Coolant change on a 1.9 n/a diesel

robt · Post by **robt** » Tue Oct 04, 2011 12:26 pm

Does anyone have any tips or advice on how to successfully change the coolant on a 1.9 diesel? Are the systems prone to air locks? The lack of temp gauge is making me wonder whether I should entrust the task to a pro, rather than mess it up and potentially cause more problems!

Thanks
Rob

Post by **Tim Leech** » Tue Oct 04, 2011 12:39 pm

Hi Rob

Always worth removing the rad if possible after draining (a row of 10mm bolts hold the panel in place above the radiator itself) and back flushing it if you can, I remove the bottom hose to start with to drain the system (let the engine cool first).

When you refill open the large screw a few turns at the top of the rad on the opposite end to the bottom hose to allow trapped air to escape, also make sure the heater is set to max.

Once filled start the car keep it ticking over with the radiator cap off and squeeze the hoses a few times each to "burp" the system, top up as necessary. Make sure heat is coming out of the vents, if its still cold and the engine is warm there be an airlock!

I use a 50/50 mix antifreeze/water.

Its quite an easy job, even for a novice, ive done all of my cars myself and im no mechanic. Worth having some spare hose clips knocking around, also if your car has the platic bleed screws be VERY careful as they have a tendency to sheer off and then leak.

Good luck.

citronut · Post by **citronut** » Tue Oct 04, 2011 1:05 pm

i usualy pull the top rad bung right out and fill the system till coolant comes out of this point, and stops sinking then re/fit that bung,

there is also bleed valves one at the thermostat houseing which is a brass allan key head (dont over tighten as they shear off very easy) then the other is on one of the heater hose's at the enginebay side of the bulk head,

quite offten you dont get much from these till the engine is running,

close those tow valves once you get coolant from them,

now continue running engine with cap off topping up as need be,

keep feeling the rad fin surface till it becomes hot evenly all over,

check coolant level once more then re/fit rad/header tank cap,

now continue running engine till rad fan cuts in and then out, one it has cut out gently open rad cap if coolant is calm the job is done,

regards malcolm

regards malcolm

Dollywobbler · Post by **Dollywobbler** » Tue Oct 04, 2011 2:01 pm

Before you start draining, make sure the heater is on and keep it open. I found this morning that raising the front end of the car on ramps helped encourage the air out of the system, as did squeezing not just the top hose but also the heater hose at the back of the engine. BE VERY CAREFUL with this last bit, as your arm gets close to the hydraulic pump belt. No flappy sleeves!

robt · Post by **robt** » Tue Oct 04, 2011 2:51 pm

Thanks for all the good advice, I'll have a go myself then.

Post by **Tim Leech** » Tue Oct 04, 2011 11:05 pm

My advice is take your time, dont set yourself a deadline, but make sure you get some new hose clips standing by just in case.

It may be worth purchasing a haynes manual from ebay, for a coupel of quid as they are useful for us non-spanner wielding gods!

citronut · Post by **citronut** » Wed Oct 05, 2011 8:47 am

Roverman wrote:It may be worth purchasing a haynes manual from ebay, for a coupel of quid as they are useful for us non-spanner wielding gods!

the BOL (book of lie's

lots of nice picy's

regards malcolm

Post by **Tim Leech** » Wed Oct 05, 2011 9:33 am

citronut wrote:
Roverman wrote:It may be worth purchasing a haynes manual from ebay, for a coupel of quid as they are useful for us non-spanner wielding gods!
the BOL (book of lie's

lots of nice picy's

regards malcolm

True but easier to reference too than having your laptop balanced on to pof your cylider head!

robt · Post by **robt** » Wed Oct 05, 2011 8:51 pm

Roverman wrote:
It may be worth purchasing a haynes manual from ebay, for a coupel of quid as they are useful for us non-spanner wielding gods!

Was one of the first things I bought

Bit lucky as I managed to get two from the same seller, one of the general manuals covering the petrol BX and one specifically for the diesel engine. Have been reading the diesel one on the train to work, what a saddo

Post by **docchevron** » Thu Oct 06, 2011 4:10 am

I discovered today that by far the easiest way to drai the coolant system on a BX is to drive through the gates into work, and watch as it all pisses away over the car park...
Sadly, refilling wasn't as easy.

citronut · Post by **citronut** » Thu Oct 06, 2011 8:11 am

arnt you spozd to open the gates

regards malcolm

robt · Post by **robt** » Mon Oct 10, 2011 3:52 pm

Well, tried to do this yesterday but fell at the first hurdle as the bottom hose clip is rusted and jammed shut. Tried using penetrant spray to loosen it, but the head of the clip screw also just disintegrated when I applied any pressure with a scredriver, so any ideas how I remove it? Getting a hack saw up there will interesting....

Way2go · Post by **Way2go** » Tue Oct 11, 2011 12:33 am

robt wrote:Tried using penetrant spray to loosen it, but the head of the clip screw also just disintegrated when I applied any pressure with a scredriver, so any ideas how I remove it?

Using a screwdriver is your mistake...............best to use a long shaft hexdriver socket from underneath the car (assuming it was oriented right last time). You still might get it off ok with the hexdriver if the head is not too butchered.

If the head is totally ruined, I guess some suitable large top cutters are needed to cut the screw clamp body off. Can't recommend a hacksaw as access is bad and you're likely to affect something else.

I would recommend that you disconnect the battery when poking around and getting frustrated in this area with tools as there are wires and connections about.

Post by **docchevron** » Tue Oct 11, 2011 12:46 am

there is of course a drain on the rad itself...

robt · Post by **robt** » Tue Oct 11, 2011 11:08 am

docchevron wrote:there is of course a drain on the rad itself...

Plan B was looked at, but the hose clip on that is also rusted and the angle they put it back on makes it tricky to get to

Unfortunately the bottom hose wouldn't take a hex, only a flat-head screwdriver so I'm a bit stuck. I agree about the hacksaw, god knows what else I'll cut into using that at an awkward angle.

I'll come back to the job next week once I've got the right tools together.

Cheers
Rob