How to keep an efficient engine warm?
 

So I have a 1985 VW diesel. So far I've been getting upper 50's (mpg US) on the highway. :cool: But the problem I've been having is warmth. Even during the summer our town is so small that if I drive to the store, work, anywhere in town, it's so close that the engine does not warm up to running temps in that distance. To make matters worse winter temperatures here are constantly below freezing and can reach well below zero Farenheit for most of January sometimes reaching as low as -40° F. This not only makes me a bit unconfortable (ya, I wear long johns, sweater, coat, hat scarf, gloves, boots, the works!) but it also worries me for the engine's sake. I'm sure that it's not good for fuel efficiency nor the enviroment when I'm billowing out huge clowds of white and black smoke as it warms up. :( I've got it adjusted so that it hardly smokes at all at full throttle when warm (only when at high RPM and full throttle). But all that smoke when the engine is cold indicates that much of my fuel is not burning completely or at all!

I think part of the reason is that my engine is a bit too efficent. With a 23:1 compression ratio I think it converts too much fuel into power instead of heat. I've tried new thermostats, different temperatures, grill block offs, and a block heater. My current block heater is a 1,600 circulating tank heater that does a very good job, if I'm where I can plug it in. But when I leave the car at work and other places it cools down fast. Now what? :confused:

So instead of using 0W-20 to keep my oil pressure from blowing my oil filter, wouldn't it be nice to have a way to warm and keep warm my engine? I'm throwing a couple of ideas out there. Any other ideas would be welcome!

Passive solar block heater
So I've been thinking of plating below and around the whole engine. I'd leave a space in the back where air from the radiator can exit. Also I'd like to keep the radiator blocked off, at least during winter. Automated louvres would be nice! Besides that I was thinking of cuting a large part out of the hood and placing a piece of glass in it. I might coat the whole inside with aluminum foil. With the black engine all that light should reflect on it and keep it warm, at least during the day. ;)

Exhaust coolant heater
I was also thinking of using exhaust heat somehow to heat the coolant. There are few ideas to this. One would be to just place one piece of tubing along the exhaust down pipe and re-route the heater hose through it so that it doesn't overwhelm the cooling system during summer use. Another idea would be to have the exhaust pass through a heat exchanger, maybe a modern TDI EGR cooler, and have an exhaust valving system that bypasses the heat exchanger once operating temperatures are reached. :D

Also there are two coolant sources on my engine for this. One is the cabin heater coolant circuit, which passes back near the exhaust system. This is constantly flowing, although probably not as much as the cold bypass circuit does when open. The cold bypass coolant circuit is on the front of the engine and it circulates coolant until the thermostat opens the radiator circuit completely, at which point it shuts off this circuit. This could be routed to the back of the engine.

Of the two each has their pros and cons. The heater does not have an air recirculating feature, so the coolant running through the heater is obviously going to be cooled quite a bit. So it makes sense to reheat this coolant as much as possible. On the other hand it is constant whereas the cold bypass circuit shuts off when hot. Yep, if I did have an overheat situation, this would generate steam at the heat exchanger. But as long as the thermostat is working, at least it would not continue to circulate coolant through the heat exchanger.

I kind of like both ideas. But maybe someone else has a better idea. What's your thoughts?

Bodge an EGR circuit into the heater/water system job done

Cold start blues, again.
 

So it's winter again. My pet peeve about owning a car with an internal combustion engine is that every time I go to start it, the engine is cold. Now I'm missing my Nissan Leaf with it's cabin preheat system.

There are a few things that can be done to and ICE car, but overall nothing seems to be a perfect solution. And now that I'm driving a new car, a 2013 Toyota Avalon Hybrid, I'm tasked with figuring out what I'm going to do to heat the engine.

Right now I have a stock block heater I installed. But the thing only outputs like 200W. I read these only keep the engine about 20°F warmer than ambient. Right now it's about 10°F outside. That means the engine is like 30°F plugged in. I wonder what it'll do when it's -40°F. So I guess my first line of priority is a better block heater. Perhaps a 1,000W or 1,500W circulating tank heater. But of course I got to figure out what water goes where and how to plumb it in.

But on the other hand only when I'm home can I be sure I'll be able to plug in my car. I just got off work with no place to plug in there. I don't have a long drive from this last place I work at and I hate warming up the engine before driving. So I had to drive home in a cold car. By the time I got home the temp gauge had only reached the C. In other words the engine never got warm, the gauge had only moved like 1/16 of an inch by the time I shut off the car. I have a few drives a day like this where the car sits for a few hours, then I have to move the car only a mile or two. Ironically, when I do my 70 mile one way commute I start at my house where I can plug in. But on my short drives during the middle of the night and early morning (janitorial work), where I would benefit most from a pre-heated engine, is where I don't have any place to plug in.

So should I just start the car and idle it anyway to warm it up like three or four times a night? I really would hate to do that! But I hate not driving far enough to get the engine warm either. Plus there's the problem of frost on and inside the windshield not wanting to cooperate.

Another thing I can do is block the radiator. But on my 70 mile drive I have to climb some 6,000ftduring the day. So the question is if I'm going to risk overheating.

The idea of a Thermos system, like on the gen 2 Prius, keeps intriguing me. Maybe I should do something like that.

How about a solar radiator system (with a fairly small reservoir) filled with engine coolant , being run trough the engine using quick-disconnect couplings ?

You basically have 3 options.

1) Recover more heat from the engine.

2) Retain more heat from the engine.

3) Add external heat from another source.


#1 isn't very common as far as DIY mods go. But you can use exhaust heat to warm up your coolant faster. This could be an inline heat exchanger, additional EGR cooler type setup, or brazing/welding tubing to your exhaust manifold and running coolant through it.

#2 means insulation basically. Grill block, block insulation, coolant thermos. They all fall into this category of not letting as much heat be lost to the atmosphere.

#3 we're all quite familiar with due to block heaters which are a fairly easy item to add.

Hopefully that helps some creative juices flowing.

Get a block heater or 2.
That is the fastest easiest way to do it.

I personally wouldn't idle to warm up.

Get a temperature gauge so you know what coolant temperatures are doing, and set an alarm for some upper limit, like 215 F. Then grill block in a way that you can quickly add/remove it. I use foam pipe insulation wedged in the grill slats.

Can you put a higher wattage block heater in? An oil heater would help too.

You could add insulation to the engine, like a blanket or something, to retain more heat.

I put a little space heater in my cars.
In my leaf it deices the car and makes the ride bare able with no heat.

My Insight suffers from this as well. The engine even has exhaust heat recovery - there's a water jacket over the exhaust. When it's below freezing and I turn on cabin heat, I start losing coolant temperature, nevermind when it's 20 below zero. Cabin air recirculation helps but then my windows fog up. A 100% grille block helps, but isn't enough. Pre-warming the engine helps, but doesn't stop it from cooling back off after I'm driving.

And before you ask, my thermostat is fine, it's only when running heat.

Assuming we're talking about the Avalon and not the VW, get a Scangauge/Ultragauge/Torque app or whatever so you can watch the coolant temp, and block the crap out of your grille! :thumbup:

Ok! I'll see what I can do to add a tank style block heater on the Avalon. I've used 1,500W tank heaters on my other cars before and they work great when you can plug them in. Not a solution for where I can't plug in, but not so expensive that it wouldn't be worth it for where I can.

Let's see here. I believe the current block heater is 200W. If I got a 1,000W tank heater that would be 1,200W. With 50 to 100W for the oil pan heater I'd still have some juice left (using a standard outlet) for a battery heater for both the traction battery and perhaps the 12V battery.

That would be a good idea. I'll see what I can do to get an easier to read gauge and perhaps a light of some sort. I guess foam wedges would work just fine, at least for now. I think I'll go get some pipe insulation right now.

I bet I could run around town with it completely blocked off. And when I go on the highway up mountain passes, I could figure out how much blockage I need to take off to keep from overheating with the temperature gauge.

I'll see what I can do about a blanket too.

Yep! I've been doing that too at home. When I had my Leaf I would use the preheat function with the car plugged into a 240V source.

I know right! With the Golf I was having that problem. Many said it was the thermostat, but I knew the thermostat was fine. It was that tiny diesel engine that couldn't keep up with the cold. On the Avalon it warms up quicker and better and stays warm so far. We'll see what it does at way below zero. But on the other hand it still takes time to warm and it uses much more fuel to do so. Plus, once it has warmed up the engine will shut off until either the hybrid system says it needs more engine power or until the engine cools down to a certain point. So the warmer I can keep things going the less fuel it should use.

For journeys of that nature I use my bicycle to avoid that very problem. Diesels are bad polluters for nitrous oxides and particulates, which kill 20,000+ people a year in the UK, and when they're cold they're particularly nasty.

You ride your bicycle in weather that's between -40°F (-40°C) to 0°F (-15°C) in blowing snow at night?!

Night, which is 16+ hours per day here for part of the year. ;(

I've often pondered making a bicycle or tricycle that has a body and a heater for my short drives. I'm not sure how well it would ride through the snow though.

I stopped riding my bike when temps got below 32F... I just wasn’t equipped to handle the cold, if he can ride in -40F weather (though I doubt it gets that cold in England) he’s more of a man than I

Back in the mid 80s I drove a B210 with a 1.3L and a 5 speed. The little car was efficient and got 42-43 mpg in the warmer months. In the winter in Central Oregon the air blowing through the grill would cool the engine to the point that the choke would start to close. The thermostat worked fine but the heater would cool the engine. Probably a grill block would have helped. I solved the choke problem by removing the temp control on the air cleaner and running the car on hot air off the exhaust manifold. The heater would still cool off the coolant but I could put the car in 4th gear for a while and it would warm back up.

Yes. My coldest commute was indicating -28 Celsius when I lived in Pennsylvania, although the weather boys reckoned it was only -21. Blowing snow is no problem, only becomes an impediment when its settled on the ground, in which I wouldn't take to the roads at all unless there's an SAR callout. Trust me, as a big feller I'm much happier in the cold than the heat! :thumbup: Its the purest pursuit of wheeled fuel economy.

Cycling in the snow is great fun and a good way to develop your control skills (I'm an MTB skills instructor), and viable means of transport. The bike will go in any conditions the average 2wd car will go. However, as aforementioned, I stay off the roads entirely if I can by that point because of all the brain donors slithering about in their cars like drunk dodgems.

Once you've unsuccesfully given CPR to a 13 year old girl having a severe asthma attack who died in your hands, then you start to get a little bit conscious of unnecessary air pollution in the urban environment. I'm not having a downer, just offering the method that works for me in the OPs situation, one so obvious that most folk overlook it (or requiring so much effort that many folk can't be arsed to consider it) that doesn't produce nasty pollution just where you need it the least.

Short of garraging the car when not in use and pre heating the coolant and sump I can't see any obvious, pactical solution to the Ops scenario

He has a point in the spring/summer/fall, regardless. ;)

Agreed... people should consider doing a human powered transport in weather that the power source can tolerate... I saved probably 5 gallons of fuel in my car by riding my bike to work this summer/fall... also saved countless cold starts and about 200 miles during which my engine never would possibly reach full temperature, even with a heavily blocked grille...

Well I got a couple pieces of cardboard and stuck them in front of the radiator. I only put a couple clips back in to hold the plastic piece that goes above the radiator. That way I can get in there and slide one cardboard piece over and reveal up to 50% of the radiator. I also left some cuts to let air into the top part that apparently cools the electric drive since even after a short drive that radiator felt warm, so I figured it probably needs to be partially uncovered, whereas the radiator for the engine can be covered up to nearly 100%.

I also like the idea of bicycling instead. I need to get my ol' 27" ten speed fixed up. It has a broken spoke on the rear on the sprocket side and because of that the rim isn't straight. So I have to adjusting the rim brakes to where they either rub or to where they don't brake. Right now I kind of have them in the middle, but the rubbing is still noticeable, enough to make pedaling harder than normal, and they don't brake like they should. The front derailleur is also a little out of whack. But that shouldn't be hard to fix.

And I need to get a headlight, especially if I'm going to be driving around at night. I did put a Schmidt's Original Nabendynamo on my wife's bike. Kind of expensive, but very nice and robust. I think I'd like to do the same to my bike. It may be overkill, but I guess I like overkill. I also got her a lamp that has a capacitor that keeps the light lit for as much as a minute after pedaling. It would be nice to have the same on mine. Anything that doesn't include batteries that can freeze would be a good idea. I've tried battery lights and they always end up dying after a few months or even weeks. Or I could try a helmet light and keep it inside where it's warm.

I kind of wish I had something with wider tires for the snow. Those fat tire bikes seem kind of expensive. I don't think I can convert my bike with it's skinny tires to fat tires without major welding. At least I can use it when there isn't a lot of snow. But regardless, I also need to get ahold of some fenders. Melting snow spray is one reason I don't drive it much.

Good points. Although I imagine it is possible to get diesel emissions down just as low as gasoline emissions. But regardless, internal combustion engines are polluters.

Which is why I at first changed out my Diesel for a Nissan Leaf. We have a hydro electric dam nearby, so I figured most of the power here comes from there. Although there's no way to know for sure.

But after a while I had to drive much farther than what the Leaf can do, although I did put it through some long trips, including a 400 mile trip and a 700 mile trip.

I had the chance to buy a newer VW diesel. The emissions would be better than the 1985 VW, but of course the problem is that they don't meet the legal emissions standards. So I decided against it. And other diesels, like the Chevy Cruze, just didn't seem to be the right choice either.

So I ended up getting a 5 year old 2013 Toyota Avalon Hybrid instead. I almost went for a Prius Prime with it's $9,500 in tax credits here in Colorado, so the engine could be shut off for those short cold trips. But the Avalon seemed to fit us better, and was less expensive. I kind of need 5 seats and having a spare tire on long trips out in the middle of nowhere is a good idea.

Insulate the block, head and oil pan. I used fiberglass cloth.

I don't, as it doesn't really help when the heating is on as well (for defogging)


Same here, and it doesn't even need to be that cold.
Idling, the coolant temp drops when you stop & the heater is on.

Driving it, the temperature goes up pretty quickly though.

I got a ScanGauge in on Friday and have been monitoring engine temps this weekend. So far I haven't seen engine temps over 186°F, even with the radiator nearly completely closed off going down the highway uphill. But around town engine temps will drop down to as cold as 125°F, and it's not even winter yet!

Right now it's 8°F outside. Getting in the Avalon right now with the engine plugged in all night I see the engine temp is 46°, almost 40° warmer than ambient temperature. I also notice that the engine cools off fast, especially where I can't plug in. I also went to the store in 35°F weather. Coming out of the store the engine was at 75°F. Saturday night, as with many days each month, I didn't have any place to plug in at all at the place I stayed.

I think trying to wrap the entire engine and transmission would be a great idea. There is no belt on this car, just a single pulley that I should be able to cover up or something. The problem is working around the exhaust. I need a material that won't catch on fire.

Goldilocks trips
 

Issac, I'm trying to understand why you still have trouble with trips that are too short for engine warmup and too far or too cold to bike. Did your LEAF not have CarWings/ Nissan Connect? The remote preheating function in EVs is awesome. My i-MiEV can melt 2" of snow off of the windshield within 30 minutes, and of course doing it while plugged in means near zero impact to the battery.

Or did you give up the LEAF because it couldn't handle the long trips?
A used first-gen EV can be the perfect car for local errands or average commutes. Sure, in summer my i-MiEV can do two of my hilly 35 mile round trip commutes, but in winter that round trip better not include any serious side excursions. However, with plugging in at work, I could commute in my skivvies in a blizzard if desired. Gaining L1 (and later upgrading to L2) EVSE at work was the functional equivalent of doubling my battery capacity on weekdays.

Battery design is a leading reason why I picked an i-MiEV over the LEAF, and it delivered the full OEM-rated battery capacity up to 94,000 miles, as Mitsu under-rated the battery by 20%. I'm now at 24% degradation and beginning to feel the loss, so I salvaged a newer low-mileage battery for pack replacement shortly after the OEM warranty against full pack failure expires at 100,000 miles, which will be sometime this winter. Since Nissan has made it near impossible to swap late packs into early cars, the early owners are at Nissan's mercy for replacement pack pricing. We have a couple of local 2011 LEAF owners with less than 30 miles of range even before winter sets in. Mitsu has been EVen less forthcoming about pricing and terms for out-of warranty pack replacement, but the need just hasn't arisen for many yet.

I might be missing something, but isn't using electricity to melt snow rather undermining the environmental credentials of an electric car?

Not in Washingon (state, not DC). They're mostly hydro/renewable.

The point isn't just to melt snow either, it's to warm the cabin while still plugged into the grid, thereby retaining full EV range upon departure.

So a lot of my driving is, 30, 50, 70 or more miles somewhere, then short drive here and short drive there, short drive here and short drive there, then the 30, 50, 70 or more miles back home, with my wife. So saying, "Honey, I'm going to throw a couple bikes on the car so we can ride around all day (or all night) in the next town in sub-zero weather" isn't exactly appealing. There are a few places I/we could use a bike. But it wouldn't work well in every situation. A bike rack would be a step in the right direction though for the summer.

A lot of people don't get why we drive so much, but most of it not work related at all. Family and other obligations make us much needed elsewhere. So it is what it is. We have to drive far, all over the state of Colorado and do it often.
We loved our Leaf! The preheating was awesome even after AT&T dumped 2G and the CarWings stopped working. I'd just go program it manually, sometimes a few times a day. But since we started to do a lot of long distance driving it didn't make sense to keep the Leaf, especially with the cold weather. We drive through a lot of long, uninhabited portions of highway where the only way to charge an EV is with a generator. Trying to make it to the next destination wasn't always so easy in the Leaf, and sometimes it was downright impossible.
The battery never was a real problem in the Leaf for us personally. I figure the cold weather does a good job at preserving any EV battery. But I do think I'd try to get a better EV the next time around.

We did try to make the Leaf work and made several +150 mile trips in the Leaf, including a 400 mile and a 700 mile trip. It can be done during the summer, but it was still a bit of a pain having to charge only from L1 all night and part of the day in some areas.

I did try to get a Prius Prime instead of the Avalon. That way the engine could be shut off for certain smaller drives and then used when most needed, on long drives. But the problem was getting the federal tax credit of $4,500 and the state of $5,000 to somehow go towards the down payment on the cheapest $25k Prime I could find in the USA. But I just couldn't get my money to work like that so I got a car I could afford after selling the Leaf and the Bug. Plus I figured I needed 5 seats and a spare tire. And there's nothing in the manual against putting on snow chains on the Avalon. So the Avalon won.

I often wish I had an EV again. But I don't see the point in having two cars right now, except that my insurance actually went up after going to just one car. (They told me because the cost to insure the last car I took off was actually cheaper than what they were giving me in the multiple car discount.) Oh well!

The idea of having an EV for around town and an ICE for long distances has also crossed my mind. But I think biking around town and using the ICE for those long distances makes more sense. It's when we do short trips elsewhere that are the main concern. I want the Avalon to last as long as possible. The longer it lasts, the cheaper it will be to own and operate. I think figuring out a way to keep the engine warm would help me do that.

Make a warm air intake helps also little with warmup times.

Hydroelectric doesn't come without environmental cost. Squandering resources for the sake of comfort for lazy folk is going to become socially unacceptable and unsustainable. The whole point of ecomodding is to eke out dwindling resources, not waste them.

Put the car in a garage, or wear some appropriate cold weather clothing.

Naw, warming the cabin is small beans. Better to have consumers wanting EVs and the benefit of starting out in a warm cabin than to prefer their ICE counterparts. We're talkin 8 cents of electricity. You can't even start a car for 8 cents worth of gasoline.

Not only that, but winter driving usually requires windows to be defrosted, which uses warm air from the vents. Better to draw as much of that power from the grid than to use the battery upon departure.

I'm all for conservation and efficiency, but that's not what is going to stem resource depletion globally. That problem will only be solved by either massive reductions in wealth, which will also massively increase all the problems associated with poverty, or a reduction in population.

Do any cars come with electric side window defrosters? I remember seeing one in a front window of a van and thought it was pretty neat. I imagine the window moving would make it very difficult.

My Leaf had a heat pump heater. Granted, it generally used the resistance heater when preheating. But I was able to make it use the heat pump heater many times for preheating. On the other hand, ever try going 70 miles at 40mph with no heater on in subzero weather with a wife in an EV? I have, and it's not really that fun.

But I agree. Heating the glass is very important for safety reasons. The '85 Golf diesel I had was notorious for not being able to keep the glass clean around town. Driving around in blizzard conditions with fogged or frosty glass is a disaster waiting to happen. I hate driving around trying not to breath and holding a scraper in one hand so I can periodically scrape the frost off the inside of the windshield.

I wonder if I could change out my windshield wipers for windshield scrapers and put another set of automated windshield scrapers on the inside.

That would be awesome! I can't even find the windshield version in the USA. Of course, they are probably illegal over here.

I agree. People look out for their comfort much more than preserving the planet we live on. It makes me upset that there are so many people around here where I live who are against things like mining but all drive full sized SUV's.

But where is the happy medium? Theoretically, if we all ditched motorized transportation, except for maybe emergency applications, the planet and even our health would be much better off, but living standards would be 1800's again. I'm absolutely positive I could stop using motorized vehicles and walk or bike everywhere I really need to go. But in today's society I also would probably end up as a divorced, friendless, uneducated and poor hermit if I did that.

I've been thinking of covering my engine and transaxle, exhaust manifold and all, with this stuff:

Fiberfrax Durablanket

What do you think?

Insulating the block is definitely a good way to keep things warm. I'd like to see you give it a go. Not many have done it.

Pretty darn expensive. How about some pink fiberglass insulation?

At what temperature does fiberglass catch on fire? I'm afraid of it igniting if it's up against the exhaust manifold.

Its basically glass strands, so really high. Here is what google says it starts to soften at 1200F.

Ok. I might try it then. I know that certain other normally non-flammable substances will ignite and burn long before their melting temps if in thin strand form. This includes metals such as aluminum, titanium and even iron.