Block heater

jenkinskg · Post by **jenkinskg** » 04 Dec 2018, 04:01

Bought a 98 s70 seems to have a block heater, 120v plug behind grill. Sny leak isdues i should worry about?
May never use it, not even sure if is stock freeze plug heater or external heater.
Connector looks like oem heater.

LOB · Post by **LOB** » 04 Dec 2018, 04:44

If it's a OEM heater (Volvo original accessories) it's a block heater (metal surface on metal surface, like an ironing iron). Those are less effective than the type that heat the coolant but they are of course trouble free. The coolant heater is connected to a 1.5 inch cooling hose.
Google "calix" or "Defa" for the alternative models that you might have. I use my coolant heater when the outside temperature is below +5c. A interior heater (in English?) is really nice during Scandinavian winter's.

There ain't no freeze plug heaters on the white block engines. Maybe there ain't space enough. I've never heard that the coolant heaters are prone to leak. Mine has worked flawlessly for 6 years.

Post by **Rattnalle** » 04 Dec 2018, 05:06

Those external block heaters are so useless you might as well not use it.

Post by **erikv11** » 04 Dec 2018, 08:23

Rattnalle wrote: ↑04 Dec 2018, 05:06 Those external block heaters are so useless you might as well not use it.

I disagree - not useless at all!

I have the factory one (500 W) and it works well. When it is 5-10˚ F here, if the heater has been on for 4 hours or so then the engine starts easy and heat is warm in just a couple minutes instead of 8 minutes or so. E.g. viewtopic.php?t=68260

And some numbers from viewtopic.php?f=1&t=67151&start=10:

Before startup:
-8.8 ˚C Outside temperature (this is 16 F)
-7.7 ˚C Temp on dash display (this is 18 F)
24 ˚C Temp at ECT (! this is 75 F)

So the block, and the oil and coolant within it are all nearly 60 degrees warmer from the block heater. Not useless.

Post by **Rattnalle** » 04 Dec 2018, 08:46

erikv11 wrote: ↑04 Dec 2018, 08:23
Rattnalle wrote: ↑04 Dec 2018, 05:06 Those external block heaters are so useless you might as well not use it.
I disagree - not useless at all!

I have the factory one (500 W) and it works well. When it is 5-10˚ F here, if the heater has been on for 4 hours or so then the engine starts easy and heat is warm in just a couple minutes instead of 8 minutes or so. E.g. viewtopic.php?t=68260

And some numbers from viewtopic.php?f=1&t=67151&start=10:

Before startup:
-8.8 ˚C Outside temperature (this is 16 F)
-7.7 ˚C Temp on dash display (this is 18 F)
24 ˚C Temp at ECT (! this is 75 F)

So the block, and the oil and coolant within it are all nearly 60 degrees warmer from the block heater. Not useless.

I guess YMMV. I never noticed a difference with mine and a lot of people say they have the same experience. Car gets warm really fast regardless though. I mostly plugged it in for the space heater that was hooked up to the interior outlet.

LOB · Post by **LOB** » 04 Dec 2018, 09:04

It's important to apply the heat distributing pasta when mounting the block heater. But even if mounted properly the vast difference in efficiency between a block heater and a coolant heater is tested and confirmed. With a coolant heater you do not need to turn it on 4 hours before departure. At -15 c they recommend to turn on the heater 1.5 hours prior to starting the engine. I guess they're not worthless but less efficient.

Post by **erikv11** » 04 Dec 2018, 09:08

Rattnalle - agreed. When you say "mine" what car are you talking about? This is a P80 forum

And LOB I agree again, good points.

Post by **Rattnalle** » 04 Dec 2018, 09:21

erikv11 wrote: ↑04 Dec 2018, 09:08 Rattnalle - agreed. When you say "mine" what car are you talking about? This is a P80 forum

And LOB I agree again, good points.

Same I5 engine block and heater block, though it was the -01 S80 I had it fitted on. I considered getting one for one of the 850s before that but after reading up on it I didn't consider it worth the work in the end. Though I should just have gotten a hose heater instead I guess.

WhatAmIDoing · Post by **WhatAmIDoing** » 04 Dec 2018, 09:30

In my experience, coolant heaters are worthless unless all you want is heat at startup. Plus you have to worry about them leaking. A block heater and oil pan blanket do a better job IMO. Block heater keeps the block, oil, and coolant warm, and oil pan blanket keeps the oil very warm. Easy starts and no time wasted warming up the oil on those -24C days.

Edit for clarity: I am referring to passive coolant heaters.

Post by **Rattnalle** » 04 Dec 2018, 09:50

The general principle behind coolant hose heaters being more efficient is that they heat a larger mass. There's usually more coolant than oil in an engine and the rising hot coolant will also heat the top of the engine. Oil on the other hand is usually a smaller amount and will stay in the oil pan thus not heating anything else. It will however heat quite quickly when pumped up into the heated top of the engine due to its relatively low mass compared to the top and coolant.

Factory installed fuel powered heaters that pretty much all premium cars over here have now always heat the coolant though usually while actively pumping it around as well. 15 min or so is usually enough with those due to the high heat output, often a couple kW.