E3 running issues begin

[Buffarea]

In the past two weeks I have been trying to drive my E3 everyday. Last week I set valves,timing,cleaned points and plugs and isolated/repaired and spark jump from a faulty plug boot. I also removed and tested the thermostat, but did not replace the coolant. The coolant and oil in the car are who knows how old but levels and condition "looked" ok.
This week the idle has been slowly going up even after fully warmed up and "blipping" the throttle to bring it down is becoming less effective. Yesterday while setting at a light I could hear a gurgling/purging liquid type noise but no loos of fluid. I noticed that there is no heat and thought that perhaps the heat/vlave control was inop., but on the way home the car began to misfire. I found #4 and #5 plugs very sooty and replaced them, at which time I checked the coolant and found it to be 1.5gals low!
After topping it up I let it run until hot, and think now the idle issue is due to a vacuum leak on the rear carb., which I presume is causing the sooty plugs, but where did the coolant go?

 

[x_atlas0]

Did you re-bleed the cooling system? You have to do it when the heater core is completely open, otherwise it will throw it off by adding additional volume to the cooling circuit. Also, why didn't you replace the coolant, it isn't that expensive, and should be replaced every 2 years or so.

 

[Buffarea]

More info. about running issues.

Although the car had sat for a year or so, the p/o had told me he that he changed the oil and coolant before parking it.
Also, I had forgotten to mention in my previous post that when I first got the car home after purchase I had to add almost a gal of coolant/h20 mix at that time. Each time I had checked the coolant since it was always visable in the o/flow tank so I didn't worry about it.
This car has so many obvious issues that I have been trying to handle the biggest ones first, in terms of complexity and investment.
My thought on the cooling system now is that the p/o had not changed the coolant correctly and there was a big air pocket in there. It is a miystery now as to what happened but suffice to say I am now planning a complete drain and refill, and plan to use the suggested bmw coolant/distilled water/water wetter combo. I also found the bleed screw on the t-stat housing but need to rear more on how to use it.

I have also just finished removing the rear carb,cleaned all the gaskets (which actually looked good) and resealed them with awesome honda gasket sealant, but I still have a intake leak down there as evidenced by spraying carb cleaner near the base and causing the revs to climb.
Ideas?

 

[61porsche]

carbs/ coolant

Try not to use sealants on the carbs. There are a lot of air fuel passages internal and external to Zeniths. Probably OK on just the intake gaskets, if that's what you did.

Try tightening everything again. Especially the rear intake and the nuts closest to the the firewall. ( The ones that are especially hard to get to.)Remove the choke housing and tighten the center screw.Small gasket with vacumn there. It's common for gaskets to settle a bit so go bak over and torque things till everything seems to stay that way. Small leaks can be troublesome to a smooth idle.

One easy way to check for vacum leaks is to cover the air bleed hole with your finger and see waht happens. ( It's the small hole cast in the top nearest to the valve cover. If it stumbles there's no leak. If it smooths out the idle there's a leak.

After rebuilding, it's common to reset the float level in place by altering the gasket(s). Is there a drip of fuel from the venturi? ( the round part in the middle of the throat of the carb.) You can actually hear it if it is dripping. May be causing your wet plugs.

Same tightening goes for all the coolant lines on and near the carbs. They can drip. Use a 1/4 ratchet and don't rely on a screwdriver.

Again it sometimes takes a while for all the parts to settle down since you may have just taken something apart that hasn't been for 40 years.

To loose coolant, there has to be a leak or the pressure relief went off and made the gurgling noise you mentioned. Is your carpet wet? Or do you notice the windows fog? Bypass the heater if you feel it's the cause.

To use the bleeder- it's a screw that opens to a small vent in the t-stat cover/ elbow to atmosphere. Sometimes ( usually) it's tight/ corroded a bit. Use channel locks to free it up, then a screwdriver. It is terribly important to bleed the air out and some do several times over a day or so.

Be methodical and pretty soon you'll narrow down and elimate the problem. As many of the old guys say- It's probably the last thing you did.

61Porsche