Coolant Capacity Query

General advice sought here from those in the know.

My LT31 2L. Petrol runs sweet as a nut and I love it..... The question is this... The rad' thermostat gave out on me the other day... starting overheating etc No big deal. Took it out and got her home safe and sound without a hitch.
Anyway decided to change the coolant as it's time and flush the system out.... During this process I've realized that my coolant capacity to the line is around 7 litres (ish)... The BOOK says it should be 9 Litres. .

I've ran the fresh water through the system and it's settled down and aint' taking no more so I'm vexed.
Temperature wise the old girl runs great somewhere between 1/4 and a 1/2 on the gauge.. never no more even on the steepest climbs.

So before I pull the Rad' off and give it a right good seeing to, is anyone out there gonna tell me that It's happened to them and there's nothing wrong. Or are you all thinking get it sorted before you drive the thing all the way down to the South of France and back which we're going to in July.

It's a 1976 LT31.

Edited by Butternut boy - 06 May 09 at 18:05

Is the heater control set to hot? Wondering if 2 litres is sitting in the heater matrix and might not be draining.

Another thought. Does the block totally drain of water? I'm sure I've seen a block drain valve on some cars because of this.

Okay I give up..... No matter what I do I cant find a problem with my coolant system.
I've had the rad' off, I've checked pipes I didn't know I had, flushed more times than a bog in Deli.
I've blown so hard into the expansion tank that I thought me ears were gonna fall off.
I've ran the engine briefly with the pipe off at the water pump to make sure it's pumping.. it is.
I've pulled the pipes off at the Matrix and it's empty and all the fresh water I'm putting in comes out looking just as fresh.
My coolant capacity is no more than 7 and a half litres... GAME OVER.
I conclude my expansion tank is smaller than everybody else's and now I'm gonna get Pished.

Had the heater pipes off both sides... Nothing stuck in there.

Thinking back to when I drained my old antifreeze last October about 8 litres came out. I don't know why I measured it now but must have been a reason. I think my capacity is 12 litres (2.4 diesel). I stuck in a full 5 litre can of antifreeze which if it is 12 litres should have given it approx 40% solution. 

Hi Butternut,

Why do you need/want to empty the block? As long as its been thoroughly flushed, there will just be clean water in there. If you have further concerns about cleanliness of the water galleries in the block, it may be worth getting some radflush and run the engine for a while, and then draining again and flushing through with a hosepipe. Its then a simple matter of topping up with enough neat antifreeze to ensure the required strenght of solution.

Rgds,
Peter.

Hi Butternut,

yes, that's usually the case. If you disconnect the top & bottom radiator hoses at the radiator end, put a hosepipe into one of them, and turn up the tap on the hosepipe fully to get a good flow. The water will circulate right around the engine and back out of the other hose - the only thing you have to think about is the thermostat will be closed so could restrict flow, so to get a good flow it may be necessary  to remove the thermostat.  As I said, I'm not familiar with the 2 ltr petrol engine, but from the Haynes manual, I can see there looks to be one main hose connected to the water pump, and the other to the top of the thermostat housing. Looking at the thermostat housing, there is another outlet (heater hose?) underneath, which looks lower than the thermostat, so this outlet should allow the flushing water to flow freely through the block without removing the thermostat. Its usual to flush both ways, first put the hosepipe down the water pump hose, then into the lower outlet of the thermostat housing, until the water runs through the other end cleanly.

Hi Butternut (me again!)

have you got a copy of the Haynes manual? - if so look on p30, bottom right photo (7.25b) you can see the plate next to the thermostat housing - definitely is a blanking into the "oily bit" of the head.

Rgds
Peter.

If you just drain and refill with water a few times you will get almost every last bit of old antifreeze out. What's left will be so diluted that it won't make a sod of difference. I did this last Oct as I had the usual ethylene/glycol antifreeze in there and wanted it all out before putting in some G12. I must have given it about 8 flushes in the end with a couple of runs up to temperature. Diluting what's in there with every drain/refill is the easiest way to get all the old stuff out. I've not tried the hose flush yet, might do that next time. I drained mine through he drain plug in the rad. Not best way and should have taken the bottom hose off, but it was cold and nasty and was taking the easy route. 

Butternut boy wrote: Cheers RR..... You know the only thing that bothers me about not being able to get the system completely empty of fluid is that I'm dull and anal enough to only use distilled water with the G12

That is exactly what I did so you are not the only one. Only difference is I saved my water from the dehumidifier I have running in the camper over winter. It produces about 3 litres of water every week and guess it must be as good as battery distilled water by the process of collecting the water from the atmosphere. Certainly more pure than tap and won't leave calcium deposits. I know some cars recommend tap water with their antifreeze. Not sure what VW say for the LT, by have a feeling I read distilled/deionised water. All this fuss. In the old days we just stuck tap water in the car and only put in antifreeze for the winter. That was about 30 years ago though when engines only lasted 60,000 miles and had a cast iron head.

I didn't know about G12 when I got my van in 2002 and stuck ordinary Ethylene Glycol in there. Stayed in until last year when I finally decided to put in the right stuff. As far as I know G12 is ethylene/glycol, with the addition of the BASF G48 anti corrosion additive. Having a tiny amount of the old Eth/Gly in there surely won't matter one jot, but no harm draining, flushing and refilling for as many times as you can before you get really fed up with it.

Must admit, when I warmed up the van after a few refills, the bottom rad hose didn't get hot, even though the temp gauge was reading normal. I think the temp gauge is looking at the head temp as that's where the temp sended is, but I would have thought the thermostat was open and letting water circulate around rad when it was reading normal. Perhaps not. I couldn't take it for a run at the time to really warm it up as didn't have tax on it.