AAZ cold start + overheating
Posted: 25 Oct 2020, 18:46
I bought my T25 in July and have been doing a fair amount of work on him since then. He started as an Aircooled in 1981 but has had an AAZ put in around 8 years ago. Once the engine is warm it runs pretty nicely but there’s a couple of issues I want to sort out.
Cold starting
As it has got colder I’ve found it harder to start the engine and the clouds of smoke coming out the back have got bigger and bigger, around 2 minutes at this point. I’m not really sure how my glow plug system works. There’s a relay at the back (90 464 952) and a new button and light at the front, when I hold down the button (previous owner said 7-8 seconds) the light is on, and off otherwise. There’s no other feedback apart from that, and that’s all the instructions I got, what can I do to check it’s all working well? The glow plugs themselves are the ones that came with the bus, so I’ll probably replace them anyway.
As far as I can tell there’s no cold start advance hooked up. There’s a cable grommet on the inside of my injection pump (1 465 530 828) so I’m guessing there’s a lever somewhere down there, does anyone know what it looks like?
Overheating
When the engine is running it sits at 3/4 on the temp meter and on any long hills it creeps up and I’ll eventually get flashing temp light. Twice I’ve badly overheated. The fan has never turned on but I’ve had a garage take a look and he said it’s because not much coolant is getting through to the radiator. Ill be draining the system soon to add a heater so I want to know if there’s anything I should be doing before/during that.
Here is a picture with most of the hoses marked:
Red and green radiator hoses are always hot when the van stops so I’m pretty sure my thermostat works to some extent, ill check that when the system is drained.
In pictures I’ve seen the thin purple hose goes to the expansion tank but here I’ve got the much wider pink one doing that job instead, is that right?
Any ideas what the blocked off section of yellow bypass hose is for?
Lastly, the blue heater hose goes straight from the front of the block back to the radiator return as there was no heater put in when the engine swap was done. I’m guessing that when the thermostat is open its much easier for the pump to just pull hot water through this that drag it all the way through the radiator. I’m fitting a heater up in the front soon using this feed so hopefully that will sort out some of my problems.
Does anyone know what’s up or is able to provide a picture of a properly circulating AAZ?
Thanks in advance!
Cold starting
As it has got colder I’ve found it harder to start the engine and the clouds of smoke coming out the back have got bigger and bigger, around 2 minutes at this point. I’m not really sure how my glow plug system works. There’s a relay at the back (90 464 952) and a new button and light at the front, when I hold down the button (previous owner said 7-8 seconds) the light is on, and off otherwise. There’s no other feedback apart from that, and that’s all the instructions I got, what can I do to check it’s all working well? The glow plugs themselves are the ones that came with the bus, so I’ll probably replace them anyway.
As far as I can tell there’s no cold start advance hooked up. There’s a cable grommet on the inside of my injection pump (1 465 530 828) so I’m guessing there’s a lever somewhere down there, does anyone know what it looks like?
Overheating
When the engine is running it sits at 3/4 on the temp meter and on any long hills it creeps up and I’ll eventually get flashing temp light. Twice I’ve badly overheated. The fan has never turned on but I’ve had a garage take a look and he said it’s because not much coolant is getting through to the radiator. Ill be draining the system soon to add a heater so I want to know if there’s anything I should be doing before/during that.
Here is a picture with most of the hoses marked:
Red and green radiator hoses are always hot when the van stops so I’m pretty sure my thermostat works to some extent, ill check that when the system is drained.
In pictures I’ve seen the thin purple hose goes to the expansion tank but here I’ve got the much wider pink one doing that job instead, is that right?
Any ideas what the blocked off section of yellow bypass hose is for?
Lastly, the blue heater hose goes straight from the front of the block back to the radiator return as there was no heater put in when the engine swap was done. I’m guessing that when the thermostat is open its much easier for the pump to just pull hot water through this that drag it all the way through the radiator. I’m fitting a heater up in the front soon using this feed so hopefully that will sort out some of my problems.
Does anyone know what’s up or is able to provide a picture of a properly circulating AAZ?
Thanks in advance!