engine temp.

ive got a 71 std. beetle 1600 dp manual trans. im having a problem with the rubber isolator going into the dist. melting. i've determined that its melting from the outside(wires are not blackish, still look like new copper) it seems to be cooling ok, or at least the fan is blowing strong. im wondering if the thermostat could have anything to do with this or if maybe carb. adjustment or timing could be the cause the car runs great untill the rubber melts and the wire inside grounds out stopping spark. it has a bosch coil, the dist. is original except for points and cond. the rest of the ignition system is aftermarket. thanks in advance for any replies matt

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187
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"...rubber isolator going into the dist...."

Is this the high tension lead from the Coil to the Distributor Cap?

Or is it the small blob of rubber which protects the Green wires that go to the condensor and points?

If it's the blob, melting would be a sign that the engine case is hot since the distrib casting is directly in contact thermally with the case.

First step would be to find out exactly how hot the engine really is. A good indicator is the oil temp. There are plenty of engine oil temp gauges on the market for VW's. Another choice is to pick up a kitchen meat thermometer with a probe long enough to reach down the dipstick hole to the oil level. You're no longer limited to the old mechanical thermometers; there are myriad electronic ones available with digital readouts and even with remote (radio) indicators. To get some idea of what is new, go to eBay and search for: "Taylor Digital Thermometer"

Back to the oil temp. A Beetle should run below ~ 105C at legal freeway speeds on a hot summer day/ And the Ignition parts should be able to withstand that.

Do the temp measurement. Then you'll know where to go next.

Speedy Jim

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Reply to
Speedy Jim

thanks jim. it is the blob where the green wires go in. i tried the digital thermometer in the dipstick hole, but the probe was about an inch to short, but i tried a test run anyway, and after driving for awhile the temp had gotten up to 223C. and the rubber had started melting again. i did remove the thermostat before i did the test run. and when i removed it i felt the air-flow with the rod up and down, and it is stronger with the rod in its normal position(up) any ideas on what i can do to get the temperature down? thanks again! matt

Reply to
187

I am assuming you are referring to the rubber insulation that protects the the wire from chafing on the dizzy body. My guess is that the heat source is not the engine, but the wire itself. Remove the dist cap. Rotate the engine until the points close. Turn on the ignition and check the wire. Is it getting hot? If it is getting unreasonably hot, chances are your ballast resitor/coil is the culprit. Changed coils lately?

Reply to
Brasso

Brasso has a fair point. The stock Bosch coil has an internal ballast. Some replacement coils need an external ballast or they will overheat. So, if the coil is original, it shouldn't overheat.

Jim

Reply to
Speedy Jim

it has a stock coil on it, so im thinking more on engine temperature. in my original post i stated the temp. was 223C, i meant 123c or about 255F. i also have an oil leak thats coming from somewhere on the top of the case. im thinking that the leak could be the oil cooler or its seals. could this have anything to do with it? thanks for the help. matt

Reply to
187

123C is waaaaay too hot for a Beetle. Something majorly wrong with cooling.

You have the thermostat rod all the way up. Good.

The rod is attached to the flaps on the right side, and then thru a bar linkage, behind the fan, to the flaps on the left side. See if that linkage is hooked up and working.

Mice could have built nests inside the cyl fins. Does happen.

The oil cooler could be blocked (rare).

Fan blades could be clogged with debris. Feel inside the fan.

Speedy Jim

Reply to
Speedy Jim

i have recently had the engine out for a clutch job, and i had the fan housing off to claen everthing up since i had the engine out anyway. everything in the fan housing was hooked up and moving. during the cleaning i did clean out all the gunk from between the fins. i even removed the cooler and flushed it with solvent, then blew it out with air. with the engine running i have got under the car and pulled on the rod, and it does decrease air flow, but with it up it blows real strong, and all the tins are in place. could air-fuel ratio do this, i know a lean engine runs hotter? thanks alot matt

Reply to
187

I really doubt that it is a mixture problem. The temps are so far out of range that something more serious must be going on (I think).

Is the engine tight? Can you turn it by hand (both when cold and when hot)?

Jim

Reply to
Speedy Jim

i can turn it by hand both when hot and cold when i had the engine out i re-painted the tins and the fan housing(just the outside of all parts) could this have adverse effects? and is there a way i can check the oil cooler? thanks again for all the help! matt

Reply to
187

Paint won't matter. Is it possible that some part of the cooling tin got re-assembled wrong so as to block flow? Don't see how it's possible but......

Only way I know to check the cooler is to remove and blow thru it (air).

Relief valve stuck? Directing oil flow away from cooler?

Jim

Reply to
Speedy Jim

i don't think that the tins are on wrong, as far as i can tell, but this is my first bug, so there may be some parts missing that i don't know are supposed to be there. everything on the engine is covered except for a square hole on each side at the bottom-rear, what looks like a place for the air to go once it passes over the engine. i dont have any unused bolt holes though. when i has the oil cooler off i cleaned it out with solvent, then blew it out with air, and it wasn't restricted. i'm not sure where the relief valve is, or how to check it. thanks matt

Reply to
187

There are 2 valves. They are under the engine, behind big screws. The one toward the rear of the car controls flow past the oil cooler. A spring pushes the plunger to the top of the valve bore. If its plunger were stuck in the bore, oil could bypass the cooler. That doesn't happen often, but it's one way the cooler wouldn't work.

I have to say that at this point you really should get a shop manual. You can find them on eBay or at Amazon.com . Bentley has the nice one, or maybe Haynes.

Jim

Reply to
Speedy Jim

Thanks jim, I'll go ahead and get a book, then I'll check the valve, and hopefully I will come back with good news!

matt

Reply to
187

An oil temp of 255F, though high, just isn't indicative of an overall case temp that would be high enough to melt the plastic insulator on your dizzy. There is plenty of other high-heat plastic used on that engine that would also be melting down. You mentioned that the wire going through the insulator, "looked like new copper". Does that wire have insulation on it? If not, it should. And if not, where did it go? The way it sounds to me, the insulator melted and you went looking for a problem. Although high oil temp was found, and may be a contributor, I suspect that oil temp has been high for some time. Long before your dizzy meltdown. Bottom line: you appear to have two (2) distinctly different problems. Solve them seperately.

A few things to consider. You wouldn't happen to have a power-pulley installed on that engine? Did you reinstall all of the tin, and in the correct configuration? Oil level up to snuff? Have you checked the oil pressure? Have you tried a different temp gauge?

Brasso

Reply to
Brasso

well, first the wire. when the rubber started melting, which was a couple weeks after i put the clutch in , i thought it was melting from inside the wire, and started changing ignition parts. first the points and condenser, still melted. so i changed the coil, still melted. so i put a ballast in place, still nothing, so i put the old coil, with the resistor in place, still nothing. so i took the resistor off. i have had to put 4 condensers in within the last 400 or so miles, because of the melting and the crimped part of the connecter grounding out on the body of the distributor. so i stripped back the wires of one of the old condensers and looked at the wires and they look fine, no signs of heat internally. i dont have a power pulley, right now everything on this engine is stock, except i have an electric fuel pump on it, which gets its ground from the generator housing, and power from the coil + im pretty sure all the tins are correct. or at least they all went back on, and i dont have anything left over. there are what look like holes made the by vw to let the air out, but thats all that isnt covered. the oil level is fine, i did recently replace the oil pressure switch, and the light works fine now. but thats the only pressure test done. as for the gauges, on this last test run i started out with an analog gauge that went up to 220F and it got up to whatever back around to 20F would be, so i stopped at wal-mart and bought a digital meat thermometer, and thats where i got my readings from. what should the pressure run, and will a manual gauge work for this test, seeing the plastic oil line woulg be so long? thanks again for the help matt

Reply to
187

QUOTE: "what look like holes made the by vw to let the air out"

Whoa! Are these "holes" in the fan housing and approx 1.5" diam each?

If so, they are supposed to have hoses connected to the heater (heat exchanger) inlets.

Cover them over (duct tape) for now.

Yes, you can use a mechanical pressure gauge. At highway running speed, you should get about 30 psi when hot. At idle, it will drop to just a few psi.

Jim

Reply to
Speedy Jim

the holes i am talking about are under the engine. there is one at the left, and one at the right side. so the air is kinda directed toward the muffler. the hoses for the heat exchangers are in place, should i remove them and cover the holes? thanks again matt

Reply to
187

Ah. Now I see. The holes at the bottom are correct.

As long as the heat exch hoses are connected up that's OK too. I was hoping we had found a reason for overheating :-(

Jim

Reply to
Speedy Jim

i with it would have been that easy. i haven't had a chance to check the oil pressure, or take the valves out yet, i had to work late today. but i did get me a haynes manual today, and hopefully that will help me some. i have been racking my brains about what i could have done while i had the engine out that would have caused this, and something hit me. when i put the distributor back, it went in smooth, until the rotor shaft locked in, then i had to tap it the rest of the way down. could the shaft be in some sort of bind now, causing enough friction to cause the distributor body to get hot enough to melt the rubber? if not, got any ideas of what i could have done wrong? thanks again matt

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187

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