Thread: P38 coolant woes

One of a few possible things in my eyes, but I'm no expert!

Head gasket
Expansion tank cap faulty
Water pump
Radiator blockage

I had a similar thing happen to me when I first got mine, turned out to be a combination of water pump and radiator blockage.

See what the other lads have to say, if it were me I'd start with the easy one and replace the expansion tank cap.

Cheers
Keithy

Keithy`s suggestions are all possible.
I think you have two issues here the second one is refilling the lost coolant once its been lost. This is no as simple as topping it off. You need to get the front of the car as high as poss. Fill the tank to level, run the engine till the level starts to rise then stop the engine and leave for a few hours. Repeat until the level stays constant. Its a pain getting the air out and this is the only successful way I have found. Told to me by a Landy expert.
1st issue is overheating to start with. If you are not loosing coolant in normal driving and temp is stable, oil clear, no bubbles in expansion tank I would suspect the Rad being partially blocked, a quite common problem. Now quite cheap on ebay around $$300 shipped and an easy job. You could try a flush. Make sure the small tube from the Expansion tank top to the rad is clear from any blockage, when the engine is running there is a steady slow flow through it. I would also extend the overflow pipe from the expansion tank so if it does overflow you wont expose your fusebox to a steam bath
Once sorted get a low coolant alarm and if not changed get a new water pump and Rad. Much cheaper than a slipped liner

Thanks guys. That's great advice!
I had previously suspected and ordered a new water pump and am awaiting its arrival and this will be my next job. I have also already changed the cap so I will check the other stuff while I'm in there and go through the process of elimination. Just as well that I don't need to drive it to work every day! I did happen to notice a lot of bubbles now that you have mentioned it coming into the expansion tank.

Worth checking the two oil coolers in front of the radiator. When I had a problem I replaced thermostat, water pump, radiator, hoses cap and then found that the gearbox oil cooler was clogged almost solid which was blocking air flow to nearly a third of the radiator. After cleaning, I found it was leaking trans fluid which I fixed, and haven't had a problem since.

John

Radiators furr up. Mine did exactly ybe same, I fitted a new radiator and job done - no more.overheating

It would seem that a new rad is the way to go.

Mmm hate to say it, but, if you have constant bubbles when running you have a blown head gasket at best.........but most likely you have a slipped liner.
If everything is in good order these vehicles dont "just boil" even in a hot climate.
Have you just bought the RR?
How many Ks?
What is the general colour in the expansion tank? what was it like when you bought it? (is it all rusty looking?)

These engines dont like to boil, the cooling system needs to be in tip top order.
Replacing good quality coolant every 2 years is a must. I change my hoses every 5 years or so. If your water pump is 10 years old and 200,000k on it you will be surprised how stuffed it is when you change it (pretty easy job).

I bought it about a year ago from Sydney and it has around 300,000k on it. The expansion tank is nice and clean and was when I got the car so no change there. I changed the hoses just last weekend along with the thermostat and carried out a rebuild on the valve block and compressor. I had just filled it with coolant so maybe it's something to do with that? I'm not ignoring your advice just hoping that it might just be something else and not the head gasket or liner. I'm still tempted to go via the process of elimination before having to carry out any major work.