Installing a glowplug in the air cleaner space? - PeachParts Mercedes-Benz Forum

JHZR2 · #1 01-23-2004, 05:51 PM

Hi,

Curious about an idea that I came up with...

What if I could install a glowplug that I switched on and off, in the center of the air cleaner? This way the air could be slightly prewarmed before going into the engine.

I ask this because today it was 15F, my car was sitting overnight, and it took a while to get started. Glowed for 3 full cycles, cranked, and it craked fast for the first few, then slowed down. Reglowed twice, cranked for 10 seconds fast, but it didnt catch.
Reglowed three times, cranked and finally it caught after firing a number of cylinders. I always hold the pedal at 1/4-1/2.

So I was thinking, it spun fast right after glowing, so it mustnt be that the oil is too thick (then it would spin slowly all the time). It finally caught after a few times, so the fuel isnt gelled, so what else could it be? Cold air?

I think I recall that the cummins engines have some sort of heater in the intake. I know from the archives some people say that old diesels were supposed to have a fire burning inthe intake.

So what if I just made a small hole, and connected the glowplug (positive and negative) to the battery? I could put an inline fuse and HD switch in the positive side, and mount it somewhere near the headlight door. Kind of liek how the block heater plug sits there. Then, when starting the car,I could switch the glowplug on, cycle the engine glow plugs (the intake would would be constantly burning), start the car, and then get out and switch the intake plug off when the car is running smoothly.

Is this a feasible or at all good idea? Would it assist my starting at all? I live in an apartment, and dont have any way to plug the car in, so I need to come up with something else besides my battery trickle charger... I know some vegoil folks rig up this sort of thing to heat their fuel, Id do kind of the same thing...

Any comments or suggestions? This cranking business is getting old, Im used to my car starting on halfway through the first cylinder cranking... And itll do that for many hours after the first start. So if I can get it started the first time, I have it made.

Valves are adjusted and GPs are all good... synth oil is being used as well.

ANy comments?

JMH

#2 01-23-2004, 06:10 PM

Just replace your glow plugs with fresh ones, and your problems will go away. A glow plug in the air cleaner would accomplish nothing except a more quickly discharged battery.

Have a great day,

franklyspeaking · #3 01-23-2004, 06:12 PM

I doubt that a glow plug would heat up the air enough to help. You would need something similar to an electric strip heater that is used in electric furnaces. The glow plug works inside the engine, because the space is so small and you are looking for a high temperature device to start the combustion process only, not transfer heat.

Why not look into a block heater...this is a guaranteed fix for your problem? If you don't have one, I have heard that the ones that attach to the oil pan do a pretty fair job, as well.

Good luck!

wolf_walker · #4 01-23-2004, 06:29 PM

Gas engines not too many years ago had a heated grill in the intake path to promote fast warm up, as they polluted more when cold. If was an iffy setup usually.

Silly as it sounds, rigging a small hair dryer in the intake tract would acomplish more than just a glow plug.

I agree though, weather in the teens shouldnt be a starting problem at all. Replace glow plugs.

psfred · #5 01-23-2004, 07:40 PM

I've seen a number of tractor engines with air pre-heaters in the intake manifold. I have no idea what they look like, but I would expect a nichrome wire grid that heats the air up pretty good in the 45 sec or so you are supposed to run them.

Must be in the manifold, though -- the air would cool off too much from the air cleaner housing.

Glowplugs are a better system.

Peter

JHZR2 · #6 01-23-2004, 10:26 PM

OK glow plugs it is...
My compression is fine, the car runs great, valves are adjusted, and any other time other than when it has sat for hours, it starts before one cylinder has fired, thats how good. Cranking is nearly nonexistant on my engine. Its just when at temps below 20.
I use a 50/50 mix of delvac 1 and delvac 1300. I think with this next oil change Ill do M1 15w-50, with a few quarts of the 0w-40 (which after 5k miles shears to a high 30wt, BTW) to make it a little thinner.

But I guess Ill bite the bullet and change the glowplugs... Being that most anytime the car starts so great, and considering the resistance test shows them all OK, I figured that are good, and from my other thread about changing them, I really felt leaving them is the best thing. But for $10.99 for bosch plugs at autozone, I guess Ill change them out. I think this ought to help, from everyones replies. I guess one or two plugs are just weak.

Thanks for the replies, I guess I wont pursue the intake idea... I didnt really know how much heat a glowplug puts out, but I guess it isnt enough.

JMH

P.S. A block heater is no good because I live in an apartment with a parking lot, and dont have a plug. And running 100ft of extension cord isnt the greatest idea

leathermang · #7 01-23-2004, 10:45 PM

Peter snuck a little item in there which I think needs to be asked directly..
Are you letting your glow plugs heat up 45 seconds before you try to crank your engine the first time ?
They continue to heat after the light goes off if you leave the key alone that 45 seconds... try this first if you have not been doing it.. time it .... don't pay any attention to how long the light is on....

JHZR2 · #8 01-23-2004, 10:49 PM

Yes, I glow them for three full cycles before I even try to start it. A full cycle is turning the key and me counting slowly to 30, so I figure doing this three times lets everything get good and hot. And it works somewhat... The first couple cranks are fast, it just doesnt catch. But after the first few, it slows down substantially.

Every time I reglow it and crank some more it gets a little faster, until finally whatever needs to heat gets hot enough and it catches (on the first cylinder fire).

JMH

leathermang · #9 01-23-2004, 10:57 PM

Just for grins.... how about timing it and using the 45 second recommendation ? It also sounds like you may need to look at your battery condition ( which produces less power in very cold conditions ) and perhaps the general condition of your starter motor....

#10 01-23-2004, 11:01 PM

The 6BT used on the Dodge trucks have a 2 stage intake heater. A sensor detects the intake temp and desides if 0, 1, or both coils should be energized. A setup like this could be made with a large hairdryer coil, but I'm not sure if running a 120v coil on 12v would work.

coachgeo · #11 01-23-2004, 11:21 PM

Quote:

Originally posted by 82-300td
The 6BT used on the Dodge trucks have a 2 stage intake heater. A sensor detects the intake temp and desides if 0, 1, or both coils should be energized. A setup like this could be made with a large hairdryer coil, but I'm not sure if running a 120v coil on 12v would work.

They make 12V hair dryers. You can find them at truck stops.

That being said.. first make sure everything else is opperating correctly. Second if anyone decides to experement w/the hair dry preheater let me know, cause when the hair dryer parts shake apart and get injested by your turbo that means I might be able to buy an ok parts car from ya

JHZR2 · #12 01-23-2004, 11:25 PM

I will do that... Thats why they put second hands on watches, right?

My battery is an autozone duralast, and was new as of the summer... The starter sure cranks fast, although I wouldnt know otherwise. But it always is up to the task. Is there any way that I can tell the condition of my starter? If mine was ever to go, Id be sure to get the high speed mitsubishi or nippon denso type, but for all I knwo I have a high speed starter. Although the tach needle barely moves to the 250rpm area when cranking...

JMH

psfred · #13 01-23-2004, 11:25 PM

Check your fuel lines for leaks, too -- if you don't get clouds of white smoke while you are cranking, you don't have fuel going in, and it won't start til you do.

The suction lines to the hand pump are the usual problem -- they get old and crack, and air gets sucked in, so that the IP has air in it. Takes a while to pressurize the injection lines properly if it sits for a while. This can also happen to a badly worn IP -- the fuel leaks out of the plungers overnight. You'd have fuel in the oil in that case, though. Hand pump can leak, too. If you don't have the new "thumb" pump, get one and install it next warm day.

I'd change the oil to a full synthetic, probably 10W-30 for the winter. 15W50 is too thick for your car if it won't start right away.

I'd also check the chain stretch and IP timing -- late timing will make it start hard cold.

Peter

#14 01-23-2004, 11:31 PM

Quote:

Originally posted by coachgeo
cause when the hair dryer parts shake apart and get injested by your turbo that means I might be able to buy an ok parts car from ya

That's why you think ahead. Put a screen after the heater. Have an amp gauge attached to the switch, if it reads 0 while it's on then you have a cleanup job to do.

wolf_walker · #15 01-23-2004, 11:34 PM

I wonder sometimes at all these hard cold start posts.

We were in the teens a few times when I was in OK around thanksgiving, and a night or two here in NC not too long ago, and mine fired right up, no more then ten seconds after the glow light went off(habit from VW diesels, if they don't start with a ten second hold over after the light, there not gonna start).

I think you ought to get your battery load tested(duralast should still be in full replacement warranty i believe) and find someone that can test the amp draw on that starter, I know advance and autozone can with it off the car, can't remember if they can do it on the car, should be able to. If the glow plugs are all at least working, it's spinning over good, and there arent any funky air leak issues, it really ought to fire up well into the teens.

Another thing I think of when I read these posts, if you've got a so-so battery, three full glow cycles is a lot of load to put on the thing and THEN try and make it spin over. You may well be better off with one good glow and a crank with a less-depleted battery.
It just all depends on the motor.

VW diesels in good repair fire up easier and idle better in the cold than the 617 seems to. But...