Difficult to start the engine at extreme cold (-27 Celsius)

[luckyforrest]

Finally installed the block heater, seems working well.

[Eggman]

Hey luckyforrest did you use some silicone grease?

[luckyforrest]

Hey luckyforrest did you use some silicone grease?

no, the manual did not mention that, and the heater seems very tight. Any issue?

[Mark]

no, the manual did not mention that, and the heater seems very tight. Any issue?

The Mitsubishi engine heater comes with silicone grease. The Kat's model definitely recommends silicone grease. Check out the youtube clip. You don't need to buy the expensive silicone grease he shows in the clip.

https://www.youtube.com/watch?v=A4xbJNbEH2c&t=18s

Should the heater fail years later, I have to believe the silicone grease will help in the removal of it. It's probably doesn't impact the operation of the heater core. I ordered my heater a couple days ago. I got the silicone grease in the mail along with a few other things I ordered on Amazon yesterday. Now, I just need the heater.

[Eggman]

no, the manual did not mention that, and the heater seems very tight. Any issue?

Yep. That grease acts as a heat bridge to assist with transferring heat from the heater to the engine block. If you don't use that grease you run the risk of the heater melting. There has been at least one reported instance of a engine block heater melting here on this forum. It melted through the plastic intake manifold and left a puddle of aluminum on the ground below.

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It's probably doesn't impact the operation of the heater core.

This doesn't make sense. If you are referring to the engine block heater, the silicone grease does certainly make a difference. If you are referring to the Mirage heater core that serves the passenger compartment, then I suppose you have a point.

[Mark]

Yep. That grease acts as a heat bridge to assist with transferring heat from the heater to the engine block. If you don't use that grease you run the risk of the heater melting. There has been at least one reported instance of a engine block heater melting here on this forum. It melted through the plastic intake manifold and left a puddle of aluminum on the ground below.

I don't think the melted plastic manifold has anything to do with grease. How would a little grease prevent that????

The story I heard on that was someone did not clip their engine block heater in tightly. It slipped/vibrated back out over time and melted their intake manifold.

Regardless of what story is right, silicone grease should be used.

[Mark]

I read TopFuel's post on installing a engine block heater before ordering one this week. I am not an expert on this. If you haven't read his detailed post, this is what he said about the topic of silicone grease.

"The dielectric grease keeps moisture away from the heater cartridge and hole. It will also prevent the heater cartridge from corroding and fusing itself inside the block cavity. The cartridge fits very snugly in the hole with less than 1mm of clearance…so there is just a very slight film of dielectric grease between the heater and the engine block."

His warning -

"WARNING: Make sure the cartridge is in completely and won't slide out!

At least one Mirage owner has had this happen. The heater cartridge came out of the hole and was lodged against the plastic intake manifold. When he plugged the heater in, it melted a hole in his intake."

This is what he said about the grease -

"If you search the web for NSCG dielectric grease, you’ll find 1 specific product under the brand name “Novagard G624”. This is available on Amazon for about $20 per 5 oz tube. FYI – that is a HUGE tube and has enough dielectric grease to install 50 block heaters! G624 is just normal silicone dielectric grease. There is nothing special about it. It is the same thing as the $3 tube of Permatex dielectric grease you can buy at AutoZone. They both have the same temperature range (-65F to +400F). I personally called the manufacturer of Kats block heaters and they told me any silicone dielectric grease is acceptable. So there’s no need to buy the huge, expensive tube of G624 on Amazon.

Some people on other forums are using this product on their block heater cartridges: Super Lube 98003. This is also a dielectric silicone (with a temperature range up to 500F) but it also contains a material to assist in the transfer of heat. You can’t go wrong using dielectric grease or this material. Note that dielectric grease is sometimes referred to as "tune-up grease" when it is packaged."

His post helped me, but I haven't done the job yet. Heater is in transit to my home.

[Eggman]

I don't think the melted plastic manifold has anything to do with grease. How would a little grease prevent that????

It helps transfer heat from the heater to the engine block.

[Eggman]

It helps transfer heat from the heater to the engine block.

I should clarify. If the heat generated by the engine block heater doesn't get transferred away, it will build up in the heater and cause problems.

Sorry for not explaining my position better. Sometimes I just don't have a lot of time to type long entries here on the forum. If nothing else, I'll give it my best spelling if I can.

[luckyforrest]

Hey guys, what you discussed scared me, so I removed the heater from the engine a moment ago. It is really a pain to remove, much more difficult than installing it. And I put some silicon thermal grease (guess some Zn or Al ingredients in it, I purchased from ebay for my old laptop CUP) on the heater surface and put it back. Now I feel much better, lol.