[skucera]

I'm getting very frustrated with a coolant leak. Last autumn I developed a coolant leak that put coolant onto the top of my timing cover on the driver's side, just under the distributor. (I have an '89 with a 3.9l.) I replaced the water pump because it was leaking a little anyway, and I figured it might be leaking from the top of the big snail-shaped gasket. That fix had no effect.

Next I figured I had a leaking cylinder head gasket. (I've had them fail on other cars and leak coolant out the side or front of the gasket to the outside of the engine, so even though I couldn't see the leak, I just figured it was there.) I replaced the head gaskets. Turned out they were about to fail; the composite layers were developing a void running from a rear coolant passage toward cylinder 7. When I got it all back together, the leak was still there under the distributor.

Next, I figured I had a leaking timing cover gasket, so I replaced that, as you might recall from my posts over the last few weeks. Today I got it all back together, and the leak is still there, as bad as ever.

I feel like I'm missing something really basic. This has be feeling like a noob, even though I have 30 years experience working on English and European cars, and even a little experience working on American cars (Oldsmobiles, mostly). What have I overlooked? I'm really beginning to pull my hair out.

Thanks in advance,
Scott

 

[parker]

Well this advice is from a noob. After changing thermostat and sensors in the same area, I noticed I had coolant pooling in the same area. Thought I had not put everything back the way it should have been. Did everything all over again. Nice and clean, no coolant. Looked under the hood a few days later and there was coolant.

The coolant was coming from a pinhole leak on the bottom side of the upper radiator hose. I could not see it until I opened the hood, hot engine, with the engine running. I could not see it leaking unless it was hot and running. New hose, no coolant now. Make sure you check all your coolant hoses in that area.

Hope your fix is that simple.

Parker
1993 LWB Plymouth Blue

 

[james]

You sound like you know what you're doing, so I hope I'm not suggesting anything you have already checked.

If I'm thinking of the right area, have you checked for leaks from the thermostat gasket?

 

[skucera]

Pinhole leak in a hose! Duh, why didn't I think of checking for that?!? Thank you for the idea.

I have checked the thermostat gasket, and it was solid last fall. However, it is worth checking again.

Thank you both for the ideas.

Scott

 

[Eric D]

Buy or borrow a coolant pressure tester. Mine came with a bunch of adapters for numerous vehicles including Rover.

I have one just like this, got it off Ebay 4 years ago.

With this tester you can safely pressurize the cooling system while the vehicle is cold.
With the system pressurized you can easily and quickly find any leak.

Now on to common issues with the Rover V8 cooling system.
If you look at your throttle body, you'll see it has 2 cooling pipes and hoses going to a bolt on plate. This plate is designed to prevent icing of your throttle body.
Over time coolant that isn't serviced every 2 years can cause pitting of the aluminum, rusting of the metal pipes, failed gasket or the pipes can work loose (they are press fit).

Gasket ETC7353

So check that out and the intake manifold metal pipe, and don't forget the temp sensors.
At the back of the timing cover, behind the water pump are hose ports. These ports can also get pitted or deteriorate thus leaking out of the hoses.
I had this issue when I first bought my RRC back in 02. I quickly replaced the timing cover with a good used one and all new hoses and water pump.

Also inspect your hoses for striations on the inside. Run your finger inside the hose and if you have black residue then you should consider replacing the hoses.

:thumb: