Engine Pre-heating

[Jiff Lemon]

No, not talking diesels now....

We all know that wear takes place when the engines are cold. Some of us older folk will remember Kenlowe Pre-heaters. Essentially you plug the car into the mains, and pre-heat the coolant. It';; eventually heat soak the block too. Kenlowe are still going and their pre-heaters are still available - they start from £300.

I then stumbled upon this (http://www.ebay.co.uk/itm/111018635512?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649) on the mighty bay. Anyone got any thoughts?

[hmmmmm]

I think it would depend on the car and the weather conditions. A modern car with proper efi and lubricants is tested to run for years without pre-heating in any weather, so i dont think you need it there. If you live in alaska it might be worth it though :) Other stuff like regular oil changes and not gunning the car when cold will make all the difference imho.

[Jiff Lemon]

Ah, but having a nice warm engine as I set off is appealing....

[hmmmmm]

I guess that depends on the power of the heater. Does it actually raise the coolant temp to a lever where you can drive it away without having to go easy for the first couple minutes. And if the coolant is up to temp, is the oil up to temp as well?
Im always a bit skeptical about these things, if its that easy, wy isnt this a factory option?

[snowtigger]

I second that having a nice warm car is a good thing on a freezing cold morning, plus your not dumping loads of fuel in to it to start the car .

My mate russ had one in his cortina when they first came out it was a fab idea only problem was he forgot to unplug it one day from the garage socket and drove backwards out of the garage with half the house electrics ripped out, they did fit a coupler after a load of complaints from angry people that when pulled by the car it just came apart and didn't wreck the car or the house electrics.

[Jiff Lemon]

I guess that depends on the power of the heater. Does it actually raise the coolant temp to a lever where you can drive it away without having to go easy for the first couple minutes. And if the coolant is up to temp, is the oil up to temp as well?
Im always a bit skeptical about these things, if its that easy, wy isnt this a factory option?

Raises temp to 60 degrees. Quite a lot of manufacturers offer preheaters for countries with weather conditions a little worse than ours.

[cdwood2010]

I quite like that idea.

Good find.

C.

[Jiff Lemon]

me too - just waiting for someone to come and piss on my chips before committing an order.....

[hmmmmm]

If you just want a warm car when you get in, it might do the trick. But i dont think it will get the oil temp up to temp for you to nail the throttle straight away. You would still need to take it easy for the first few miles. And i guess install a coupler so you dont rip you're electrics out :) Wish i was there when that happened!

[Spook]

I was offered a pre-heater on my RX7 when they re-built the engine, theyve done loads of them with particular benefit in fuel consumption & emmissions. I was told you had to allow the oil temp to come up to par but that would happen a lot quicker. Normal driving no flying around for first miles.
The only reason I didnt go for it was the amount of money i had already spent, ie. no more left on credit card!

[MMaddict]

You could make one yourself, just get an old water-cooker and take it apart. Looks like a nice experiment :)

There are even 12V ones!

[OlberJ]

As long as you have an oil temp. Gauge then yeah, good for pre-warning the heater.

Remember its not the block u want warm its the oil so its thin and gets everywhere.

[Paul Woods]

Ok the only negative i can think of is that your cold starting may be impaired, you've all got that puzzled what the fuck is Woodsy smoking faces on right now.... my thinking is it raises the coolant temp to 60*, which is fine and dandy, except it's also telling your EFI temp sensor it's a 60* engine.... i'm not sure what the engine will start like from stone cold with the EFI telling the ECU it doesn't need any cold start fuelling.

Part of me thinks it will be fine, the other part is thinking it might not be great during cold starts..... opinions?

[hmmmmm]

Hmmmmm good point.. But where does the ecu get that information? Im guessing with modern cars it's not just a temp sensor in the rad? There are a bazilion sensors so wont it use multiple inputs to calculate a proper f/a ratio to cold start?

[Paul Woods]

I gets it straight from the EFI temp sensor, which will be saying 60*, but only the coolant will be 60*, unless it was left to heat for ages then the block/oil would start to heat i guess, but 95% of the oil would be in the sump not circulating and stone cold....

[snowtigger]

Well efi stuff was not on the Tina it was carbs and points always worked fine, it could be ok only a suck it and see approach on a more modern car would sort the question out.

[Paul Woods]

Yes but carbs and points don't rely on an EFI sensor for cold starting, big difference there, on modern engines the EFI temp sensor is very important.

[MMaddict]

Yes but carbs and points don't rely on an EFI sensor for cold starting, big difference there, on modern engines the EFI temp sensor is very important.

Isnt this how the cooling works?


Engine heats up the coolant in the engine till ±82°C then the thermostat opens and the coolant starts flowing, the coolant in the rest of the circuit is way colder and then takes energy from the engine...

If so I don't see the problem paul, if it only heats up to 60°C the thermostat won't open and the EFI never gets the warmer coolant because the engine heats up the coolant in the engine all by itself.....

[Paul Woods]

I'm really not sure, just playing devils advocate , my only concern is the Efi sensor is being told the engine is much hotter than it really is, it would probably not matter

[Limeymk1]

I would have thought the EFI sensor would also be in the the engine coolant loop so the thermostat would not need to open for it to see hot coolant, if it was outside the engine loop then the cold start fueling would remain engaged for quite a long time. A lot of the time isn't it located pretty close to the cylinder head so will heat up pretty damn quick.

No expert myself but the old Mk1s used to start up no problems with the cold start injector unplugged.

[Paul Woods]

Ah there's usually a separate cold start injector time switch for that, the EFI one is a constant temp reading for enrichment when cold, i guess it all depends where that pump/heater is plumbed in too.

[MMaddict]

I would have thought the EFI sensor would also be in the the engine coolant loop so the thermostat would not need to open for it to see hot coolant, if it was outside the engine loop then the cold start fueling would remain engaged for quite a long time. A lot of the time isn't it located pretty close to the cylinder head so will heat up pretty damn quick.

No expert myself but the old Mk1s used to start up no problems with the cold start injector unplugged.

The thing is, that if the thermostat isn't opened there is no loop out side the engine block. the EFI sensor is usually screwed somewhere in the engine block.

Technically it would be very hard to install a pre-heater unit between te EFI temp sensor and the block it self without moving the EFI sensor.

So I guess a pre-heater is only helping, and not leading since it never even gets close to thermostat opening temp.

[sketchy]

given the water is in the block, if the water temp is 60 degrees, most of the block will be getting close too. as you wont have a near cold block with warm water in it...but given there is no flow. will take a while for the temp to increase all over. would be talking probably hours, especially in near zero temps..

there is no reason why you couldnt add a loop of steel coolant pipe through the sump to aid with preheating the oil too though, seems a bit over the top to me, but you COULD...like "t" off one of the manifold coolant lines. Ill get my coat...

probably better off just putting an electric heater under the sump before bed...and turn it on as you get up...

[MMaddict]

given the water is in the block, if the water temp is 60 degrees, most of the block will be getting close too. as you wont have a near cold block with warm water in it...but given there is no flow. will take a while for the temp to increase all over. would be talking probably hours, especially in near zero temps..

there is no reason why you couldnt add a loop of steel coolant pipe through the sump to aid with preheating the oil too though, seems a bit over the top to me, but you COULD...like "t" off one of the manifold coolant lines. Ill get my coat...

probably better off just putting an electric heater under the sump before bed...and turn it on as you get up...

http://www.hiking-gear-and-equipment-used-for-camping.com/images/Primus-Multi-fuel-Camping-Stove.jpg

[weegaz22]

I can see the appeal, my E39 has an option to plug in a webasto telestart module and have the diesel pre-heater warm the block off a remote with an (allegedly) 1km distance, and after 5 mins it'll activate the climate control turn up the heat and turn on the blowers to defrost the front and rear windows, dunno if you could have space retro fit one in an mr2 bay, maybe the boot? (especially one thats been.. ahem.. brutalised) and then have it supplied by its own diesel resevoir and pump, its the better option than running a cable out to your car IMO, but i guess it depends on your circumstances as well, between garage/driveway/street parking on whether its conveinient enough for you

the cable operated one is only going to offer that extra bit of protection and nice and toasty comfort 50% of the time, cos when you drive to work or the shop in winter by the time you come back your car is stone cold when you have to drive back home, so from that point of view that's why i wouldnt pay for one of the plug in electric ones.