Freeze plugs?

[lionvt]

I am considering putting the genuine block heaters into my 91 Range Rover and my 95 Disco. I know from considering the heater plugs that they go into the "freeze plug." My question: where are these and how would I recognize it? And does anyone have any advice/warnings about this proposal. I would also be curious what people think of the radiator hose heaters that are offered out there. It seems to be possibly an easier solution. Ideas?

 

[Bouvier]

If by radiator hose heater you are talking about the circulating type heaters they are fantastic. I worked seismic in northern Alberta as a kid and thats all they used and they worked great. When you start there is even warm air available right away. The engine is gently warmed and starting is easy. The diesel rigs had block heaters as well but often they were just left running all night. I have used them regularly and will likely fit my D1 with one. I have a block heater in mine and I will follow the line and see where it is but I'm sure it won't be in an easy spot. Removing frost plugs isn't too bad it's putting them in thats tricky.
When its -20 I'd rather have the circulating heater over the block and when it -40 I'll use both.

 

[parthog]

The tank-heaters are easier to install, hang in a heater hose, rely on convection to circulate. The frost-plug heaters are more direct engine heat, work great also, I've had both and prefer the block heaters (frost-plug) simply because they are inside the engine and out of the way.

Magnetic oil-pan heaters are also available, if it's really cold one on the transmission is a good idea (or full-syn fluid, but the heater warms the t-case also).

- Jeff Miller

 

[apg]

While practically the whole world calls 'em freeze plugs, these plugged-up holes are actually an artifact of the block casting process. It's how all of the mold material gets shaken out of the coolant and other internal passages when the block drops onto the shake table after casting. These are saucer- or frisbee-shaped discs about an 1 1/2" in diameter, partially hidden by the exhaust manifolds.

I'm told that it is possible to remove one and refit the block heater without removing the manifold. Looks kinda tough to me.... I've had a block heater on the Series III for 20 or more years, but the Rover 2.25 engine has a nice 1" NPT port for that purpose.

 

[lionvt]

Pictures?

Anybody have any pictures or diagrams to help show what I'm looking for? Thanks.

 

[alex3324]

Google Image Search

Anybody have any pictures or diagrams to help show what I'm looking for? Thanks.

Freeze Plugs:

Photo of freeze plugs in a block (they're in the center of the painted portion of the block - there's three of them in this picture

 

[lionvt]

Thanks! How do you get them out? Do they unscrew or do you tap them out somehow?

 

[Rocky]

Start by draining all the coolant. once done you can simply er whack them out.....Then reinstall the heater (mine ws $40 from RN). Get heat out of the engine into the car within feet of starting up. Start up is much easier too. Electric plug exits at the radiator grill.

Oh yeah don't forget to fill with fresh coolant

 

[jec]

FWIW, on our 95 D1, the heaters were installed by the dealer on both sides of the block, in the freeze plug immediately behind the engine mount; don't know how that will translate to your 91 RR. This puts them about the center front-to-rear of the engine, which seems a logical location. Couple of hours plugged in does a great job of warming up the engine, and as other posters noted, yields hot heater air right away.
John

 

[lionvt]

I hate to ask but do you remember how much the dealer install was?

 

[jec]

Will:
invoice shows 4.0 hours, or $180.00 in 1994 Seattle dollars, to install two heaters.
John

PS: After I looked at that again, I said "wow, that was a cheap labor rate!"

 

[CRASH05]

A couple of L/R magazines did write up on these. Might be worth a look.

www.wolverineheater.com

 

[lionvt]

Lower Hose Heater

I was in Roversnorth yesterday and talked to them about it. They recommended the hose heater as being easier to install and just as effective. I am going to give it a try.