uk/forum/viewtopic.php?f=2&t=51630

Sorry to contradict, and to post a totally useless reply. Yes, my top hose exploded in dramatic fashion, but the head gasket does not appear to have blown. I cannot see what caused the problem! The head gasket was not brilliant but no obvious blow! Do these engines only need a slight leak to blow a hose? If they do then maybe, just maybe, it was a head gasket problem. The head is certainly not cracked (according to local engine rebuild specialist). Oh! and the water pump was fine as well. Rad not blocked, nor the pipes front to rear.
Hope this helps
PS, getting a new hose and pressure test is probably the best option! Good luck.

[Simon Baxter]

If there is sufficient pressure to blow a hose like that then you have problems.
Remove head, check for level and reface as needed.
Did you find that the water level behind the flap always goes up and always some air in the tank in the engine bay?

[Wavehead]

Thanks Meggles all noted ...

Simon, I dont recall seeing the symptoms you describe however at no point did the expansion cap let any pressure out of the system so nothing went into the tank behind the number plate flap. The heater worked intermittently but apart from that I thought I had cured the problem .... until it blew!!
I guess the only definitive way is to have the head off as you suggest and examine for defects?

kEITH

[gavnjax]

boy am i glad i read this!, my 85 1.6 diesel has had simular problems recently as the hoses keep leaking. set off to norwich from leicester today, gingerly watching the temp. pulled in for a pitstop near swaffham as i pulled away BANG! a hose split and threw all the water out. made a roadside repair with gaffer and filled up at filling station, any advice , as i'm on holiday here this week and not got a computer after tomorrow,

[Wavehead]

I have just received a replacement hose but am in Dublin at the moment (having seen Springsteen ....AWESOME!!) so have had to leave the van sat on my drive until I get time to play with it again. I will post an update with the outcome but not likely to be until next week?

Keith