M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine management => Topic started by: brenters on August 14, 2008, 02:45:24 PM
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I see that alot of people have cleaned up the big mess of vacuum and water lines under the intake manifold. I would like to get rid of the water heating on the throttle body but my issue is that I live in Canada and I do drive the car in the winter.
Has anyone removed those plates and driven on a very cold winter day, does the intake actually freeze up without it?
thanks,
Brent
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I see that alot of people have cleaned up the big mess of vacuum and water lines under the intake manifold. I would like to get rid of the water heating on the throttle body but my issue is that I live in Canada and I do drive the car in the winter.
Has anyone removed those plates and driven on a very cold winter day, does the intake actually freeze up without it?
thanks,
Brent
I have not had any problems with cold starting or anything.. but i live in oregon
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Ya i'm sure it would be fine normally, I'm just wondering about the -40 degree celcius days. I've been told that ice can form on the throttle body but i wanted to hear it from someone to make sure
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Yeah I'd probably leave it alone in your extreme situation. It shouldn't really hurt anything up there. I certainly removed mine here in Texas.
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That's kinda what i was thinking, I'll leave it alone for now, thanks.
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It probably wouldn't be a bad idea in your case to just replace all of the cracked hoses with oem stuff and retain the tb heater. Won't be as cheap as pulling it off but at least you get rid of vacuum leaks.
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Actually, cold weather isn't a problem. Cold air is so dry that there is little moisture in it to freeze up the throttle body.
The heater is there for cool, moist air. The freezing is from the venturi effect of air rushing through the throttle body. It has nothing to do with ambient temp. Think of a compressed air can or LP tank for that matter. When you let air rush out of them they get frost on the outside. The more humid the air the more frost. Same with throttle bodies. In fact freeze up is more likely to occur on a cool evening that follows a hot, humid summer day down south than -40c days in Canada.
At least that's my understanding of it from a technical paper posted here some time ago.
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That definitely all makes sense, except that I think the ambient temperature would be a factor. The air cools as it passes through the venturi and the ambient temp would dictate whether it cools below the freezing point or not. From that point on I'd say you're right that you would need moisture in the air to cause a problem.
I was fairly familiar with all the theory about it, that's why I thought I'd check if anyone has ever frozen up in any conditions? It seems like alot of people have cleaned up everything under the intake manifold and no one's mentioned that they've encountered any problems, at least I haven't read about anyone freezing up.
I think I'll leave it on for now and try taking it off in the dead of winter just to experiment, I'll find out what it'll actually do, if anything.
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I didn't want to take it off just to make things cheaper, it was more for the performance side of things. You want the coolest air possible going into the engine, I'm not sure how much the throttle body heater would actually warm the air but I know that I don't want it warmed at all. A little something's better than nothing.
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Im also planning to remove the heater plate, but the winters might get very cold here in Estonia (-30c is possible,but usually +2 to -10c). I dont think that anything bad will happen, but lets see:p
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I really cannot imagine the heater plate cooling the air at all. The coolant heats up quickly and if anything it keeps the temp of the TB much warmer than without. I have never heard of anyone having problems with a freezing TB or anything negative, there were even people in Canada that were doing the mod. Besides the M42 how many engines do you know of that require a throttle body heater anyway, I just flat out don't think its necessary.
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I've got a mechanic buddy and he said a throttle body heater plate is actually fairly common, ford's, volvo's etc. I guess those one's seem to do a better job of not having such a mess of hose though.
The coolant in the heater plate definitely won't cool the air at all, if anything it would certainly warm it a couple degrees.
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I've got a mechanic buddy and he said a throttle body heater plate is actually fairly common, ford's, volvo's etc. I guess those one's seem to do a better job of not having such a mess of hose though.
The coolant in the heater plate definitely won't cool the air at all, if anything it would certainly warm it a couple degrees.
Most non turbo Volvos have a throttle heater but its a completely different system. They used a thermostat in the lower airbox to draw in either cold outside air or hot air from near the exhaust manifold. The thermostat would automatically adjust between the two sources in an effort to maintain at least 70f intake air temperature in all conditions. Sounds brilliantly simple on paper. Unfortunately after about 10 years or 100k miles, each and every one of these thermostats fail in the full hot air position. The engine breaths in 180f degree air all the time through the 1.5" hot air hose instead of the 3" cold air intake. Ever heard of a slow volvo? Unless the mechanic knows what to look for, most of these cars have atrocious fuel economy and fail emissions test with extremely high NOx levels. They all end up in the junkyard.
(http://farm3.static.flickr.com/2105/2190370098_8372259eee.jpg)
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Interesting looking design there.
I definitely recommend removal of the throttle body heaters, and running new vacuum line to the appropriate components bypassing that mess. If nothing else it makes removing the throttle body much simpler later on, and you can easily relocate the ICV in case it starts acting up so it's more accessible.
Adam
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Besides the M42 how many engines do you know of that require a throttle body heater anyway, I just flat out don't think its necessary.
Actually, do a search online. They are very common.
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any gain in hp after removal?
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i haven't done it yet, still trying to get the engine to run first. I think the engine would run more efficient and healthier without heating the air coming in but I would be surprised if you'd actually feel a hp increase. I wanted to do it more because of proper engine theory as opposed to actual hp increases.
The other way would be to wrap the exhaust to heat the back end of the motor more. In basic high school chemistry we were taught engine theory, any kind of engine will run more efficient if the temperature difference between the intake and exhaust is as great as it possibly can be. So I know the theory, now it's just a matter of putting it all together.
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i haven't done it yet, still trying to get the engine to run first. I think the engine would run more efficient and healthier without heating the air coming in but I would be surprised if you'd actually feel a hp increase. I wanted to do it more because of proper engine theory as opposed to actual hp increases.
The other way would be to wrap the exhaust to heat the back end of the motor more. In basic high school chemistry we were taught engine theory, any kind of engine will run more efficient if the temperature difference between the intake and exhaust is as great as it possibly can be. So I know the theory, now it's just a matter of putting it all together.
Problem with wrapping exhaust is it tends to make it crack ALOT faster :)
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Yes I noticed .025hp gain. I can really feel how much cooler the air is going in ;)
People make a big deal out of it, but if you feel the intake manifold after running hard for a 20 minutes or more it gets HOT. I have to imagine the air is heated more going through the (engine) heated intake runners than the little throttle body plate anyways.
My car is definitely making more power than when I bought it (133k on the clock now, bought it at 130k) but that's due to a combo of better NGK plugs and new wires, a Mark D 93 octane chip and a full exhaust from the headers back. I've also replaced all of the vacuum lines (after removing the throttle body heater plates), and fixed some things like a sticky throttle cable with a new one and a new TPS / ICV. All easy stuff and all of which have made the car run much better. It feels like a nice smooth running BMW now :)
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Yes I noticed .025hp gain. I can really feel how much cooler the air is going in ;)
People make a big deal out of it, but if you feel the intake manifold after running hard for a 20 minutes or more it gets HOT. I have to imagine the air is heated more going through the (engine) heated intake runners than the little throttle body plate anyways.
My car is definitely making more power than when I bought it (133k on the clock now, bought it at 130k) but that's due to a combo of better NGK plugs and new wires, a Mark D 93 octane chip and a full exhaust from the headers back. I've also replaced all of the vacuum lines (after removing the throttle body heater plates), and fixed some things like a sticky throttle cable with a new one and a new TPS / ICV. All easy stuff and all of which have made the car run much better. It feels like a nice smooth running BMW now :)
OT: what headers did you get? i've yet to find a decent M42 header.