[demarpaint]

I have block heaters and oil pan heaters. Given a choice IMO an oil pan heater is better for cold starts and the engine, and a block heater is better for getting heat a bit faster. I use both in one vehicle.

An oil pan heater is much easier to install. It also warms the coolant a bit too, since it is installed on the lowest point of the engine, the oil pan, and heat rises. It makes a big difference when temps really drop. Check out Wolverine Oil Pan Heaters website. The 250W unit is the way to go. If you're really OCD and live where it's very cold you can put one on your transmission pan as well. They also have battery warmers too. Their CS is great, and if you have any questions they're very knowledgeable and helpful.

Keep in mind a block heater can cause leaks as someone already mentioned.

 

[Tom95YJ]

Interesting, that makes perfect sense. Winters in Southwest Ohio only reach negatives at the peak of winter, but I'd rather drive in a warm Jeep than a cold Jeep, without having it run for awhile. If I need to push it turning out of my neighborhood, I'd rather everything be at operating temperature. I'm not really expecting instant heat, but at least have the engine register or almost register on the gauge (100*F+) within a few minutes of running. I was at first thinking about the heater that went inside the freeze plug holes, but heard that it causes too many leaks. I like the inline coolant heater, as they're only $25 and my dad said that his lasted two seasons, but I'd rather that the correct size exist before I slice open my radiator hose. I'll be replacing the radiator and flushing the coolant and radiator core in the next month, so I'd like to install a coolant heater at that time. I saw a YouTube video where a guy had a battery wrap heater and a silicone oil pan heater. His oil temperature was at 50*F while the outside temp was closing in on zero. That's not bad at all, it gives the engine the initial heat jump and keeps everything from getting too brittle.

I run a coolant type that splices in the hoses for my YJ its been on for 3 years. Works great I love the almost instant scorching hot heat

 

[MudMagnetYJ]

I run a coolant type that splices in the hoses for my YJ its been on for 3 years. Works great I love the almost instant scorching hot heat

Is there a chance you know which part it was? The ones I have found don't say which size hose it's for.

I have block heaters and oil pan heaters. Given a choice IMO an oil pan heater is better for cold starts and the engine, and a block heater is better for getting heat a bit faster. I use both in one vehicle.

I think I'll do the inline coolant heater for now, since I just ordered my radiator so the coolant will be out anyway, and see how that goes. I'll get an oil pan heater if I have extra money and it has trouble starting. Sounds like a good gift idea. Thanks for the input, I'm in the process of winterizing. We just had t shirt and jeans weather last week, and hat and glove weather yesterday, so it's unpredictable.

 

[ADee1]

I bought a used PU with a heater installed in a radiator hose, I took it out after it started leaking about 6 months after I bought the truck. I installed a pan heater, way better for cold starts than the heater in the hose was. No worries about leaks either. if its fast heat you are after the hose heater is better. If its better cold oil flow for a faster easier start and cutting down on engine wear nothing beats an oil pan warmer.

 

[MudMagnetYJ]

I bought an inline heater from AutoZone for $25, part number 14600. They had four different sizes, and were not labelled for the correct size.

According to the lower radiator hose they had in stock, I have a 1 1/2 inch inner diameter hose, so I got the heater with a 1 1/2 inch outer diameter.

I'll let you know how it fits. It looks very durable. Only problem is the short cord, but I'll need an extension cord anyways.

 

[ADee1]

It should work OK, just look for leaks often.

 

[MudMagnetYJ]

It was a breeze to install. All I had to do was drain the coolant, use a utility knife (with a new blade) to cut the hose, and in it went.

Here is a guide for anybody looking for one. I found four part numbers with different diameters. AutoZone has them for $25 each, but no diameters. Amazon has them for $40 with diameters.

When you look for one, know the INSIDE DIAMETER of your lower radiator hose, or whatever hose you're installing it on. Then, measure the OUTSIDE DIAMETER of the heater, including the raised ring around it. These numbers should match. To find my inside hose diameter, I just looked up the part at the auto store and found the inside diameter.

Kat's Lower Radiator Hose Heater

14500 - 1.25" diameter
14600 - 1.5" diameter
14700 - 1.75" diameter
14800 - 2.0" diameter

 

[Y-Yes]

Great thread, and I don't feel like a "high-jacker," since we're discussing a number of engine "pre-heaters."

However (at the risk of repeating myself, but to save typing, because I'm LAZY--LOL) here were a couple of questions that I'd like to re-ask, as they seem to have gotten missed, given all the good, healthy debate:

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
"2. ....Does that Katz, in-line heater have an internal pump, or does it simply rely on convection, to circulate the heat?

And if the Jeep's thermostat is CLOSED (i.e., it's normal position, when engine is cold, right?) how can the Katz-style heater circulate warm coolant throughout the entire block, even with (an electric) pump (which I doubt it has)? (Not that anyone in this thread claimed it could--I'd just like the idea of being able to partially warm up the entire engine, first, if possible.

I've had block heaters on (non-Jeeps) that went into one of the mis-named "freeze plugs" in the block, and looked like a small "water heater-style" heating element. So, at least that was warming the coolant within the engine block itself, not out in the hoses, or in the heater core--which I admit is a nice advantage for the passengers, but perhaps less-so for the engine, than the in-block heater I'm discussing.

The problem with one of the "in-block" heaters I had is it caused the "freeze plug" it replaced to begin leaking. Happily, I caught it in time, carefully refilled (the running) engine, and limped home."
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

That said, I'd like to freely acknowledge that the point made (in bold red, below) by ADee1 had completely escaped my notice, despite my lifelong automotive passions--to wit:

I bought a used PU with a heater installed in a radiator hose, I took it out after it started leaking about 6 months after I bought the truck. I installed a pan heater, way better for cold starts than the heater in the hose was. No worries about leaks either. if its fast heat you are after the hose heater is better. If its better cold oil flow for a faster easier start and cutting down on engine wear nothing beats an oil pan warmer.

I'm actually embarrassed to admit I'd never considered the (perhaps MOST important?) benefit of an oil pan heater, as so eloquently described by ADee1, above.

However, I remain concerned about (cold) piston/cylinder fitment, and, thus, it seems to me that BOTH a magnetic, oil-pan heater AND and internal, engine block-water (heater) style, block heater, would be the best setup.

But can ANYbody please explain to me how the "Katz-style," i.e., in-line, heater-hose style of *cough* BLOCK heater, can possibly heat more than the passengner-compartment's HEATER CORE, when the engine's THERMOSTAT IS CLOSED, as it would be in cold temps, with the engine sitting, overnight?

IOW, it seems like the in(hose)line, "Katz-style" heater can ONLY heat the water in the coolant lines running to the heater core--or is the argument that the "Katz-style" heater is SO hot that it actually causes the engines THERMOSTAT to OPEN, allowing THERMOSPYHONING to occur, i.e., the natural process of heat cycling through an engine, that the early models of Ford Model T's used? (The early "T's" had NO water pump, and relied on the thermosyphoning princple, with decent results, obviously, though Henry later added a waterpump).

My point is--IMO, a "Katz-style", in-line heater--especially if it has no built-in water pump (a question no one has yet addressed--is ONLY going to heat the water in the Passenger's HEATER CORE), which is [physically] HIGHER than the Katz heater) and NOT heat the water in (much of) the engine block, for two reasons:

1. Much of the lower block is BELOW the typical location of a "Katz-style" heater, and;

2. THE THERMOSTAT ON A COLD ENGINE IS CLOSED, meaning there CAN BE NO HOT/WARM WATER CIRCULATING INSIDE THE ENGINE'S WATER JACKETS.

ALL of which makes me think the Katz-style heater presents a warm passenger compartment, but an (initially) cooler engine, than would the "water heater-style" heating element inserted into one of the (mis-named) "freeze plugs" in the engine block itself, as the latter is ALREADY HEATING WATER INSIDE THE ENGINE'S WATER JACKETS, DESPITE THE FACT THAT THE ENGINE'S THERMOSTAT IS CLOSED.

So...since I'm clearly biased toward an IN-block, electric water heater-style block heater, CAN ANYONE RECOMMEND THE BEST BRAND/MODEL OF THIS TYPE OF BLOCK HEATER?

Help? LOL

Thanks,

Y-Yes

 

[demarpaint]

You can also get an oil pan heater, which sticks onto the oil pan. Wolverine makes a good unit and it really helps with cold starting. No cutting hoses or removing freeze out plugs is necessary to install it, so no leaks to worry about. ADEE nailed it.

The only advantage to a block heater is you'll get heat faster, but better cold oil flow goes to the pan warmer. I use both, but I order my vehicles with a block heater factory installed.

 

[harcosparky]

Good battery is a great idea.

BATTERY TENDER is also a good idea ........ Extreme Cold is tough on batteries, and a BATTERY TENDER helps negate that.

I have vehicles here with batteries that are over 8 years old and they act like new, all are on a BATTERY TENDERS.


I like the idea of that engine coolant heater ..... hmmmm.

 

[Y-Yes]

Good battery is a great idea.

BATTERY TENDER is also a good idea ........ Extreme Cold is tough on batteries, and a BATTERY TENDER helps negate that.

I have vehicles here with batteries that are over 8 years old and they act like new, all are on a BATTERY TENDERS.


I like the idea of that engine coolant heater ..... hmmmm.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
And I like the idea of a BATTERY TENDER--both for the Jeep and my compact tractor.

Can you (or anyone else?) provide links to "known-good" battery tenders (i.e., the kind of low-amp, "Smart Chargers" that actually STOP charging, when the battery doesn't need it, so you can LEAVE THEM CONNECTED FULL-TIME)?

I'm in the U.S.A. (for now).

Thanks muich!

Y-Yes

 

[Luckymac]

I have several battery tenders from Batteries Plus. I keep one attached to every vehicle that isn't driven at least a couple times a week. ATV, lawn mower, generator and a marine Battery tender for my camper. I had one each on my wifes and my motorcycles before we sold them. I used to replace my motorcycle battery every year or so. Once I started using battery tenders, my motorcycle battery would last for 5 years.

Harbor Freight has them cheap, but I go for the more expensive units for assured reliability.

Good Luck, L.M.

 

[harcosparky]

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
And I like the idea of a BATTERY TENDER--both for the Jeep and my compact tractor.

Can you (or anyone else?) provide links to "known-good" battery tenders (i.e., the kind of low-amp, "Smart Chargers" that actually STOP charging, when the battery doesn't need it, so you can LEAVE THEM CONNECTED FULL-TIME)?

I'm in the U.S.A. (for now).

Thanks muich!

Y-Yes

The only ones I use come from these folks ( Deltran ) .......

Chargers

I keep everything hooked up to one of their units 24/7/365

The only time they get disconnected is when the vehicle/machine is in use.

Read up on the various models and choose accordingly.

I have several different models ..... some are even waterproof and lay out on the driveway when in use.


They might be a little more expensive than others but I have never had one fail, or cause a problem with any battery.

 

[MudMagnetYJ]

But can ANYbody please explain to me how the "Katz-style," i.e., in-line, heater-hose style of *cough* BLOCK heater, can possibly heat more than the passengner-compartment's HEATER CORE, when the engine's THERMOSTAT IS CLOSED, as it would be in cold temps, with the engine sitting, overnight?

IOW, it seems like the in(hose)line, "Katz-style" heater can ONLY heat the water in the coolant lines running to the heater core--or is the argument that the "Katz-style" heater is SO hot that it actually causes the engines THERMOSTAT to OPEN, allowing THERMOSPYHONING to occur, i.e., the natural process of heat cycling through an engine, that the early models of Ford Model T's used? (The early "T's" had NO water pump, and relied on the thermosyphoning princple, with decent results, obviously, though Henry later added a waterpump).

You are entirely correct! Though the inline coolant heater is not as effective as the frost plug style, it is cheaper, easier to install, and less prone to leaks. That's the benefit.

The Katz coolant heaters do not heat the engine enough to open the thermostat. OEM thermostats open at 195° but for me, the heater doesn't even register on my temperature gauge (<100°). However, on a below zero night, I decided to pop the hood and feel the valve cover. The valve cover was warm!

Now some science...
Heat and energy is transferred through multiple ways. We'll look at conduction and convection.

Conduction is heat transferred through, like it sounds, conductors. Insulators, such as rubber and plastic, are STILL CONDUCTORS. Everything conducts to a certain extend, "insulators" just have really high resistance.
Convection is heat transferred through liquid/gas, like cooking pasta, or your convection oven.

The cooling system has two circuits. One in the engine, one in the engine bay (radiator portion). The Katz heaters are outside the engine. Therefore, it heats up the outside circuit through convection.

------------------------------------------------------------

The frost plug heaters heat up the inside of the engine through convection. Then the rest of the engine block is kept warm through conduction.

------------------------------------------------------------

The inline coolant heaters heat up the outside circuit through convection, then heat up the engine through conduction.

------------------------------------------------------------

So... Each heater warms up the engine through a path of CONVECTION --> CONDUCTION. Thing is, the inline coolant heaters are subject to dissipate heat through the radiator hose into the air, and there is less surface area contact with the engine block.

The difference between the inline heater and frost plug heater will become more apparent as the temperature drops. This is because of the heat dissipating. The engine is an incubator for the coolant to warm, but the radiator hoses have more surface area that will dissipate heat out of the engine.

Both should work about the same until temperature starts to get in the teens, and then the frost plug heater will be much better.

 

[ADee1]

How about an oil pan warmer installed on the bottom of the oil pan the lowest point of the engine. Heat rises. I went to a shipmate's house for a ski weekend and plugged in my Rubicon's oil pan heater and had 90F coolant temps when it was -2F.

 

[MudMagnetYJ]

How about an oil pan warmer installed on the bottom of the oil pan the lowest point of the engine. Heat rises. I went to a shipmate's house for a ski weekend and plugged in my Rubicon's oil pan heater and had 90F coolant temps when it was -2F.

That's pretty damn good, I might have to get one now. The motives of a coolant heater and oil heater are for heat and reduced engine wear.

Since it's coolant and not oil that goes into the heater core, usually oil pan heaters are thought to just help the engine start easier.

That is a good point though, since it is keeping the engine itself warm, which warms the coolant. Both at the same time would be best, because you're heating the coolant and the engine at the same time.

Still, these just give your engine a head start on getting warm. I doubt any heat would come out until the engine runs for a couple minutes.

 

[ADee1]

That's pretty damn good, I might have to get one now. The motives of a coolant heater and oil heater are for heat and reduced engine wear.

Since it's coolant and not oil that goes into the heater core, usually oil pan heaters are thought to just help the engine start easier.

That is a good point though, since it is keeping the engine itself warm, which warms the coolant. Both at the same time would be best, because you're heating the coolant and the engine at the same time.

Still, these just give your engine a head start on getting warm. I doubt any heat would come out until the engine runs for a couple minutes.

I spent a bit of time talking to Kevin over at Wolverine Heaters. You'd be amazed how much the thing helps. I ran the engine about 1 minute after I started and by the end of my buddies driveway about 100' or so I had coolant temps of about 110F. Not too bad, add a block heater and you'll have heat in about 2-3 minutes. If you buy one get the 250W unit, you'll be glad you did.

 

[DryCreek]

Although it doesn't get to subzero temperatures here in Central Texas, I will still plug up our trucks if I know I will be driving them. I do like the instant heat and quick starting it offers. I would be really tempted to put one of those coolant hose heaters on my old YJ since it is now my daily driver. I'm old, and I don't like to be cold for those four miles before the heater cam warm me up. I do have a 200 watt magnetic oil pan heater I keep on my wife's tractor (glow plugs are a bit cantankerous). I may also nab that too.

As a note, I have never had a factory installed block heater leak on me. And that goes all the way back to my 1978 Dodge Power Wagon I had when stationed in Idaho Falls, ID.

 

[MudMagnetYJ]

As a note, I have never had a factory installed block heater leak on me. And that goes all the way back to my 1978 Dodge Power Wagon I had when stationed in Idaho Falls, ID.

"Factory installed" is the key, you're exactly right. Diesels come factory with block heaters, and I never hear of those leaking. I'm waiting to hear someone who installed a block heater that works as well as a factory heater.

 

[demarpaint]

"Factory installed" is the key, you're exactly right. Diesels come factory with block heaters, and I never hear of those leaking. I'm waiting to hear someone who installed a block heater that works as well as a factory heater.

You got that right, the best block heater is factory installed. I have one in my 88 E-150 which is now pushing 29 years old, no leaks and it still works.