Coolant Flush and Heating Problem

[DCPAus]

Dear All

This is driving me nuts(although possibly I was anyway because I bought a D2)

I have a '99 D2 TD5, and have a Low Coolant Alarm fitted.

A month ago I noticed that my heater wasn't working and that my coolant was low, so I flushed and did a full refill of the system - without removing the bottom drain bolt, just by running more than 15litres of OAT (Nulon Red) through the system, by lifting the coolant tank above the battery box, and running a hose from the top bleed screw back into a clean container.

After doing this whole process twice, I still do not get warm/hot air in the cabin. I also did a manual Aircon Panel test with no faults recorded - so all these bits seem to be ok.

And then finally today I took of the shroud above the Radiator and noticed a small dry patch of OAT on the top right hand side of the radiator (could just be spillage so have rinsed and will monitor over the next few days)

Any brilliant ideas?

[Discovery-94]

Probably need to bleed the system.
Don't know about the TD5, but in my 300td D1 refilling the system as follows:

first radiator (which is the lowest point) -close when full
then through the thermostat housing (which is the highest point) with the overflow tank open until coolant is at level in the tank -close tank
then fill up thermostat housing until full.

after this I need to run the engine until warm, turn the heater on and open thermostat housing plug and bleed until no air bubbles (and until heater is warm) - this can take a little while (30min)

Hope this helps.


I also keep an eye on how much coolant I fill in (plus a bit that spills while waiting for the air to escape) so I know how much I am off the total capacity

[Zute]

If you find coolant on top of the radiator again, check the lenght of the plastic tank where it joins the core.
I had a sticking thermostate and the extra heat caused it to leak around the rubber seal that join these two parts. It was the coolant on top that drew my attention to it.
Also after you have taken it for a longish drive, check both ends of the radiator. If the drivers side is cold and the other end hot, than water is not flowing through and it could mean the thermo is not working. ie opening.
If after the drive both ends are cold, than it could mean the thermo is stuck fully open. And this may account for the cold heater.
A Nanocom will give you a better reading of the ENGINE temperature. Dont trust the in dash one.
Also check the hoses that go through the fire wall, next to the clutch master cylinder (and fuel block on the engine) Both hot, than the water is flowing to the heater.
Best of luck.

[Zute]

Just checked the Rave disc and water should allways be flowing through the heater. When it leaves the heater it travels to the fuel cooler. It opens at 82c.
Check these hoses to see if warm water is flowing.
If these hoses are cold than a blockage must be present.

[biggin]

If you are getting hot heater lines in and out, the problem is more likely to be in the heater matrix, probably the blend motors. Read section 80 of the RAVE worshop manual for details.

[DCPAus]

If you find coolant on top of the radiator again, check the lenght of the plastic tank where it joins the core.
I had a sticking thermostate and the extra heat caused it to leak around the rubber seal that join these two parts. It was the coolant on top that drew my attention to it.

Does that mean that you can replace that rubber seal and not necessarily the whole radiator?

[DCPAus]

If you are getting hot heater lines in and out, the problem is more likely to be in the heater matrix, probably the blend motors. Read section 80 of the RAVE worshop manual for details.

Don't think it is the blend motors, as all combinations of Feet, Demist, Aircon at 16 C on left and "hot" air on right etc. seems to work, so think it is coolant flow, I may just have to bite the bullet and place all hoses, drain system properly and flush.

[Blknight.aus]

if its second hand make sure that someone hasnt bypassed the heater matrix.

[Zute]

Does that mean that you can replace that rubber seal and not necessarily the whole radiator?

You can, But..
Its all crimped together. Ive been told that it dosnt like being done a second time.
Mine hasnt leaked since replacing the thermo. I now have a Nanocom and can better keep an eye on the temp if pushing it hard.

[DCPAus]

OK, update

I have decided to buy a new Radiator to solve that leak, replace my hoses as I am doing all the work anyway, but the heater issue has been resolved, I "palpated" all the hoses, flushed the system again and did a drive, I then noticed that my heater was working but that in the tank there was some "gunk" now floating around.

I then stripped down the fuel heater and noticed that that was also full of gunk, so I can only believe that my coolant system was contaminated and the heater matrix was blocked.

So I believe that after flushing, replacing the hoses and the radiator it will be all much better.

[Jason789]

Hello DCPAus,

Try pulling the water pump off. I did a complete cooling system overhaul(radiator,pipes,t/stat and pump)with factory radiator and pump.

The water pump was of concern to me as the bottom 1/4 of it and the galleys leading from it were blocked with a waxy pink crud. I cleaned it but have kept it as a spare.

It may be worth a check as I have never seen any thing like the crud that was on mine.

PS. My cooling system(TM2 fitted) has not leaked a drop since the overhaul. No top ups with coolant since the sytem has found its level and no temp spikes(not even on the hill going into Toowoomba, or the Tambourine Mountains hill...FIGJAM...woohoo )

Cheers,

Jason

[DCPAus]

Since I originally posted this, I have
Replaced Radiator
Heater Matrix
Every single Coolant Hose
Thermostat
Expansion Tank Cap
Water Pump (24 hrs ago)
Oil Cooler Housing (24 hrs ago)
Oil Cooler "Matrix" (24 hrs ago)
Water Housing (on Head) (24 hrs ago)
Repaired Fuel Cooler (replaced gaskets)

I had noticed that there was severe corrosion on the Oil Cooler Housing and the Water Housing.

I am now hoping that I have at last resolved all obvious areas where I could have been losing coolant.

If I still continue to lose coolant then I will have to suspect a Head Gasket issue :(

If anyone can think of any obvious areas I have missed let me know.

[alien]

3 easily over looked suspects to check for leaks.
1-The short steped hose tucked up under the turbo(Falcon heater hose fitts just nice).
2- The plug in the head on the exhaust side(from memory between cyl3/4).
3- Top tank radiator tanks due to screws holding the shroud being to long(remove screws to check).

[DCPAus]

3 easily over looked suspects to check for leaks.
1-The short steped hose tucked up under the turbo(Falcon heater hose fitts just nice).
2- The plug in the head on the exhaust side(from memory between cyl3/4).
3- Top tank radiator tanks due to screws holding the shroud being to long(remove screws to check).

HI Alien

Thanks for that,
I replaced the stepped hose, with all the other hoses, so that still seems fine, the radiator tank, is also ok, but I had not thought about the plug in the head, will have a look this weekend, if I still continue to lose coolant.