Engine Cooling System

[ccmorr08]

Gents,

Great to meet all of you. I am in the Washington DC area and have a 1965 SIIA in case anyone else is in the area. I have been on the boards for some time but this is my first post. Having some issues with my cooling system.

Some background. I purchased my SIIA 88 in March 2012 in California. I drove it for about a year with no issues at all. In April of 2013 I moved to Georgia and began to have some cooling problems. The engine was overheating regularly and i did a full system flush to remedy the issue. It seemed to correct the issues for the most part.

In October I moved to DC and the cooling problems have changed a bit. It continues to run cool when there is plenty of coolant in the system, but I am losing coolant at an alarming rate. Sometimes while driving I will have water/coolant pour out of the heater unit and empty at my feet and I have observed some leaking from below where the heater is mounted on the firewall. It doesn't look like it is leaking from anywhere else.

The pipes/hoses where the cooling system enters the firewall appear dry and solid, so I think the leak is somewhere in the heater.

Has anyone else experienced problems like this? How complicated is it to find the actual source of the issue? Do I need to remove the entire heater to find the issue? Recommendations?

[ccmorr08]

Further, what is the best way to diagnose a water pump malfunction? Could this have something to do with the issue? - Perhaps water not circulating properly and therefore causing further problems in the cooling system?

[Revtor]

the easiest way to deal with it is to plug up the inlet/outlet ports on the engine that go to the heater. You may have a valve near the radiator coming out of the top of the thermostat housing that is designed to stop the coolant from flowing to the heater. If you can stop the heater from leakign you can then see if it stops losing coolant.

other than this "ill deal with it later" solution, you're gonna have to get the heater core 'outta there and fix it up.. Because its obviously a big problem and it will only get worse.

If there is no weeping coolant coming out of the water pump then don't worry about it, deal with the heater. You can plug the hoses or ports and run with it like that until you find a replacement.

~Steve

[stomper]

As Steve said, you need to remove the heater matrix. It is likely full of pin holes and will look like someone shot it with a shotgun. Undo the hose clamps and remove the inlet and outlet hoses. Unbolt all the bolts that hold the heater box to the bulkhead. (Around 8 of them) and undo the motor from the heater box. That should get it out of the engine bay for you.

[ccmorr08]

Thanks for the answers. I will have an opportunity to take a look at the issues tomorrow and will let you guys know what I find out. I do remember there being a valve, but if I remember correctly, it is back near the bulkhead, not adjacent to the radiator. I will post a picture of it once I am able to get back under the hood.

Chris

[LR Max]

I pulled my heater core a couple years back. Pulled the entire thing and box and took it to a radiator shop. He said it was so clogged, he had to leave it in the hot tank overnight.

If nothing else, I've got good heat now. I took a moment and sealed up said box to help but I doubt it did anything. Overall, $25, not a lot of work, I'm good to go. I hope you find a similarly awesome shop.

[o2batsea]

Hi Chris
For your consideration, the Washington DC area is the home of one of the largest and most active Rover enthusiast groups in the country. We have, arguably, the largest monthly gathering at the NoVa Happy Hour every third Thursday of the month at Kilroy's off Braddock Rd at the Beltway.
I'm in Kensington MD. I would be willing to take a look if you want a second set of eyes. PM me.

[ccmorr08]

Gents,

I have fixed the problem by reworking the plumbing to bypass the heater. There was indeed a valve, but it on top of the engine block and interrupts the flow OUT of the heater rather than stopping water from entering. Any idea what the purpose of this valve is?

I will post some pictures once I get the heater unit out of the vehicle.

Thanks for the help!

[Revtor]

the valve is to keep hot water from flowing through the heater. mounted on the block sounds odd, but anything is possible on 40+ year old utility beater vehicles like these.

[ccmorr08]

Revtor,

Interesting that there is no other function. Having it on the back end of the heater flow simply results in even more coolant being forced out of the heater by increasing the pressure in that portion of the plumbing. Either way, I corrected the issue by bypassing the heater. Maybe I can relocate this valve to front end of the system with a bit of work.

Chris

[LaneRover]

Revtor,

Interesting that there is no other function. Having it on the back end of the heater flow simply results in even more coolant being forced out of the heater by increasing the pressure in that portion of the plumbing. Either way, I corrected the issue by bypassing the heater. Maybe I can relocate this valve to front end of the system with a bit of work.

Chris

I don't think the heater cares which way the fluid goes through it. I would just switch the hoses so that the valve is before the heater. That's how it is on my 109.